WO2013113333A1

WO2013113333A1 - Stiffening device for a blood pressure measuring device

Info

Publication number: WO2013113333A1
Application number: PCT/EP2012/000499
Authority: WO
Inventors: Matthias FÄHLE; Sebastian Kisban; Anna-Luisa UHLITZ; Ulrich Pfeiffer
Original assignee: Up-Med Gmbh
Priority date: 2012-02-03
Filing date: 2012-02-03
Publication date: 2013-08-08

Abstract

The invention relates to a stiffening device (10) for a blood pressure measuring device (100), wherein the stiffening device (10) can be reversibly stiffened and has a flexible sleeve (20) comprising an external side (22) and an interior (21) as well as at least one layer-like filling material (30) arranged in the interior (21) of the sleeve (20). The filling material (30) has at least two superimposed layers (31) and consists of a plurality of partial surfaces (32) that can be moved towards each other, each partial surface being connected to at least one adjacent partial surface (32) inside a layer (31). The invention further relates to a blood pressure measuring device (100) comprising a pressure sensor element (60), a compression device (70) and a stiffening device (10) of said type.

Description

Stiffening device for a blood pressure measuring device

The invention relates to a stiffening device for a blood pressure measuring device and a blood pressure measuring device. In many medically relevant situations, it is desirable to obtain information about the condition of the circulatory system of a human or animal patient. Especially in patients who require intensive care treatment and care, there is a regular task to influence the cardiovascular system targeted. Such an influence may be, for example, a replenishment of the cycle. However, it is u.a. the amount of fluid to be delivered, required and tolerated by the patient, is a very sensitive factor. The administration of various cardiovascular influencing agents is to be regarded as a highly sensitive intervention. In order to be able to make a decision on the specific treatment, it is therefore necessary to collect certain reliable parameters.

In addition to the blood pressure as such, above all, the heart-lung interaction (HLI) plays a major role. The mechanical ventilation of the patient to be treated leads to periodic pressure fluctuations in the chest, which affect both the filling of the right and left heart. As a result, the left ventricular stroke volume varies, which in turn is reflected in a variation of the arterial blood pressure curve. Typical HLI parameters in this context include stroke volume variation (SVV), pulse pressure variation (PPV), and pre-ejection period variation (PEPV). However, these indices prove to be problematic in that they are measured with high quality standards by an invasive method by measuring the arterial blood pressure. have to. This requires a time-consuming and costly and fraught with a complication risk cannulation or catheterization of an arterial vessel.

In the field of much more comfortable for the patient non-invasive blood pressure measurement, various technical methods are known. Thus, conventional blood pressure measurement methods are based on a mostly quite error-prone acoustic signal acquisition, in which the so-called Korotkow creeps are observed. In order to counteract this, for example, US Pat. No. 5,255,686 A1 provides a device and a method for oscillometric blood pressure measurement in which the interference-prone acoustic signal detection of the sounds is replaced by a technically simple pressure measurement. The device provided for this purpose consists of an air-filled cuff with a sensor and a device for controlling the cuff pressure and the temperature.

The principle of the oscillometric blood pressure measurement is based on the observation that the pulse wave of the blood flowing through the arteries leads to a slight expansion of the artery and consequently to a change in the shape of the cuff. In a cuff filled with air or fluid, this volume change is converted into a pressure change according to the law of gas. The volume changes of the artery are converted into a change in the shape of the cuff. The forces necessary for this change in shape lead to a pressure change in the fluid of the sleeve. In this way, the cuff pressure oscillates in a small frame as a function of the pulse pressure wave. The pulse pressure wave in the artery to be measured is also called a pulsatile signal. It can be observed that the oscillation amplitude of the signal is not constant. When a cuff pressure slightly above the systolic pressure is applied and then released slowly, it is found that the oscillation amplitude initially increases until a maximum oscillation amplitude is reached and then decreases again. It is assumed that the maximum oscillation amplitude occurs when the cuff pressure corresponds to the mean blood pressure. Here, the mean blood pressure is defined as the time average of the arterial blood pressure during a heartbeat. The amplitude at application of a cuff pressure of an air-filled cuff at the level of the systolic pressure is approximately 45-57% of the maximum amplitude pressure, the amplitude when applying a cuff pressure at the level of diastolic pressure about 75- 85% of the maximum amplitude. In this context, however, the problem with the use of conventional blood pressure measuring devices which have a pneumatic or hydraulic pressure cuff is the damping effect which the change in shape of the air or fluid cushion present in the compression element has with respect to the pressure fluctuations to be measured. This can go as far as a distortion or too poor signal-to-noise ratio of the observed pulsatile fluctuations, which is so strong that the signal quality is not suitable for a reliable measurement. A reliable collection of HLI parameters without additional invasive control is, if at all, only possible to a very limited extent with such blood pressure measuring devices.

In order to counteract this, DE 10 2009 039 257 A1 provides a blood pressure measuring device in which a stiffening device is arranged between a pressure sensor which is intended to detect the pulsatile signals and in a conventional pressure cuff which has corresponding fluid posters. This stiffening device is intended to minimize as far as possible the damping effect that the fluid-padded cuff exerts on the signal to be detected. The problem with such a stiffening device, however, is that it can only be stiffened to a limited degree without the formation of kinks or folds under which air pockets between the stiffening device and the body part to be measured occur when the stiffening device no longer bears optimally against the body part. However, such air inclusions again have a dampening effect and are thus disruptive to the signals to be detected. In addition, creases or wrinkles have a strong disabling effect when they are near the pressure sensor. The object of the present invention is therefore to overcome these and other disadvantages of the prior art and to provide an improved stiffening device. In particular, a stiffening device is to be provided with which the signal quality can be improved in non-invasive measurements of pulsatile signals compared with the prior art. An improved detection of static signal components is also desirable. Moreover, it is an object of the invention to provide an improved blood pressure measuring device. In particular, an improved blood pressure measuring device is to be provided, with which the detection of pulsatile fluctuations is possible on a non-invasive way. The object is solved by the appended independent claims. Advantageous developments are defined in the subclaims. In particular, the object is achieved by a stiffening device for a blood pressure measuring device wherein the stiffening device is reversibly stiffened and a flexible, airtight envelope having an outer side and an inner space and at least one arranged in the interior of the shell, layered filling material, wherein the filling material at least two stacked layers comprising a plurality of mutually movable partial surfaces, wherein each partial surface is connected to at least one adjacent partial surface within a layer.

Two surfaces, in particular two partial surfaces of a layer, are considered to be movable relative to one another when both surfaces or partial surfaces are movable, whereby the spatial orientation and / or arrangement which the surfaces have relative to one another can be changed.

A first great advantage of the solution according to the invention is that the layers of the filling material arranged in the airtight envelope consist of a multiplicity of mutually movable partial surfaces. Namely, such partial surface layers can particularly well mold the three-dimensional shape of a body part, for example, when wound or laid around a body part. Each partial surface is applied to a corresponding section of the body part to be molded. As a consequence of the mobility of the partial surfaces against each other, adjacent partial surfaces can be arranged in different spatial orientations. At the same time, the layer can be obtained as such if the adjacent partial surfaces within a layer are each connected to at least one further partial surface of the respective layer. The coherent layer of the filling material can thus optimally invest in the body part. However, this does not require a bending operation of the entire layer surface (and thus not the application of a correspondingly large bending force) in order to follow the three-dimensional shape of the body part when applying the layer, so that the body part is largely contoured precisely, but it must be align only the individual faces in corresponding relation to each other. Overall, the rigidity of a single layer consisting of (several) partial surfaces is significantly reduced, while the partial surfaces themselves continue to exhibit the rigidity of the corresponding layer material. At the same time, a further advantage of the invention lies in the fact that, in the stiffening device according to the invention, at least two such layers are stacked in the flexible, airtight envelope. For stiffening and in this respect for fixing a surrounding body part or an entire patient, in such a stiffening device according to the invention, the layers adapted to the contour of the body part can then be pressed onto one another. This is preferably done by applying a negative pressure in the flexible, airtight envelope. As a result, the frictional force between the abutting surfaces of the adjacent layers increases such that a frictional connection occurs between the layers. The layers thus pressed together can then act as a layer composite. In this case, the thickness-dependent area moment of inertia and thus the rigidity of the filling material increases such that it essentially no longer measures according to the thickness of the individual layers, but now according to the total thickness of the layer stack of layers pressed together and bonded together in a force-fitting manner. The corresponding pressure to press the layers against one another is exerted by the atmospheric pressure applied to the outside of the shell, which pressure is higher than the pressure inside the shell when the negative pressure is applied.

It can be seen that it makes sense if the casing has a connection piece, for example an air inlet and / or outlet, which can be connected to a vacuum pump.

It is advantageous if the arranged in the shell, stacked layers in the unstiffened state of the stiffening device to a certain extent, which is preferably predetermined by the dimensions of the interior of the shell, can move against each other. This is the case, for example, if the same pressure conditions prevail both on the outside and in the interior of the shell and the volume of the interior of the shell is slightly greater than the volume occupied by the filler material. Due to the flexibility of the airtight envelope, the envelope can also be optimally adapted to the contour of a body part or an entire patient adapt. If such a shell with the layers of filler contained therein is placed around a body part, in this way each of the layers can assume an optimal position with their partial surfaces, without being affected by contact with a layer adjacent thereto and the frictional force acting thereon under tension or tension To get pressure and to be prevented from the necessary movement. The flexible sheath and the filling material arranged in it can in this way shape the body part contour-accurate.

The formation according to the invention of the layers of the filling material in the form of interconnected partial surfaces offers the advantage, on the one hand, that the individual layers as a whole have very low rigidity and can thus optimally adapt to the shape of a body part to be stabilized or fixed. At the same time, however, they can also be stacked on top of one another in such a way that they can form a layer composite of relatively high rigidity if they are connected to one another in a force-fitting manner, for example by means of a normal force acting on them. It can thus be achieved in the unadjusted state optimal Anformung to be stabilized or fixed body part and at the same time in the stiffened state optimal fixation.

It is also particularly favorable if the layers of the filling material have recesses which subdivide the layers into the partial surfaces, wherein the recesses preferably form the edges, in particular the shaping edges, of the partial surfaces. In this respect, the recesses can, for example, be regarded as holes which are or are introduced into the layers of filling material which initially consist of continuous material. The recesses may for example be formed as simple cuts in a continuous material surface. The partial surfaces of the layers of the filling material according to the invention can therefore arise from an initially continuous material layer by holes, punches, cuts or similar recesses are introduced into this original layer. The introduction of the recesses can be done for example by means of laser beam cutting, water jet cutting, micro perforating, punching or a combination of such methods.

Such a subdivision of the layers into partial surfaces with the aid of these recesses has the great advantage that individual sections of the layers can be tension-relieved or relieved of pressure as required. This is particularly advantageous if the retention device is applied to a body part having a spherical, cylindrical or conical shape. When a stack of multiple layers is placed around such a mold, not all of the stacked layers usually have the same radius of curvature. Rather, the radius of curvature of the layers depends on whether, because of their position in the layer stack, they are arranged closer to or further away from the body part to be shaped. The same applies of course to individual layer sections which follow different three-dimensional curvature geometries of the body part to be shaped. However, the frictional forces acting between adjacent layers may cause a layer or layer portion having a larger radius of curvature to be tensioned by contact with an adjacent layer having a smaller radius of curvature, while a layer or layer portion, the or has a smaller radius of curvature than its adjacent layer, can be pressure loaded. However, such a tensile or compressive load can counteract the bending force that is or has been used to conform the layer to the surface of the body shape being molded. As a result, it may come to fundamentally less desirable deformation to kinking. Such deformations or even buckling can not only adversely affect the dimensional stability of the layer composite in the stiffened state, but also, for example, lead to pressure or friction points on the body part to be supported.

This can be counteracted advantageously with the aid of the recesses according to the invention. If a layer stack according to the invention is applied to a body part with a stiffening device according to the invention, it usually assumes a more or less complex three-dimensional geometry. Within such a three-dimensional geometry, both tensile-stressed and pressure-loaded layers or layer sections can be stacked on top of each other. With the aid of the recesses introduced into the layers according to the invention, these layers or layer sections can be relieved of pressure or strain independently of each other. In this case, a strain relief by an elongation of the recesses and the corresponding layers, a pressure relief by shortening of the recesses and the corresponding layers or layer sections take place. Overall, the expansion behavior within the layers of the filling material can be made approximately isotropic in this way. At the same time the frictional force between adjacent adjacent partial surfaces of adjacent remains Layers large enough to produce an effective laminate. Overall, it is advantageous if the contribution to the friction between the layers surface portion of the stacked layers at least a surface portion of about 50% or more, preferably about 80% or more of the total surface of the layer. That is, in a preferred embodiment, it may be beneficial if at least about 50%, preferably at least about 80% of the total surface area of each layer is in frictional contact with an adjacent layer of the layer stack.

It is also conceivable that the loading forms within a layer of the filling material can be designed to be directed in this way by introducing a geometry of recesses adapted to a body part into the layers. This is particularly advantageous if the stiffening device is to be applied to a body part which has different bending radii, for example an upper arm with a well-developed bicep or the transition region between the shoulders and neck of a patient. This may also be favorable if the stiffening device is intended to fix, for example, a joint in an angled state or to transport a patient in a specific posture. If the recesses are introduced in a corresponding pattern, it is possible, based on the configuration of the pattern of the partial surfaces and recesses, to make the modulus of elasticity of the corresponding layers or the stiffening device different, depending on the direction. Overall, an optimal compromise between adaptability to the anatomical conditions in the non-evacuated state and the stiffness in the evacuated state can thereby be achieved. It can be seen that a stiffening device according to the invention in the non-stiffened state can initially be applied exactly to a body part at which the corresponding hemodynamic parameters are to be detected. In this case, the individual layers of the filling material, with their partial surfaces stacked on top of one another, contour the body part and shape it accordingly, without the formation of kinks or other air pockets between the body part and the flexible, airtight envelope. If a vacuum is subsequently applied to the stiffening device in order to non-positively connect the layers of the filling material and in this way to stiffen the stiffening device, they retain the subdivided into the partial surfaces Layers the previously adopted three-dimensional shape. This is assisted in particular by the design of the layers as mutually movable partial surfaces, in that the subdivision of the layers into these partial surfaces significantly minimizes the tensile or gravitational forces acting within the layer that occur during deformation of the layers. In this way, the emergence of unwanted kinks, air pockets or wrinkles can be effectively avoided. Rather, the stiffening device rests against the contour of the corresponding body part both in the non-stiffened and in the stiffened state. In a further preferred embodiment, it is provided that the partial surfaces are connected to one another via connecting elements. Such connecting elements can serve to keep the partial surfaces of the layers in contact with each other, but movable against each other in the non-applied state. The surface of the connecting elements is preferably small in relation to the partial surfaces. Adjacent subareas are only partially interconnected. In the case of larger recesses and a connection through a small bridge is conceivable. Moving the faces against each other requires so far only the pivoting about the fasteners. For example, multiple adjacent faces, similar to, say, the links of a mailing shirt, can be oriented without problems in different directions relative to each other without interfering with each other, blocking, or being subjected to an unfavorable tensile or compressive force. The connecting elements thus ensure, on the one hand, a cohesion of the partial surfaces of the individual layers and thus the stackability of the layers without them falling apart, but on the other hand also optimal mobility of the partial surfaces against each other with little expenditure of force.

It can be seen that it is advantageous if the connecting elements are formed integrally with the partial surfaces. For example, it is conceivable that the connecting elements are made of the same material as the partial surfaces of the layers and that the recesses, which are introduced in the layers of the filling material, are designed such that they delimit both the partial surfaces and the connecting elements. Of course, it is also conceivable that the connecting elements are made of a different material than the partial surfaces and for example cohesively with the partial surfaces are connected. For example, partial surfaces can be applied to a carrier network.

However, it is favorable if the layers in the region of the connecting elements have a smaller thickness than in the region of the partial surfaces. It may be particularly advantageous if the layers in the region of the connecting elements can break more quickly due to this smaller thickness than in the area of the partial surfaces. In particular, as soon as the layers of the filling material come under tensile and / or compressive stress when the stiffening device is applied, the connecting elements can act as predetermined breaking points or "predetermined cracking points." As a consequence, the partial surfaces of the individual layers can shift more freely relative to one another The advantage of this is that the combination of the layers stacked on top of each other can be adapted even better to the individual anatomy.Also, an even better tension or pressure relief during stiffening of the device can be achieved Namely, such a stiffening device is preferably designed as a disposable item, which prevents, for example, unhygienic multiple uses of a corresponding article from inexpensive as possible easily procured and easy-to-process materials, such as paper as filler, is made.

The different thicknesses of the layers can be produced, for example, by introducing the recesses, for example by means of laser beam cutting, water jet cutting, microperforating, punching or a combination of such methods. Ideally, the planar shape of the layers or of the paper is not impaired by the structuring with the aid of the recesses. It is conceivable, for example, that when the recesses are introduced with the aid of a laser beam, the paper is thinned, for example by increasing the cutting speed or reducing the power in the region of the desired connecting elements.

In a further advantageous embodiment, it is provided that the layers of the filling material are stacked one above the other in such a way that the partial areas adjacent to one another are not stacked congruently one above the other. In this way It can be ensured that there is always a total area-wide composite of frictionally connected layers. In particular, it can be effectively avoided that holes form in the layer composite when partial surfaces of layers stacked on top of each other come to rest precisely over one another in such a way that the recesses between the partial surfaces also form as continuous recesses in the layer composite.

In a further preferred embodiment it can be provided that the layers of the filling material have a structured surface. This is particularly advantageous for further improving the adhesion between the layers. It is conceivable, for example, that the individual layers of the layers are provided with a golf ball-like structure. The structuring can be carried out both on one side and on both sides on both surfaces of a layer. For example, it is conceivable that a first surface of each layer is provided with corresponding elevations, while the opposite surface of the layer is embossed. If two such layers are adjacent to each other in such a way that in each case one surface with elevations and one surface with embossings lie opposite one another, then the frictional connection arising when the vacuum is applied can be intensified by a positive connection between the elevations and embossings of the adjacent layers. Of course, this can also be achieved by other geometries in which structures are present on the surface of the layers, which can engage correspondingly in adjacent structures of adjacent layers. It is also possible to envisage surface geometries with inter-engaging structures, as well as structures in general, which overall lead to an increase in the roughness of the surface and thus to an increase in the frictional force between adjacent layers.

In a preferred embodiment, the filler material is preferably paper or a paper-like material. It may also be a coated paper to positively influence the frictional forces between adjacent stacked layers. For example, synthetic fiber paper, plastic films, siliconized paper, waxed paper or coated paper can be used. In any case, the low frictional force between the layers of the filler material in the unevacuated state causes the conformability of the mold to result from the low rigidity of the individual layers. The stiffness in the non-evacuated state results from the thickness the individual layers. In the evacuated state, however, determines the stiffness of the paper stack or stack of paper-like material formed from the total thickness of the layer composite formed by the frictional force between the layers. In addition to many other positive features, paper offers the advantage that it is a relatively inexpensive, readily available, easily and safely processed, environmentally friendly raw material. In addition, with a configuration of the filling material in the form of paper layers, on the one hand, a low rigidity of the individual layers, but on the other hand, a very high rigidity of a layer composite can already be realized with a few layers stacked one above the other. In this respect, a low stiffness in the non-evacuated and a high rigidity in the evacuated state can be achieved.

It can be seen that in a further preferred embodiment it is advantageous if the stiffening device in the stiffened state has a flexural rigidity at least 100 times greater, preferably at least 1000 times greater, than in the unadjusted state. It is also conceivable that the flexural rigidity in the stiffened state even at least 10,000 times or more, about particularly preferably at least 100,000 times higher than in the unstiffened state. The relatively low bending stiffness in the unstiffened state is determined by the flexural rigidity of the individual layers. The high bending stiffness in the stiffened state then results from the formation of the frictional layer composite. In particular, when using paper or a paper-like material formed a particularly advantageous, large ratio between a low bending stiffness in unstiffened and a high bending stiffness in the stiffened state can be achieved. In a further preferred embodiment, it is provided that the filling material 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19 , 20-30, 31-40, 41-50, 51-60, 61-70, 71-80, 81-90, 91-100, 101-1 1, 0.1 1 1 -120, 121 -130, 131 -140, 141 -1 50 or 1 50 to 200 or more layers, preferably 10 to 200 layers, more preferably 40 to 100 layers. The number of layers depends on the desired stiffening ratio. With a layer composite having a corresponding number of layers, a good stiffening of the stiffening device can be achieved. At the same time, however, the overall thickness of the stiffening device is acceptable and the stiffening device is easy to handle. In this connection, it is also advantageous if the layers of the filling material have a thickness less than or equal to about 3 mm, preferably from about 0.01 mm to about 0.5 mm, particularly preferably from about 0.05 to about 0.2 mm. Depending on the type and geometry of the filling material, the thickness of the individual layers of the filling material can be adapted to the stiffness desired in the stiffened state, wherein the thickness of the individual layers can influence the total thickness and the number of layers which can be used particularly advantageously. The sheath in which the filling material is arranged is preferably foil-shaped, particularly preferably made of a plastic, very particularly preferably of a thermoplastic material, most preferably for example of thermoplastic polyurethane (TPU), polyethylene (PE), fluoropolymers or the like. In this case, composite films made of several different materials can be used, for example, metal coatings are conceivable for particularly thin polymer films. It is also advantageous if the shell is fluid-tight, preferably airtight. In this case, the wall of the shell preferably has a thickness of less than or equal to 1 mm, preferably less than or equal to 500 μm, very particularly preferably less than or equal to 250 μm. The thinner the shell is formed, the less stiff and stable are kinks that may form in the shell. As a result, such kinks can exert less disturbing influences on the function of the stiffening device. It is also conceivable that the shell consists of two cohesively connected layers of different thickness, between which the filling material is arranged. The thinner of the two layers can then represent in use, for example, the side of the shell, which rests against the body part to be molded and should be as flexible as possible in order to promote good moldability. The thicker of the two layers can be the outside of the envelope, which should be as stable and insensitive to external influences as possible. In a particularly preferred embodiment, for example, the outer layer may have a thickness of about 250 pm while the inner layer has a thickness of about 100 pm. It is favorable if the casing also consists of an incompressible material. In addition, the sheath may have an area serving as an overlapping area. This overlapping area is particularly helpful in order to be able to place the stiffening device around a body part without gaps. NEN. The overlap area may either contain filler or be free of filler.

Overall, thus, the thickness of the stiffening device in a range between see about 1 mm and about 35 mm, preferably between about 1 mm and about 20 mm, more preferably between about 1 and about 9 mm move. The rigidity or the area moment of inertia of the device is proportional to the diameter of a corresponding limb at which the device is to be applied. The smaller the diameter of the limb, the smaller is the minimum required thickness of the device. It can be assumed as a very rough rule of thumb that the minimum necessary cuff thickness corresponds to 0.04 times the extremity diameter. Overall, it is preferred that the volume enclosed by the cuff is not more than 80%, preferably not more than 50%, more preferably not more than 30%; of the pulsatile blood volume. The pulsatile blood volume is the volume change that occurs in the blood vessel to be measured during a pulse. It can be seen that a stiffening device according to the invention overall is extremely space-saving feasible.

According to a further embodiment, it is preferred that the filling material at atmospheric pressure has a thickness of 1 mm to 30 mm, preferably of 2 mm to 10 mm, particularly preferably of 3 mm to 6 mm. The individual optimum thickness of the stiffening device as described above also depends on the individual body part to be measured. Overall, however, it is favorable if this thickness does not substantially change during stiffening of the device. This is the case, in particular, when the layered filling material used is essentially incompressible. As a result of the application of a negative pressure to the shell containing the filler material, the total thickness of the filler material also changes only to an extremely small extent. This measure is determined by the volume of air present in the envelope. It is preferred if the change in thickness when applying the negative pressure, ie when transferring the device in the stiffened state, less than about 75%, preferably less than about 50%, more preferably less than about 25% to the thickness in not stiffened state amounts. So it is also advantageous if the pressure applied in the stiffened state in the shell at least a negative pressure of 250 mbar, preferably more than 500 mbar, particularly preferably more than or equal to 750 mbar, very particularly preferably more than or equal to 850 mbar relative to the pressure applied to the outside of the shell atmospheric pressure. The total thickness of the stiffening device in the stiffened state advantageously differs only in the air volume, which is present in the unstiffened state in addition to the filling material in the flexible, airtight envelope.

It can be seen further that it is favorable if the filling material already fills the interior of the casing as far as possible in the unstiffened state. For example, in one preferred embodiment, the length and / or width of the layers of fill material may be between about 70 and 100%, preferably between about 80% and about 90%, of the length and width of the interior of the envelope. In this case, the volume of air contained in the shell is just large enough that the layers of the filling material can move sufficiently against each other to optimally shape the contour of the body part to be measured. In this case, the sheath is preferably dimensioned so that the filling material while it adapts to the body part or the patient contour does not abut the boundary of the sheath, so that the risk of buckling is formed by such abutment as possible avoided. However, the volume of the casing is at the same time small enough to have the least possible influence on the total thickness of the stiffening device. In this case, air is preferably only at the locations in the preferably flexibly formed casing, on which a volume is spanned by the filling material in the casing. In this respect, one recognizes the advantage of a further preferred embodiment in which the circumference and the shape of the layers of the filling material correspond to the circumference and the shape of the interior of the envelope. The layers of such filler fill the interior of the shell almost optimally and the additional air volume contained is relatively small, typically less than about 50%, preferably less than about 30% of the volume of the filler. As a consequence, it is also possible to apply a corresponding negative pressure with a relatively small vacuum pump. Such a vacuum pump is easy to transport and can also be used under difficult conditions, for example in mountain rescue, at accident sites. According to a further embodiment, it is favorable if at least one further filling material is arranged in the casing. Such a further filling material, like the surface structuring described above, can serve to further reinforce the frictional connection between the layers. By way of example, these may be particles which can fit into the embossing of the surface applied by the structuring or else intercalate into the fiber mesh of the paper present per se. In this case, particle dimensions are preferred which are similar to the dimensions of the cavities of the embossing or of the paper fiber braid, so that the particles indeed get caught in the embossing or in the fiber braid but can not completely submerge. The particles entangled in this way thus lead to an increase in the surface roughness and may favor the positive connection between adjacent layers. As a consequence, the achieved frictional connection is increased when the negative pressure is applied. Overall, the stiffness during the evacuated state compared to the flexibility in the non-evacuated state can still be increased. It can be seen here that it is favorable in a further embodiment if the further filling material is a powder or fluid which can be intercalated between the layers of the layer material. Such a powder is preferably formed with a granular structure.

It can be seen, moreover, that it also makes sense if the envelope is preferably made of an incompressible material. Particularly preferred is a material that is insensitive to the vacuum to be applied. At the same time, the material should be as stiff as possible in order to be able to adapt as well as possible to the corresponding shape to be contoured.

In a further preferred embodiment, it is provided that the airtight envelope has at least one air inlet and / or air outlet. This is particularly meaningful in that the airtight envelope is to be evacuated to reach the transition from the non-stiffened to the stiffened state. Furthermore, it is favorable if the stiffening device has a control device with a vacuum pump for evacuating the airtight envelope.

It can be seen insofar that a stiffening device according to the invention is optimally suited for use in a blood pressure measuring device, to attenuating effects of an optionally fluid or gas cushion filled compression device, the one to can distort the measuring signal, counteract it. In this case, the stiffening device according to the invention can preferably be used such that it is arranged between a pressure sensor element and a corresponding compression device, wherein the pressure sensor element rests against the body part on which a pulsatile signal is to be detected.

According to a further preferred embodiment, the invention therefore also relates to a blood pressure measuring device with a pressure sensor element and a compression device, which has a stiffening device according to the invention. It is advantageous if the stiffening device is arranged between the pressure sensor element and the compression device.

The pressure sensor element is preferably a pressure sensor embedded in a gel pad. Particularly advantageously, the pressure sensor is located in the center of the gel pad. In this way, an optimal coupling of the pressure sensor element to the body part to be measured is possible. However, it is also conceivable that the pressure sensor is arranged outside the blood pressure measuring device and connected to the gel pad, which is arranged between the stiffening device and the body part, via a tube system according to the principle of communicating tubes.

The gel pad allows in each case a large-area contact of the pressure sensor element with the body part. In this way, pressure changes emanating from a blood vessel of the body part can be transferred to the gel pad without being damped. These may spread unhindered due to the gel fluid in the pad and be measured by the sensor disposed in the gel pad (or a corresponding externally connected but connected sensor).

According to the present invention, the pressure sensor element is surrounded by the stiffening device as already described above. Pressure changes which act on the gel cushion can thus no longer be passed on from the pressure sensor element to the surrounding pressure cuff in the stiffened state of the stiffening device, but are completely absorbed by the gel cushion and thus forwarded without distortion to the pressure sensor of the gel cushion. The main dampening These effects are due to the dampening effect due to the tissue surrounding the artery. Due to the optimal Konturenpassbarkeit the stiffening device in the non-stiffened state and the optimal preservation of the assumed contour in the stiffened state between the stiffening device and the body part, between the pressure sensor element and the stiffening device or the pressure sensor element and the body part optionally existing air cushion can be significantly reduced, to a almost complete avoidance in the most optimal case, when the sphygmomanometer is correctly applied. In this respect, the damping effects that could arise from such air cushions can be effectively avoided. As a result, almost all of the signal energy is transmitted from the body part to the pressure sensor element, thereby significantly improving the signal-to-noise ratio.

The pressure sensor element can also have further sensors, for example electrodes for impedance and / or potential measurement and / or photoelectric detection or excitation elements and / or capacitive measuring sensors and / or acceleration sensors.

The compression device of the blood pressure measuring device according to the invention serves to generate the necessary pressure, which counteracts the pressure exerted by the artery and in this way makes it possible to detect the pressure fluctuation emanating from a blood vessel of a body part and thus to detect an arterial pressure curve.

In a first preferred embodiment, the compression device is an air-filled sleeve. This may be, for example, a conventional cuff of a blood pressure measuring device. Such a cuff can be either tubular or wound around a corresponding body part, for example a humerus, a leg or a tail. By inflating the cuff while the inner circumference of the cuff can be reduced, so that a corresponding pressure is exerted on the surrounding body part. It is also conceivable, for example, that the air-filled sleeve is flow-connected to the stiffening device, so that the air to be pumped out of the airtight casing of the stiffening device is transferred into the air-filled cuff of the compression device. Again, the airtight sheath of the stiffening device is again preferably made of a material which is both flexible and impermeable to air. Overall, however, the airtight envelope is preferably tubular or tubular. It may be mat-like, preferably with a rectangular mat surface or else with a frustoconical surface, be formed or have approximately the shape of a torus. Such a torus can then be filled with the above-described filling material and, for example, with a prefabricated diameter as a tube, be placed over a limb, wherein the extremity can be inserted through the torus opening.

Overall, the airtight envelope of the stiffening device and insofar the entire stiffening device on the inside of the compression device, namely the air-filled cuff, arranged. When the sphygmomanometer is then wrapped around a body part or, if tubular, it is slipped over a body part, the stiffening device comes to rest between the compression device and the pressure sensing element. Thereafter, for example, first the pressure can be increased by the compression device is inflated, at the same time the stiffening device assumes the shape of the surrounding body part contour. If the pressure is further increased, it is then conceivable that either the stiffening device is first evacuated in an intermediate step, or first the maximum pressure that is to be present for detecting the desired parameters is set, and then the stiffening device is stiffened.

If the corresponding measuring pressure is initially applied, the following procedure is conceivable: In a first step, the blood pressure measuring device is positively applied to the body part to be measured; in a second step, the pressure is increased by the compression device until the desired measuring pressure is applied, in a third step If the stiffening device is stiffened and in a fourth step, the pressure difference between the compression device and the stiffening device resulting from the stiffening is adjusted accordingly. In particular, in the fourth step, for example, the pressure equalization can be done simultaneously with the stiffening of the stiffening device, when the stiffening device, in particular the flexible airtight shell of the stiffening device and the sleeve of the compression device fluidly connected and the air to be evacuated from the stiffening device can be pumped into the compression device.

In a further preferred embodiment of the blood pressure measuring device, it is provided that the compression device is a mechanical, in particular fluid-free, preferably gas cushion, gas mixture cushion and / or fluid cushion-free, pressure cuff. One particular advantage of such a blood pressure measuring device is, inter alia, that the force exerted on the compression element by the change in volume of the artery can be transmitted almost undamped to the pressure sensor element. Even if residual damping by the stiffening device should still be present, a corresponding signal can not be distorted by the compression device. It is particularly advantageous if the compression device is a Zugbandvorrichtung, which is performed substantially anelastisch. The term "anelastic" is usually understood to consist of a non-stretchable material. It is also advantageous if the compression element is formed from a monodirectionally anelastic material. Such a material has a first direction in which it is not stretchable and a second direction in which it is - at least to some degree - extensible. Typically, such a material is, for example, a motor vehicle seat belt or the like. Such a mechanical, fluid agent-free pressure cuff can expand neither by an involuntary tightening or twitching of the spanned muscles, nor by the low arterial pulse pressure wave. Also, external influences do not cause vibrations that may possibly adversely affect the pressure wave detection. It can also be seen that it is favorable if such a mechanical compression device has a hydraulic, pneumatic or mechanical regulation device. Such a regulation device preferably serves to adapt the pressure exerted by the compression device accordingly. In this case, the pressure adjustment takes place in particular in that the regulation device can increase or decrease the inner circumference of the compression device. Such a mechanical regulation device can be realized in different ways. For example, in a simple embodiment, it is conceivable that it is a regulation device which acts in the manner of an iris diaphragm. In this case, the compression element, for example, consist of several sub-elements which are mutually displaceable such that the inner circumference of the compression element is variable. Such sub-elements are preferably made anelastic.

In a further embodiment, the mechanical regulation device may, for example, comprise a carrier device, a force transmission device and / or at least one dynamic element. The regulation device is then preferably a transmission device which has all three of these elements. However, variants are also conceivable in which only one or two of the three elements are realized.

A carrier device can be a stable or flexible plate or a tissue reinforcement. On or on the support device - if present - the dynamic element and / or the power transmission device can be mounted.

A corresponding dynamic element is preferably an element which provides a force which is transmitted from the power transmission device to the compression device and can cause a corresponding contraction or relaxation of the compression element, thus a reduction or enlargement of the inner circumference of the compression element. In a preferred embodiment, the dynamic element is a motor. The power transmission device is preferably an element that transmits the applied force to a reduction or enlargement of the inner circumference of the compression element. For example, it is conceivable that the power transmission device includes a cable or a ring belt, which is steered via one or more guide elements. In a first variant of the regulation device, which can be realized particularly simply technically, the force can be exerted by the simple manual action on the force transmission device. For example, it is conceivable that the carrier device is possibly reinforced holes, which are located in opposite directions Ends of a fabric band, which forms the compression element, are formed. The transmission element can then be a rope or rope-like element guided through the holes, at the ends of which the contraction element compresses, similar to the principle of a corset. The holes act accordingly not only as a support device, but also as guide elements for the power transmission device. Of course, it is also conceivable that in place of holes pulleys, hooks, eyes o. The like. Be used as guide elements.

In a more preferred embodiment, the regulation device comprises a motor as a dynamic element. This motor may for example be mounted on the carrier device. These are, for example, a carrier plate whose shape can correspond more or less exactly to the contour of the body part.

A regulating device designed in this way can be designed in a first variant on the side of the compression element facing away from the body part, that is to say on the outside of the compression element. In an alternative variant, the regulation device can also be arranged on the inside of the compression element, that is to say between the pressure cuff and the body part to be measured. In further embodiments that can be combined with the abovementioned embodiments, the regulating device can apply a force to the compression element in different directions, which leads to a change in the effective inner circumference of the compression element. The effective inner circumference of the compression element corresponds to the clear width of the blood pressure measuring device applied to the body part to be measured. In addition to the force exerted on the compression element, it also depends on the arrangement of the components which form the blood pressure measuring device according to the invention.

If the regulation device is located on the outside of the compression element, the clear width and thus the effective inner circumference of the compression element is essentially determined only by the compression element itself. "Essentially" means, for example, any gaps between the ends of the compression element that can be bridged by the regulation device, contribute to the effective inner circumference of the compression element. However, there are no other components involved in the formation of the inner circumference.

On the other hand, if the regulation device is located on the inside of the compression element, it may be involved, in particular by the carrier device, in the formation of the effective inner circumference.

In a first embodiment it is provided that the compression element can be mechanically acted upon by the regulation device in the circumferential direction of the compression element with a force. This is particularly favorable if the regulation device is located on the outside of the compression element. Thus, it is conceivable, for example, that the regulation device has a cable pull or a cable-like element as a force transmission element whose effective length can be shortened or extended with the aid of the dynamic element, for example by the dynamic element being able to wholly or partially wind up the force transmission element. The compression element can be designed as a band with two ends, which can be drawn by the winding of the power transmission device to each other, thereby reducing the inner circumference of the compression element. In an alternative embodiment, it is provided that the compression element can be acted upon mechanically by the regulation device radially to the axial direction of the body part with a force. This can be favorable, for example, if the regulation device is arranged between and the stiffening device. The compression element may then be embodied, for example, in the form of a closed ring, which is pressed by the regulation device to the outside.

In both cases, the dynamic element may be a motor with a rotatable shaft.

In a first variant, this wave can cause a change in the effective length of an element of the power transmission device. For example, it may be used as a cable drum or rope-like element, the use of the term "cable drum" always meaning and including a cable drum-like element in the following is arranged on the outside of the compression element or when the force transmission device is or has a rope-shaped element, which can be shortened or extended by winding on or unwinding from the spindle. The shortening, ie the winding on the spindle, thereby causing a pulling on the rope-shaped element. Such a rope-shaped element of a power transmission device may be fastened with one end to the compression element and with the other end to the shaft of the motor acting as a cable drum, ie, on the dynamic element. The compression element may then, as described above, be in the form of a band, the two ends of which face each other when the compression element around the stiffening device according to the invention is applied around the corresponding body part. The rope-shaped power transmission element can connect the two ends, for example, zigzag with each other. As guide elements for such a power transmission device deflecting elements in the form of simple holes, but also rollers, hooks, eyes or the like may be formed at the two ends, which is guided by the rope-shaped transmission element. The shortening of the transmission element by winding on the cable drum, that is on the shaft of the dynamic element, then causes the two ends of the compression element to be pulled towards each other and that reduces as a result, the inner circumference of the compression element.

In a further variant, the shaft can cause an eccentric deflection of the compression element. The shaft of the engine designed as a dynamic element can be used as a drive for an eccentric. Such an eccentric is preferably mounted on the shaft axis so that its center of gravity can rotate about the shaft axis. It is particularly advantageous if the regulation device is arranged on the inside of the compression element. For example, it is conceivable that the dynamic element, ie the motor, is mounted on a carrier plate. The eccentric may then have, for example, an off-axis and a near-axis end. About the eccentric compression element, which is then preferably a closed annular band, are performed. In a rotation about the axis of the spindle then the off-axis end of the eccentric can be alternately in a small and a long distance to the support plate. Serves the off-axis end of the eccentric at the same time as a guide element for the Compression element, the compression element is deflected by the eccentric to the outside, when the off-axis end is located at a great distance to the support plate. It can be seen that such eccentric-equipped regulation device acts on the compression element in the radial direction to the axial direction of the body part around which the stiffening device and the mechanical compression element are laid around.

In another variant, it is also conceivable that the regulation device causes a deflection of a rope-shaped element of the force transmission device in a direction radial to the axial direction of the body part. For example, it is conceivable that the mechanical compression element in turn is a band whose short ends lie opposite one another in the state placed around the stiffening device. For example, the ends can slide at least a little way over a carrier plate of the regulation device. The rope-shaped element of the power transmission device can then be attached with its one end at a certain distance from the first end of the compression element and with its second end at a certain distance from the second end of the compression element to the compression element. The dynamic element can then be designed so that it presses, for example with a hydraulic, pneumatic or a simple mechanical plunger, the middle part of the rope-shaped element in the radial direction to the axial direction of the body part to the outside. The two ends of the rope-shaped element are drawn towards each other and cause the result that also move the two ends of the compression element to each other. As a result, in turn, the effective inner circumference of the compression element can be shortened.

In a further preferred embodiment, the mechanical compression element of the blood pressure measuring device according to the invention consists of relative to each other movable part surfaces, as already mentioned in the case of the iris-like embodiment. However, in other embodiments as well, for example, it is conceivable that the compression element has the basic shape of a rectangular band which can be placed around the body part or around the stiffening device. Other basic shapes are of course conceivable, such as the shape of a lateral surface of a truncated cone or a closed annular band. The partial surfaces may, for example, be substantially mutually rectangular strips arranged parallel to one another. The strip-shaped faces can be juxtaposed to give the rectangular base. Preferably, at least three such strips are present. It is conceivable that the strip-shaped partial surfaces each have a long side and a short side, wherein the long side of the partial surfaces can be aligned either parallel to the long side or parallel to the short side of the basic body. Each of these partial surfaces can then be equipped, for example, with its own regulation device, for example with a regulation device which has an eccentric as described above. However, it is also conceivable that the partial surfaces are regulated by a common regulation device, for example in which they are connected or coupled by a cable-shaped element of a power transmission device.

The faces can also form a spiral band that lays around the body part. It is also conceivable that the faces have a different shape, for example. The shape of triangles or other polygons.

Due to their relatively given mobility, the partial surfaces can optimally rest against the surface of the body part to be measured. It is particularly advantageous if the faces consist of a flexible, but not stretchable material.

It can also be seen that it is expedient if the partial surfaces are interconnected. The interconnected partial surfaces of the compression element can move in this way relative to each other, similar to a joint. This supports the optimal adaptation of the compression element to the outer contour of the body part, as already described above for the partial surfaces of the layers of the filling material. The partial surfaces can cover the surface of the body part in this way over the entire contact surface of the compression element, without the occurrence of wrinkles or contact-free air spaces. This in turn has a favorable effect on a uniform force transmission from the compression element to the body part, on which the desired parameters are to be measured. The connection of the faces with each other also happens here preferably by means of fasteners. In the simplest case, this can be strips arranged between the partial surfaces and made of the same material from which the partial surfaces are also formed. For example, it is conceivable that the flexible compression element itself, as already shown above, is formed from a large strip of material in a rectangular shape. The material is preferably flexible but not elastic, hence anelastic. In these strips of material can then be incorporated at certain intervals parallel rows of slots. These rows of slots divide the rectangular base body of the flexible compression element into the partial surfaces according to the invention. The connecting elements can then be formed by remaining material webs arranged between the slots. The connecting elements are preferably flexible in the sequence, but anelastic. , It is also conceivable that the compression element is a material strip of a non-stretchable fabric. This strip of material can be divided by the targeted removal of warp threads of the fabric into partial surfaces. At the tissue sites where the warp threads have been removed, an isotropic, flexible connection of the partial surfaces through the weft threads of the tissue can subsequently arise.

It is also conceivable that the connecting elements are made of a different material than the main body of the flexible, mechanical compression element. Overall, the connecting elements act as joints, which allow a movement of the partial surfaces relative to each other, as described above.

With regard to the use of a blood pressure measuring device according to the invention with a mechanical compression element, it is conceivable, as for a blood pressure measuring device with a pneumatic or hydraulic compression element, that the blood pressure measuring device with the stiffening device according to the invention and the mechanical compression element is first placed around the body part with a loose fit at which the desired parameters are to be measured. It is both conceivable that only the stiffening device is applied and then the compression element is coated or -vertülpt, as well as that the stiffening device and the compression element applied as a common component become. Different variants are conceivable, which of course can also be realized in connection with a blood pressure measuring device with a pneumatic or hydraulic compression element. Thus, the stiffener according to the invention and the compression element can form a two-layered mat that can be easily wrapped around a body part. A first layer of this mat can be formed by the stiffening device and a second layer by the compression element. Also conceivable is a tubular formation of such a first and second layer, which can then be pulled like a stocking or sleeve over a body part. In any case, a pressure sensor element, as described above, is arranged on the inside of the stiffening device, that is to say between the stiffening device and the body part to which the device is applied. In this case, when using the blood pressure measuring device according to the invention, the pressure sensor element can be arranged on the body part in a separate step before the stiffening device is applied, or it can be firmly attached to the stiffening device and can be arranged together with the latter on the corresponding body part.

In any case, after applying the blood pressure measuring device according to the invention with the aid of the regulating device, the inner circumference of the loose fitting on the body part compression element can be reduced until the compression element firmly and immovably rests on the body part. Next, the inner diameter inner circumference of the compression element can then be further reduced, whereby the body part to be measured is compressed. As a result, an artery in the body part can be compressed by the surrounding tissue structures. If the pressure which the compression element exerts on the body part is greater than the blood pressure prevailing in the artery, the blood flow in the artery is interrupted. In this case, the interruption of the blood flow, as long as the pressure is greater than the diastolic, but less than the systolic pressure, at intervals corresponding to the heart rhythm (waterfall / gush-like blood flow). As soon as the pressure becomes greater than the systolic pressure in the artery, there is a complete suppression of blood flow.

The pressure sensor element of the blood pressure measuring device according to the invention is preferably arranged on the body part facing side of the stiffening device. If the blood pressure measuring device is attached to the body part, comes in this way, the pressure sensor element between the body part and the stiffening device to lie. It is insofar pressed by the compression element against the body part. Characterized in that the compression element preferably, as described above, exerts its force without the use of fluid pads, in particular without the use of air cushions, on the body part, in that it is anelastic and also in that they - thanks to their outer contour of the body part adaptable shape - with even contact pressure on the body part rests, it causes the pressure sensor element with low loss of the body part outgoing pressure pulses of the arterial blood pressure measures. It acts like a Cegenlager for the force exerted by the arterial pulse pressure force and prevents attenuation in the transmission of the pulse signals to the pressure sensor or the pressure sensor element.

Further features and characteristics of the invention can be taken from the following description of specific embodiments and with reference to the drawings. Show it:

1 shows a schematic view of a stiffening device according to the invention;

Fig. 2a: A cross-section along the line X-X of the embodiment of Figure 1 in non-stiffened state;

FIG. 2b shows a cross section along the line X-X of FIG. 1 in a stiffened state; FIG. 2c shows a cross section through a further exemplary embodiment of a stiffening device;

3a shows a detailed view of two layers of the stiffening device according to the invention in cross section;

Fig. 3b: Another cross-sectional view of another embodiment of two

Layers of the stiffening device according to the invention;

4a shows a schematic view of a subdivided layer of the filling material of a stiffening device according to the invention;

Fig. 4b: Detail view of Fig. 4a;

5a shows another schematic view of a subdivided layer of the filling material of a stiffening device according to the invention; A detail enlargement of Fig. 5a;

Another schematic view of a subdivided layer of a stiffening device according to the invention;

An enlarged detail of Fig. 6a;

A further exemplary embodiment for a schematic view of a subdivided layer of a filling material according to the invention of a stiffening device according to the invention;

A detailed view of partial surfaces and recesses and connecting webs of a layer of a filling material according to the invention of a stiffening device according to the invention;

A cross section along the line Y - Y of Fig. 8a;

A cross-section through a blood pressure measuring device according to the invention with a stiffening device, in a state applied to a body part;

A further embodiment in cross section for a blood pressure measuring device according to the invention in the applied state

A schematic section of a mechanical, in particular fluid-free compression device of a blood pressure measuring device according to the invention;

Another embodiment of a mechanical compression device;

Top view of the embodiment of Figure 12a in the state applied schematically to a bicep-shaped body part state.

Another embodiment of a mechanical compression device of a blood pressure measuring device according to the invention;

A cross section through a regulation device of a compression device according to the invention of Figure 13 along the line Z - Z;

A side view of a compression device according to the invention of a blood pressure measuring device with a mechanical regulation device; A further embodiment of a blood pressure measuring device according to the invention with a stiffening device and a mechanical compression device; Fig. 1 7: Another embodiment of a blood pressure measuring device according to the invention with a stiffening device and a mechanical regulation device of a mechanical compression device. FIG. 1 shows a stiffening device 10 according to the invention for a blood pressure measuring device. The stiffening device 10 consists of a casing 20 with an air inlet or outlet 24. In the example shown, the casing 20 is preferably flexible and impermeable to air. The shell 20 has an outer side 22 and an inner space 21. In the interior 21, a filling material 30 is arranged. It can be seen in FIG. 1 that the illustrated embodiment represents a stiffening device 10 with a substantially rectangular basic shape. The stiffening device 10 is mat-shaped and can be particularly easily wrapped around a body part in this way, as shown for example in Figures 9, 10, 1 6 and 1 7. Of course, however, other embodiments are conceivable in which the stiffening device 10, for example, the basic shape of a truncated cone surface or other shapes, which are adapted to the respective body part to be encompassed. It can be seen further in Fig. 1 that the filling material 30 fills the interior 21 of the shell 20 in large parts. In terms of the rectangular basic shape of the mat-shaped stiffening device 10, the width B of the filling material 30 is thus just greater than the width b of the inner space 21 of the casing 20 such that abutment of the filling material at one end of the casing during bending of the stiffening device during the Creation is prevented. The same applies to the length S of the filling material 30 and the length s of the interior 21 of the casing 20. The filling material 30 is a stacked layers 31 of paper or a paper-like material. However, other layered, stackable materials are also conceivable. The layers 31 have a preferred thickness of less than 60 μητι. The thickness of the layers 31 may vary, but are more preferably at least about 0.01 mm and at most about 3 mm thick. All values in between are imaginable and possible. Corresponding to the above already stated corresponds to the width B of a layer 31 of the filling material 30 of the width b of the inner space 21 of the shell 20 and the length S of such a layer 31 of the length s of the inner space 21st Also in the case of other geometries of the shell 20, the outer dimension of the layers 31 and the contour of the layers 31 correspond to the inner dimension and contour of the inner space 21 of the shell 20 with a corresponding tolerance range for movement of the filling material 30 in the shell 20. It can be seen in Fig. 2a, which shows a cross section along the line X - X of Fig. 1 that the layers 31 of the filling material 30 are loosely stacked in the unadjusted state. A certain volume of air 25 is present in the airtight, flexible envelope 20, so that corresponding air-filled intermediate spaces 26 are formed or present between the individual layers 31. Furthermore, it can be seen in FIG. 2 a that the layers 31 of the filling material 30 almost completely fill the interior 21 of the casing 20, and that the air volume 25 is relatively small in relation to the volume occupied by the filling material 30.

If the air is now pumped out of the flexible sheath 20 through the air outlet 24, for example by means of a vacuum pump as shown in FIGS. 9 and 10, the external atmospheric pressure applied to the outside 22 of the hermetic flexible sheath 20 presses the flexible sheath and arranged in the flexible shell layers 31 of the filling material 30 together, so that a layer composite of frictionally interconnected layers 31 of the filling material 30 is formed. In this case, the pressure difference between the pressure applied to the outside 22 and the pressure prevailing in the interior 21 is at least 250 mbar, preferably more, for example 750 mbar or even 850 mbar. Even lower or higher pressure differences are conceivable. The adhesion between see the stacked layers 31 is formed by the acting between the layers 31 of the filling material 30 frictional forces. The frictional force between the layers 31 increases approximately proportionally to the standing on the layers 31 normal force. While the individual layers 31 are decisive for the rigidity and elasticity of the filling material 30 and therefore for the rigidity and elasticity of the stiffening device 10 before the adhesion is produced, these properties are measured after the occurrence of the frictional connection, as shown in FIG. 2b, now according to the total thickness the stack of interconnected layers 31.

The frictional forces between the individual layers 31 can be enhanced if, as in the exemplary embodiment illustrated in FIG. 2c, another filling material 40 is present in the airtight envelope 20 of the stiffening device 10 according to the invention. It can be seen in FIG. 2 c that the further filling material 40 is granular particles which are arranged in the intermediate spaces 26 between the individual layers 31 are. In this case, the intermediate spaces 26 in the unstiffened state - as in the example shown in Fig. 2a - also air-filled. When the air is now pumped out of the casing 20 through the air outlet 24, the particulate parts of the second filling material 40 enhance the frictional force acting between the individual layers 31 of the filling material 30.

A further reinforcement of the frictional force or of the frictional connection between the individual layers 31 of the layer-shaped filling material 30 can, for example, be effected by a corresponding surface design of the layers 31. Thus, it can be seen in FIG. 3 a that the one side surface 31 1 of such a layer 31 is provided with elevations 313, while the other, opposite side surface 312 of the layer 31 has an embossment 314. As can be seen in FIG. 3 a, the elevations 313 in the first layer 31 can interact positively with the embossings 314 of the adjacent layer 31 and in this way enhance the frictional force between the layers 31 of the layered filling material 30. The elevations 313 can intervene on the one hand form-fitting in the embossments 314. On the other hand, however, the frictional force is already amplified even when the elevations 313, as shown in the cutout area marked C, find a simple stop at the edge of such an embossment 314. Preferably, many embossments 314 and elevations 313 are randomly distributed on the layer 31, so that in each position a portion embossments 314 and elevations 313 is interlocked.

It is also conceivable that in the layers 31, as can be seen in FIG. 3 b, only embossings 315 are introduced into which the particles of the second filling material 40 can dip. In this case, the embossings 31 5 are preferably formed so that the particles 40 do not completely dip into the embossments 31 5 but protrude beyond them and thus likewise favor a positive connection between two adjacent layers 31, which reinforce the frictional force between the layers 31 of the filling material 30 can.

FIG. 4 a shows a schematic design of a single layer 31 of the filling material 30 of the stiffening device 10 according to the invention. It can be seen that this layer 31 consist of a plurality of partial surfaces 32 with a square basic shape. The partial surfaces 32 are delimited on all four sides by recesses 34, which are introduced into the layer 31. These recesses 34 can be introduced, for example, by laser cutting or punching in the layer 31. One recognizes that between the individual partial surfaces 32 connecting elements 33 are formed. These arise through short distances between the recesses 34. The recesses 34 in the example shown in Fig. 4a are particularly simple. It is merely a slot-shaped straight recesses, which are, for example, by a punching particularly easy to introduce. In Fig. 4b it can be seen that the connecting elements 33 in relation to the partial surfaces

32 have a very small area. The connecting elements 33 are therefore web-shaped in the illustrated embodiment. The connecting elements 33 can be bent very easily in this way, whereby the part surfaces 32 can be moved very well against each other.

5a shows a further embodiment variant for the design of the layers by partial surfaces 32. The partial surfaces 32 shown here have a triangular basic shape and are formed by inserting star-shaped recesses 34, each having three beams, into the layers 31 each three star-shaped recesses 34 form a hexagon, wherein in this hexagon centered a fourth star-shaped recess 34 is arranged. This creates a hexagonal grid with trigonal base elements. Here again, bar-shaped connecting elements 33 are formed between the individual partial surfaces 32, which stop during the introduction of the recesses 34 between adjacent recesses 34. Again, it can be seen in the detail enlargement in Fig. 5b, that the surface of the connecting elements

33 is very small in relation to the surface 32 of the partial surfaces.

The exemplary embodiment illustrated in FIG. 6a for a layer 31 of the filling material 30 subdivided into sub-areas 32 and the detail enlargement of this pattern of the layer 31 according to the invention shown in FIG. 6b has hexagonal subareas 32, which in turn are interconnected by connecting elements 33. The partial surfaces 32 are arranged honeycomb-like

Finally, FIG. 7 shows yet another exemplary embodiment of a layer 31 of the filling material 30 according to the invention consisting of partial surfaces 32. The partial surfaces 32 likewise have a hexagonal symmetry here. However, the corresponding partial surfaces 32 have a first longitudinal axis and a second, shorter, perpendicular to the longitudinal axis transverse axis. The expansion behavior of such a layer 31 is in this way in the longitudinal direction of the layer 31 other than in the transverse direction perpendicular thereto. In this way, the stiffening device can be particularly well on, for example, create biconical shaped body parts, such as an upper arm with a well-developed biceps. One recognizes in Fig. 8a, an enlarged detail of such example, in Fig. 7 geometry shown by partial surfaces 33, recesses 34 and web-shaped connecting elements 33, a layer 31 of the filling material according to the invention 30. Again, it can be seen that the surface of the connecting elements 33rd as well as the surface of the faces 32 is bounded by the recesses 34. The connecting elements 33 are formed in one piece with the partial surfaces 32, ie the partial surfaces 32 and the connecting elements 33 consist of a continuous common piece of material. However, the surface of the connecting elements 33 in relation to the surface of the partial surfaces 32 is extremely low. It can also be seen in the cross-sectional representation of FIG. 8b, which shows a section along the line Y-Y of FIG. 8a, that the layer 31 is thinner in the region of the connecting elements 33 than in the region of the partial surfaces 32. The thickness d 'of FIG The connecting element 33 acts in this way as a predetermined breaking point between the adjacent partial surfaces 32. Such a geometry of the surface can, for example. With the aid of laser beam cutting on the surface of the layer 32 er- be aimed by the laser beam in the region of the connecting elements 33 is guided faster over the surface of the layer 31, as in the region of the trainees recesses. As a result, the connecting element 33 with the smaller thickness d 'remains. The connecting elements 33 act in this way not only as predetermined breaking points, but are also much easier to bend, as the much thicker faces 32 of the layer 31st They act in this way as joints between the faces 32nd

FIG. 9 shows a first exemplary embodiment of a blood pressure measuring device according to the invention in a schematic illustration in a state applied to a body part K. In this case, the body part K is shown in cross section. In the middle of the body part K, a bone, for example the os humeri, H is shown schematically. Around the body part K around the stiffening device 10 according to the invention is applied in a first layer, so that it rests positively on a circumference U of the body part K. Between the body part K and the stiffening device 10 is, as in the in Fig. 1 6 and Fig. 7 shown embodiments, preferably a (not shown) pressure sensor element 60 is arranged. Around the stiffening device 10, a compression device 70 is disposed. This compression device 70 in the illustrated embodiment is a conventional pneumatic blood pressure cuff with a corresponding air cushioning. A hydraulic embodiment of the compression device 70 is conceivable. The inflation of the blood pressure cuff of the compression device 70 causes a reduction in the inner circumference I of the compression device applied to the stiffening device 10 and consequently a reduction in the inner circumference of the stiffening device 10 thus reducing the circumference U of the body part K and increasing the pressure on an arranged in the body part K but not shown artery. The blood pressure measuring device 100 according to the invention also has a control device 90. The control device 90 can be, for example, a computer-controlled pump system with a first pump 91 for inflating the compression device 70 and a second pump 92 for pumping the air out of the flexible air-permeable sleeve 20 of the stiffening device 10. It is also conceivable that the control device 90 is designed in this way in that the air from the flexible casing 20 of the stiffening device 10 is pumped into the air-cushion pressure cuff 70, ie, into the compression device 70. The exertion of a corresponding pressure is thus accompanied at the same time with the stiffening of the stiffening device 10. Overall, with such an arrangement very effective damping effects of the air pressure cuff 70 with the aid of the reinforcing device 10 counteracted.

A further exemplary embodiment of a blood pressure measuring device 100 according to the invention can be seen in FIG. 10. Again, the body part K is surrounded by a stiffening device 10 according to the invention at its circumference U. Between the body part K and the stiffening device 10, as in the exemplary embodiments shown in FIGS. 16 and 17, a pressure sensor element 60 (not shown) is preferably arranged. Disposed about the stiffening device is a mechanical compression device 70 'having a mechanical regulation device 71. Both the stiffening device 10 and the mechanical regulation device 71 of the mechanical compression device 70 'are connected to a control device 90. The control device 90 in this case again has a vacuum pump 91, which serves to stiffen the stiffening device 10. In particular, the vacuum pump is used 91 to pump out the air from the airtight, flexible sheath 20 of the stiffening device 10. The compression device 70 'is preferably an at least mono-directionally anelastic but flexible tension band. A reduction of the inner circumference I of the compression device 70 'in the state applied to the body part K is preferably effected by the regulation device 71. In this case, for example, the regulation device 71 may be designed such that the reduction of the inner circumference I is effected by a contraction of the compression device 70 '.

FIG. 11 shows a section of a draw-band device, a mechanical compression device 70 '. The drawstring 70 "consists of a substantially rectangular base body 701. This has two opposite longitudinal sides 702 and two short sides 703. In the applied state, the short sides 703 are opposite each other, whereby the one short side 703 is at the first end 72 of the main body 701, while the second short side 703 is formed on the second end 73 of the main body 701.

1 1, that the main body 701 of the drawstring 70 "consists of three partial surfaces 704 which extend in the longitudinal direction L of the compression device 70. The partial surfaces 704 are interconnected by means of connecting elements 1 1, both the partial surfaces 704 and the connecting elements are formed by the fact that in the main body 701 of the tension band 70 "of the compression device 70 'two rows of mutually parallel recesses 705 are introduced. In the example shown, the recesses 705 may be slightly oblique to the longitudinal direction L of the compression device 70 'due to the tensile load after adaptation to the body part K. In the load-free state, the recesses 705 are preferably arranged transversely to the longitudinal direction L. However, it is also conceivable that they run transversely or parallel or at any angle to the longitudinal direction L. It can be seen that the partial surfaces 704 are separated from one another by the rows of the recesses 705. The connecting elements are webs of the material of the base body, which remain between the individual recesses 705 and thus connect the partial surfaces 704 integrally with one another. The first end 72 and the second end 73 of the main body 701 of the drawstring 70 "of the compression device 70 'are interconnected by means of a regulation device 71. The connection is made by means of a force transmission device 101, in the present example a cable pull, which surrounds several deflection elements 102 The deflection elements 102 of the illustrated example are rollers which are formed both at the first end 72 and at the second end 73 of the tension band 70 "of the compression device 70 '. The power transmission device 101, namely the cable of the cable, winds in a zigzag between the roller-shaped deflecting elements 102 of the first end 72 and the second end 73 back and forth. In addition, one end of the power transmission device 101 is wound around a coupling member 103, namely, a cable drum, a motor 104. By rotating the motor 104, the power transmission device 101 can be shortened or lengthened. It is useful if the other end of the power transmission device 101 is fixed to a mounting 106. A shortening of the force transmission device 101 then causes the compression device 70 ', in particular the tension band 70 ", to contract, while an extension of the force transmission device 101 leads to an enlargement of the inner circumference of the compression device 70'. smaller than the circumference U of the body part K, the compression device 70 'exerts a corresponding pressure on the body part K. It can also be seen in FIG. 11 that the motor 104 of the regulation device 71 is mounted on a support 105 which is formed on the second end of the compression device 70 '. On the support 105 and the deflecting elements 102, the second end 73 of the compression device 70 'are formed. Also at the first end 72, a carrier 105 is formed.

It can be seen further in FIG. 11 that a guide element 107 is formed on the carrier 105. The guide element 107 serves to guide the power transmission device 101 from the coupling element 103 formed as a cable drum to the first deflection element 102 formed on the opposite first end 72 of the tension band 70 " a force sensor 107 'is also provided in the guide element 107. A combination solution of guide element 107 and force sensor 107' is also possible. FIGS. 12a and 12b show further embodiments of a tension band of a mechanical compression device 70 '. FIG. 12a shows the tension band 70 "of the compression device 70 'in the state not applied to a body part K, while FIG. 12b shows the tension band 70" of the compression device 70' in the state applied to a bicep-shaped body part K, for example. In this case, a curvature of the drawstring 70 "can arise, which is seen perpendicularly from above in FIG. 12b, whereby the curvature which may form appears flat in the illustration 12 and 12b, only a few longitudinal threads 704 'and a few transverse threads Q are shown by way of example for illustration, wherein the fabric is preferably at least in the longitudinal direction of the drawstring 70 " Compression device 70 'formed anelastisch. The longitudinal threads 704 'run parallel to the longitudinal direction L of the drawstring 70 "of the compression device 70' .The longitudinal direction L in the circumferential direction is applied to a body part. be considered. The longitudinal threads 704 'can be displaced parallel to one another in the longitudinal direction L, for example if the drawstring 70 "is to be applied to a biceps-shaped body part as shown in Fig. 12b Anelastic longitudinal threads 704 'follow.

On the short side 703 of the first end 72 and in the embodiment of Figures 12a and 12b in each case three carriers 105 are arranged on which deflecting elements 102 are formed. It can be seen that each carrier consists of a first section 105a and a second section 1 05b. The first section 105a is connected to the main body 701, while the second section 105b carries the deflecting element 102. The edge 105c of the second portion 105b is obliquely formed in the illustrated embodiments, so that the carriers 105 can be moved relative to each other without interfering with each other. This is particularly advantageous if the carriers 105 are arranged in the state applied to the body part K at an angle α to each other. The latter is particularly advantageous in the embodiment illustrated in FIG. 12b in the state applied to a biceps-shaped body part. The beveled edges 105c prevent the carriers 105 of the outer longitudinal threads 704 'from colliding with the carrier 105 of the inner longitudinal threads 704' and thus interfere with one another.

13 shows a further exemplary embodiment of a mechanical compression device 70 'with a flexible tension band 70 ". The base body 701 of the tension band 70" of the compression device 70' consists of a plurality of partial surfaces 704 which are movable relative to one another. At its second end 73, in turn, a carrier 105 is arranged, on which a motor 104 is arranged centrally with a coupling element 103 designed as a cable drum, which belongs to a regulation device 71. The regulation device 71 furthermore comprises a number of deflecting elements 102, which are arranged on the carrier 105 or on the opposite carriers 105 'of the first end 72 of the drawstring 70 " Compression device 70 ', a force sensor 107' is arranged, which guides the power transmission device 101 from the coupling element 103 to the first deflecting element 102 while at the same time the force applied to the power transmission device 101, measures. Based on the measured force can be determined with what pressure the tension band 70 "of the compression device 70 'is contracted and according to what pressure by the tension band 70" of the compression device 70' is applied to the of the tension band 70 "of the compression device 70 'surrounded body part K. ,

It can also be seen in FIG. 13 that the end region of the main body 701 is designed at the first end 72 such that the partial surfaces 704 which run parallel to one another in the longitudinal direction L of the main body 701 are separated from one another by recesses 7041. However, the partial surfaces 704 are connected to one another with the aid of a linking device 7042. By means of the linking device 7042, the recesses 7041 are prevented from diverge during use of the drawstring 70 "of the compression device 70 'to such an extent that the functionality of the device is impaired. The linking element 7043 is at an upper one Attachment 7044 and a lower attachment 7045 attached to a respective face 704 of the main body 701 of the drawstring 70 ", wherein each linking device 7042 connects two adjacent faces 704. The linking element 7043 is zigzagged over the recess 7041 back and forth In the present example, deflecting points 7046 are deflecting rollers, but eyelets, deflection rollers, deflecting pins, hooks or the like are also conceivable.It is apparent that the upper attachment 7044 is preferably in the region of the carrier 105 In addition, it can be seen that each partial surface 704 is provided with its own carrier 105.

14 shows a cross-section through the mechanical compression device 70 ', in particular by a drawstring 70 ", in the assembled state, which leads through the line Z - Z of FIGURE 1. It can be seen that the support 105 is rigid but preformed and As a result, the body part K and the carrier 105 as well as the base body 701 can be adapted to one another It can be seen that the motor 104 in the installed state is arranged on the carrier 105 in such a way that it changes the inner circumference of the tension band 70 "to the corresponding body part K is not impaired. The same applies to the deflection elements 102nd

1 5 shows a cross section through a mechanical compression device 70 ', which has a flexible tension band 70 "It can be seen schematically how the carriers 105, 105' are attached to the base body 701 and face each other in the connection area In addition, the motor 104 is mounted on both the support 105 and on the support 105 'in each case a deflecting element 102 can be seen in the cross-section around the deflecting elements 102, the power transmission device 101 winds - in the example shown a cable - the gap between the second A shortening of the power transmission device 101 immediately leads to a reduction of the gap width, while an extension of the power transmission device 101 leads to an increase of the gap width, consequently a shortening of the power transmission device 101 results in the application of pressure by the tension belt 70 " on the body part K surrounded by the compression device 70 '. It can be seen in Figure 1 5 further that on the carrier 105 and support 105 'is in each case a cover 1051 is formed, which surround the deflection elements 102. The covers 1051 thus provide effective protection of the deflecting elements 102 and of the force-transmitting device 101 bound around the deflecting elements 102.

1 6 shows a further exemplary embodiment for a blood pressure measuring device 100 according to the invention with a mechanical compression device 70 ', in which the regulation device 71 is arranged on the inside of the tension band 70 "of the compression device 70." The stiffening device 10 is located between a body part K and The stiffening device 10 and the compression device 70 'engage around a pressure sensor element 60 arranged between the body part K and the stiffening device 10. The compression device 70' here too has a carrier device 71 1 on which a dynamic element 712 is arranged ,

The carrier device 71 1 consists of a flexible, round plate. On the plate of the carrier device 71 1, a motor with a coupling device 7121 is mounted as a dynamic element 712. The coupling device 7121 is a lift rod which is connected to the power transmission device 713 via a transmission point 7133. It is seen that the coupling device 7121 can push the power transmission device 713 outward via the transmission element 526 in the direction R that extends radially to the axial direction of the body part K. As a result, it is possible to press the transmission belt 713 the inner circumference I of the tension band 70 "can be reduced. In a further (not shown) variant embodiment, instead of the belt ring and the tension band 70 "itself be stretched over the lift ram so that the lift rod-shaped coupling device 7121 can serve as a power transmission device 71 3 at the same time by directly the force of the dynamic element 712 on the drawstring 70 "transmits. 1 7, the regulation device 71 is likewise arranged on the inner side of the tension band 70 "of the compression device 70. The regulation device 71 can support the compression device 70 'in a direction R extending radially to the axial direction of the body part K. The regulation device 71 here also has a carrier device 71 1 in the form of a roundish, flexible plate, on which a motor with a shaft serving as a coupling device 7121 is mounted as a dynamic element, on the coupling device 7121 as the force transmission device 713 an eccentric which is pivotable about the shaft-shaped coupling device 7121 of the dynamic element 712 in the direction of rotation V. The eccentric has an off-axis end 7131 and a proximal end 7132. The off-axis end 7131 serves as a transfer point 7133 and provides the contact t to the tension band 70 "of the compression device 70 'forth. The tension band 70 "in the example shown is a closed ring belt which extends around the eccentric, ie around the force transmission device 713 of the regulation device 71. When the eccentric is pivoted about the shaft 7121 of the dynamic element 712, the transmission point 7133 is alternately at a short distance Near the body part K and at a greater distance away from the body part K, it deflects the tension band 70 "of the compression device 70 'outward in the position away from the body part K, thereby exerting a force in the radial direction R on the compression device 70' , This causes a total reduction of the inner circumference I of the compression device 70 ', in particular the tension band 70 ".

Also in this example, the stiffening device 10 is disposed between a body part K and the compression device 70 '. The stiffening device 10 and the compression device 70 'engage around a pressure sensor element 60 arranged between the body part K and the stiffening device 10. The compression device 70' here too has a carrier device 71 1 on which a dynamic element 712 is arranged.

The invention is of course not limited to the above exemplary embodiments, but may be varied or modified in many ways. All of these features may be essential to the invention, either individually or in combination.

LIST OF REFERENCE NUMBERS

A artery K body part

α angle L longitudinal direction b width Q transverse thread

B width R direction

C cutout area U circumference

d, d 'thickness V rotation direction

H bone X line

I inner circumference Y line

S, s length z line

10 stiffening device 21 interior

22 outside

100 blood pressure measuring device 24 air inlet / outlet

101 Power transmission device 25 air volume

102 deflecting element 26 intermediate space

103 coupling element

104 motor 30 filling material

105 carrier 31 layer

105 'carrier 31 1 side surface

105a section 312 side surface

105b section 313 survey

105c edge 314 embossed

1051 cover 315 embossed

106 Fastening 32 partial surface

107 guide element 33 connecting element

107 'force sensor 34 recess

20 sheath 40 filling material 60 pressure sensor element 705 recess

71 Regulation device

70 Compression device 71 1 Carrier support

70 'compression device 712 dynamic element

701 Main body 7121 C o ntrol pr ection

702 Longitudinal side 713 Power transmission proce dure

703 short side 7131 off-axis end

704 partial surface 7132 near the axle end

704 'longitudinal thread 7133 transfer point

7041 recess 72 end

7042 Assignment Preliminary 73 End

7043 linking element

7044 Mounting 90 Control device

7045 Mounting 91 (vacuum) pump

7046 turning point 92 pump

Claims

claims

1 . Stiffening device (10) for a blood pressure measuring device (100) wherein the stiffening device (10) is reversibly stiffenable and a flexible sheath (20) having an outer side (22) and an inner space (21) and at least one in the interior (21) of the sheath (20 ), characterized in that the filling material (30) comprises at least two stacked layers (31) consisting of a plurality of mutually movable partial surfaces (32), each partial surface having at least one adjacent partial surfaces (32) is connected within a layer (31).

2. stiffening device according to claim 1, characterized in that the layers (31) of the filling material (30) recesses (34) which divide the layers (31) in the partial surfaces (32), wherein the recesses preferably the edges (35) , in particular the shaping edges (35), the part surfaces (32) form.

3. stiffening device according to one of claims 1 or 2, characterized in that the partial surfaces (32) via connecting elements (33) are interconnected.

4. stiffening device according to claim 3, characterized in that the connecting elements (33) are formed integrally with the partial surfaces (32).

5. stiffening device according to claim 3 or 4, characterized in that the layers (31) in the region of the connecting elements (33) have a smaller thickness than in the region of the partial surfaces (32).

6. stiffening device according to one of claims 1 to 5, characterized in that the layers (31) of the filling material (30) are stacked one above the other, that the partial surfaces (32) adjacent superimposed layers (31) are non-congruent one above the other.

7. Stiffening device according to one of claims 1 to 6, characterized in that the layers (31) of the filling material (30) have a structured surface (36).

8. stiffening device according to at least one of claims 1 to 7, characterized in that the stiffening device in the stiffened state has at least 100 times greater, preferably at least 1000 times greater bending stiffness than in the unstiffened state.

9. stiffening device according to at least one of claims 1 to 8, characterized in that the filling material (30) is preferably paper or a paper-like material formed.

10. stiffening device according to one of claims 1 to 9, characterized in that the length (S) and width (B) of the layers (31) of the filling material (30) of the length (s) and width (b) of the interior (21). the sheath (20) corresponds.

1 stiffening device according to one of claims 1 to 10, characterized in that the length (S) and / or width (B) of the layers (31) of the filling material (30) between about 70 and 100%, preferably between about 80% and about 90%, the length (s) and width (b) of the interior (21) of the shell occupies.

12. stiffening device according to one of claims 1 to 1 1, characterized in that the filling material (30) 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1, 12, 1 3, 14, 15 , 16, 17, 18, 19, 20-30, 31-40, 41-50, 51-60, 61-70, 71-80, 81-90, 91-100, 101-1 10.1 1 1 -120, 121 -130, 131-140, 141-150 or 1 50 to 200 or more layers (31), preferably 10 to 200 layers (31), particularly preferably 40 to 100 layers (31).

13. stiffening device according to one of claims 1 to 12, characterized in that the layers (31) of the filling material (30) has a thickness (d) less than or equal to 3 mm, preferably from 0.01 mm to 0.5 mm, particularly preferably 0 , 05 to 0.2 mm.

14, stiffening device according to one of claims 1 to 13, characterized in that the filling material (30) at atmospheric pressure has a thickness of 1 mm to 30 mm, preferably from 2 mm to 10 mm, more preferably from 3 mm to 6 mm.

15. stiffening device according to one of claims 1 to 14, characterized in that the in the stiffened state in the interior (21) of the shell (20) applied pressure of at least about 250 mbar, preferably more than 500 mbar, more preferably more than 750 mbar, more preferably, more than 850 mbar is less than the atmospheric pressure applied to the outside (22) of the shell (20).

1 6. stiffening device according to one of claims 1 to 1 5, characterized in that in the sheath (20) at least one further filling material (40) is arranged.

1 stiffening device according to claim 1 6, characterized in that the further filling material (40) between the layers (31) of the filling material (30) intercalatable bares powder or fluid, preferably a substantially incompressible powder or fluid.

18. stiffening device according to one of claims 1 to 1 7, characterized in that the sheath (20) is formed film-shaped, preferably made of a plastic, more preferably of a thermoplastic material, most preferably for example of thermoplastic polyurethane (TPU), polyethylene ( PE), fluoropolymers or the like.

19. stiffening device according to one of claims 1 to 18, characterized in that the sheath (20) is formed fluid-tight, preferably airtight.

20. stiffening device according to one of claims 1 to 19, characterized in that the sheath (20) has at least one air inlet and / or air outlet (24).

21. Stiffening device according to one of claims 1 to 20, characterized in that it comprises a control device (50) with a vacuum pump (51) for evacuating the sheath (20).

Blood pressure measuring device (100) with a pressure sensor element (60) and a compression device (70, 70 '), characterized in that it comprises a stiffening device (10) according to one of claims 1 to 21.

Blood pressure measuring device according to claim 22, characterized in that the stiffening device (10) between the pressure sensor element (60) and the compression device (70, 70 ') is arranged. 24. Blood pressure measuring device according to one of claims 22 or 23, characterized in that the compression device (70) is an air-filled cuff.

Blood pressure measuring device according to one of claims 22 or 23, characterized in that the compression device (70 ') is a mechanical, in particular a fluid-free, preferably gas cushion, gas mixture cushion and / or fluid pad-free, pressure cuff.

26. Blood pressure measuring device according to one of claims 22 to 25, characterized in that the compression device (70, 70 ') has a hydraulic, pneumatic or mechanical regulation device (71).

27. Blood pressure measuring device according to one of claims 22 to 26, characterized in that the pressure sensor element (60) is a pressure sensor embedded in a gel pad.