Physiological parameter sensing system and method

Abstract

An apparatus for sensing a physiological parameter of a subject, the apparatus comprising: a force sensor having a force sensing surface, wherein the force sensor is configured to generate a first signal representative of a force displacement of an organ of the subject; a displacement sensor associated with the force sensor, the displacement sensor having a displacement sensing surface, wherein the displacement sensor is configured to generate a second signal representative of a displacement velocity of the organ of the subject; and a coupler arranged on one of the force sensor and the displacement sensor, the coupler configured to mechanically couple the force sensor and the displacement sensor with the organ; and wherein the displacement sensing surface is uniform or smaller in size relative to the force sensing surface.

Description

Technical Field

[0001] The present invention relates generally to signal sensing, and more specifically to sensor components for sensing signals related to at least one physiological parameter of a subject. Background Technology

[0002] In the medical field, non-invasive monitoring of physiological parameters in patients or subjects using sensors is crucial. Devices with coupled different sensors have been developed to acquire multiple signals or data while simultaneously monitoring several physiological characteristics of the subject. While these devices with coupled different sensors have been developed, the specific combination of different sensors needs to consider the intended purpose, which may differ from or be unsuitable for different types of physiological monitoring compared to the original intended purpose. For example, when the initial intended purpose is to determine the subject's pulse and blood oxygen saturation, a pulse oximeter sensor would be able to sense the pulse rate and measure the blood oxygen level. However, blood pressure information would be omitted from the readings because it exceeds the intended purpose, limiting the combination of sensors required in the device.

[0003] There is always a need to optimize the specific coupling of a particular sensor to be optimal for sensing relevant signals associated with the target organ and / or physiological parameters. There is a genuine need for devices capable of continuous and non-invasive monitoring of mechanophysiological events, such as changes in blood volume in the subject's circulation, blood pressure, and oxygen saturation, with at least one force-sensing resistor and piezoelectric sensor coupled together. Improvements in the sensitivity and accuracy of sensing physiological parameters are also required, as effective detection of irregular signals is crucial for early diagnosis and treatment. Furthermore, optimizing the sensor's construction to improve contact with the subject will allow for better signal acquisition.

[0004] While various sensors and systems exist for measuring signals placed around a volume, particularly for measuring and monitoring physiological parameters in living subjects, consistently and reliably providing a useful output signal representing the measured parameter remains a challenge. Furthermore, doing so while ensuring the sensor / system for measuring the parameter can be comfortably accommodated in a living subject is also challenging, especially when the subject needs to wear the sensor / system for extended periods.

[0005] Any discussion of documents, actions, materials, devices, articles of manufacture, etc., included in this specification shall not be construed as an admission that any or all of these contents form part of the prior art, or that they are common general knowledge in the relevant field of this disclosure because they existed prior to the priority date of each appended claim. Summary of the Invention

[0006] The problem to be solved

[0007] Providing a force sensor that can initially be calibrated relative to a gold standard blood pressure measuring device such as a cuff or a finger device such as Biopac would be advantageous. This step would allow for continuous calibration of the force measured by the sensor, and thus continuous measurement of blood pressure.

[0008] The following can be advantageous, including force sensors and optical and / or displacement sensors to provide additional signals related to changes in blood volume in the subject's circulation. Having additional signals will allow for greater accuracy regarding the subject's physiological condition.

[0009] The device's use of force-sensing resistors (FSRs) and piezoelectric sensors such as displacement sensors can be advantageous. Together, different types of sensors provide crucial information about the subject's physiological parameters.

[0010] It is advantageous to operate piezoelectric sensors to detect body sounds, which can also be advantageously used to monitor the health of subjects by means of sounds produced by the normal function of organs, such as, but not limited to, lungs (for breathing sounds) and heart (for monitoring heartbeat sounds), and to determine whether the sounds heard are irregular.

[0011] Using a coupler with a maximum planar area smaller than that of the force sensor can be advantageous. This planar construction allows the force and displacement sensors mechanically coupled to the coupler to ensure that force is mechanically transmitted from the subject to each sensor. Another advantage is that, utilizing force and displacement sensors mechanically coupled to the coupler and mechanically coupled to the subject's surface, the sensor assembly is configured to generate simultaneous force-displacement and displacement-velocity signals. These signals are then used to enable continuous and non-invasive monitoring of mesophysiological events.

[0012] Advantageously, the force sensor and displacement sensor are concentrically arranged on the operable rear surface of the coupler, so that the displacement sensor can effectively sense body sounds produced by the subject's organs.

[0013] The purpose of this invention is to overcome or improve at least one of the disadvantages of the prior art, or to provide a useful alternative.

[0014] means for solving problems

[0015] According to a first aspect of the invention, an apparatus for sensing physiological parameters of a subject is provided, the apparatus comprising: a force sensor having a force-sensing surface, wherein the force sensor is configured to generate a first signal representing a force displacement of an organ of the subject; a displacement sensor associated with the force sensor, the displacement sensor having a displacement-sensing surface, wherein the displacement sensor is configured to generate a second signal representing a displacement velocity of an organ of the subject; and a coupler disposed on one of the force sensor and the displacement sensor, the coupler being configured to mechanically couple the force sensor and the displacement sensor to the organ; and wherein the displacement-sensing surface is dimensionally consistent with or smaller than the force-sensing surface.

[0016] Preferably, the force sensor can initially be calibrated relative to a gold standard blood pressure measuring device such as a rubber cuff or a finger device such as Biopac. This step will allow for continuous calibration of the force measured by the sensor, and thus continuous measurement of blood pressure.

[0017] Preferably, the device may include a force sensor and an optical sensor, the latter used to replace or together with the displacement sensor to provide additional signals related to changes in the volume of blood circulating in the subject's circulation.

[0018] Preferably, the first force sensor measures a signal on the patient's chest, and the second force sensor can be located on the user's finger or wrist. The second force sensor can also be located on the upper chest, such as at the suprasternal notch.

[0019] Preferably, the force sensor may include a first force-sensing resistor (FSR). The displacement sensor may include a piezoelectric sensor. Operating the displacement sensor allows for the detection of body sounds.

[0020] Preferably, the coupler can have a maximum planar area smaller than that of the force sensor. Alternatively, the maximum planar area of ​​the coupler can be approximately equal to that of the displacement sensor.

[0021] Preferably, the force sensor can be mounted on the displacement sensor.

[0022] Preferably, the force sensor may include an operable front surface coupled to an operable rear surface of the coupler and an operable rear surface coupled to an operable front surface of the displacement sensor.

[0023] Preferably, the force sensor and the displacement sensor may each have an operable front surface coupled to an operable rear surface of the coupler. The force sensor and the displacement sensor may be arranged concentrically on the operable rear surface of the coupler. The displacement sensor may be configured such that a second signal represents a body sound produced by an organ of the subject.

[0024] Preferably, the device may further include at least one optical sensor configured to generate a third signal representing changes in blood volume in the subject's circulation. In such embodiments, at least one optical sensor may be configured to be positioned separately from the force sensor, displacement sensor, and coupler on the subject. Alternatively, at least one optical sensor may be fixed relative to (including adjacent to) the force sensor.

[0025] Preferably, the coupler can be shaped to at least partially surround the optical sensor, such that the coupler is mechanically separated from the optical sensor.

[0026] Preferably, the device may include multiple optical sensors that can operate together to generate a fourth signal representing the level of blood oxygen saturation.

[0027] Preferably, the coupler can be configured as a conductive electrode electrically coupled to a processing circuit configured to measure bioelectric potential when the coupler is positioned against a subject. In such an embodiment, the processing circuit can be configured to measure the subject's electrocardiogram (ECG) and generate a fourth signal representing the ECG.

[0028] Preferably, the coupler may include a temperature sensor and be electrically coupled to processing circuitry configured to measure temperature in response to the coupler being arranged against a subject.

[0029] Preferably, a ring-shaped conductive electrode can be configured to surround the device. The ring-shaped conductive electrode is electrically coupled to a processing circuit configured to measure biopotential when the coupler is positioned against a subject. In such an embodiment, the processing circuit can be configured to measure the subject's electrocardiogram (ECG) and generate a fourth signal representing the ECG.

[0030] Preferably, the device may include a first conductive electrode configured as a ring, the ring being electrically coupled to a processing circuit configured to measure bioelectric potential when the ring is positioned against a subject.

[0031] Preferably, the device may include a second conductive electrode arranged spaced apart from and isolated from the first conductive electrode to allow it to be positioned against another part of the subject. The second conductive electrode is coupled to processing circuitry to allow measurement of additional bioelectric potentials when the first and second conductive electrodes are positioned against the subject.

[0032] Preferably, the device may include a third conductive electrode arranged spaced apart from and isolated from the first and second conductive electrodes to allow for placement against another portion of the subject. The third conductive electrode is coupled to processing circuitry to allow for the measurement of additional bioelectrical potentials when the first, second, and third conductive electrodes are positioned against the subject. The third conductive electrode is movable relative to the first and second electrodes.

[0033] Preferably, the processing circuitry can be configured to measure the subject's electrocardiogram (ECG) in response to any conductive electrode arranged against the subject, and is configured to generate a fourth signal representing the ECG.

[0034] Preferably, in the case where the second and third ECG electrodes are combined in the device, they can be isolated from the first electrode and arranged to allow the subject's hand to complete the ECG circuit while holding the second electrode, or arranged on a second sensor that is attached to the subject and connected to the processing circuitry.

[0035] Preferably, the coupler may include a front surface configured to contact an organ. The front surface may be dome-shaped, mushroom-shaped, conical, or pyramidal. Alternatively, the coupler may be cylindrical or cuboid. The coupler may include at least one of a rigid plastic material (e.g., acrylic resin) and a conductive material.

[0036] Preferably, the device may further include a second force sensor configured to measure the force applied to the operable rear surface of the device. The second force sensor can be calibrated to a known force in production, allowing the signal from the first force sensor to be quantized to generate a blood pressure estimate. The second force sensor may be a force-sensing resistor (FSR). The second force sensor may be coupled to the operable rear surface of a displacement sensor.

[0037] Preferably, the device may further include a fixation device configured to secure the device to an organ of the subject. The fixation device may include at least one of the following: a) a strip; b) a belt; c) an adhesive patch.

[0038] Preferably, the device may further include at least one processor configured to determine physiological parameters based on a first signal and a second signal. The at least one processor may be configured to calibrate the second signal received from the displacement sensor based on the first signal.

[0039] Preferably, the physiological parameters may include at least one of the following: cardiac parameters, such as heartbeat; blood pressure, such as central or peripheral blood pressure; uterine contractions; fetal activity; respiration; body sounds, such as heart sounds; opening time of the subject's heart valves; closing time of the subject's heart valves; level of contractility of the subject's heart; elasticity of blood vessels; stroke volume of the subject; cardiac output; and blood pulse conduction time. Preferably, the device further includes a first morphological sensor configured to generate a respiratory signal representing changes in thoracic volume, and wherein the morphological sensor communicates with the sensor. Preferably, the device further includes a second morphological sensor configured to detect physiological signals to allow identification of the subject. Preferably, the first or second morphological sensor includes an accelerometer for detecting the subject's position and motion.

[0040] On the other hand, a method is provided for enhancing the signal-to-noise ratio of a signal generated by a sensor assembly including a force sensor and a displacement sensor, the method comprising: placing the displacement sensor at a location on a subject, the displacement sensor being configured to generate a first signal representing displacement; placing the force sensor at the same location on the subject, the force sensor being configured to generate a second signal representing force displacement; and operating at least one processor coupled to the displacement sensor and the force sensor and configured to process the force and displacement signals.

[0041] Preferably, the process may include multiplying the first signal and the second signal.

[0042] In another aspect, a method for measuring physiological parameters of a subject is provided, the method comprising: receiving a first signal from a first force sensor at a first position mechanically coupled to the subject; receiving a second signal from a second force sensor at a second position mechanically coupled to the subject, the second position being separated from the first position; and determining the physiological parameters based on a comparison of the first and second signals.

[0043] Preferably, the first force sensor measures a signal on the patient's chest, and the second force sensor can be located on the user's finger or wrist. The second force sensor can also be located on the upper chest, such as at the suprasternal notch.

[0044] Preferably, the comparison may include the difference between the first signal and the second signal. The comparison may also include timing between the first and second signals, wherein the timing is equal to the pulse conduction time (PTT) from the first position to the second position. PTT is a measurement representing blood pressure. It is understood that PTT can be measured at any different predetermined location.

[0045] Preferably, one or more of the first force sensor and the second force sensor can be a force sensing resistor (FSR).

[0046] Preferably, the physiological parameters may include at least one of the following: cardiac parameters, such as heartbeat, pulse conduction time, pulse arrival time; blood pressure, such as central blood pressure or peripheral blood pressure; uterine contractions; fetal activity; respiration; body sounds, such as heart sounds; opening time of the subject's heart valves; closing time of the subject's heart valves; level of contractility of the subject's heart; stroke volume of the subject's heart; cardiac output; and blood pulse conduction time.

[0047] Preferably, the first location can be on the subject's upper chest, such as at or near the xiphoid process. The second location can be on the subject's lower chest. The physiological parameter to be measured can be central blood pressure.

[0048] In another aspect of the invention, the first location may be on the subject's chest. The second location may be near the subject's femoral artery and subclavian artery or one of other peripheral arteries. In this case, the physiological parameter to be measured may be peripheral blood pressure.

[0049] In another aspect of the invention, the first and second force sensors can be on a single assembly, wherein the back force sensor is disconnected from the front force sensor. When the assembly is placed on the user's heart, the user's finger can apply force to the coupler of the second force sensor. The timing difference of the cardiac signal from the heart to the finger is the pulse conduction time.

[0050] Preferably, the method may further include receiving a third signal from a third force sensor mechanically coupled to the subject at a third position separate from the first and second positions, and determining physiological parameters based on a comparison of the first, second, and third signals. The third force sensor may be an FSR.

[0051] Preferably, the method may further include mechanically coupling one or more of the first sensor and the second sensor to the subject.

[0052] Preferably, the method may further include using a device having a force sensor and a displacement sensor, wherein the signal from the displacement sensor is multiplied by the signal from the force sensor to avoid the need to modulate the signal from the displacement sensor.

[0053] According to another aspect, a system for measuring physiological parameters of a subject is provided, the system comprising: a first force sensor configured to generate a first signal representing a force displacement at a first position of the subject; a second force sensor configured to generate a second signal representing a force displacement at a second position of the subject; and at least one processor configured to determine the physiological parameters of the subject based on a comparison between the first signal and the second signal.

[0054] Preferably, the comparison may include the difference between the first signal and the second signal. Furthermore, the comparison may include the timing difference between the first and second signals.

[0055] Preferably, at least one of the first force sensor and the second force sensor can be a force sensing resistor (FSR).

[0056] Preferably, the physiological parameters may include: cardiac parameters, such as heartbeat, pulse conduction time, pulse arrival time; or blood pressure, such as central blood pressure or peripheral blood pressure; uterine contractions; fetal activity; respiration; body sounds, such as heart sounds; the opening time of the subject's heart valves; the closing time of the subject's heart valves; the level of contractility of the subject's heart; the subject's stroke volume; cardiac output; and blood pulse conduction time.

[0057] Preferably, the first location can be on the subject's upper chest, such as at or near the xiphoid process. The second location can be on the subject's lower chest. The physiological parameter to be measured can be central blood pressure.

[0058] In another aspect of the invention, the first location may be on the subject's chest. The second location may be near the subject's femoral artery and subclavian artery or one of other peripheral arteries. In this case, the physiological parameter to be measured may be peripheral blood pressure.

[0059] Preferably, the system may further include a third force sensor configured to generate a first signal representing a force displacement at a third position of the subject, separate from the first and second positions. Physiological parameters can then be determined based on a comparison of the first, second, and third signals. The third force sensor may be an FSR (Force Separator Rating).

[0060] Preferably, one or more of the first force sensor and the second force sensor can be the first force sensor of the device as described above.

[0061] According to another aspect, an apparatus for sensing at least one parameter of a subject is provided, the apparatus comprising: a flexible sensor member having impedance that varies with flexure; and a flexible carrier surrounding the flexible sensor member and configured to hold a contact surface of the flexible sensor member close to the surface of the subject, such that a change in the shape (e.g., radius) of the subject's surface causes the flexible sensor to bend.

[0062] Preferably, the flexible sensor component may include a force-sensing resistor (FSR).

[0063] Preferably, the carrier can be at least one of a fabric carrier and an elastomer carrier. The carrier can include strips or adhesive patches. The carrier can include clothing worn by the subject. The clothing can include a shirt, vest, jacket, or coat.

[0064] Preferably, the subject's surface can be skin, such as the skin of the subject's chest. The flexible carrier can be configured to remain close to the skin's contact surface, such that the expansion and contraction of the skin (e.g., the expansion and contraction of the chest due to breathing) causes the flexible sensor to bend.

[0065] Preferably, the device may further include at least one processor configured to generate at least one parameter based on the impedance of the flexible sensor element.

[0066] Preferably, the parameters may include cardiac parameters, such as heartbeat; or blood pressure, such as central or peripheral blood pressure; uterine contractions; fetal activity; respiration; body sounds, such as heart sounds; the opening time of the subject's heart valves; the closing time of the subject's heart valves; the level of contractility of the subject's heart; the subject's stroke volume; cardiac output; and / or blood pulse conduction time.

[0067] According to another aspect, a method for sensing at least one parameter of a subject is provided, the method comprising: positioning a flexible sensor as described above at a first location close to an organ of the subject; and determining at least one parameter based on the impedance of the flexible sensor component.

[0068] According to another aspect, an apparatus for sensing physiological parameters of a subject is provided, the apparatus comprising: a force sensor configured to generate a first signal representing a force displacement of an organ of the subject; at least one optical sensor configured to generate a second signal representing a volume change of blood in the subject's circulation; and a coupler disposed on the force sensor, the coupler being configured to mechanically couple the force sensor to the organ.

[0069] Preferably, at least one optical sensor in any of the above embodiments can use at least one light wavelength to sense the resulting signal.

[0070] According to another aspect, a system for identifying a subject is provided, the system comprising: at least one first force sensor configured to generate a force signal representing a force; a displacement sensor configured to generate a displacement signal representing a displacement, the force sensor and the displacement sensor being arranged relative to each other to allow positioning at substantially the same location on the subject so as to allow signal generation; and at least one processor coupled to the force sensor and the displacement sensor, the at least one processor being configured to process the force signal and the displacement signal to determine the identification of the subject.

[0071] Preferably, at least one processor may be coupled to the memory and further configured to determine the subject's identity based on at least one standardized historical signal of the same subject stored in the memory.

[0072] Preferably, the system may further include an optical plethysmography sensor configured to generate an optical plethysmography signal and a pair of electrocardiogram (ECG) electrodes configured to generate an ECG signal, and at least one processor coupled to the optical plethysmography sensor and / or the pair of ECG electrodes, the optical plethysmography sensor and / or the pair of ECG electrodes being configured to process at least one of force and displacement signals and at least one of the optical plethysmography and ECG signals to determine the identification of the subject.

[0073] Preferably, at least one processor may also be configured to determine the subject's identity based on a combination of at least two standardized historical signals of the same subject stored in memory.

[0074] Preferably, each operation of the system can generate one or more signals, causing one or more corresponding standardized historical signals to be updated.

[0075] Preferably, using the system may include arranging the system to contact the palm side of the user's fingers to allow the generation of force and displacement signals. The system may be configured to contact the fingertip of the index finger.

[0076] Preferably, in response to the subject adjusting one or more of the contact force and contact cycle applied by the finger, the processor can be configured to transmit an alarm signal to one or more remotely located devices or systems.

[0077] Preferably, in response to the subject adjusting one or more of the contact force and contact cycle applied by the finger, the processor is configured to transmit at least one of the recorded signal and the analyzed signal to one or more remotely positioned devices or systems. Attached Figure Description

[0078] Embodiments of this disclosure will now be described by way of example with reference to the accompanying drawings, in which:

[0079] Figure 1a This is a schematic diagram of a first embodiment of the sensor assembly;

[0080] Figure 1b This is a schematic diagram of a second embodiment of the sensor assembly;

[0081] Figure 1c This is a schematic diagram of a third embodiment of the sensor assembly;

[0082] Figure 1d This is a schematic diagram of a fourth embodiment of the sensor assembly;

[0083] Figure 1e This is a schematic diagram of a fifth embodiment of the sensor assembly;

[0084] Figure 1f This is a schematic diagram of a sixth embodiment of the sensor assembly;

[0085] Figure 1g This is a perspective view of a seventh embodiment of the sensor assembly;

[0086] Figure 1h This is a perspective view of the eighth embodiment of the sensor assembly;

[0087] Figure 1i This is a perspective view of the ninth embodiment of the sensor assembly;

[0088] Figure 1.j and Figure 1k This is a perspective view of the tenth embodiment of the sensor assembly;

[0089] Figure 11 This is a perspective view of the eleventh embodiment of the sensor assembly;

[0090] Figures 2a to 2g It shows Figure 1a and 1b Variations of the coupler;

[0091] Figures 3 to 6c Embodiments of sensor components in various arrangements on human subjects are shown;

[0092] Figure 7 A signal processing chain for processing signals received from sensor components is shown;

[0093] Figures 8 to 10 It shows the result of Figure 7 An example processing circuit for generating force signals from a force sensor in a sensor assembly of Figure 1 or Figure 2, implemented in the signal conditioning stage of the signal processing chain.

[0094] Figures 11 to 13 It shows the result of Figure 7 The circuit diagram shows an example processing circuit implemented in the signal conditioning stage of the signal processing chain to generate force signals based on the characteristics of the force sensor and the second force sensor of the sensor assembly in Figure 2.

[0095] Figure 14 It shows the result of Figure 7 The signal conditioning stage of the signal processing chain is implemented for... Figure 1a or Figure 1b A block diagram of an exemplary processing chain for a displacement sensor in a sensor assembly to generate a regulated velocity signal;

[0096] Figure 15a It shows the result of Figure 7 The signal conditioning stage of the signal processing chain is implemented for... Figure 1a A first embodiment of the processing circuit for generating a regulated velocity signal from the displacement sensor of the sensor assembly of 1b;

[0097] Figure 15b It shows the result of Figure 7 The signal conditioning stage of the signal processing chain is implemented for... Figure 1a or Figure 1b A second embodiment of the processing circuit for generating a regulated velocity signal from the displacement sensor of the sensor assembly;

[0098] Figure 16 A signal processing chain for processing signals received from multiple sensor components is shown;

[0099] Figure 17 It is shown that, as Figure 3 The location shown is on the subject's sternum. Figure 1a The force versus time curve recorded by the sensor components;

[0100] Figure 18 It is shown that, as Figure 3 The location shown is on the subject's sternum. Figure 1a The force versus time curve recorded by the sensor components;

[0101] Figure 19 The lower view shows the sum of two force signals from the force sensors of the sensor assembly located at the suprasternal notch and the apex of the heart of the subject, respectively, and the upper view shows the signal obtained using ECG electrodes.

[0102] Figure 20 It is a comparison from Figure 1a The graph shows the integral of the force signal from the force sensor of the sensor assembly with the displacement velocity signal from the displacement sensor of the sensor assembly in Figure 1.

[0103] Figure 21 It is a graph comparing an electrocardiogram (ECG) with force and displacement signals from the sensor assembly in Figure 1;

[0104] Figure 22 It shows from Figure 1a The force signal from the force sensor of the sensor assembly, the respiratory signal of the force signal together with the ECG, and the curve of the respiratory signal from the ECG;

[0105] Figure 23 It shows from Figure 1a The force and accelerometer signals from the sensor components, as well as the heart sound signal, ECG, and optical volumetric plethysmography (PPG) plots;

[0106] Figure 24 It shows from Figure 1a A graph of raw respiratory-related data from the sensor components:

[0107] Figure 25a It shows the relationship with the source Figure 1a A graph showing the correlation between sound and seismogram data from the sensor components;

[0108] Figure 25b Two graphs are shown; the upper graph shows the force and displacement signals, while the lower graph shows the signals from... Figure 6b or Figure 6c The sensor components contain red and infrared light signals;

[0109] Figure 26 This is a cross-sectional view of an embodiment of the sensor assembly;

[0110] Figure 27 yes Figure 26 A plan view of an embodiment of the sensor assembly shown;

[0111] Figure 28 The image shows the arrangement on the subject's thorax. Figure 26 Paired sensor assemblies;

[0112] Figure 29 It comes from Figure 26 The respiratory signal from the sensor components;

[0113] Figure 30 This is a cross-sectional view of another embodiment of the sensor assembly;

[0114] Figure 31 This is a cross-sectional view of another embodiment of the sensor assembly;

[0115] Figure 32 It was from the subject's resting time Figure 1a A graph of pulse conduction time (PTT) of the sensor components;

[0116] Figure 33 It comes from the subject after exertion. Figure 1a The PTT curve of the sensor component;

[0117] Figure 34 It was from the subject's resting time Figure 1a A graph of cardiac activity from the sensor components;

[0118] Figure 35 It comes from the subject after exerting force at a low rate. Figure 1a A graph of cardiac activity from the sensor components;

[0119] Figure 36It is from the subject after applying a high rate of force. Figure 1a A graph of cardiac activity from the sensor components;

[0120] Figure 37 Two graphs are shown, representing the sound recorded using a conventional digital stethoscope and the sound recorded using one of the sensor components shown in the previous figure.

[0121] Figure 38A is a block diagram illustrating the stages of operating the sensor assembly to detect sound; Figure 38B is another block diagram similarly illustrating the stages of operating the sensor assembly to detect sound.

[0122] Figure 39A is a block diagram illustrating a system configured to identify a subject; Figure 39B is another block diagram similarly illustrating a system configured to identify a subject; Figure 39C shows a flowchart of using machine learning to update a comparison signal used to identify a subject.

[0123] Figure 40 This is a schematic diagram illustrating the use of a sensor assembly configured to identify a subject;

[0124] Figures 41a to 41c It is a graph of force and displacement signals obtained from subjects who intermittently apply force to the sensor assembly, such as... Figure 40 Figure 41d is a schematic diagram showing the specific construction for identifying a subject leaving the fingertip; Figure 41e shows a method for generating an alarm based on varying pressure, varying time, and the force applied intermittently by the subject to the sensor assembly; Figure 41f shows examples of the types of signals obtained and the physiological parameters transmitted.

[0125] Figure 42A shows three signals obtained from three different subjects who intermittently contacted the sensor assembly; Figure 42B is another schematic diagram showing the sensor assembly and multicolor optical volumetric plethysmography / pulse oximeter used on the same side of the finger; Figure 43C (left) is a schematic diagram showing the sensor assembly used on the top surface of the finger and the multicolor optical volumetric plethysmography / pulse oximeter used on the bottom surface of the finger, and Figure 43C (right) is a front view of Figure 43 (left).

[0126] Figures 43a to 43d Various methods are shown for applying a finger to a post-coupler to measure the pulse conduction time from above the heart to the fingertip.

[0127] Figure 44 It shows the result of Figure 43a The embodiment in the example generates a timing difference between two pulses, which provides a direct measurement of pulse conduction time.

[0128] Figure 45The image shows a comparison of signals from piezoelectric and force sensors on the arm and chest with electrocardiogram (top) and blood pressure (bottom) signals from the fingers.

[0129] Figure 46a Two sensors are shown placed on the chest, one above the apex of the heart and the second above the suprasternal notch / aortic arch. Figure 46b The obtained signal is shown, which allows for the measurement of the delay between trigger (R peak on ECG) and apical motion, and also the delay between apical and aortic arch ejection time.

[0130] Figure 47a Signals from a piezoelectric sensor, force sensor, and finger BP monitor are shown. Various artifacts from breathing and movement are present. Figure 47b The image shows a signal with artifacts removed, revealing a similar shape to the signal.

[0131] Figure 48a An embodiment is shown where a back force sensor is connected to a front skin contact force sensor and a piezoelectric sensor. The assembled sensor can be calibrated in grams per Newton.

[0132] Figure 48b The difference between the calibrated DC component of the force measured by the anterior FSR and the DC component of the force measured by the posterior FSR is shown, and thus the difference in tissue compliance between the chest and the wrist is shown. Detailed Implementation

[0133] Embodiments of this disclosure relate to sensing systems and methods for monitoring biomechanics based on local measurements of the force exerted on the skin surface by displacement of organs, muscles, blood flow, and fluid displacement (i.e., digestion, swallowing, respiration, etc.) and the speed of its propagation.

[0134] Some embodiments use force sensors, such as force-sensing resistors (FSRs), mechanically coupled to the subject in the chest or upper abdomen to measure the recoil force generated by the contraction of the heart and the pumping action of blood, a process known as "force cardiography (FCG)". Thus, embodiments can achieve continuous and non-invasive monitoring of the mechanical events of each cardiac cycle in a subject. Specifically, by using multiple force sensors typically mechanically coupled to the subject at the skin, information about physiological parameters can be obtained, such as the identification and duration of each phase of the cardiac cycle, the timing of heart valve opening and closing, the level of cardiac contractility, stroke volume, cardiac output, pulse conduction time, and central arterial pressure. Furthermore, morphological bands can be combined to determine changes in the subject's chest volume. A morphological band is one that deforms with the monitored body in a manner that is negligible or has no mechanical resistance. Since heart failure is a complex and multifaceted disease, it can affect multiple organ systems, including the respiratory system. Additional information from the morphological bands allows for the acquisition of respiratory signals. Quantitative measurements of force and pressure can be calculated relative to known force calibration forces. Furthermore, information about heart disease and / or dysfunction can be obtained, such as, but not limited to, heart failure, mechanical asynchrony (e.g., as a result of bundle branch block), valvular disease (e.g., aortic and mitral regurgitation, stenosis), etc.

[0135] When positioned near peripheral pulse points or major blood vessels (i.e., the neck pulse, radial pulse, etc.), force sensors can be used to measure force and its propagation time, thereby measuring the velocity of blood movement and flow. This flow can include venous return and changes in hydrostatic pressure due to respiration. Thus, embodiments allow the respiratory rate to be inferred from force measurements of the peripheral limbs.

[0136] Some embodiments use one or more force sensors (e.g., FSRs) combined with a displacement sensor (e.g., a piezoelectric sensor), both mechanically coupled to the subject to simultaneously measure the subject's force displacement and the velocity or rate of such displacement. The compressive force (DC baseline of the force sensor signal) and dynamic force (AC component of the force sensor signal) applied to the force sensor can be used to calibrate the displacement velocity signal generated by the displacement sensor, allowing for precise and continuous direct measurement of the velocity or rate of skin displacement, as well as the force displacement itself. Thus, precise and continuous measurements of blood pulsation and, consequently, heart pulsation can be obtained solely from the movement of the skin.

[0137] In some embodiments, the force sensor may initially be calibrated relative to a gold standard blood pressure measuring device such as a rubber cuff or a finger device such as Biopac. This step will allow for continuous calibration of the force measured by the sensor, and thus continuous measurement of blood pressure.

[0138] In another embodiment, the force sensor may have a force-sensing surface, and the displacement sensor may have a displacement-sensing surface. Each sensing surface is a surface that allows the detection of a signal from a target area or a subject. Although each surface has a certain shape and size, it is advantageous to have the displacement sensing surface of the displacement or piezoelectric sensor have a profile shape and size that is consistent with or smaller than that of the force-sensing surface of the force-sensing resistor (FSR) in order to allow optimal coupling and contact between the sensors. For example, the force-sensing resistor may have a circular force-sensing surface, and the displacement sensor may also have a circular force-sensing surface. It is understood that the surface, which may be planar in shape, is not limited to a circle, but can be any shape that allows the sensor to sense. For example, a possible size measurement for a consistent-shaped sensing surface for a force-sensing surface could be 10 mm. 2 For displacement sensing surfaces, the thickness can be 9mm. 2 This serves as a means of describing how uniformly sensing surfaces can have sizes that are larger or smaller than each other. While the above measurements are mentioned by example, they are not limited to these values, and it can be understood that surfaces can have different sizes.

[0139] Some embodiments use one or more force sensors (e.g., FSR) combined with one or more optical sensors (e.g., optical volumetric plethysmography (PPG) sensors), both in contact with the subject's skin, to simultaneously measure force displacement of the subject's skin and changes in blood volume or flow within organs or blood vessels beneath the skin. Other embodiments include displacement sensors, such as piezoelectric sensors, combined with one or more force sensors and optical sensors. Typically, embodiments including optical sensors also have a ring arranged to allow the optical sensors to be positioned in contact with the subject's skin.

[0140] While the sensor components described herein have been specifically developed for measuring physiological parameters, such as cardiac and respiratory activity, directly from the skin of a living organism, those skilled in the art will understand that embodiments of the disclosed force and displacement sensor components can be used by means of one or more layers of fabric (e.g., clothing or bedding) arranged on the skin. In some such embodiments, the sensor components can be held in place by embedding or attaching to a padded or other fabric-covered structure, such as a mattress of a bed, the seat of a chair including a wheelchair and vehicle seat, a steering wheel of a vehicle, or a seatbelt attached to a vehicle.

[0141] While the sensor assembly described herein has been specifically developed for measuring physiological parameters of living subjects, such as cardiac and respiratory activity, those skilled in the art will understand that the sensor assembly, which is the subject of this disclosure, can be used with other objects in which forces are applied by components beneath the sensor assembly. Therefore, the sensor assembly described herein can be used in industrial applications, such as soft robots or other inanimate objects that apply such forces.

[0142] Figure 1a This is a cross-sectional view of a first embodiment of a sensor assembly 100 for sensing at least one physiological parameter of a subject. The sensor assembly 100 includes a force sensor 102, a displacement sensor 104, and a mechanical coupler 106. The force sensor 102 and displacement sensor 104 are arranged on the coupler 106 such that any force applied to the front surface 108 of the coupler is transmitted to the force sensor 102 and displacement sensor 104. The coupler 106 may be formed of a conductive material and is configured to operate as an ECG electrode. It should be understood that at least two electrodes are required to form a single-lead ECG, and one or both of these electrodes may be embedded in a separate sensor assembly.

[0143] Coupler 106 comprises a rigid material, such as rigid plastic or rubber. In some embodiments, coupler 106 may comprise acrylic resin. In other embodiments, coupler 106 may be partially or entirely conductive. For example, coupler 106 may comprise partially or entirely a conductive material, such as silver or silver chloride. The front surface 108 of coupler 106, configured to face and preferably positioned to contact the surface of the subject, may be dome-shaped to press against the subject's supple surface, such as skin. Providing a dome-shaped front surface 108 helps improve coupling of mechanical displacement from the subject to force sensor 102 and displacement sensor 104. Other shapes of the front surface 108 that provide a similar effect include conical, mushroom-shaped, etc.

[0144] When viewed in a plane parallel to the plane facing the subject of the sensor assembly 100, the coupler 106 has a generally circular cross-section. In addition to coupling motion (force and displacement), the coupler 106 can be configured as a biopotential electrode and can be electrically coupled to processing circuitry (not shown) for measuring biopotentials (e.g., electrocardiogram (ECG), electromyography (EMG), electroencephalography (EEG), etc.).

[0145] Force sensor 102 is mounted to the rear surface of coupler 106 via force sensor carrier 110 comprising a flexible medium. Force sensor 102 is mounted to carrier 110 by adhesive, lamination, or other means. Electrical connection to force sensor 102 is achieved using two or more electrodes 112, which also serve as anchoring points for anchoring force sensor 102 to sensor carrier 110. Force sensor 102 is a force-sensing resistor (FSR) or load cell. As will be described in more detail below, the characteristics of force sensor 102 change in response to a force signal applied to the force sensor, representing a force displacement of an organ in contact with the front surface 108 of coupler 106. This characteristic is, for example, the impedance of force sensor 102 or its output current or voltage. In the case where force sensor 102 is an FSR, the change in resistance of force sensor 102 represents a force displacement that can produce an output voltage, as will be described in more detail below.

[0146] In one embodiment, the force sensor 102 has a front surface facing the subject with an area of ​​approximately 5 mm. 2 and 25mm 2 The surface area between, for example, 7mm 2 15mm 2 Or 20mm 2 .

[0147] Force sensor 102 and displacement sensor 104 are mounted together via an optional rigid interface layer 114. The rigid interface layer 114 is disposed on the rear surface of force sensor 102. The rigid interface layer 114 may comprise brass, rigid plastic, or a similar rigid material. In some embodiments, the rigid interface layer 114 may be a double-sided PCB, with force sensor 102 mounted on a first surface of the PCB (i.e., the surface facing the subject in use) and displacement sensor 104 mounted on the opposite second surface of the PCB.

[0148] In all cases, the displacement sensor 104 is mechanically coupled to the rear surface of the force sensor 102, such as Figure 1a As shown. Therefore, the displacement of the coupler 106 due to the movement of the organ in contact with the coupler 106 causes the displacement sensor 104 to move. The displacement sensor 104 generates a velocity signal representing the speed or displacement velocity of the sensor 104. When mechanically coupled to an organ such as the subject's skin, this velocity signal is proportional to the displacement velocity of the organ.

[0149] In one embodiment, the front surface of the displacement sensor 104 facing the subject has a depth of approximately 5 mm. 2 and 25mm 2 The surface area between, for example, 7mm 2 15mm 2 Or 20mm 2 .

[0150] Advantageously, the surface areas of the force and displacement sensors 102 and 104 are substantially matched to ensure uniform transmission of displacement from the force sensor 102 to the displacement sensor 104. Therefore, for similar reasons, the force and displacement sensors 102 and 104 are also preferably axially aligned along the central operable vertical axis of the assembly 100.

[0151] An optional protective cover 116 may be provided around the rear surface of the displacement sensor 104. The protective cover 116 may be separated from the rear surface by a fluid gap filled with air or other gas or by a vacuum. In doing so, the protective cover 116 protects the displacement sensor 104 from impacts to the operable rear of the assembly 100 that is not facing the subject.

[0152] In addition to the force sensor 102 and displacement sensor 104, the sensor assembly 100 may optionally include an accelerometer 120. The accelerometer 120 is configured to measure acceleration on one or more axes. For example, the accelerometer 120 may be configured to measure acceleration on at least one axis perpendicular to the subject's surface, to which the sensor assembly 100 is fixed in use. Preferably, the accelerometer 120 also measures acceleration in one or more planes parallel to the subject's surface, to which the sensor assembly 100 is fixed in use, so as to measure the motion of the sensor assembly in such planes or axes. The accelerometer 120 may be located anywhere on the sensor assembly 100 if mechanical coupling (directly or indirectly) to the coupler 106 is provided. For example, the accelerometer 120 may be coupled to the rear of the protective cover 116.

[0153] Housing 118 encapsulates sensor assembly 100 to protect its components from debris, such as dust, grit, water, and / or any other substances that may affect its operation, and to prevent foreign objects from entering the assembly 100. An operable front surface 108 of coupler 106 extends through an opening in housing 118. Alternatively, housing 118 may include at least one flexible portion (not shown) extending over and conforming to the front surface 108 of coupler 106, thereby completely encapsulating force sensor 102, displacement sensor 104, and coupler 106.

[0154] During operation, the front surface 108 of the coupler 106 of the sensor assembly 100 is positioned in contact with the surface of the subject (e.g., the subject's skin), and the sensor assembly 100 is secured relative to the subject by one or more securing devices (e.g., belts, adhesive patches, tapes, etc. (not shown)). Such belts may be made of materials used to manufacture motion bands (also known as muscle tape). With the force and displacement sensors 102, 104 mechanically coupled to the coupler 106 and the coupler 106 mechanically coupled to the subject's surface, the sensor assembly 100 is configured to generate synchronized force-displacement and displacement-velocity signals. These signals are then used to achieve continuous and non-invasive monitoring of mechanophysiological events, which will be described in more detail below.

[0155] Figure 1b This is a cross-sectional view of another embodiment of the sensor assembly 200, which is Figure 1a A variation of the sensor assembly 100 shown. (Reference) Figure 1a ,exist Figure 1b Unless otherwise stated, the same reference numerals denote the same parts.

[0156] In addition to the components of sensor assembly 100, Figure 1b The sensor assembly 200 also includes a second force sensor 202, similar to and having similar characteristics to the force sensor 102. The second force sensor 202 is operatively mounted behind the displacement sensor 104, for example, on an operative outer surface of the protective cover 116. Similar to the force sensor 102, the second force sensor 202 is configured to generate (actively or passively) a signal representing the force applied at the second sensor 202. Therefore, the second force sensor 202 is used to measure the force applied to the operative rear portion of the assembly 200, for example, due to one or more fixation devices used to apply the sensor assembly 200 to the surface of a subject.

[0157] The measured external force signal can be used to compensate for carrier pressure (i.e., the force applied to the rear of sensor assembly 200 by the fixing device) and the surface elasticity of the subject (i.e., how elastic the surface of the sensed subject is). For example, knowing the pressure applied from the external carrier or the operator of assembly 200 will allow for the elimination of artifacts. For example, a sudden tap or shearing of the sensor (i.e., during movement) can alter the pressure applied to force sensor 102, which may in turn produce artifacts in the signal from force sensor 102. Additionally, rhythmic motion caused by activities such as running by the subject can introduce baseline drift and associated artifacts into the signal from force sensor 102. Such artifacts can be eliminated (in real time or in post-processing) using signals derived from each of the two force sensors 102, 202 and displacement sensor 104, as will be described in more detail below.

[0158] Now refer to the attached diagram. Figure 1c and 1d Other embodiments of sensor assemblies 100 and 200 are shown. Referring again to the preceding figures, unless otherwise stated, the same reference numerals denote the same parts.

[0159] In both embodiments, the coupler 106 includes a collar 109 housed within a housing 118, with a dome-shaped surface 108 of the coupler 106 extending through an opening (not shown) in the housing 118. This opening has a smaller diameter than the collar 109, such that the collar 109 helps to retain the coupler 106 confined relative to the housing 118 and prevents the coupler 106 from separating from the housing 118.

[0160] Furthermore, in both embodiments, the diameter of the coupler 106 at its base (i.e., the portion of the coupler 106 that contacts the sensor carrier 110) (referred to as the "base diameter") is smaller than the diameter of the force sensor 102. However, it is desirable and preferred that the coupler 106 distributes its force over the entire surface area of ​​the displacement sensor 104. Thus, the base diameter of the coupler 106 is close to the diameter of the displacement sensor 104. Typically, the base diameter of the coupler 106 is approximately 70% to 90% of the diameter of the force sensor 102, for example, approximately 80%.

[0161] exist Figure 1d In the illustrated embodiment, the sensor assembly 200 further includes a rear pressure applicator or coupler 111. Typically, this coupler 111 is covered during use by a component through which the sensor assembly 200 is secured to the subject's organ, such as a strip, belt, strap, etc. (not shown). This component applies a displacement force to the force sensor 202 via the coupler 111 and helps to remove artifacts recorded by the sensor assembly 200 caused by external factors such as movement of the sensor assembly 200 associated with the subject's organ.

[0162] Although coupler 111 is shown as a plate-like structure, it should be understood that coupler 111 can have any suitable shape, including a dome shape similar to coupler 106. Similarly, the diameter of coupler 111 is smaller than the diameter of force sensor 202, typically about 70% to 90% of the diameter of force sensor 202, for example, about 80%.

[0163] As described above, the dome-shaped coupler 106 facilitates insertion into a compliant surface of the subject, such as skin. Therefore, providing the coupler 106 with a dome-shaped front surface 108 improves the coupling of mechanical displacement from the subject to the force sensor 102 and the displacement sensor 104.

[0164] The aforementioned sensor assemblies 100 and 200 include force and displacement sensors arranged in a "sandwich" configuration relative to each other. However, embodiments of this disclosure are not limited to this arrangement. For example, in other embodiments, the force and displacement sensors may be arranged in a planar structure, such as adjacent to each other or concentrically (one within the other), and may be arranged on a common substrate or on different, separate substrates. In each embodiment, each force sensor and displacement sensor is preferably mechanically coupled (directly or indirectly) to a coupler, for example... Figures 1a to 1d Couplers 106 and 111 are used to ensure the mechanical transmission of force from the subject to each sensor.

[0165] Figure 1e This is a plan view of an embodiment of sensor assembly 400, which is Figures 1a-1d Variations of the sensor assemblies 100 and 200 shown. Referring to these figures, in Figure 1e Unless otherwise stated, the same reference numerals denote the same parts.

[0166] The sensor assembly 400 includes a coupler 406 arranged to transmit force to the force sensor 102 and optionally to the displacement sensor 104. Figure 1e (Not shown in the diagram). Coupler 406 is configured to at least partially surround at least one optical sensor such that forces applied to coupler 406 are not transmitted to the optical sensor. In the illustrated embodiment, the optical sensor is in the form of a multicolor optical volumetric (PPG) sensor 402, which is arranged with a cavity 408 defined by the annular coupler 406. In other embodiments (not shown), the PPG sensor is replaced by a pulse oximetry sensor, or arranged in series with a pulse oximetry sensor. In some embodiments, the optical sensor is operatively arranged above a force sensor 102, and the force sensor 102 defines an aperture (not shown) to allow the optical sensor to be electrically coupled through the aperture to other components of assembly 400.

[0167] PPG sensor 402 is arranged to be substantially aligned with the operable top surface of coupler 406, allowing PPG sensor 402 to be placed against the subject's skin while the skin applies force to coupler 406. Typically, coupler 406 is formed of an opaque material to suppress light passing through coupler 406 that could affect the readings of PPG sensor 402. PPG sensor 402 is configured to sense blood volume biometry simultaneously with other sensors 102, 104, deriving further information related to the state of the subject's cardiovascular system.

[0168] Figures 1f to 11 It shows Figures 1a-1dAlternative embodiments of the sensor assemblies 100 and 200 shown are provided, wherein the same reference numerals denote the same features. Figures 1f to 11 The illustrated embodiments may include electrocardiogram (ECG) electrodes attached to and electrically isolated from the sensor assemblies 100, 200. In some embodiments, coupler 106 may include a temperature sensor and be connected to processing circuitry configured to measure temperature.

[0169] Figure 1f and Figure 1g Embodiments of assemblies 100 and 200 including a first conductive electrode in the form of an annular ring 140 are shown. The annular ring 140 is disposed on one side of the sensor assemblies 100 and 200, which are arranged to allow contact with a subject. In the illustrated embodiment, the ring 140 is secured to a housing 118 to surround the periphery of the base of the sensor assemblies 100 and 200. The ring 140 is electrically insulated from the housing 118 and is configured to form a lead for an ECG circuit. The ring 140 is electrically connected to processing circuitry configured to generate an ECG signal in response to placing the ring 140 against a subject.

[0170] Figure 1g The illustrated embodiment also includes a temperature sensor 154 disposed within the electrode ring 140, allowing it to be placed against the subject simultaneously with the ring 140. The temperature sensor 154 is connected to processing circuitry configured to generate a temperature signal in response to the sensor 154 being placed against the subject.

[0171] Figure 1h Another embodiment of component 100 is shown, which includes a second electrode in the form of a gripping portion 150 (arranged to at least partially surround the sidewall of housing 118). The gripping portion 150 is electrically insulated from the housing and connected to ECG processing circuitry to form ECG circuit leads. The gripping portion 150 is shaped and arranged to allow a subject to hold the gripping portion 150 and thus contact the second electrode, while an annular ring 140 including the first electrode is arranged to abut against the subject. Therefore, this arrangement allows the subject to form simultaneous connections with both electrodes 140 and 150, allowing for an alternative ECG signal compared to that obtainable with a single electrode 140 embodiment.

[0172] Figure 1i It shows Figure 1h Another embodiment of the component shown. In this embodiment, the second electrode includes a gripping portion 150 and a handle member 160. The handle 160 is electrically connected to the gripping portion 150 to effectively extend the surface area of ​​the other electrode 150. This arrangement enhances the ease of holding the components 100, 200 against the subject while also forming an electrical connection with the second electrode 150.

[0173] Figure 1j and Figure 1k Another alternative embodiment of components 100, 200 is shown, which includes a third electrode in the form of a contact pad 170 disposed on a handle 160 to allow it to be positioned against a subject simultaneously with the first electrode 140. The pad 170 is spaced apart from the annular ring 140 by a defined distance via the handle 160. The pad 170 is electrically insulated from the handle 160 and connected to the ECG processing circuitry to form a third lead in the ECG circuitry. Configuring components 100, 200 in this way allows the first electrode 140 and the third electrode 170 to be positioned against a subject while the subject is in contact with the second electrode, or to form a three-electrode system by gripping the grip portion 150 and / or the handle 160. This can allow the acquisition of an ECG signal different from that obtained in the aforementioned embodiments.

[0174] Figure 11 yes Figure 1j and Figure 1k An alternative embodiment of the shown example has a third electrode in the form of an adhesive pad 180 configured to adhere to the skin and connected via a wire 182 to a housing 118 for connection to ECG processing circuitry. The wire 182 is isolated from the housing 118 and the gripping portion 150. This embodiment allows the third electrode 180 to be arranged substantially spaced from the first and second electrodes 140, 150, allowing for the acquisition of an alternative ECG signal. This embodiment also allows the third electrode 180 to be placed at a range of different locations on the subject's body, which can allow for influence on the ECG signal.

[0175] Figures 2a to 2g It shows Figure 1a Several variations of the coupler 106 in Figure 1.j can replace... Figure 1a and Figure 1b The coupler 106 is shown in the figure. As previously stated, unless otherwise specified, the same reference numerals denote the same parts.

[0176] Figure 2a This is a cross-sectional view of a sensor assembly 100 with a mushroom-shaped coupler 201, which includes a dome-shaped front surface 203 and a dome-shaped rear surface 205 configured to contact a force sensor 102. The dome-shaped rear surface 205 provides a smaller contact surface area between the coupler 201 and the force sensor 102, thereby increasing the force applied to the sensor per unit area, which in turn increases the sensitivity of the sensor 102 to forces applied to the front surface of the coupler 201.

[0177] Figure 2b It shows something similar to Figure 2a The sensor assembly 100 is an embodiment, but includes those described above. Figure 1dThe coupler 111 that acts on the force sensor 202, as described in the sensor assembly 202.

[0178] Figure 2c and Figure 2d Perspective (enlarged) and side views of coupler 204 are provided, which includes a dome-shaped front surface 206 and a dome-shaped rear surface 208, configured to contact force sensor 208, similar to... Figure 2a and 2b Coupler 201. Optionally, coupler 204 is held in place relative to housing 118 and force sensor 102 by one or more fasteners 210 (e.g., elastic or elastomeric connectors). In other embodiments, coupler 204 may be held in place by rear pressure on housing 118 and in contact with the surfaces of the subject and carrier (not shown). Figure 2d As shown, the dome-shaped rear surface 208 creates a small contact surface area between the coupler 204 and the force sensor 102, thereby increasing the force applied to the sensor per unit area, which in turn increases the sensitivity of the sensor 102 to the force applied to the front surface of the coupler 204. As described above with respect to the coupler 106, it has been found that providing the dome-shaped front surface 206 improves the coupling of mechanical displacement from the subject to the force sensor 102 and the displacement sensor 104. Other shapes of the front surface 206 and rear surface 208 that provide similar effects include conical, mushroom-shaped, etc.

[0179] Figure 2e and Figure 2f Another coupler 212, a variation of coupler 204, is shown. Coupler 212 includes a ball or sphere 214 supported within a housing 118 by a lip 216 extending circumferentially around a ball 214. The lip 216 may form part of the housing 118. Optionally, a seal 218, such as a gasket or O-ring, is provided between the ball 214 and the lip 216 to prevent the ingress of dust and other harmful substances.

[0180] Figure 2g Coupler 220 is shown as a variant of coupler 212, in which ball 214 has been replaced by double mushroom-shaped or waist-shaped coupling member 222. The waist of coupling member 222 is engaged by lip 216 and held in place in coupler 220, which also prevents separation of coupling member 222 from housing 118.

[0181] Both sensor assemblies 100 and 200 described above include a displacement sensor 104. However, it should be noted that embodiments of this disclosure are not limited to the use of a combination of force and displacement sensors. For example, various novel techniques will be described below for detecting various physiological parameters using multiple force sensors located at different positions on a subject. Such techniques do not require synchronized displacement sensing. Such techniques can use the sensor assemblies 100 and 200 described above, or they can use sensor assemblies that only include force sensors and couplers. Such sensor assemblies can include any conceivable coupling arrangement, such as... Figures 1a to 2g Any of the arrangements shown. For example, an embodiment may use a variation of the sensor assembly 100 shown above, but omitting the displacement sensor 104.

[0182] Figure 3 Figures 6 to 6 illustrate various arrangements of the sensor assembly, such as Figure 1a Sensor assembly 100 Figure 1b Sensor assembly 2001b, sensor assembly 200 or a variant thereof.

[0183] exist Figure 3 In this embodiment, a chest strap 304 is used to secure a single sensor assembly 302 relative to the xiphoid process of the sternum. The chest strap 304 is configured to apply external pressure from the rear of the sensor assembly 302 and hold the sensor assembly 302 at or near the xiphoid process of the sternum.

[0184] exist Figure 4 In this process, adhesive patches 404 are used to secure multiple sensor assemblies 402 to the skin of the subject 300. Similar to the chest strap 304, each adhesive patch 404 is configured to apply external pressure from the rear of the sensor assembly 402 to hold it in a predetermined position on the subject 300, typically the subject's chest.

[0185] Figure 5 Another arrangement is shown in which multiple sensor assemblies 502 are secured to the chest of a subject 300 using a common adhesive patch 504 configured to apply external pressure from the rear of the sensor assemblies 502 to hold them in a predetermined position relative to the subject 300. Alternatively or additionally, the multiple sensor assemblies 502 can be secured to the back of the subject 300 in any suitable manner. By providing multiple sensor assemblies 502 around the subject's torso, force-comprehension X-rays of the chest region can be generated based on data from sensors of the sensor assemblies 502.

[0186] Figure 6aAnother arrangement is shown in which a single sensor assembly 602 is fixed relative to the radial vein or radial artery located on the wrist 604 of the subject 300. The sensor assembly 602 may be held in place on the wrist 604 by a wristband 606 (or adhesive or other means), which also applies an external force to the rear of the sensor assembly 602 to maintain contact between the assembly 602 and the wrist 606.

[0187] Figure 6b Another arrangement is shown in which a single sensor assembly 610 is fixed relative to the finger 612 of the subject 300, typically held in place by a releasable or elastically deformable mechanism (e.g., a band or sleeve (not shown)). It should be understood that the assembly 610 shown fixed to the finger 612 is merely exemplary, and the assembly 610 may be configured to be fixed to other parts of the subject 300's body. The sensor assembly 610 includes a sensor 100 adjacent to the optical sensor arrangement, which in this embodiment is a multicolor PPG sensor 614. In other embodiments (not shown), a pulse oximetry sensor is additionally or alternatively arranged to the PPG sensor 614. This arrangement allows for the simultaneous collection of blood volume signals from individual sensors 100, 614 located on the same side of the assembly 610 to sense the position of adjacent arrangements on the finger.

[0188] Figure 6c Another arrangement is shown in which a single sensor assembly 650 is fixed relative to the finger 612 of the subject 300, typically held in place by a releasable or resiliently deformable mechanism such as a band or sleeve (not shown). It should be understood that the assembly 650 shown fixed to the finger 612 is merely exemplary, and the assembly 650 may be configured to be fixed to other parts of the subject 300's body. The sensor assembly 650 includes a sensor 100 arranged opposite an optical sensor, in this embodiment a multicolor PPG sensor 614. In other embodiments (not shown), a pulse oximetry sensor is additionally or alternatively arranged to the PPG sensor 614. This arrangement allows for the simultaneous collection of blood volume signals from individual sensors 100, 614 located on opposite sides of the finger 612.

[0189] Figure 7This is a block diagram illustrating an exemplary signal processing chain 700 for processing changes in signals and / or parameters of a force sensor 102, a displacement sensor 104, a second force sensor 202, and an optional accelerometer 120 generated from a living body. In the examples below, force sensor 102 and the second force sensor 202 will be described below as force-sensing resistors (FSRs), FSR1 and FSR2, whose resistance is proportional to the force applied thereto. However, it should be understood that the embodiments are not limited to using FSRs as force sensors, and other force sensors or force sensors may be used instead of FSRs without departing from the scope of this disclosure. Similarly, in the examples below, displacement sensor 104 will be described in some instances as a piezoelectric sensor PZT that generates a voltage in response to changes in displacement. However, the embodiments are not limited to using a piezoelectric sensor as displacement sensor 104. Other exemplary displacement sensors include, but are not limited to, resistive, inductive, capacitive, eddy current, ultrasonic, magnetoresistive, and optical encoder displacement sensors.

[0190] Displacement sensor 104, second force sensor 202 and accelerometer 120 are in Figure 7 The figures are shown in dashed lines because some embodiments of this disclosure require only one or more of the force sensor 102 for operation, and the displacement sensor 104, the second force sensor 202, and the accelerometer 120.

[0191] The signal processing chain 700 includes a signal conditioning stage 702, an analog-to-digital conversion stage 704, and a filtering stage 706, which generates representations of one or more physiological parameters, including but not limited to respiration, blood jet pulse, force parameters, velocity parameters, heart sounds, and blood pressure.

[0192] During signal conditioning stage 702, the resistance FSR1 of force sensor 102 is converted into output voltage Vn in post-processing via hardware (processing circuitry) or software.

[0193] Exemplary hardware for performing this conversion Figures 8 to 10 As shown in the image. (Reference) Figure 8 The resistor FSR1 of the force sensor 102 forms one tail of the voltage divider 802, and the output of the voltage divider 802 is provided to the input of the non-inverting amplifier 804, producing an output voltage Vn proportional to the resistor FSR1 of the force sensor 102. In another embodiment, refer to... Figure 9 The change in resistance FSR1 of the force sensor 102 is converted using the transimpedance amplifier 902, and the resistance FSR1 is configured as the variable input impedance of the amplifier 902. In another embodiment, as... Figure 10 As shown, the force sensor 102 is integrated into the current mirror 1002, and the resistor FSR1 of the force sensor 102 is configured as the bias resistor of the current mirror 1002.

[0194] As described above, the second force sensor 202 can be used to calibrate varying forces applied to the rear (non-subject-facing) side of the sensor assembly 200 by any restraint device or the subject himself. See again Figure 7 During signal conditioning 702, the signal conditioning circuit is implemented to further bias the resistance of the force sensor 102 based on the resistance FSR2 of the second force sensor 202. Figures 11 to 13 Each example shows a hardware layout suitable for this function.

[0195] Figure 11 yes Figure 9 A variation of the transimpedance amplifier device, wherein a bias voltage V2 is coupled to the non-inverting input of amplifier 1102, and the bias voltage V2 is changed by the current sink through the resistor FSR2 of the second force sensor 202.

[0196] Figure 12 It shows Figure 9 Another variation of the device includes a transimpedance stage 1202 and another stage 1204, which is configured to inject a current proportional to the resistance FSR2 of the second force sensor 202 into the inverting input of stage 1202, thereby reducing the output voltage Vn as the resistance FSR2 increases. Figure 11 and Figure 12 The values ​​of the DC voltage V1 and the passive resistors R1 and R2 are set according to the power supply used and the desired dynamic range of the output voltage Vn.

[0197] Figure 13 Another variation is shown, in which the resistor FSR2 of the second force sensor 202 is positioned in the feedback loop of the transimpedance stage 1302. The gain of stage 1302 is proportional to the resistor FSR2, and therefore proportional to the pressure applied to the rear surface of the sensor assembly 200. Similarly, the resistor R1 is set according to the power supply used and the desired dynamic range of the output voltage Vn.

[0198] It should be understood that any of the above hardware solutions can be alternatively implemented in software, either in real time or after recording signals from two or more of sensors 102, 104, and 202.

[0199] It should also be understood that, in addition to calibrating the first sensor 102, the signal from the first sensor 102 can be used to determine muscle compliance, for example, to differentiate tissue (fat / muscle percentage, etc.). This measurement can be used to determine the amount of fat under the subject's skin.

[0200] As described above, in some embodiments, the displacement sensor 104 includes a piezoelectric sensor configured to generate a current in response to changes in displacement. In this case, it may be necessary to adjust or calibrate the DC offset and AC voltage swing of the signal output from the displacement sensor 104. For this purpose, the signal conditioning stage 702 implements, as shown in the example... Figure 14 , 15a The processing circuit shown in 15b is used to condition the signal output from the displacement sensor 104.

[0201] refer to Figure 14 The displacement sensor 104 (PZT) is polarized using a current source 1402 (which can be digitally controlled) to regulate the AC voltage swing caused by displacement changes. A subsequent voltage amplifier 1404 is provided to adjust the DC offset.

[0202] Figure 15a An exemplary implementation of signal conditioning 702 for displacement sensor 104 is shown. For example... Figure 14 As shown, current is injected into displacement sensor 104, and the resulting high-pass filtered signal V1 is provided to voltage amplifier stage 1502 to adjust the DC offset. Note that the feedback resistor R7 and input impedance R3 of the non-inverting input of amplifier stage 1502 are selected to match the impedance of displacement sensor 104 (PZT).

[0203] Figure 15b Another exemplary implementation of the signal conditioning circuit 1502 for the displacement sensor 104 is shown. (Refer to the accompanying drawings.) Figure 15a Unless otherwise specified, the same reference numerals denote the same parts. The signal conditioning circuit 1502 utilizes Miller's theorem based on the following equation to increase the signal transmitted by displacement.

[0204]

[0205]

[0206] Input impedance (RIN) detected by sensor 104:

[0207] This improves the overall low-frequency response of the signal conditioning circuit 1502 by reducing the high-pass cutoff frequency, which is chosen to reduce any potential phase shift introduced by the high-pass response, even at the lowest frequency of interest, i.e., the lower limit of the respiratory signal band, to aid in comparison with the signal from the force sensor 102. In some applications, the cutoff frequency is set in the range of approximately 0.01–0.05 Hz.

[0208] To enable the use of different displacement sensors 104 without requiring custom circuitry, the signal conditioning circuit 1502 can be adjusted based on the specific capacitance of the selected displacement sensor 104. Using surface mount device (SMD) resistors in a bootstrap configuration allows for smaller resistance values, thus reducing the cost of circuit 1502. As an example, a 100MΩ resistor R1, a 100Ω resistor R3, and a 100kΩ regulator R2 can be used in circuit 1502 such that when R2 is set to 0, displacement sensor 104 "sees" a 100MΩ impedance RIN (thus providing a 0.05Hz cutoff frequency for the 30nF capacitor of displacement sensor 104). By adjusting R2 to increase the fine-tuning resistance, RIN can be increased to 10¹¹Ω.

[0209] Refer again Figure 7 During the signal conditioning phase 702, a conditioned force signal Vn representing the force applied to the coupler 106 and a conditioned displacement signal Vd representing the displacement velocity at the coupler 106 are generated. Optionally, an acceleration signal Va representing the acceleration at the coupler 106 may also be generated. These analog signals are then converted into digital representations of force F, displacement velocity V, and acceleration A, respectively, using an analog-to-digital converter (ADC) stage 704 of one or more ADCs 708. In some embodiments, a single ADC 708 may be provided, with the conditioned signals Vn, Vd, and Va provided to the ADC via a multiplexer (not shown). In other embodiments, the conditioned signals Vn, Vd, and Va may be provided to a multiplexer such as... Figure 7 The standalone ADC 708 is shown.

[0210] The digital signals F, V, and A are then provided to a digital filter stage 706, which is configured to implement one or more filters 710, 712, 714, and 716 to filter the force, velocity, and (optionally) accelerometer signals F, V, and A, thereby generating one or more outputs representing the subject's physiological parameters. These parameters are specific to the location of components 100 and 200 on the living subject during the measurement. For example, when... Figures 3 to 5 When positioned on the subject's chest, as shown, the digital filter stage 706 is operable to extract data related to cardiac activity (e.g., choreographed heartbeats, heart sounds, etc.) in addition to respiration and pulse-cardiography. By positioning components 100 and 200 on the wrist, the digital filter stage 706 is only able to extract data related to respiration and blood pulse.

[0211] The respiratory signal 720 from the subject is extracted by low-pass filtering the force signal F using a low-pass filter 710. The low-pass filter 710 may, for example, have a low-pass threshold of approximately 0.5 Hz.

[0212] A pulse signal is generated from the force signal F by bandpass filtering using a bandpass filter 712. The bandpass filter may, for example, have a passband between approximately 0.5 Hz and approximately 8 Hz.

[0213] By employing another bandpass filter 714 to bandpass filter the signals F and V, force and velocity parameters specific to the monitored living organ are extracted from each of the force and velocity signals F and V, respectively. For example, for the force and velocity parameters of the heart, the bandpass filter 714 may have a passband between approximately 8 Hz and approximately 40 Hz.

[0214] Using a bandpass filter 716, body sounds can also be extracted from force and velocity signals F and V. This bandpass filter 716 has a lower threshold of approximately 20 Hz, approximately 30 Hz, approximately 40 Hz, or approximately 50 Hz, and an upper threshold typically of approximately 150 Hz, which reaches approximately 5000 Hz in certain applications, namely wheezing, crackles, and snoring. Acoustic analysis of wheezing is clinically important because it is the sound produced by airflow through abnormally narrowed or compressed airways. Timely identification and intervention of early-onset asthma from wheezing can reduce the risk of long-term disease. Early detection and treatment of these sounds are expected to reduce the prevalence of symptoms and improve health-related quality of life. Sound analysis and timing of crackle sounds are also important because these sounds allow clinicians to confirm whether a patient or subject has severe airway obstruction (early inspiratory / expiratory crackles), restrictive lung diseases such as pulmonary fibrosis and interstitial pulmonary edema (late inspiratory crackles), and left ventricular failure (inspiratory crackles). Acoustic analysis of these snoring sounds is clinically important in examining sleep characteristics, breathing disturbances, and other detectable abnormalities in subjects. Key applications include, but are not limited to, predicting surgical outcomes, assessing snoring before and after treatment intervention, and distinguishing primary snoring from obstructive sleep apnea (OSA). These can be used to study snoring in adult and pediatric patients. Early identification of these sounds allows clinicians to recognize abnormalities early, as early diagnosis and treatment will allow patients to reduce their risk of cardiovascular disease. Further benefits of early treatment include saving or avoiding more expensive future treatments, such as the use of ventricular assist devices, which may have to be implanted for severe heart failure potentially caused by OSA. In some embodiments, the bandpass filter 716 may have a passband between approximately 40 Hz, approximately 300 Hz, and even 5000 Hz. Depending on the position of the sensor assemblies 100 and 200, body sounds may include one or more of the following: heart sounds (e.g., blood rushing, valve movement), bowel sounds (e.g., gas replacement), breathing, snoring, swallowing, and fetal sounds (including fetal movement, fetal heart sounds, fetal breathing, fetal gas replacement, etc.), and muscle contractions around the airway (e.g., trachea).

[0215] Airway reduction can be monitored by changes in the sound emitted from the neck region. For example, wheezing or higher-pitched sounds or vibrations in the neck can indicate insufficient breathing (partial reduction in respiration), sleep apnea, asthma, and other lung and respiratory conditions. See below for reference. Figure 23 The body sounds discussed can also be extracted from the signals received from the accelerometer 120. Body sounds can be generated based on two or more of the force, velocity, and acceleration signals F, V, and A.

[0216] The extracted body sounds can be output to one or more speakers or headphones for hearing by a clinician. Thus, sensor assemblies 100, 200 can be used as digital stethoscopes providing a high-definition digital representation of the body sounds. The extracted body sounds can be modulated and / or shifted in frequency to make them more easily heard by the human ear. For example, the extracted body sounds can be shifted in frequency to the center of the human hearing range.

[0217] It should be noted that the various filters 710, 712, 714, and 716 of the digital filter stage 706 are provided only as examples of filters that can be implemented to extract information from force and velocity signals F and V. Depending on the physiological parameters to be extracted and the location of components 100 and 200 on the subject, one or more of filters 710, 712, 714, 716, and 718 may be omitted or other filters may be added.

[0218] With multiple sensor components positioned at different locations on the subject, each of the force, velocity, and accelerometer signals generated from these components can be compared with the above reference. Figure 7 Similar descriptive methods are filtered. For example, where the same reference numerals denote the same parts. Figure 16 As shown, the digital force, velocity, and acceleration signals F1-FN, V1-VN, and A1-AN can be provided to the digital filter stage 1606 from N sensor assemblies 1602 and 1604, respectively. For simplicity, the sensor assemblies 1602 and 1604 include signal conditioning and A / D conversion circuitry for generating the force, velocity, and acceleration signals.

[0219] In addition to filtering individual force and velocity signals from one or more sensor components 1602, 1604, the digital filter bank 1606 is also configured to combine force and / or velocity signals from two or more sensor components 1602, 1604 before or after filtering. For example, the filter bank 1606 may include a bandpass filter and a combining module 1608 configured to combine force signals F1, FN from two of the sensor components 1602, 1604 located at different positions on the subject to generate a blood pressure signal 1610. Signals F1, FN may be bandpass filtered before being combined, or the signals may be combined and a bandpass filter may be applied to the combined signals to generate the blood pressure signal 1610.

[0220] The filter bank 1606 is configured to combine any combination of signals received before or after filtering in any manner without departing from the scope of this disclosure.

[0221] Considering the above, Figure 17 Figures 20-25 illustrate various signals extracted by exemplary sensor assemblies 100, 200 fixed at various locations on human subjects.

[0222] Figure 17 The illustration shows the sternum positioned at the xiphoid process and secured by a belt 304 on the subject's sternum. Figure 3 The sensor assembly 300 acquires the extracted force signal 1702. The corresponding ECG signal 1704, measured simultaneously, is also shown for comparison. It can be seen that various cardiac parameters, including but not limited to the P wave component 1706, QRS complex 1708, and T wave component 1710, can be identified in the force signal 1702. Thus, the sensor assembly 300 can be used to diagnose conditions such as arrhythmias (e.g., atrial fibrillation). Additional parameters can also be extracted from the force signal 1702, including the duration of each phase of the cardiac cycle, the opening and closing times of the heart valves 1712 and 1714, the level of cardiac contractility, stroke volume, cardiac output, and pulse conduction time.

[0223] Figure 18 The illustration shows a point at or near the xiphoid process, similar to... Figure 3 The extracted force signal 1802 is acquired by the sensor assembly shown, which is positioned in a similar location where an adhesive patch is used instead of a belt 304. The corresponding measured ECG signal 1804 is also shown for comparison. It can be seen that, similar to... Figure 17 Force signal 1802 provides various cardiac indications corresponding to ECG signal 1804.

[0224] Figure 19 The diagram illustrates combined signal 1902, which is composed of... Figure 4The algebraic sum of force signals generated by the force sensors of the sensor assembly 402 shown, with one sensor assembly 404 placed on or near the suprasternal notch in the upper chest and another sensor assembly 402 placed on or near the apex of the heart in the lower chest, is also provided for reference. A corresponding ECG signal 1904 obtained by using a coupler 106 configured as a conductive dome as an ECG electrode is also provided for reference. It can be seen that the synthesized combined signal 1902 represents an estimate of the central arterial pressure through the heart, from which various parameters, including peak reflected waves and emitted waves P1, P2, can be estimated. Therefore, it should be understood that differential measurements of force and / or velocity using the sensor assemblies described herein can determine the blood pressure gradient between different parts of the subject, not just the central arterial pressure. For example, measurements of force and / or velocity using two or more sensor assemblies at the suprasternal notch and femoral artery (or subclavian artery or other peripheral arteries) can be compared to determine peripheral blood pressure.

[0225] Figure 20 The diagram illustrates the force signal 2002 generated from the force sensor 102 (FSR) of the sensor assembly 100 and the force signal 2002 generated from the sensor located at, for example, Figure 3 The figure shows the integral signal 2004 of the displacement velocity signal generated by the displacement sensor 104 (PZT) of the sensor assembly 100 at or near the xiphoid process. The figure illustrates the fundamental similarity between the integral 2004 of the velocity signal and the force signal 2002, where velocity is the first derivative of force and displacement. Therefore, it can be seen that the force signal 2002 can be used to calibrate the velocity signal 2004 in real time before sensor operation or during monitoring to address sensor drift, especially when using a piezoelectric sensor. Figure 20 It can also be seen that the P-wave is visible in both the force signal 2002 and the integral signal 2004, highlighted by the corresponding circles 2006 and 2008 in the figure. Additionally, a double-peak notch can also be observed in both signals 2002 and 2004. Figure 20 Each figure is highlighted with large arrows indicating 2010 and 2012.

[0226] Figure 21 The diagram illustrates the force signal 2102 generated from the force sensor (FSR) and the displacement velocity signal 2104 generated from the displacement sensor (PZT) of the sensor assembly 602 located at or near the radial artery on the wrist 604 of the subject 300, as shown in Figure 6. A corresponding ECG signal 2106 is also shown for comparison. Circles in each figure highlight the visible p-wave measured in each signal 2102, 2104, 2106. Large arrows indicate biphasic notches in each force and velocity signal 2102, 2104. Figure 20 It can be seen that the P wave can be observed from the force and velocity signals 2102 and 2104 received at wrist 604.

[0227] Figure 22 The diagram illustrates low-pass filtering, for example, using the reference above. Figure 7 The low-pass filter 710 described extracts respiratory signals 2102 and 2104 from the corresponding force and ECG signals 2106 and 2108.

[0228] As described above, sensor assemblies 100 and 200 may be provided with one or more accelerometers configured to measure the acceleration of sensor assemblies 100 and 200. Figure 23 The diagram illustrates the accelerometer signal 2302 obtained from accelerometer 120 and the signal from accelerometer 120 located at... Figure 3 The force signal 2304 obtained by the force sensor 102 of the sensor assembly 100 at or near the xiphoid process is shown. For comparison, recorded heart sounds 2306, photoplethysmography (PPG) 2308, and ECG 2310 signals are also shown. It can be seen from this figure that the signal 2302 received at the accelerometer 120 has similar characteristics to the recorded heart sound signal 2306, which has similar features. Thus, it can be seen that the accelerometer 2302 can be used to generate sound signals representing body sounds, as shown above. Figure 7 As stated above.

[0229] Figure 24 The diagram shows from Figure 1a The raw data extracted by sensor component 100. Figure 24 In the diagram, ECG signal 2402 is provided as a reference, trace 2404 shows five respiratory cycles recorded by displacement sensor 104, and trace 2406 shows five respiratory cycles recorded by force sensor 102.

[0230] Similar to Figure 23 , Figure 25a The diagram shows from Figure 1a The sensor assembly 100 extracts sound and electrocardiogram data. In Figure 25, trace 2502 represents the raw data from force sensor 102 after respiratory artifacts have been filtered out from the signal, and trace 2504 represents the raw data from displacement sensor 104 after respiratory artifacts have been removed. Trace 2506 is used... Figure 7 The signal conditioning circuit extracts the echocardiogram from the displacement sensor 104. Trace 2508 is the acoustic pattern extracted from the displacement sensor 104. Trace 2510 is the ECG signal provided for comparison purposes. Therefore, it can be seen that, with appropriate signal conditioning, signals representing body sounds and providing an echocardiogram can be extracted from the displacement sensor 104 without the need for an ECG device. Thus, subjects wearing sensor assemblies 100 and 200 can be monitored while engaged in activity, without waiting for the activity to complete or attaching an ECG device to the subject's body.

[0231] Figure 25b It shows from Figure 1e The sensor assembly 400 shown or Figure 6b The two graphs extracted by sensor devices 610 and 650 shown in diagram 6c are as follows. The upper graph 2520 shows the force and displacement signals generated by force sensor 102 and displacement sensor 104, in which case force sensor 102 is an FSR and displacement sensor 104 is a piezoelectric sensor actuated by the finger 612 of the subject 300. The lower graph 2522 shows the red and infrared light signals from an optical sensor, in this case, PPG sensors 402 and 614 placed against the finger 612. It should be understood that there is a direct correlation between the optical data in the lower graph 2522 and the displacement data obtained from displacement sensor 104 in the upper graph 2520.

[0232] The optical signal represented by graph 2522 can be used to calculate blood oxygen saturation at the locations of PPG sensors 402 and 614. Alternatively, PPG sensors 402 and 614 can be used in place of one or both of force sensor 102 and displacement sensor 104 to allow heart rate tracking. The post-FSR signal is not shown in this example, and only red and infrared light signals are shown because these signals have been found to enhance the accurate calculation of blood oxygen saturation.

[0233] Figure 26 and Figure 27 These are, respectively, a cross-sectional view and a plan view of a sensor assembly 2300, which includes a flexible sensor 2302 at least partially encapsulated in a flexible carrier layer 2304. Figure 1a Similar to the force sensor 102 of component 100, the force sensor 2302 may be an FSR, whose impedance changes as the flexible sensor 2302 is bent or flexed. The flexible carrier layer 2304 is flexible, thereby enabling the sensor 2302 to conform to the curvature of the surface of the subject on which the sensor 2302 is applied.

[0234] The flexible carrier layer 2304 is preferably made of a material that, while flexible, is substantially not stretchable in a direction perpendicular to the surface of the subject to which the layer 2304 can be adhered. Thus, bending of the carrier layer 2304, and therefore the flexible sensor 2302, results in a change in the resistance of the flexible sensor 2302 (at FSR), or a change in the characteristics of the flexible sensor 2302. The sensor assembly 2300 also includes a securing device 2306 for holding the sensor assembly 2300 in place relative to the subject. For example, the securing device 2306 is an anchor point for attaching the sensor assembly 2300 to a carrier (e.g., clothing worn by the subject). The clothing can be a shirt, strip, belt, vest, etc. Similarly, the sensor assembly 2300 can be worn in a pocket of clothing without the securing device 2306. Any adjustment or signal processing modules or circuits described above with respect to sensor assemblies 100, 200 can also be used to adjust or generate signals from the flexible sensor 2302.

[0235] In use, the sensor assembly 2300 is positioned at a fixed location on the surface of the subject 2500, the surface having a radius of curvature that varies over time. For example, as Figure 28 As shown, the sensor assembly 2300 is fixed to the chest of the subject 2500. During breathing, the expansion of the ribcage causes the flexible sensor 2302 to bend, thereby changing the characteristics (resistance or other) of the flexible sensor 2302.

[0236] Figure 29 The illustration shows a clear, periodic respiratory signal generated from the flexible sensor 2302 of the sensor assembly 2300, which is integrated into, for example... Figure 28 The seam of the shirt worn by subject 2500 is shown.

[0237] Figure 30 A schematic cross-sectional view of sensor assembly 2700 is shown, which is a variation of sensor assembly 2300, wherein, with reference to Figure 26 and 27 Unless otherwise specified, the same reference numerals denote the same parts. Sensor assembly 2700 also includes a flexible displacement sensor 2702 configured to generate a velocity signal representing the velocity or displacement rate of sensor 2702. Displacement sensor 2702 is coupled to the rear surface of flexible carrier layer 2304. Displacement sensor 2702 is optionally at least partially encapsulated in the additional flexible carrier layer 2704. In one embodiment, displacement sensor 2702 is a piezoelectric sensor.

[0238] Figure 31 A schematic cross-sectional view of sensor assembly 2800 is shown, which is a variation of sensor assembly 2700, wherein, with reference to Figure 30 Unless otherwise specified, the same reference numerals denote the same parts. Sensor assembly 2800 also includes components mounted on a similar... Figure 1b A second force sensor 2802 is shown on the displacement sensor 2702 of the force sensor 202 of the component 200. Optionally, the second force sensor 2802 is at least partially encapsulated in a flexible carrier layer 2304 similar to that of the sensor component 2700. Similar to the force sensor 202, the force sensor 2802 changes its resistance when an external pressure is applied to the component 2800. Therefore, this externally applied force (and associated artifacts) can be taken into account, and the flexible sensor 2302 can be calibrated accordingly.

[0239] The operation of sensor assemblies 2700 and 2800 is similar to that of the corresponding sensor assemblies 100 and 200, so they will not be described in detail here.

[0240] Figure 32 and Figure 33 Sensor assemblies 100 and 200 are shown to be used to measure pulse conduction time (PTT) and the change in PTT as the subject's blood pressure increases.

[0241] Sensor assemblies 100 and 200 are placed on the chest wall of a healthy subject and on the subject's right common iliac artery. Trace 3202 represents the pulse velocity detected by displacement sensor 104 at the iliac crest after removing respiratory artifacts, and trace 3204 represents the pulse velocity detected by displacement sensor 104 near the apex of the subject after removing respiratory artifacts at the subject's chest wall.

[0242] exist Figure 32 Traces 3202 and 3204 were measured before the subjects performed the exercise, more specifically, push-ups. Notably, based on resting blood pressure of 123 / 68 healthy subjects, the iliac crest-apex lag was approximately 146 ms before the subjects began exercising. Figure 33 The study showed a significant reduction in PTT hysteresis after exercise, with the subject's blood pressure rising to 144 / 79. Iliac crest-apex hysteresis decreased to approximately 59 ms after exercise. This indicates that sensor assemblies 100 and 200 are capable of detecting PTT when attached to the subject.

[0243] Figures 34-36 The use of sensor assemblies 100 and 200 to measure cardiac activity, and more specifically, to measure the stroke volume of healthy subjects during exercise. Figure 34 Various parameters of healthy subjects at rest are shown. Figure 35 The parameters of the subjects performing the weightlifting at the first low rate are shown, while Figure 36The same parameters were shown for subjects lifting weights at the second highest rate.

[0244] In this test, sensor assemblies 100 and 200 were attached to the subject's chest wall. The subject was then asked to lift weights at two different rates to achieve two different levels of effort. In these graphs, trace 3402 represents a low-frequency force electrocardiogram (FCG) measured by force sensor 102 of sensor assemblies 100 and 200. Trace 3404 represents a high-frequency FCG measured by force sensor 102 of sensor assemblies 100 and 200. Trace 3406 represents respiratory effort measured by displacement sensor 104 of sensor assemblies 100 and 200. Trace 3408 represents a standard ECG and is used for comparison.

[0245] The results clearly demonstrate a consistent increase in the amplitude of both low-frequency and high-frequency FCGs, proportional to the subjects' cardiac exertion levels. Specifically, regarding FCG values ​​measured before exercise, the amplitude of the low-frequency FCG doubled in response to lifting at a low rate and tripled in response to lifting at a higher rate. Conversely, the high-frequency FCG, known to be highly correlated with the echocardiogram extracted by displacement sensor 104, increased by approximately 1.5 times in response to lifting at a low rate and almost doubled in response to lifting at a higher rate. These results demonstrate that the two FCG components carry different information about cardiac mechanics, with the low-frequency FCG being more correlated with stroke volume than the high-frequency FCG.

[0246] Figure 37 Two graphs, 3702 and 3704, are shown. Graph 3702 represents the sound recorded by a conventional Littman electronic (digital) stethoscope, and graph 3704 represents the sound recorded by sensor assemblies 100 and 200, each placed on the subject's chest. Graph 3704 is the result of a scalar multiplication of the signals generated by force sensors 102 and 202 and the signal generated by displacement sensor 104, producing a signal with minimized or completely avoided additional modulation. "S1" and "S2" identify portions of signals 3702 and 3704 indicating typical heart sounds. The first heart sound, commonly referred to as S1 or "lub," is caused by the turbulence generated by the closure of the mitral and tricuspid valves at the beginning of systole. The second heart sound, commonly referred to as S2 or "dub," is caused by the closure of the aortic and pulmonary valves, marked at end-systole.

[0247] Figures 38A and 38B are block diagrams illustrating the use of sensor components 100 and 200 to detect sound. Only component 100 is shown in these figures; however, it should be understood that component 200 can also be used as shown.

[0248] Figure 38A, and similarly, Figure 38B, illustrates two method branches 3802 and 3804, each employing bandpass filtering only in steps 3806 and 3808. It should be understood that other filters are also suitable, and within the scope of this disclosure, such as higher-order filters, to allow sound extraction using components 100 and 200. As shown in step 3810, the force and displacement signals generated by sensors 110 and 104 can be processed after filtering and normalization, for example, by scalar multiplication, to enhance sound clarity or otherwise improve the signal-to-noise ratio. In step 3812, the sound output can be modulated using a user-defined pitch as a carrier, for example, amplitude modulation, wherein the user-defined pitch is perceptible within the human auditory bandwidth (e.g., 200 Hz), thereby allowing auscultation in environments with high levels of background noise.

[0249] Figures 39A and 39B are block diagrams of a system 3900 configured to allow identification of a subject. System 3900 is shown to include component 200. In other embodiments, system 3900 additionally or optionally includes component 100. System 3900 is configured to receive raw signals generated by force sensors 102, 202 and displacement sensor 104 of components 100, 200 in response to a subject (person) at contact coupler 106, and process these signals to identify the subject. Figure 39C shows a flowchart of using machine learning to update comparative signals for identifying the subject. The process can begin by acquiring signals / data, where the data can be divided into predetermined percentages for training or testing. In this particular embodiment, 80% of the acquired data can be allocated to the machine to be trained, and this can be training data. Another 20% of the acquired data can be allocated to the machine for testing, and this can be test data. It is understood that the predetermined percentages used for training and testing can vary. The trained data can be formed into a training model by classifying continuous or discrete variables using the following parameters. The trained model can then be moved to the test model, where it is used on a different percentage of the test data. The suitability of the test model can be evaluated using a confusion matrix. This matrix compares the actual target values ​​with those predicted by the machine learning model. The model's error can be assessed using RMSE or root mean square calculations on the predicted quantitative data.

[0250] It should be understood that identification of a specific person can be achieved by utilizing a processor to identify one or more unique physiological signals or unique portions of signals (e.g., signals generated in response to a person operating sensor components 100, 200). Examples of related ECG-based methods are disclosed in “Individual Identification by Electrocardiogram Analysis” by Antonio Fratini, Mario Sansone, Paolo Bifulco, and Mario Cesarelli, published in Biomedical Engineering Online on August 14, 2015 (Fratini et al., BioMed Eng OnLine (2015) 14:78, DOI 10.1186 / s12938-015-0072-y).

[0251] Unique physiological signals or aspects of signals may be stored in memory. These signals may be generated in response to user contact with sensor components 100, 200 of system 3900, or obtained using alternative systems or devices. The temporal, frequency, and morphological characteristics of signals generated in response to a subject operating components 100, 200 may be compared by a processor with samples stored in memory to allow identification of the subject. This may include determining identification based on at least one standardized historical signal of the same subject stored in memory. In some embodiments, system 3900 includes at least one of an optical plethysmography sensor configured to generate an optical plethysmography signal and a pair of electrocardiogram electrodes configured to generate an electrocardiogram signal. In such embodiments, subject identification may be based on a combination of at least two standardized historical signals of the same subject stored in memory. A morphological point worn or attached by the user may communicate with a morphological band and force sensor in the device. While the morphological point may require contact with the user's fingers, it may also advantageously include an accelerometer for determining the user's position and / or movement during use in order to obtain vital signs of the user, in the event of an emergency. This location information is important, especially for elderly patients, as it indicates whether the subject has suddenly fallen or is in a resting, lying position. In the event of a sudden fall, the morphological point can communicate or issue an alarm to caregivers or the person responsible for the patient or subject. If the fall causes the user to lose consciousness, the alarm can sound even without the user's finger touching the morphological point. This is advantageous because it alerts someone and allows for immediate care of the subject, even if the subject is alone or unrestrained at the time of the event.

[0252] Operating system 3900 may involve a person manually applying a coded pattern of touch or force to components 100, 200, for example, varying the pressure and / or contact duration over a defined time period, as described in more detail below. The coded pattern may be stored in memory as a specifically configured password or other authentication code, allowing or triggering further actions, such as access to a digital or physical environment. For example, a processor may be configured to recognize specific patterns that trigger emergency alarm beacons. In some embodiments, as shown in FIG39, system 3900 is configured to provide feedback to the user in a “closed-loop” manner via coded vibrations, for example, induced in sensor components 100, 200 by operating displacement sensor 104, which in this embodiment is a piezoelectric element. This feedback is typically configured to allow the user to perceive the identified coded pattern and authorized further actions.

[0253] Figure 40 Embodiments of sensor assemblies 100, 200 are illustrated, which are configured to identify a subject and generate signals using components 100, 200 disposed at or near the subject's fingertip 4002. The subject can be identified in response to a single or combination of unique aspects (e.g., specific peaks and troughs) of the generated signals.

[0254] Figure 40 The illustrated embodiment can be operated by placing the finger 4004 in contact with the palm side to cause components 100, 200 to generate signals, thereby identifying the subject. This embodiment typically includes sensor components 100, 200 connected to a battery (not shown) and a computer module (not shown), the computer module being configured to process, store, and transmit signals to another computing device such as a PC, smartphone, or hub, or to a remote host server (“cloud computer”) for comparison with a signal database, for example via Bluetooth or Wi-Fi wireless communication protocols.

[0255] In some embodiments, components 100, 200 may be embedded in a device or structure, such as a keyboard key, a smartphone screen, or a furniture area, and / or disposed on the subject. This can allow digitally authorized actions, such as securely turning an electric device, such as a vehicle, computer, or mobile phone, or granting access to a building or area. The method can also authorize access to digital systems that require a level of security exceeding that of conventional manual or biometric authorization, or alternatives to conventional manual or biometric authorization, such as passwords, text codes, fingerprints, eye scans, or facial recognition methods.

[0256] operate Figure 40Embodiments of components 100 and 200 shown may involve a subject manually adjusting one or more of the following: pressure / force applied to components 100 and 200; duration of contact with components 100 and 200; or achieving intermittent contact with components 100 and 200, for example, a specific contact pulse within a defined period. When operated in this manner, this embodiment of components 100 and 200 is configured to detect one or more defined modes of force and thus perform further actions, which may allow for additional levels of safety. For example, the method may authorize, for instance, sending an alarm signal to another electronic device or system after an event such as a decline or adverse change in health status.

[0257] operate Figure 40 Embodiments of components 100 and 200 shown may include a subject manually and intermittently contacting the coupler 106 with the palmar side of their fingers, such that the resulting force and / or displacement signals, or analysis and recording of the signals (e.g., heart rate, respiratory rate, or blood pressure), are transmitted to another device or system. For example, in some embodiments, data may be transmitted to individuals or groups located remotely from the subject to prompt action in response to adverse changes in health status.

[0258] Figures 41a to 41c The graphs of force signals 4102, 4104 and displacement signal 4106 are shown, from which force signals 4102, 4104 and displacement signal 4106 originate. Figure 40 The components 100 and 200 shown in the embodiments are obtained and operated by a subject who intermittently contacts the components 100 and 200 to generate a pulse signal, as described above. Signals 4102, 4104, and 4106 may be unique or define unique aspects individually or in combination, and thus allow processing to identify the subject.

[0259] Figure 42A shows from Figure 40 The embodiments of components 100 and 200 shown produce three graphs of signals 4202, 4204, and 4206, operated by three different subjects who intermittently contact components 100 and 200 to generate three pulse signals, as described above. As shown in Figure 42A, each subject generates a unique signal graph, which can be processed to allow for subject identification. For example, a particular subject may cause variations in any of the following: pulse width, the presence and timing of a biphasic notch, and the amplitude of the signal peak.

[0260] Figure 42B illustrates another arrangement in which a single sensor assembly 610 is fixed relative to a subject's finger 612, typically held in place by a releasable or elastically deformable mechanism (e.g., a band or sleeve (not shown)). It should be understood that the assembly 610 shown fixed to the finger 612 is merely exemplary, and the assembly 610 may be configured to be fixed to other parts of the subject's body 300. The sensor assembly 610 includes a sensor 100 adjacent to an optical sensor arrangement, in this embodiment a multicolor PPG sensor 614. In other embodiments (not shown), a pulse oximetry sensor is additionally or alternatively arranged to the PPG sensor 614. This arrangement allows for the simultaneous collection of blood volume signals from individual sensors 100, 614 located on the same side of the assembly 610 to sense the position of adjacent arrangements on the finger. Figure 42C illustrates another arrangement in which a single sensor assembly 650 is fixed relative to a subject's finger 612, typically held in place by a releasable or elastically deformable mechanism (e.g., a band or sleeve (not shown)). It should be understood that the component 650 shown attached to the finger 612 is merely exemplary, and the component 650 may be configured to be attached to other parts of the subject's body 300. The sensor component 650 includes a sensor 100 arranged opposite the optical sensor, which in this embodiment is a multicolor PPG sensor 614. In other embodiments (not shown), a pulse oximetry sensor is additionally or alternatively arranged to the PPG sensor 614. This arrangement allows for the simultaneous collection of blood volume signals from separate sensors 100, 614 located on opposite sides of the finger 612.

[0261] Figures 43a to 43d Various methods are illustrated for applying a finger to a rear coupler to measure the pulse conduction time from above the heart to the fingertip. When the pulse signal / pressure wave received from the finger is compared to a forward force sensor located above the heart, the timing difference between the signals is the pulse conduction time of the cardiac signal from the user's heart to the finger. The speed of arterial pressure wave propagation (or timing over a fixed distance) is proportional to blood pressure.

[0262] Figure 43a It shows according to Figure 1d The components are applied to the fingers 113 on the rear coupler 111 in the form of an auxiliary air pressure mound. A pulse response can be detected by a back force sensor 202 having a disconnect gap 4302, which can be easily created to allow the back force sensor to be mounted in a flap or door. Figure 1c The front sensor assembly senses signals from the skin surface 4301 on the heart.

[0263] Figure 43b It shows according to Figure 1bTwo separate sensor components, one located on the chest 4301 and the other on the finger 113.

[0264] Figure 43c Another structure is shown, wherein the embodiment on finger 113 does not include, as Figure 1c The back force sensor shown.

[0265] Figure 43d Another arrangement is shown in which the sensor assembly on finger 113 is only the forward force sensor assembly 4303 and does not include displacement sensors 114, 104, 116.

[0266] Figure 44 It shows that simultaneously from Figure 43a The embodiments recorded various signals, including ECG 4404, displacement sensor 4405, forward force sensor 4406, force sensor from the finger, and gold standard blood pressure signal from the finger 4407. The timing difference between two pulses allows for the measurement of pulse conduction time 4401. In this case, two force sensors are located on one device, with the forward force sensor above the chest and the finger on the back force sensor, disconnected from the forward sensor. This embodiment measures the pulse conduction time 4401 from the chest to the fingertip. It should be noted that the time from the ECG to the peripheral site measurement is called the pulse arrival time (PAT) 4402 and includes the pre-ejection phase (PEP) 4403; therefore, PAT is the R wave to the second site with the pulse wave, PTT is the pulse wave arriving at the pulse wave, and the difference is calculated as PAT - PTT = PEP.

[0267] Figure 45 A comparison of signals from the arm and chest using piezoelectric sensor 4504 and force sensor 4505 is shown. These are compared to an ECG signal (4503) and a blood pressure signal (4506) from a finger. Signals are periodically highlighted, displaying the PAT (Packet Attack) of the chest 4501 and arm 4502 signals.

[0268] Figure 46a Two sensors are shown located on the chest, one above the apex of the heart 4601 and the second above the suprasternal notch / aortic arch 4602. Figure 46b It shows that simultaneously from Figure 46a The embodiments recorded various signals, including an ECG 4603, a displacement sensor 4604, a forward force sensor 4605, and a gold-standard blood pressure signal from a finger 4606, allowing measurement of the delay between trigger (R peak on the ECG) and apical movement 4607, and also measuring the delay between the apex and aortic arch ejection time 4608. The resulting PAT gives the measurement of central blood pressure.

[0269] Figure 47a Signals from ECG 4701, piezoelectric sensor 4702, force sensor 4703, and finger BP monitor 4704 are shown. Various artifacts are present in breathing 4705 and movement 4706. Figure 47b Signals 4707, 4708, and 4709, which have had artifacts removed, are shown, revealing a similar shape of the signal. If the piezoelectric and force sensor signals are calibrated against a single beat from a finger blood pressure monitor (systolic and diastolic components) 4710, the piezoelectric or force sensor can be used for ongoing blood pressure measurements.

[0270] Figure 48a An embodiment is shown where a back force sensor 4801 is connected to an anterior skin 4806 in contact with a force sensor 4803 and a piezoelectric sensor 4802. The assembled sensors can be calibrated by measuring the back force (FSR), applying calibration mass, and / or progressive calibration force, in grams per Newton (g / Newton). Net force can be used to calibrate the piezoelectric sensor. Once the large DC component has been analogously removed, a higher recording gain can be achieved using a back FSR.

[0271] The difference between the calibrated DC component of the force measured by the anterior FSR 4804 and the DC component of the force measured by the posterior FSR 4805 provides an indication of body region / tissue compliance. Figure 48b This difference in compliance 4809″ is shown between the chest 4807 and the wrist 4808.

[0272] One or more sensor components described herein can be integrated into a medical device in any combination for in-situ monitoring of a subject under various conditions. For example, these sensor components can be mounted in or on a mattress, chair, or seat; a car seatbelt or steering wheel; an animal collar, leash, attached patch, harness, or ear tag; and configured to monitor one of several physiological parameters of the subject (e.g., any of those described above). Furthermore, the sensor components can be configured to detect and monitor the movement and position of the subject relative to the sensor components on a seat, bed, or mattress. Such monitoring is advantageous in preventing pressure sores (where the sensor components are integrated into the mattress, etc.).

[0273] It should be understood that the embodiments of this disclosure can be used to diagnose and monitor a variety of human and animal diseases and conditions, wherein such diseases and conditions can be diagnosed and monitored by measuring the force, displacement, and / or acceleration of the skin. Non-limiting examples of cardiac conditions and diseases include benign murmurs, sclerosis, hypertension, angina pectoris, myocardial infarction, ventricular aneurysm, mitral valve prolapse (MVP), isolated short murmurs and murmurs, mitral regurgitation, mitral stenosis (MS), tricuspid regurgitation (TR), mitral regurgitation, aortic regurgitation, aortic stenosis, hypertrophic obstructive cardiomyopathy, cardiomyopathy, pericarditis, pulmonary hypertension, atrial septal defect, ventricular septal defect, patent ductus arteriosus, pulmonary stenosis, aortic coarctation, tetralogy of Fallot, coronary artery disease, heart failure, cardiac asynchrony, systolic heart failure, diastolic heart failure, pulmonary embolism, cor pulmonale, arterial stiffness, etc.

[0274] It can also diagnose lung diseases and lung conditions, including pulmonary congestion. Embodiments of this disclosure can also be used to diagnose and monitor sleep disorders, such as sleep apnea, for example by placing one or more sensor components as described herein at or near the trachea or in other locations around the subject's neck. The sensor components can be configured to monitor snoring, swallowing, muscle contractions around the airway (e.g., the trachea), and, optionally, reduction in size within the airway, in addition to breathing.

[0275] Arterial and / or venous conditions (calcification, collapse, etc.) can be diagnosed and monitored by placing one or more sensor components described herein on or near the artery or vein to be monitored on a subject. In some embodiments, for example, the sensor components may be positioned bilaterally at the left and right arteries of both arms or legs, or at the respective left and right arteries of one arm and one leg, and comparisons can be made between the left and right arteries in different limbs to determine the condition of one or the other artery (or both).

[0276] In any of the above embodiments, the sensor components can be integrated into the wearable device for short-term or long-term use, and can collect and store force, velocity and / or acceleration measurements, thereby enabling, for example, remote health consultation or real-time monitoring of symptoms and diseases over time.

[0277] The sensor assembly described herein can also be used to monitor uterine contractions during pregnancy. Pregnant subjects can wear one or more sensor assemblies at a location on the skin near the uterus; contractions cause force displacement of the skin, and the corresponding signals are derived from force and displacement sensors and, optionally, an accelerometer within the sensor assembly.

[0278] The sensor components described herein can be used not only to measure, diagnose, and monitor human or animal subjects, but also to monitor fetal activity in these subjects. For example, one or more sensor components, such as sensor components 100, 200, can be placed in a location around the stomach to monitor fetal movement, respiration, and cardiac signals in the uterus of an animal or human subject in a manner similar to that described above with reference to the human or animal subject itself. By comparing fetal signals (e.g., movement and / or heart rate) with other sensors positioned to measure maternal signals, changes in fetal signals can be correlated with changes in maternal signals (e.g., blood pressure in a mother at risk of preeclampsia).

[0279] In the embodiments described herein, particularly with reference to Figures 3 to 5 The sensor assembly is fixed to the front of the torso. For example, Figure 4 A sensor assembly is shown in a frontal auscultation position. It should be understood that one or more sensor assemblies can be attached to the back of the torso of an animal or human subject, for example, in a standard auscultation position on the back of the torso, without departing from the scope of this disclosure.

[0280] In particular, those skilled in the art should understand that, with the benefit of this disclosure, the various operations described herein, especially those described in conjunction with the accompanying drawings, can be implemented by other circuitry or other hardware components. The order in which each operation of a given method is performed can be changed, and various elements of the system shown herein can be added, reordered, combined, omitted, modified, etc. This disclosure is intended to encompass all such modifications and changes, and therefore, the above description should be considered illustrative rather than restrictive.

[0281] Similarly, although this disclosure refers to specific embodiments, certain modifications and changes may be made to these embodiments without departing from the scope and coverage of this disclosure. Furthermore, any benefits, advantages, or solutions to problems described herein with reference to specific embodiments are not intended to be construed as critical, essential, or necessary features or elements.

[0282] Similarly, other embodiments benefiting from this disclosure will be readily understood by those skilled in the art, and such embodiments should be considered to be included herein.

[0283] For many applications, embodiments can be implemented on DSPs (Digital Signal Processors), ASICs (Application-Specific Integrated Circuits), or FPGAs (Field-Programmable Gate Arrays). Therefore, the code can include conventional program code or microcode, or code for setting up or controlling the ASIC or FPGA, for example. The code can also include code for dynamically configuring reconfigurable devices such as reprogrammable logic gate arrays. Similarly, the code can include code for hardware description languages ​​such as Verilog™ or VHDL (Very High Speed ​​Integrated Circuit Hardware Description Language). As those skilled in the art will understand, the code can be distributed among multiple coupled components that communicate with each other. Where appropriate, embodiments are implemented using code running on programmable analog arrays or similar devices to configure analog hardware.

[0284] Note that, as used herein, the term "module" will be used to refer to a functional unit or block that may be implemented at least in part by a dedicated hardware component such as a custom-defined circuit, and / or at least in part by one or more software processors or appropriate code running on a suitable general-purpose processor. A module itself may include other modules or functional units. A module may be provided by multiple components or submodules that do not need to coexist in one location, and may be provided on different integrated circuits and / or run on different processors.

[0285] Those skilled in the art will understand that various changes and / or modifications can be made to the above embodiments without departing from the broad scope of this disclosure. Therefore, these embodiments are to be considered illustrative rather than restrictive in all respects.

Claims

1. A device for sensing physiological parameters of a subject, the device comprising: A force sensor having a force-sensing surface, wherein the force sensor includes a first force-sensing resistor (FSR) and is configured to generate a first signal representing a force displacement of an organ of the subject; A displacement sensor associated with the force sensor, the displacement sensor including a piezoelectric sensor and having a displacement sensing surface, wherein the displacement sensor is configured to generate a second signal representing the displacement velocity of the subject's organ and representing the body sound produced by the subject's organ; A coupler disposed on one of the force sensor and the displacement sensor, the coupler being configured to mechanically couple the force sensor and the displacement sensor to the organ; as well as At least one processor is configured to determine the physiological parameter based on the first signal and the second signal, and to calibrate the second signal received from the displacement sensor based on the first signal; Wherein, the displacement sensing surface is the same size as or smaller than the force sensing surface; The coupler has a maximum planar area smaller than the maximum planar area of ​​the force sensor; and The force sensor is mounted on the displacement sensor, and the force sensor includes an operable front surface coupled to the operable rear surface of the coupler and an operable rear surface coupled to the operable front surface of the displacement sensor.

2. The device according to claim 1, wherein, The force sensor is mounted on the rear surface of the coupler via a force sensor carrier comprising a flexible medium, wherein the diameter of the portion of the coupler in contact with the sensor carrier is smaller than the diameter of the force sensor.

3. The device according to claim 1, wherein, The force sensor and the displacement sensor are axially aligned along the central operable vertical axis of the device.

4. The device according to claim 1, wherein, The coupler includes a front surface configured to contact the organ, wherein the front surface is one of a dome shape, a mushroom shape, a cone shape, or a pyramid shape.

5. The device of claim 1, further comprising a second force sensor configured to measure a force applied to an operable rear surface of the device.

6. The device according to claim 5, wherein, The second force sensor is a force-sensing resistor (FSR), and the second force sensor is coupled to the operable rear surface of the displacement sensor.

7. The device of claim 1, further comprising a fixation device configured to secure the device to an organ of the subject, wherein the fixation device comprises at least one of a strip and an adhesive patch.

8. The device according to claim 1, wherein, The physiological parameters include at least one of the following: blood pressure, uterine contractions, fetal activity, respiration, the opening time of the subject's heart valves, the closing time of the subject's heart valves, the level of contractility of the subject's heart, the stiffness of the subject's blood vessels, the subject's stroke volume, cardiac output, and blood pulse conduction time.

9. The device according to claim 8, wherein, The physiological parameter is blood pressure, and the parameter to be measured includes at least one of central blood pressure and peripheral blood pressure.

10. The device according to claim 1, wherein, The coupler is configured as a first conductive electrode and electrically coupled to a processing circuit configured to measure bioelectric potential when the coupler is positioned against the subject.

11. The device of claim 1, further comprising a first conductive electrode configured as a ring, the ring being electrically coupled to a processing circuit configured to measure bioelectric potential when the ring is arranged against the subject.

12. The device of claim 10, further comprising a second conductive electrode arranged spaced apart from and isolated from the first conductive electrode to allow it to be arranged against another portion of the subject, and wherein the second conductive electrode is coupled to the processing circuitry to allow measurement of additional bioelectric potentials when the first conductive electrode and the second conductive electrode are arranged against the subject.

13. The device of claim 12, further comprising a third conductive electrode arranged spaced apart from and isolated from the first and second conductive electrodes to allow it to be arranged against another portion of the subject, wherein the third conductive electrode is coupled to the processing circuitry to allow measurement of additional bioelectric potentials when the first, second, and third conductive electrodes are arranged against the subject, and wherein the third conductive electrode is movable relative to the first and second conductive electrodes.

14. The device according to claim 12, wherein, The processing circuit is configured to measure the subject's electrocardiogram (ECG) in response to the first and second conductive electrodes being arranged against the subject, and is configured to generate a fourth signal representing the ECG.

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