BLOOD PRESSURE MEASURING DEVICE

Description

[0001] The invention relates to a device for measuring blood pressure.

[0002] A blood pressure monitor, also known as a sphygmomanometer, is a device used to measure a patient's arterial pressure externally, either on the upper arm or wrist. These devices, which operate using different methods, display the upper (systolic) and lower (diastolic) arterial pressure with varying degrees of accuracy.

[0003] Commercially available blood pressure monitors measure arterial pressure on the inside of the wrist and are easy to use. The monitor and cuff form a single unit. The device is placed on the inside of the wrist, near the pulse point, and secured with the cuff. After the measurement is started, an electric pump inflates the cuff to an initial measurement pressure until blood flow through the artery is completely stopped. An electrically controlled valve then gradually reduces the pressure in the cuff. Sensors detect the current pressure and changes in blood flow sounds. Using pattern recognition, the device records the systolic and diastolic blood pressure readings. In addition, other parameters such as pulse rate and cardiac arrhythmias can be recorded, and an overall assessment status can be calculated.

[0004] Modern upper arm blood pressure monitors display the readings on an integrated screen. The cuff can be detached from the monitor to accommodate different cuff sizes. They are less user-friendly and more expensive than monitors that measure on the inside of the wrist. However, their accuracy is a major advantage.

[0005] In indirect arterial pressure measurement, often abbreviated as RR (after Riva-Rocci) or less frequently as "NIBP" ("non-invasive blood pressure"), the arterial pressure is measured using a blood pressure monitor on an extremity, usually the arm.

[0006] In auscultatory measurement, a pressure cuff of suitable width is inflated on the upper arm until it exceeds the expected arterial pressure. As it is slowly deflated, the appearance and subsequent disappearance of a Korotkoff sound can be heard (auscultated) using a stethoscope placed over the arm artery. The pressure reading on the instrument's scale at the first time the sound is audible corresponds to the upper, systolic arterial pressure; that is, the systolic pressure at that moment is greater than the cuff pressure. The pressure is then released at a suitable rate. When the cuff pressure falls below the minimum arterial pressure, the sound disappears. This value is called the diastolic pressure and is recorded as the lower value. Auscultatory measurement is the standard procedure among non-invasive blood pressure measurement methods.

[0007] In palpation-based blood pressure measurement, a pressure cuff is applied to the upper arm. As the pressure is released, the pulse is felt at the radial artery. The pressure reading on the measuring device's scale at the first palpation of the pulse corresponds approximately to the upper, systolic arterial pressure. The diastolic value cannot be determined in this way. This method is suitable for noisy environments, particularly in emergency medical services. Even less accurate is palpation without a pressure cuff. In this method, the radial artery is palpated with two fingers, and the blood vessel is compressed with the finger closest to the heart until no pulse can be felt with the finger furthest from the heart. The force exerted by the finger closest to the heart provides an approximate indication of the blood pressure.

[0008] Oscillatory measurement is performed in principle like the other two methods; the upper and lower values ​​are estimated based on the amplitude profile of a pulse-synchronous pointer deflection on the measuring device, which represents the transmission of vibrations from the vessel wall to the pressure cuff. Manual measurement using this method yields only imprecise results. However, this measurement technique is used quite reliably by automated devices for continuous monitoring, e.g., postoperatively in the recovery room. These devices measure the patient's arterial pressure at intervals of a few minutes as an alternative to continuous invasive pressure measurement. The oscillatory measurement method is also used in the now widespread wrist blood pressure monitors.

[0009] The same principle underlies ambulatory blood pressure monitoring (ABPM). In this method, the patient wears a blood pressure cuff continuously (usually for an entire day) that automatically inflates and measures blood pressure at set intervals, along with a recording device. This method is considered the gold standard for detecting and assessing the severity of arterial hypertension.

[0010] Measurement using pulse wave analysis is also possible. This involves interpreting optical signals such as the pulse pattern of the arteries and estimating blood pressure from this data. The advantage of this method is that it allows for continuous and non-invasive measurement, requiring only a wristband without a pressure cuff.

[0011] The following documents are examples of the relevant prior art and relate to devices for measuring blood pressure, their components and associated measuring methods: DE 3004011 A1, DE 3632592C2, DE 4439253 A1, DE 10214220 A1, EP 0165505 A1, EP 0334652 B1, EP 0467 853 A1, WO 2005 / 046466 A1, WO 2009 / 141171 A2, EP 0744155 A1, US 5 025 793, US 2012 / 0238887A1, US 2013 / 0226015 A1, US 2019 / 0320980 A1, US2019 / 0374116 A1, WO2017 / 183106 A1, WO 2018 / 231711 A1, WO 2019 / 209679 A1, WO 2020 / 112555 A1, WO 2021 / 110597 A1.

[0012] Other relevant devices are known from documents US 2007 / 287923 A1 and US 2017 / 055854 A1.

[0013] These conventional devices and methods have the disadvantage that inflating the cuff is perceived as very unpleasant or even painful. This can lead to skin lesions, especially in older people. Particularly with thin skin, inflammation, and repeated measurements at a high frequency, these methods are uncomfortable and can cause large pressure sores.

[0014] Although WO 2009 / 141171 A2 proposes pressureless blood pressure measurement, the sensor disclosed therein requires an additional cuff that must be pressurized with air for calibration. This calibration usually has to be repeated every time the cuff is applied. Such blood pressure measurement is therefore cumbersome.

[0015] Therefore, there are no simple and, above all, compact systems that can do entirely without such unpleasant pressure exertion using air cushions.

[0016] The invention is therefore based on the objective of providing a device for measuring blood pressure that is simple in design and does not have an air cushion for pressurization.

[0017] To solve this problem, a device for measuring blood pressure with the features of claim 1 is provided.

[0018] The device according to the invention for measuring blood pressure comprises a carrier, a bending sensor arranged on the carrier which is designed to detect a bending of the carrier, two legs which are arranged at an angle to the carrier on opposite sides of the carrier, and an evaluation unit which is designed to determine a blood pressure value on the basis of sensor signals from the bending sensor.

[0019] The invention is based on the idea that the bending sensor is bent by the arterial and venous pulsation of the blood pressure, allowing the resulting sensor signals to be evaluated and used to determine the blood pressure. The bending exerted on the bending sensor generates a tensile stress, which in turn triggers the sensor signals. The blood pressure measurement device according to the invention enables a particularly sensitive measurement of blood pressure and its temporal profile, requiring only a small preload compared to measuring devices known in the prior art. This avoids an unpleasant feeling of pressure and discomfort for the patient. The blood pressure measurement device according to the invention is therefore particularly suitable for long-term patient monitoring.

[0020] Within the scope of the invention, it is preferred that the bending sensor is a piezoelectric sensor. Such sensors are small and characterized by high sensitivity.

[0021] Preferably, the bending sensor can be designed as a bimorph sensor arrangement with two individual sensors arranged around the neutral fiber. The individual sensors have antiparallel polarity and are arranged symmetrically around the neutral fiber. When the bimorph sensor arrangement mounted on the support is bent in one direction, one of the individual sensors is stretched, while the other individual sensor is compressed to the same extent. With such an opposing load on the two individual sensors, their signals are added together.

[0022] It is also within the scope of the invention that the bending sensor of the device according to the invention is designed as a multimorph bending sensor and has several pairs of individual sensors with alternating antiparallel polarity. The sensitivity can be increased by providing several pairs of individual sensors.

[0023] According to the invention, one or both legs are articulated to the support. This articulated attachment allows for adaptation to different sized body parts, for example, fingers of different sizes. One or both legs of the support have a bearing surface.

[0024] Preferably, the support is designed to allow a defined connection to an underlying vessel such as an artery or vein. Preferably, the support may have a narrow, linear protrusion that can be placed perpendicularly onto the vessel. In a device worn on the finger, the support is preferably segment-shaped.

[0025] The device according to the invention for measuring blood pressure can have a clamping element to apply a defined force to one leg. Naturally, both legs can also have such a clamping element. The device according to the invention thus comprises the bending sensor arranged on the support, the two angled legs, the evaluation unit, and optionally at least one clamping element.

[0026] According to the invention, a pulse pressure-induced pulsation of a volume, in particular of a body part of a patient on which a blood pressure measurement is to be taken, is converted into a bend by a U-shape of the carrier.

[0027] The clamping element clamps the pulsating area of ​​the volume between the legs of the U-shaped support with a preferably defined preload force. In this way, the pulse pressure-induced pulsation of the body part or a section thereof, particularly a finger, can be converted into a bending motion by the U-shape of the support. This bending motion is detected by the bending sensor. The bending sensor is preferably located at the point where the bending is at its maximum.

[0028] A preferably constant clamping force is applied to the body part via the clamping element. Preferably, the clamping surface of the clamping element covers the areas beneath which the pulsating vessels run. The clamping surface (= clamping surface) of the clamping element is preferably designed such that the force can be distributed evenly across it. This can be achieved, for example, by a skin-friendly pad made of a flexible material such as rubber or foam, or by means of an air cushion.

[0029] With such a device according to the invention for measuring blood pressure, a weak deflection of a body part or its surface caused by an arterial and / or venous pulsation, or of a body part at least partially clamped therein or encompassed by it, can be converted into a bend at the location of the bend sensor and thus into an electrical signal.

[0030] In particular, with the help of such an arrangement, the arterial and / or venous pulsation in the finger, caused by the superficial blood vessels, which manifests itself as a pulsating local deflection of the surface or volume of certain points on the finger, can be mechanically transmitted to the bending sensor and converted into an electrical signal by the bending sensor, whereby the pulse pressure profile can be recorded by measuring electronics in the evaluation unit.

[0031] The recorded electrical sensor signal exhibits a high signal-to-noise ratio. Due to the high signal quality of the electrical sensor signal, the pulse pressure curve can be reproduced in detail with all systolic and diastolic components.

[0032] Due to the high sensitivity of the device according to the invention, it is readily possible to detect the pulse signals with high accuracy, even when using a comfortable cushion and a very low, and therefore maximally comfortable, fastening force. Thus, a deflection of one or both arms caused by a pulsation of the blood pressure triggers a bending of the support, which is detected by the bending sensor and can be evaluated by the evaluation unit. Preferably, the evaluation unit can determine the time course of the blood pressure.

[0033] Vital data (e.g., blood pressure values, pulse) can be determined by analyzing the characteristics (e.g., extreme values ​​and their time intervals) of the pulse pressure curve.

[0034] Vital signs can also be collected using artificial intelligence or machine learning, whose networks have been previously trained on a comprehensive patient database. This training database can contain not only measurement curves but also any other medical data or diagnoses of the patients.

[0035] In the simplest case, the force exerted by the clamping element is constant. However, designs are also possible in which the force exerted by the clamping element is adjustable. In the device according to the invention, a clamping element can be supported on the support on one side and on a leg on the other.

[0036] As already mentioned, the support and / or the support having the legs of the device according to the invention is U-shaped.

[0037] The essential components of the blood pressure measurement device are described below.

[0038] With regard to the sensor element, the preferred variant provides at least one bending sensor, preferably a bimorph bending sensor arrangement with antiparallel polarity. Alternatively, however, multimorph bending sensors can also be used, which are composed of several sensor pairs (in the form of films or beams) with alternating antiparallel polarity. The bimorph bending sensor arrangement is particularly preferably a piezoelectric bimorph bending sensor arrangement in which the sensors are piezoelectric sensors. Such a sensor element is very sensitive to bending. A bimorph bending sensor arrangement consists in principle of two sensor layers arranged symmetrically around the neutral fiber (beam theory). When this arrangement is bent in one direction, one of the sensingly active bending sensor layers is stretched, while the other is compressed equally. When bent in the other direction, the opposite occurs.Due to the antiparallel polarity of the two sensor layers, the signals from these opposing loads add up constructively (since they have the same sign), thus increasing the overall signal. Conversely, effects acting in the same direction (e.g., interfering temperature effects, pyroelectric effects) are largely canceled out and thus compensated. In addition to a bending sensor, the sensor element can also contain other sensor elements, such as an optical sensor.

[0039] The support on which the bending sensor is mounted has two legs. The support is thus U-shaped and has at least one bending sensor, preferably a bending sensor element. When the legs of the U-shaped support are deflected relative to each other, this deflection results in a bend at the location of the sensor element.

[0040] By clamping a pulsating object volume, such as a finger, between the arms, the arms move relative to each other perpendicular to the clamped surface. Due to the lever formed by the arms against the support, even the smallest deflections can, with appropriate design, be transmitted as a bend at the sensor location, allowing them to be detected by the bending sensor. The U-shaped support can also be designed as a ring that can be worn by a patient on their finger or arm.

[0041] In the blood pressure measuring device according to the invention, the bending sensor is connected via a flexible or elastic unit in such a way that the device can be applied to and clamped onto the pulsating body part, for example a finger, with a defined clamping force. The pulsating vessels of the body part are located under a support of the leg or a support of the clamping element of the leg, or they touch the support of the clamping element.

[0042] Flexibility can be achieved by incorporating an elastic element, preferably a spring element, into the clamping element. Preferably, the clamping element can be opened by applying force, for example, via a lever mechanism. Particularly preferably, for greater flexibility of the clamping element, at least one joint with a spring-loaded return mechanism can be provided. The spring-loaded return mechanism can also include an electromechanical, pneumatic, hydraulic, or piezoelectric actuator. For example, a pneumatic actuator can include a manual pump, a multi-way valve, and a pressure gauge to achieve a defined, preferably constant, force on the flexible clamping element. Instead of a manual pump, an electric pump with a control loop can also be provided.

[0043] Preferably, the spring force of such a spring-loaded return mechanism can be adjusted manually or automatically. Manually, this can be done, for example, using a torque wrench. Particularly preferably, the spring force of such a spring-loaded return mechanism is independent of, or at least largely independent of, the deflection, at least within a certain tolerance range. Accordingly, the force of the clamping element is largely constant.

[0044] Flexibility can be achieved through a spring or elastic material connecting one or both clamping arms to the support. The clamping pad(s) are designed to reproducibly clamp the area of ​​the body where blood pressure is to be measured. Ideally, the area of ​​the patient's body where the deflection is greatest is selected. The clamping pad can be positioned over the artery or vein so that it crosses it. The clamping pad forms a defined point of force application. The deflection of the clamping pad caused by the pulsation of the artery or vein is transmitted to the bending sensor and can be detected by it.

[0045] The pad can preferably adapt to the surface of the pulsating body part. For this purpose, the pad of the clamping element can be at least partially padded. Preferably, the pad or the padding is made of skin-friendly material. In a particularly advantageous embodiment, the flexible part of the blood pressure measuring device is designed like a ring, e.g., a finger ring or bracelet.

[0046] The force with which the clamping element rests against the respective body part can be adjustable. This can be achieved, for example, by means of at least one adjustable spring. In a further advantageous embodiment, the device also includes an indicator for the clamping force. Such an indicator can be implemented, for example, with a tension spring that, via a mechanical transmission (e.g., lever, pulley, or gear), transforms a small force into a large deflection of a force indicator.

[0047] The device allows for tension adjustment down to fractions of a Newton. The adjustment can be made in increments of 1 / 10 of a Newton, for example, or in increments as low as 1 / 100 of a Newton. This enables the device to be attached for blood pressure measurement with a very small yet precisely defined tension. This is advantageous for determining absolute blood pressure values.

[0048] In another advantageous embodiment, a preset tension force generated by a spring automatically adjusts itself when the device is attached to a finger or other body part. This can be achieved, for example, electronically using a force sensor in combination with an actuator.

[0049] In a particularly preferred embodiment, a compression spring that is as long and as strongly pre-tensioned as possible is used, the force change of which in a limited adjustment range is only a fraction of the adjustment travel relative to the total spring length.

[0050] In addition, further embodiments of the blood pressure measuring device according to the invention are possible. The device can also be designed in a ring shape through miniaturization. The ring is preferably worn over the fingertip in front of the first joint. However, it is also possible to wear the ring at any point on the finger. Such a ring can also be worn on the arm, leg, or even the neck, since the tension required for pulse pressure sensitivity is very low. The ring can thus be designed as a ring, bracelet, or necklace. Similarly, the ring can also be designed as a component of a watch or smartwatch.

[0051] In a particularly advantageous embodiment, the blood pressure measuring device comprises an at least partially elastic element, preferably a partially linear-elastic element, e.g., a coil spring, which at least partially surrounds the finger. This part is hereinafter referred to as the ring element. By setting a defined tension force, only a one-time calibration of the device according to the invention is necessary. This allows the device to be delivered in a calibrated state.

[0052] By using multiple devices on different body regions, it is possible to make statements about, for example, certain vascular diseases in these regions. Furthermore, with at least two such rings at different positions (e.g., on the arm or finger), it is readily possible to determine the pulse wave velocity from the phase shift between the signals.

[0053] The evaluation unit comprises measurement electronics containing an amplifier, signal conditioning electronics, an analog-to-digital converter (ADC), and a wireless and / or wired interface. It may also include a display and various control elements, such as selection buttons. Ideally, the signal conditioning, ADC, and wireless transmission module of the measurement electronics are located on or within the carrier. This transmits the digitized signal, for example, via Bluetooth or another wireless transmission method, to a monitoring gateway or a mobile display device. This could also be a smartphone or a smartwatch. The carrier can also be designed as part of a smartwatch that incorporates all the components necessary for acquiring and processing the sensor signals, in particular the measurement and electronic components associated with the bending sensor. These components can also be in the form of miniaturized and integrated circuits such as FPGAs.Such circuits can be manufactured cost-effectively and easily integrated into a smartwatch or similar system.

[0054] The measuring electronics can also be connected, at least partially, to the bending sensor via a cable and placed in a housing at a different location on the patient's body, e.g., at the wrist. This housing can also contain a display.

[0055] Surprisingly, the device according to the invention has demonstrated that pulse pressure can be recorded with exceptionally high signal quality. This allows even the smallest fluctuations in pulse pressure, previously only measurable invasively, to be detected non-invasively. The device according to the invention thus enables the identification of more correlations and, consequently, more clinical pictures than was possible with previous non-invasive methods.

[0056] The evaluation of the course is carried out via analytical evaluation of the curve characteristics such as peaks, e.g. maxima, minima, notch, peak shapes, relative peak positions, relative peak amplitudes, pulse frequency, areas under the peaks, areas under systolic and diastolic curve sections, and links between the characteristics.

[0057] The device according to the invention enables the recording of vital data, in particular pulse and pulse pressure profile, at almost any point on the body, even through a soft cushion, by attaching it to the corresponding body part in such a way that at least one superficial blood vessel is located under the contact surface.

[0058] Due to the high signal quality of the pulse pressure curves, even the pulse wave velocity can theoretically be determined via the dicrotic notch. For this, only the geometry of the examined body parts needs to be measured and included in the calculation. The transit time until the reflected pulse wave is referred to as the dicrotic notch. Therefore, the device according to the invention enables its use as a portable monitoring device for measuring biomedical data for medical purposes.

[0059] In addition, the invention relates to a method for measuring blood pressure, comprising the following steps: clamping a body part between two arms of a device for measuring blood pressure, wherein the two arms are arranged on opposite sides of a carrier, angled to the carrier, wherein a bending sensor is arranged on the carrier which is designed to detect a bending of the carrier, and determining the blood pressure value by an evaluation unit on the basis of sensor signals from the bending sensor.

[0060] Further advantages and details of the invention are explained below with reference to exemplary embodiments and the drawings. The drawings are schematic representations and show: Fig. 1 is an embodiment of a device according to the invention for measuring blood pressure, which is attached to a patient's finger; Fig. 2 is a top view of the device shown in Fig. 1 device shown; Fig. 3 a detail of the in Fig. 1 device shown; Fig. 4 a further detail of the in Fig. 1 The device shown; Fig. 5 a further embodiment of a device according to the invention for measuring blood pressure in the tensioned state; Fig. 6 the one shown Fig. 5 The device shown is in its relaxed state; Fig. 7 is a further embodiment of a device according to the invention; Fig. 8 is an embodiment of a device for measuring blood pressure attached to a wristband; Fig. 9 is a further embodiment of a device for measuring blood pressure attached to a wristband; Fig. 10 is a similar embodiment of a device for measuring blood pressure as shown. Fig. 9 ; Fig. 11 Examples of the in the Fig. 8 bis 10 The devices shown during blood pressure measurement; Fig. 12 a further embodiment of a device for measuring blood pressure; Fig. 13 a bottom view of a device for measuring blood pressure; Fig. 14 a sectional view of the device. Fig. 13 ; and Fig. 15 a top view of the device of Fig. 13 .

[0061] The Fig. 1 bis 4 show a device for measuring blood pressure, wherein Fig. 1 the device attached to a patient's finger shows, Fig. 2 is a top view Fig. 3 and Fig. 4 Each shows a detail of the device.

[0062] The device 1 comprises a two-part carrier 2, which includes two legs 3. A bending sensor 4 is held between the two symmetrical legs 3. The carrier 2, formed by the legs 3 and the bending sensor 4, is U-shaped. The bending sensor 4 is a piezoelectric sensor designed as a bimorph sensor and has two individual sensors arranged around the neutral fiber of the bending sensor 4.

[0063] Each leg 3 comprises an arc-shaped support 5 with a narrow, linear central elevation 45. The support 5 is positioned so that it runs perpendicular to the patient's underlying blood vessels. Preferably, the support 5 is integrated into a cushion. The support 5 is pivotally mounted on the underside of the leg 3 via two joints 6. Fig. 1 It can be seen that the shape of the arc-shaped support 5 is adapted to the outer contour of the index finger 7 of a patient.

[0064] The bending sensor 4 is connected to an evaluation unit 9 via a cable 8. The evaluation unit 9 comprises a housing 10 which has a wristband 11, so that the evaluation unit 9 can be worn on the wrist like a watch.

[0065] The patient's heartbeat causes arterial and venous pulsation in the blood vessels, which can also be measured on the patient's index finger. The device 1, in particular its support 5, encloses the patient's index finger 7 with a specific contact or clamping force. This contact or clamping force acts on the underlying arterial or venous blood vessels within a narrow area defined by the shape of the support 5. The arterial and / or venous pulsation causes a minimal movement of the support 5, resulting in a changing bend in the slightly pre-tensioned bending sensor. This bending is detected by the bending sensor 4 and converted into an electrical signal, which is transmitted via the cable 8 to the evaluation unit 9. The evaluation unit 9 uses this electrical signal to determine the blood pressure. The blood pressure value can be used in various ways.For example, it can be stored in memory so that it is available for later analysis. Alternatively, it can be displayed on a screen. It is also possible for the evaluation unit to transmit 9 blood pressure readings to another device via a wireless communication link.

[0066] The Fig. 5 und 6 are cutaway illustrations and show a device 12 for measuring blood pressure, wherein Fig. 5 the device in the tensioned state and Fig. 6 The device is shown in its relaxed state. In accordance with the first embodiment, the device 12 comprises a U-shaped support 13 with two symmetrical legs 14, which are pivotally attached to the support 13. The bending sensor 4 is housed in the support 13. Each leg 14 has a curved support 15, which is shaped such that both supports 15 can partially enclose a patient's finger. The two supports 15 are designed, at least approximately, as circular segments. The supports 15 can have a pad, which may consist, for example, of foamed plastic, rubber, or a silicone material. The pad has a narrow, linear elevation that forms a defined point contact area. Alternatively, a support 15 can directly have a narrow, linear elevation as a contact area.These narrow, linear protrusions are placed as perpendicular as possible to the underlying blood vessels of a patient. This creates defined connections at the intersections between the narrow, linear protrusions and the blood vessels. With conventional wide pads that lack protrusions, such a defined connection cannot be achieved. The pad can also contain a gel or be filled with air.

[0067] In the sectional views of Fig. 5 und 6 It can be seen that both legs 14 each have a clamping element 16, which is designed as a spring element, more precisely as a coil spring. The clamping element 16 is supported on one side by the U-shaped support 13 and on the other side by the leg 14. When the device 12 is attached to a finger, the clamping elements 16 are compressed and exert a defined clamping force on the finger. This state is in Fig. 5 shown. On the other hand, when the device 12 is not used for blood pressure measurement, the clamping elements 16 are relaxed, so that the supports 15 of the legs 14 are pressed together.

[0068] Fig. 7 Figure 1 shows another example of a device 17 for measuring blood pressure. The device 17 comprises a carrier 18 with the bending sensor 4 and two U-shaped arms 19, which are arranged so that they are located above the patient's finger during blood pressure measurement. A spiral compression spring is arranged between the two arms 19 as a clamping element 20. At the opposite end of each arm 19 is a support 21 for the finger. The clamping element 20 causes the arms 19 to be pressed apart and the two supports 21 to be pressed together, so that the supports 21 are pressed against the finger with a defined force.

[0069] Fig. 8 Figure 1 shows an embodiment of a device 22 attached to a wristband 11. The device 22 comprises a U-shaped carrier 23 which has the bending sensor 4. In this embodiment, legs 24 are integrally formed on the carrier 23. On the side of the device 22 that can be placed on the body surface directly over an artery of a patient for blood pressure measurement, a linear support 25 is located on the bending sensor 4, which is shown in the sectional view of Fig. 8 The device 22 is represented as a circular segment or a bulge. The support 25 serves for the targeted and defined positioning of the device 25 above an artery running perpendicular to it. The device 22 can preferably be worn on the wrist.

[0070] Fig. 9 shows a similar embodiment as Fig. 8 The device 26 comprises a U-shaped carrier 27 with the bending sensor 4 arranged thereon. The carrier 27 has integrally formed angled legs 28, which are attached to the wristband 11. The legs 28 enclose a pad 29, which rests on the body surface of a patient, for example in the area of ​​the wrist, for measuring blood pressure. On the side facing outwards from the U-shaped carrier 27 is another pad 30, on which an evaluation unit 31 is attached. In the Fig. 9 The device 26 shown does not depict a support. In other embodiments, a support may be located at a position on the bracelet 11 that, when worn, lies directly over an artery or vein.

[0071] Fig. 10 shows a similar device 32 to the one in Fig. 9 The device 26 shown. The legs 33 forming a support, between which the bending sensor 4 is arranged, are, however, designed separately. On the outwardly facing side of the legs 33 is a pad 34, on which the evaluation unit 31 is attached. On the outside of the bending sensor 4 is a pad 35, and on the inside is a pad 36, which fills the space between the legs 33. In the Fig. 10 The device 26 shown also does not depict a support. In other embodiments, a support may be located at a position on the bracelet 11 that, when worn, lies directly over an artery or vein.

[0072] Fig. 11 shows examples of the in the Fig. 8 bis 10 The devices shown are used during blood pressure measurement. In the upper part of Fig. 11 Device 22 is shown, with its wristband positioned on a patient's wrist. The blood pressure measuring device 22 rests on the inside of the patient's wrist, directly over the arterial or venous blood vessels. Instead of device 22, the previously described devices 26 and 32 can also be attached in the opposite position, i.e., on the outside of the wrist. In the lower part of Fig. 11 The device 22 is located on the outside of the wrist and is worn similarly to a wristwatch.

[0073] Fig. 12 Figure 1 shows an embodiment of a device 37, comprising a wristband 11 and a carrier 38 (shown only schematically) which carries the bending sensor (not shown). The carrier 38 has a support 39 on its inwardly facing side. The wristband 11 has a closure element 40, for example, a buckle or a hook-and-loop fastener. The wristband 11 is provided with padding 41 on its inner side. In addition, the wristband 11 includes a device 42 for adjusting a tensile tension, which can be adjusted either manually or automatically. The wristband 11 also has a display 43 for indicating the tensile tension or the fastening force.

[0074] Several variations of the device 37 are possible. For example, the support 39 can also be arranged at a location remote from the carrier 38, for example opposite the carrier 38, near the locking element 40. The padding 41 on the inside of the wristband 11 is optional and can therefore be omitted.

[0075] The Fig. 13 bis 15 show an embodiment of the device 37, wherein Fig. 13 a view from below Fig. 14 is a cutaway view and Fig. 15The figure shows a top view. The device 37 comprises the wristband 11, on which the carrier 23 with the bending sensor 4 is located. A narrow, strip-shaped support 25 is located on the underside of the bending sensor 4. A cushion 29 is located in a space between the legs of the carrier 23. The device 37 is designed as a "smartwatch". A display 44 can show, for example, blood pressure values, pulse, and other information – similar to a smartphone. Reference symbol list

[0076] 1 Device 2 Carrier 3 Leg 4 Bending sensor 5 Support 6 Joint 7 Index finger 8 Cable 9 Evaluation unit 10 Housing 11 Wristband 12 Device 13 Carrier 14 Leg 15 Support 16 Clamping element 17 Device 18 Carrier 19 Leg 20 Clamping element 21 Support 22 Device 23 Carrier 24 Leg 25 Support 26 Device 27 Carrier 28 Leg 29 Pad 30 Pad 31 Evaluation unit 32 Device 33 Leg 34 Pad 35 Pad 36 Pad 37 Device 38 Carrier 39 Support 40 Locking element 41 Pad 42 Device 43 Display 44 Display 45 Elevation

Claims

1. A device (1, 12, 17) for blood pressure measurement on a part of the body with blood vessels, comprising: - a support (2, 13, 18), - a bending sensor (4) arranged on the support (2, 13, 18), which is designed to detect a bend in the support (2, 13, 18), - an evaluation unit (9) which is designed to determine a blood pressure value using sensor signals from the bending sensor (4), wherein the support (2, 13, 18), in which the bending sensor (4) is accommodated, is U-shaped, and comprises two legs (3, 14, 19), which are arranged on opposite sides of the support (2, 13, 18) at an angle to the support (2, 13, 18), wherein the bending sensor (4) is held between the two legs (3, 14, 19), wherein the legs (3, 14, 19) each have a support (5, 15, 21), wherein one leg (3, 14, 19) or both legs (3, 14, 19) are arranged in an articulated manner on the support (2, 13, 18), wherein the device (1, 12, 17) is designed such that a movement of the support (5, 15, 21), caused by an arterial and / or venous pulsation of the blood vessels of the body part, causes a bending of the bending sensor (4), via the legs (3, 14, 19) of the U-shaped support (2, 13, 18), wherein said bending is converted into the sensor signal.

2. Device according to claim 1, wherein the bending sensor (4) is a piezoelectric sensor.

3. Device according to claim 1 or 2, wherein the bending sensor (4) is designed as a bimorph sensor arrangement with two individual sensors arranged around the neutral fiber.

4. Device according to any one of the preceding claims, wherein the bending sensor (4) is designed as a multimorph bending sensor and has several pairs of individual sensors with alternating antiparallel polarity.

5. Device according to any one of the preceding claims, wherein the legs (3) each have a support (5, 15, 21) which is in the shape of a segment of a circle.

6. Device according to any one of the preceding claims, wherein at least one clamping element (16, 20) is provided in order to apply a defined force to a leg (14, 19).

7. Device according to claim 6, wherein a clamping element (16, 20) is assigned to each leg (14, 19).

8. Device according to claim 6 or 7, wherein the clamping element (16, 20) has a spring element by means of which either one leg (14, 19) or both legs (14, 19) can be subjected to a force.

9. Device according to any one of claims 6 to 8, wherein the force exerted by the clamping element (16, 20) is adjustable.

10. Device according to any one of claims 6 to 8, wherein a clamping element (16, 20) is supported on one side on the support (13) and on the other side on a leg (14).

11. Device according to one of the preceding claims, wherein the evaluation unit (9) is designed to determine a temporal course of the blood pressure.

12. Method for blood pressure measurement, with the following steps: - clamping of a body part between two legs (3, 14, 19) of a device (1, 12, 17) for measuring blood pressure according to any one of claims 1 to 11, the two legs (3, 14, 19) being arranged on opposite sides of a support (2, 13, 18), angled with respect to the support (2, 13, 18), wherein one leg (3, 14, 19) or both legs (3, 14, 19) are arranged in an articulated manner on the support (2, 13, 18), a bending sensor (4) being arranged on the support (2, 13, 18), which is designed to detect a bending of the support (2, 13, 18), and - determination of the blood pressure value by an evaluation unit (9) using sensor signals from the bending sensor (4).