Devices for measuring blood pressure

Abstract

To provide a device and method for measuring blood pressure having a simple structure without an air cushion for pressurization. [Solution] The blood pressure measurement device 1, 12, 17, 22, 26, 32, 37, 42 comprises a support 2, a bending sensor 4 provided on the support 2 and configured to detect bending of the support 2, two legs 3 provided on both sides of the support 2 at an angle to the support 2, and an evaluation unit 9 configured to measure a blood pressure value based on a sensor signal from the bending sensor 4.

Description

[Technical field]

[0001] The present invention relates to an apparatus for measuring blood pressure. [Background technology]

[0002] A blood pressure monitor, also known as a sphygmomanometer, is a measuring device that can be used to measure arterial pressure externally at a patient's upper arm or wrist. These measuring devices operate according to a variety of methods and display upper (systolic) and lower (diastolic) arterial pressure with varying degrees of accuracy.

[0003] There are commercially available measuring devices that are easy to use and measure the arterial pressure on the inside of the wrist. Together with the cuff, this measuring device forms one unit. The device is placed on the inside of the wrist over the artery and attached to the cuff. When the measurement starts, the cuff is inflated by an electric pump to an initial measuring pressure at which blood cannot flow through the artery. The pressure in the cuff is gradually reduced by an electric control valve. A sensor records the current value of the pressure and the changes in the blood flow sound. By pattern recognition, the device registers the systolic and diastolic arterial pressure points. In addition, other important values ​​such as pulse rate and cardiac arrhythmias are also recorded so that an overall evaluation status can be determined.

[0004] Newer upper arm devices display the readings on an integrated screen and may have a removable cuff for a different size. These devices are more difficult to use and more expensive than inner wrist devices, but they provide more accurate results.

[0005] Indirect arterial pressure measurement, sometimes abbreviated as RR (Riva-Rocci) or rarely "NIBP" ("non-invasive blood pressure"), measures arterial pressure in one of the limbs (usually the arm) with a blood pressure monitor.

[0006] In auscultatory measurement, a pressure cuff of appropriate width is inflated on the upper arm above the expected arterial pressure. During the gradual release of pressure, the appearance and subsequent disappearance of Korotkoff sounds can be heard with a stethoscope over the arteries of the arm (auscultation). The pressure that can be read on the scale of the measuring device when the sounds are first heard corresponds to the upper (systolic) arterial pressure value. That is, the systolic pressure at this time is higher than the pressure in the cuff. The pressure is further released by an appropriate amount. When the pressure in the cuff falls below the lower limit of the arterial pressure value, the sounds disappear. This value is called the diastolic pressure and is the lower value. Auscultatory measurement is the standard non-invasive measurement method.

[0007] In the palpation measurement method, a pressure cuff is also applied to the upper arm. As the pressure is released, the pulse is palpated over the radial artery. The pressure that can be read on the scale of the measuring device when the pulse is first palpated corresponds approximately to the upper (systolic) arterial pressure value. This method does not allow for the determination of diastolic values. For example, this method is particularly suitable for noisy environments such as emergency medical care. A less accurate palpation measurement method is to pressurize the blood vessels with the finger closest to the heart without a pressure cuff, until the pulse can no longer be felt with the finger furthest from the heart, and then palpate the radial artery with two fingers. The force applied with the finger closest to the heart is a rough indication of blood pressure.

[0008] Oscillometry is performed in principle in the same way as the other two techniques, but estimates of the upper and lower values ​​are made by the amplitude curve of the deflection of the pulse-synchronous pointer of the measuring device, which indicates the transmission of vibrations from the vessel wall to the pressure cuff. This method gives inaccurate results when measured manually. However, with automatic measuring devices, this method is very reliable and can be used for continuous monitoring, for example in the postoperative recovery room. This method measures the patient's arterial pressure at intervals of several minutes, as an alternative to continuous invasive blood pressure measurement. Oscillometry is also used in the wrist measuring devices that are now widely used.

[0009] Long-term blood pressure monitoring (ABDM) is based on the same principle: the patient wears a blood pressure cuff and a recording device permanently (usually all day) and the blood pressure cuff is automatically inflated at set intervals to measure. This technique is considered the gold standard for detecting and assessing the severity of arterial hypertension.

[0010] Measurements can also be made by pulse wave analysis, which interprets optical signals such as the arterial pulsation and estimates blood pressure from this data. The advantage of this method is that the measurement is permanent and non-invasive, and does not require a pressure cuff, just a wristband.

[0011] The following publications are examples of relevant prior art and relate to devices for measuring blood pressure, their components and corresponding 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 / 0238887 A1; US ​​2013 / 0226015 A1 (Patent Document 13); US 2019 / 0320980 A1 (Patent Document 14); US 2019 / 0374116 A1 (Patent Document 15); WO 2017 / 183106 A1 (Patent Document 16); WO 2018 / 231711 A1 (Patent Document 17); WO 2019 / 209679 A1 (Patent Document 18); WO 2020 / 112555 A1 (Patent Document 19); and WO 2021 / 110597 A1 (Patent Document 20). [Prior art documents] [Patent documents]

[0012] [Patent Document 1] German Patent Application Publication No. 3004011 [Patent Document 2] German Patent No. 3632592 [Patent Document 3] DE 4439253 A1 [Patent Document 4] DE 10214220 A1 [Patent Document 5] European Patent Application Publication No. 0165505 [Patent Document 6] European Patent No. 0334652 [Patent Document 7] European Patent Application Publication No. 0467853 [Patent Document 8] International Publication No. 2005 / 046466 [Patent Document 9] International Publication No. 2009 / 141171 [Patent Document 10] European Patent Application Publication No. 0744155 [Patent Document 11] U.S. Pat. No. 5,025,793 [Patent Document 12] US Patent Application Publication No. 2012 / 0238887 [Patent Document 13] US Patent Application Publication No. 2013 / 0226015 [Patent Document 14] US Patent Application Publication No. 2019 / 0320980 [Patent Document 15] US Patent Application Publication No. 2019 / 0374116 [Patent Document 16] International Publication No. 2017 / 183106 [Patent Document 17] International Publication No. 2018 / 231711 [Patent Document 18] International Publication No. 2019 / 209679 [Patent Document 19] International Publication No. 2020 / 112555 [Patent Document 20] International Publication No. 2021 / 110597 Summary of the Invention [Problem to be solved by the invention]

[0013] A drawback of these conventional devices and methods is that the inflation of the cuff can be very uncomfortable and even painful, especially for elderly people, and can cause skin damage. The above measurement methods can be very uncomfortable when the skin is thin or inflamed, or when repeated measurements are made frequently, and can also cause bedsores over large areas.

[0014] WO 2009 / 141171 A2 (Patent Document 9) proposes a non-pressurized blood pressure measurement method, but the sensor disclosed therein requires an additional cuff, which is pressurized with air pressure, for calibration. Generally, this calibration needs to be repeated every time the cuff is worn. This type of blood pressure measurement method is therefore cumbersome.

[0015] In other words, there is no simple system, especially no small system, that can function completely without this troublesome pressurization by air cushions.

[0016] The invention is therefore based on the object of providing a device for measuring blood pressure which has a simple construction and does not have a pressurizing air cushion. [Means for solving the problem]

[0017] In order to solve this problem, a blood pressure measuring device having the configuration of claim 1 is provided.

[0018] The blood pressure measuring device according to the present invention comprises a support, a bending sensor provided on the support and configured to detect bending of the support, two legs provided on either side of the support at an angle to the support, and an evaluation unit configured to measure a blood pressure value using a sensor signal from the bending sensor.

[0019] The invention is based on the idea that the bending sensor is bent by arterial and venous blood pressure pulsations, and the resulting sensor signal is evaluated, allowing the blood pressure to be measured. The bending of the bending sensor generates tensile stresses, which generate the sensor signal. The blood pressure measuring device according to the invention allows a very sensitive measurement of blood pressure and its time course, so that a smaller pretension force is required compared to measuring devices known from the prior art. This avoids any discomfort or bothersome pressure for the patient. The blood pressure measuring device according to the invention is therefore also very suitable for long-term monitoring of patients.

[0020] Preferably, in the context of the present invention, the bending sensor is a piezoelectric sensor. Such a sensor is characterised by a small size and a high sensitivity.

[0021] Preferably, the bending sensor may be configured as a bimorph sensor arrangement with two individual sensors arranged around a neutral axis. The individual sensors are of opposite polarity and symmetrically arranged around the neutral axis. When the bimorph sensor arrangement on the support is bent in one direction, one of the individual sensors expands and the other of the individual sensors contracts equally. When the two individual sensors are subjected to such opposing loads, their signals become constructive.

[0022] It is also within the scope of the present invention to configure the bending sensor of the device according to the invention as a multimorph bending sensor, comprising several pairs of individual sensors with opposite and alternating polarization, which can increase the sensitivity.

[0023] In a further refinement of the invention, one or both legs are hinged to the support. Such an articulated attachment allows for adaptation to different sizes of body parts, for example different sizes of fingers. One or both legs of the support may comprise a support. Preferably, the support is configured for a predefined connection to an underlying blood vessel, such as an artery, vein or the like. Preferably, the support may have a linear narrow raised portion that can be placed perpendicularly on a blood vessel. In the case of a device that can be worn on a finger, the support is preferably arc-shaped.

[0024] The blood pressure measuring device according to the present invention may comprise a clamping element for applying a predefined force to one of the legs. Of course, both legs may be provided with such a clamping element. In other words, the device according to the present invention comprises the bending sensor provided on the support, the two angled legs, the evaluation unit and, optionally, at least one clamping element.

[0025] Pulsations caused by pulsating pressure of a volume of the patient's body, in particular at the site where the blood pressure measurement is performed, can be converted into bending of the U-shaped support. The pulsating part of this volume is clamped by the clamping element between the legs of the U-shaped support, preferably with a pretension. This makes it possible to convert pulsations of a body part or a part of a body part, in particular a finger, caused by pulsating pressure into bending of the U-shaped support. This bending is detected by the bending sensor. Preferably, the bending sensor is arranged at the point of maximum bending.

[0026] A contact pressure, preferably a constant contact pressure, is applied to the body part by the clamping elements. Preferably, the clamping surface of the clamping elements covers the area beneath which the pulsating blood vessel passes. Preferably, the clamping surface of the clamping element (which is equivalent to the contact surface) is configured in such a way that the force can be evenly distributed over the clamping surface. This can be achieved, for example, by skin-friendly pads made of flexible material such as rubber or foam, by air cushions, etc.

[0027] The blood pressure measuring device according to the present invention as described above makes it possible to convert weak bending caused by arterial and / or venous pulsation of a body part or the surface of a body part at least partially clamped or surrounded by the device into bending at the position of the bending sensor, i.e., into an electrical signal.

[0028] Specifically, with the above-described arrangement, arterial and / or venous pulsations occurring in blood vessels near the surface of a finger appear as localized pulsation bending on the surface or volume of a specific part of the finger, which can be mechanically transmitted to the bending sensor and converted into an electrical signal by the bending sensor, making it possible to record a pulse pressure curve using the electronic measurement system of the evaluation unit.

[0029] The recorded electrical sensor signal has a high signal-to-noise ratio, and the high signal quality of the electrical sensor signal allows the pulse pressure curve to be reproduced in detail with all systolic and diastolic components.

[0030] The device according to the invention is highly sensitive, so that the pulse signal can be easily detected with high accuracy even with comfortable padding and very low clamping force (i.e. as comfortable as possible). That is, bending of one or both legs caused by blood pressure pulsations results in bending of the wearer, which can be detected by the bending sensor and evaluated by the evaluation unit. Preferably, the evaluation unit is capable of determining the blood pressure over time.

[0031] By analyzing the characteristics of the pulse pressure curve (eg, limits, time intervals between limits, etc.), vital data (eg, blood pressure, pulse rate, etc.) can be determined.

[0032] The vital data may also be derived using artificial intelligence or machine learning, with the network being trained on a comprehensive database of patients, which may include measurement curves as well as any other medical data or patient diagnoses.

[0033] In the simplest case, the force exerted by the clamping element is constant. However, embodiments are also possible in which the force exerted by the clamping element is adjustable. In the device according to the invention, the clamping element can be supported on the one hand on the support and on the other hand on a foot.

[0034] Preferably, as mentioned above, the support and / or the support together with the legs of the device according to the invention are U-shaped.

[0035] The main components of the device for measuring blood pressure will now be described.

[0036] In a preferred variant, at least one bending sensor is provided as a sensor element, preferably a bimorph bending sensor arrangement with opposite polarization. Alternatively, however, a multimorph bending sensor consisting of several pairs of sensors (in the form of thin films or elongated bodies) with opposite and alternating polarization may be used. Very preferably, the bimorph bending sensor arrangement is a piezoelectric bimorph bending sensor arrangement, in which the sensors are piezoelectric sensors. Such a sensor element responds very sensitively to bending. In principle, a bimorph bending sensor arrangement consists of two sensor layers arranged symmetrically around a neutral axis (beam theory). When the arrangement is bent in one direction, one of the sensor-active bending sensor layers expands and the other contracts equally. When bending in the opposite direction, the opposite happens. As the two sensor layers are oppositely polarized, the signals of such opposing loads add constructively (since they have the same sign) and increase the overall signal. On the other hand, collateral effects (such as interferometric temperature effects, pyroelectric effects, etc.) are largely cancelled out and therefore compensated for. In addition to bending sensors, other types of sensor elements, such as optical sensors, can also be mentioned as the sensor elements.

[0037] The support on which the bending sensor is provided comprises the two legs, i.e. the support is U-shaped and comprises at least one bending sensor, preferably a bending sensor element, such that if the legs of the U-shaped support are bent in opposite directions, this bending results in a bending at the location of the sensor element.

[0038] When a volume of a pulsating object, for example a finger, is clamped between the legs, the legs move against each other perpendicular to the clamping plane. With proper design, even small bending can be transferred as bending at the sensor location due to the leverage the legs form against the support, and thus detected by the bending sensor. The U-shaped support may also be configured as a ring that the patient can wear on a finger or arm.

[0039] In the device for measuring blood pressure according to the invention, the bending sensor is connected by a flexible or elastic unit so that the device can be placed and clamped with a defined clamping force on a pulsating body part, for example a finger, whose pulsating blood vessel is located under the support of the leg or the support of the clamping element of the leg or is in contact with the support of the clamping element.

[0040] The clamping elements may be provided with an elastic body, preferably a spring body, to achieve flexibility. Preferably, the clamping elements may be opened by the application of force, for example by a lever mechanism. Very preferably, at least one joint with a telescopic return mechanism may be provided to increase the flexibility of the clamping elements. The telescopic return mechanism may include an electromechanical, pneumatic, hydraulic or piezoelectric actuator. In the case of a pneumatic actuator, a manual pump, a multiport valve, a pressure gauge, etc. may be provided to provide the flexible clamping elements with a predetermined force, preferably a constant force. Instead of a manual pump, an electric pump with a control circuit may be provided.

[0041] Preferably, the spring force of such a telescopic reset mechanism can be adjusted manually or automatically. This can be done manually, for example by means of a torque wrench. Very preferably, the spring force of such a telescopic return mechanism is independent of the bending or at least largely independent of the bending, at least within certain tolerances, so that the force of the clamping element is more or less constant.

[0042] Flexibility may be achieved by connecting one or both clamping legs to the support by a spring or elastic body. The support of at least one of the legs is configured so as to be able to clamp reproducibly the part of the body for which the blood pressure is to be measured. For this purpose, if possible, a place in the patient's body where the bending is greatest is selected. The support may be placed on an artery or vein so as to cross it. The support represents the point of application of a predetermined force. The bending of the support due to the pulsation of the artery or vein may be transmitted to and registered by the bending sensor.

[0043] Preferably, the support can be adapted to the surface of the pulsating body part. For this purpose, the support of the clamping element can be at least partially padded. Preferably, the support or pad consists of a skin-friendly material. In a highly advantageous embodiment, the device for blood pressure measurement has a flexible part formed like a ring, for example a finger ring, wristband or the like.

[0044] The force with which the clamping elements are placed on the corresponding body parts may be adjustable. This may be achieved, for example, by at least one adjustable spring or the like. In a further advantageous embodiment, the device further comprises an indicator of the clamping force. Such an indicator may be achieved by converting a small force, for example a tension spring, into a large deflection of the force indicator by means of a mechanical transmission (for example a lever, pulley, gears, etc.).

[0045] The device may be capable of adjusting the clamping force down to a fraction of a Newton. For example, it may be possible to adjust it in increments of 1 / 10 Newton. However, it may also be possible to adjust it in increments of 1 / 100 Newton or less. This allows the device for blood pressure measurement to be attached with a very small but defined clamping force, which is advantageous for measuring absolute blood pressure values.

[0046] In another advantageous embodiment, the pre-set tension provided by the spring automatically self-adjusts when placed on a finger or other part of the body, which can be accomplished electronically, for example, by a combination of load cells and actuators.

[0047] In a highly preferred embodiment, a maximally long and highly pre-tensioned compression spring is used, the force of which, within the limited adjustment range, varies only over a portion of the adjustment path relative to the entire spring length.

[0048] Other examples of the blood pressure measuring device according to the present invention are possible. The device may be designed in the shape of a ring by miniaturization techniques. Preferably, the ring is placed on the tip of the finger in front of the first joint. However, the ring can be placed anywhere on the finger. Such a ring may also be placed on the arm, leg, or even the neck, since the clamping force required for the sensitivity of the pulse pressure is very small. That is, the ring may be configured as a ring jewel, arm jewel, or neck jewel. Similarly, the ring may be configured as part of a wristwatch or smartwatch.

[0049] In a highly advantageous embodiment, the blood pressure measuring device comprises an at least partially elastic, preferably partially linear elastic, element, such as a spiral spring, which at least partially surrounds the finger. This part is hereinafter referred to as the ring element. Due to the predefined clamping force, the device according to the invention only needs to be calibrated once, i.e. the device can be delivered in a calibrated state.

[0050] By using multiple devices at different parts of the body, for example, it is possible to make an interpretation of a particular vascular disease at each of these parts of the body, and by having two or more such rings at different locations (e.g., on the arm and finger), it is possible to easily make an interpretation of the pulse wave velocity from the phase shift between the signals.

[0051] The evaluation unit includes measurement electronics, which have an amplifier, signal conditioning electronics, an AD converter and a wireless and / or wired interface. The evaluation unit may further include a display and various operating elements, such as, for example, selection buttons. Ideally, the signal conditioning, AD conversion and wireless transmission modules of the measurement electronics are provided on or in the support. This allows the digitized signal to be transmitted to a monitoring gateway or a mobile display device by wireless transmission, for example Bluetooth. This may be a smartphone or a smartwatch. The support may also be configured as a part of a smartwatch that includes all the components required for recording and processing the sensor signals, in particular the measurement components and electronics assigned to the bending sensor. These components may also be in the form of miniaturized integrated circuits, such as FPGAs. Such circuits can be produced cost-effectively and easily integrated into a smartwatch or similar system.

[0052] However, the measuring electronics may also be located in a housing at another location on the patient's body, e.g. in the arm joint, at least partially connected to the bending sensor by a cable, which housing may also include a display.

[0053] Surprisingly, it has been found that the device according to the invention is able to record the pulse pressure curve with an exceptionally high signal quality. This means that even the slightest fluctuations in the pulse pressure curve, which could only be measured invasively up until now, can now be detected non-invasively. The device according to the invention can reveal more correlations, i.e. more clinical pictures, than previous non-invasive methods.

[0054] Progression is assessed by analytical evaluation of curve characteristics such as peaks (e.g., maxima, minima, etc.), notches, peak shape, relative peak locations, relative peak amplitudes, pulse frequency, areas under the peaks, areas under the systolic and diastolic portions of the curve, and relationships between features.

[0055] By attaching the device of the present invention to a corresponding part of the body so that at least one blood vessel near the surface is located under the contact surface, the device can record vital data such as pulse, pulse pressure curve, etc. at almost any part of the body, even through a soft pad.

[0056] Due to the high signal quality of the pulse pressure curve, it is theoretically also possible to determine the pulse wave velocity by the dicrotic notch. For this purpose, it is only necessary to measure the geometry of the body part under investigation and include it in the calculation. The time elapsed until the reflected pulse wave is called the dicrotic notch. This allows the device according to the invention to be used as a portable monitoring device for measuring vital data for medical purposes.

[0057] The present invention further provides a method for measuring blood pressure, comprising the steps of: - a support provided with a bending sensor configured to detect bending of the support in a blood pressure measuring device, the step of clamping a body part between two legs provided on both sides of the support at an angle to the support; - measuring a blood pressure value based on a sensor signal of the bending sensor by an evaluation unit; The present invention relates to a method comprising:

[0058] Further advantages and details of the invention are explained below with reference to the drawings, each of which is a schematic diagram. [Brief description of the drawings]

[0059] [Figure 1] FIG. 1 shows an embodiment of a blood pressure measuring device according to the present invention attached to a patient's finger. [Diagram 2] FIG. 2 is a plan view of the device shown in FIG. [Diagram 3] FIG. 2 is a detailed view of the device shown in FIG. [Figure 4] FIG. 2 is a further detailed view of the device shown in FIG. [Diagram 5] FIG. 2 shows a further embodiment of a device for measuring blood pressure according to the invention in a stressed state. [Figure 6] FIG. 6 is a diagram of the device shown in FIG. 5 in a relaxed state. [Figure 7] FIG. 4 shows a further embodiment of the device according to the invention. [Figure 8] FIG. 1 is a diagram showing an example of a blood pressure measurement device attached to a wristband. [Figure 9] FIG. 13 shows a further example of a blood pressure measuring device attached to a wristband. [Figure 10] FIG. 10 is a diagram showing an example of a blood pressure measurement device similar to that shown in FIG. [Figure 11] FIG. 11 is a diagram showing the example of the device shown in FIGS. 8 to 10 during blood pressure measurement. [Figure 12] FIG. 11 is a diagram showing another example of a blood pressure measuring device according to the present invention. [Figure 13] FIG. 2 is a bottom view of the blood pressure measuring device according to the present invention. [Figure 14] FIG. 14 is a cross-sectional view of the device of FIG. 13. [Figure 15] FIG. 14 is a plan view of the device of FIG. 13. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0060] Figures 1 to 4 show a blood pressure measurement device. Figure 1 shows the device attached to a patient's finger. Figure 2 is a plan view of the device, and Figures 3 and 4 are detailed views of the device.

[0061] The device 1 comprises a two-part support 2 with two legs 3 between which a bending sensor 4 is held. The support 2 formed by the legs 3 and the bending sensor 4 has a U-shape. The bending sensor 4 is a piezoelectric sensor configured as a bimorph sensor and has two individual sensors arranged around the neutral axis of the bending sensor 4.

[0062] Each leg 3 has a circular arc-shaped support 5 with a straight narrow raised portion 45 in the middle. The support 5 is positioned perpendicular to the patient's underlying blood vessels. Preferably, the support 5 is integrated into a cushion. The support 5 is pivotally attached to the underside of the leg 3 by two joints 6. In FIG. 1, the shape of the curved support 5 is depicted as adapting to the outer contour of the patient's index finger 7.

[0063] The bending sensor 4 is connected by a cable 8 to an evaluation unit 9. The evaluation unit 9 comprises a housing 10 with a wristband 11 so that it can be worn on the wrist like a watch.

[0064] The beating of the patient's heart causes arterial and venous pulsations in the blood vessels. This can also be measured on the patient's index finger. The device 1, in particular the support part 5 of the device 1, surrounds the patient's index finger 7 with a certain contact pressure or clamping force. This contact pressure or clamping force acts on the arterial or venous blood vessels passing under a narrow area defined by the shape of the support part 5. A minimal movement of the support part 5 due to the arterial and / or venous pulsations changes the bending of the slightly pre-tensioned bending sensor. The resulting 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 the electrical signal to measure the blood pressure. This blood pressure value can be used in various ways. For example, it can be stored in a memory for later evaluation. Alternatively, it can be displayed on a display. It is also possible for the evaluation unit 9 to transmit the blood pressure value to another device via a wireless communication link.

[0065] 5 and 6 are cross-sectional views of a blood pressure measuring device 12, in which FIG. 5 shows the device in a tense state and FIG. 6 shows the device in a relaxed state. In a first embodiment example, the device 12 comprises a U-shaped support 13 with two symmetrical legs 14, which are hinged to the support 13. The bending sensor 4 is housed in the support 13. Each leg 14 comprises a curved support part 15, which is shaped so that both supports 15 can partially enclose the patient's finger. The two supports 15 are formed as at least substantially circular arcs. The support parts 15 can comprise a pad, which can be made of, for example, foamed plastic, rubber, silicone material, etc. The pad has a linear narrow raised part that forms a predetermined point contact surface. As a variant, the support parts 15 can directly have a linear narrow raised part as a support surface. Such a narrow linear ridge is placed as perpendicular as possible to the underlying blood vessel of the patient, so that the narrow linear ridge and the blood vessel are joined at a predetermined intersection point. Conventional wide pads without a ridge do not provide a clear boundary connection. The pad may be gel-filled or air-filled.

[0066] In the cross-sectional views of Figures 5 and 6, it can be seen that each of the two legs 14 is provided with a clamping element 16, designed as a spring body, specifically as a spiral spring. The clamping element 16 is supported on the one hand by the U-shaped support 13 and on the other hand by the leg 14. When the device 12 is attached to a finger, the clamping element 16 is compressed and exerts a defined contact pressure on the finger. This state is shown in Figure 5. Conversely, 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 towards each other.

[0067] FIG. 7 shows another example of a device 17 for measuring blood pressure. The device 17 comprises a support 18 with a bending sensor 4 and two U-shaped legs 19, which are arranged so as to be above the patient's finger when measuring blood pressure. A spiral compression spring is provided between the two legs 19 as a clamping element 20. At the opposite end of each leg 19, a finger support 21 is present. The clamping element 20 presses the legs 19 apart and brings the two supports 21 closer to each other, so that each support 21 is pressed against the finger with a predetermined force.

[0068] FIG. 8 shows an embodiment of the device 22 attached to the wristband 11. The device 22 comprises a U-shaped support 23 with a bending sensor 4. In this embodiment, the legs 24 are integrally formed with the support 23. On the side of the device 22 that can be placed directly on the body surface above the patient's artery to measure blood pressure, there is a linear support 25 on the bending sensor 4, depicted as an arc or bulge in the cross-sectional view of FIG. 8. The support 25 is used to selectively and pre-determine the position of the device 22 on the artery that passes perpendicularly to the device. Preferably, the device 22 can be worn on the wrist.

[0069] FIG. 9 shows an embodiment similar to that of FIG. 8. The device 26 comprises a U-shaped support 27 on which the bending sensor 4 is provided. The support 27 comprises legs 28 integrally formed at an angle thereto and attached to the wristband 11. The legs 28 surround a pad 29 which is placed on a surface of the patient's body, for example in the wrist region, for measuring the blood pressure. On the outer-facing side of the U-shaped support 27 there is a further pad 30 on which an evaluation unit 31 is attached. In the device 26 shown in FIG. 9 the support is not shown. In another embodiment the support may be provided on the wristband 11 in a position directly above an artery or vein when the wristband is worn.

[0070] FIG. 10 shows a device 32 similar to the device 26 shown in FIG. 9. However, each leg 33 constituting the support is separate, and the bending sensor 4 is provided between the legs 33. On the outer side of the legs 33 there is a pad 34, to which the evaluation unit 31 is attached. On the outer side of the bending sensor 4 there is a pad 35, and on the inner side of the bending sensor 4 there is a pad 36, which fills the free space between the legs 33. In the device 26 shown in FIG. 10, the support is also not shown. In another embodiment, a pad may be provided on the arm band 11 at a position that is directly above an artery or vein when the arm band 11 is placed.

[0071] FIG. 11 is a diagram of the example of the device shown in FIGS. 8 to 10 during blood pressure measurement. In the upper part of FIG. 11, device 22 is depicted as a wristband placed on the patient's wrist. The blood pressure measurement device 22 is located on the inside of the patient's wrist, directly above the arterial or venous blood vessels. Instead of device 22, the above-mentioned devices 26, 32 can also be attached in the opposite position, i.e., on the outside of the wrist. In the lower part of FIG. 11, device 22 is placed on the outside of the wrist and worn like a wristwatch.

[0072] In Fig. 12 an example of a device 37 is shown, which comprises a wristband 11 and a support 38. The support 38 comprises a bending sensor, which is only shown diagrammatically and is not shown. The support 38 comprises a support 39 on its side facing inwards. The wristband 11 comprises a fastening element 40, for example a clasp, a hook and loop fastener or the like. The wristband 11 is provided with a pad 41 on its inner side. The wristband 11 further comprises a tension setting device 42, by means of which the tension can be set manually or automatically. The wristband 11 further comprises a display 43 for displaying the tension or fastening force.

[0073] The device 37 can have several variants: for example, the support 39 can be provided at a position remote from the support 38, near the fastening element 40, for example on the opposite side of the support 38. The pad 41 on the inside of the wristband 11 is optional, i.e. it can be omitted.

[0074] 13 to 15 show an embodiment of the device 37. FIG. 13 is a view from below, FIG. 14 is a cross-sectional view, and FIG. 15 is a plan view. The device 37 includes a wristband 11, and a support 23 including a bending sensor 4 is provided on the wristband 11. A narrow belt-shaped support 25 is provided below the bending sensor 4. A pad 29 is provided in the free space of the wearer 23 between the legs. The device 37 is configured as a "smart watch." The display 44 may display information such as pulse rate, for example, like a smartphone, in addition to blood pressure values. [Explanation of symbols]

[0075] 1 device 2 Support 3 legs 4 Bending Sensor 5 Support part 6 Joints 7 Index Finger 8 Cable 9 Evaluation Section 10. Housing 11 Wristbands 12 Equipment 13 Support 14 Legs 15 Support part 16 Clamping element 17 Equipment 18 Support 19 Legs 20 Clamping element 21 Support part 22 Equipment 23 Support 24 Legs 25 Support part 26 Equipment 27 Support 28 Legs 29 Pad 30 Pads 31 Evaluation Department 32 Equipment 33 Legs 34 Pad 35 Pad 36 Pad 37 Equipment 38 Support 39 Support part 40 Fastening elements 41 Pad 42 Equipment 43 Display section 44 Display section 45 Protruding part

Claims

1. A support (2, 13, 18), A bending sensor (4) is provided on the support (2, 13, 18) and configured to detect bending of the support (2, 13, 18), An evaluation unit (9) configured to determine a blood pressure value using a sensor signal from the bending sensor (4), A device for measuring blood pressure in a body part having blood vessels (1, 12, 17) is provided, The support (2, 13, 18) that houses the bending sensor (4) is U-shaped and has two legs (3, 14, 19) on both sides of the support (2, 13, 18) that are provided at an angle to the support (2, 13, 18). The bending sensor (4) is held between the two legs (3, 14, 19), Each of the two legs (3, 14, 19) has a support portion (5, 15, 21), One or both of the legs (3, 14, 19) are articulated to the support (2, 13, 18), The device (1, 12, 17) is configured such that the movement of the support portion (5, 15, 21) caused by the pulsation of the arteries and / or veins of the blood vessels in the body part causes the bending of the bending sensor (4) via the two legs (3, 14, 19) of the U-shaped support (2, 13, 18), and the bending is converted into a sensor signal. An apparatus characterized by the following features.

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

3. The apparatus according to claim 1 or 2, wherein the bending sensor (4) is configured as a bimorph sensor arrangement structure comprising two individual sensors arranged around a neutral axis.

4. The apparatus according to any one of claims 1 to 3, wherein the bending sensor (4) is configured as a multimorph bending sensor, and comprises a plurality of pairs of individual sensors with polarities in opposite directions and alternating polarities.

5. The apparatus according to any one of claims 1 to 4, wherein each of the leg portions (3) is provided with a support portion (5, 15, 21) and an arc-shaped support portion.

6. The apparatus according to any one of claims 1 to 5, wherein at least one clamping element (16, 20) is provided to apply a predetermined force to the leg portion (14, 19).

7. The apparatus according to claim 6, wherein the clamping elements (16, 20) are distributed to each leg portion (3).

8. The apparatus according to claim 6 or 7, wherein the clamping element (16, 20) comprises a spring body capable of applying force to one leg (14, 19) or both legs (14, 19).

9. The apparatus according to any one of claims 6 to 8, wherein the force applied by the clamping elements (16, 20) is adjustable.

10. The apparatus according to any one of claims 6 to 8, wherein the clamping elements (16, 20) are supported on one side by the support (13) and on the other side by the leg (14).

11. The apparatus according to any one of claims 1 to 10, wherein the evaluation unit (9) is configured to determine the time course of blood pressure.

12. A method for measuring blood pressure, - A process of clamping a body part between two legs (3, 14, 19) of a blood pressure measuring device (1, 12, 17) according to any one of claims 1 to 11, wherein the two legs (3, 14, 19) are positioned on both sides of a support (2, 13, 18) at an angle to the support (2, 13, 18), one or both of the two legs (3, 14, 19) are articulated on the support (2, 13, 18), and a bending sensor (4) configured to detect bending of the support (2, 13, 18) is positioned on the support (2, 13, 18), and the clamping process is as follows: - The evaluation unit (9) measures the blood pressure value using the sensor signal from the bending sensor (4), A method that includes [a certain feature].

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