Vibration suppression device

Abstract

Systems and methods for reducing vibrations perceived by a person attributed to a prosthetic heart valve include a vest wearable about a torso of the person, a plurality of sensors mounted to the vest, a plurality of vibration-generating actuators mounted to the vest, and a controller. The plurality of sensors detect vibrations generated within the person's body by the prosthetic heart valve. The controller is operable to receive signals representative of the detected vibrations from the plurality of sensors and is operable to generate anti-vibration signals that substantially attenuate the detected vibrations. A first sensor of the plurality of sensors is positioned proximate a first vibration-generating actuator of the plurality of vibration-generating actuators to form a sensor / actuator group. In the sensor / actuator group, the anti-vibration signals generated by the controller for the first vibration-generating actuator correspond to the vibrations detected by the first sensor.

Description

[0001] Related applications

[0002] This application claims priority to U.S. Provisional Application No. 63 / 084,559, filed on September 28, 2020, entitled “Vibration Suppression Apparatus,” which is hereby incorporated by reference in its entirety. Background Technology

[0003] Artificial internal devices within and / or around the heart, such as artificial heart valves, generate vibrations that propagate through the body's internal bone structures, tissues, and so on. The fluttering (opening and closing) of the valves transmits these vibrations throughout the body, and as these vibrational waves propagate, they are felt by the patient.

[0004] The amplitude of these vibrations can be large enough that many patients suffer from sleep deprivation and other conditions. In different body postures, the vibrations can be very uncomfortable, making it difficult for patients to fall asleep at night. Studies on the impact of heart valve vibrations on patients' quality of life (QOL) have shown that heart valve recipients may experience severe sleep disturbances, which can subsequently lead to further health problems such as chronic stress. Some solutions to these sleep problems aim to improve the design of mechanical heart valves. Other solutions involve therapies for patients, including pharmacological interventions (such as sedatives) or non-pharmacological interventions (such as cognitive behavioral therapy and wearing noise-canceling earplugs). However, the impact of mechanical heart vibrations on patients' quality of life remains a significant and ongoing issue. Summary of the Invention

[0005] In one embodiment, a system for reducing vibrations perceived by a person as attributable to an artificial heart valve includes: a vest wearable around a person's torso; a plurality of sensors mounted to the vest; a plurality of vibration-generating actuators mounted to the vest; and a controller. The plurality of sensors detect vibrations generated within the human body by the artificial heart valve. The controller is operable to receive signals representing the detected vibrations from the plurality of sensors and is operable to generate an anti-vibration signal that reduces the detected vibrations. A first sensor of the plurality of sensors is positioned near a first vibration-generating actuator of the plurality of vibration-generating actuators to form a sensor / actuator group. In the sensor / actuator group, the anti-vibration signal generated by the controller for the first vibration-generating actuator corresponds to the vibration detected by the first sensor.

[0006] In one implementation, a device for reducing vibrations perceived by a person as attributable to the artificial heart valve is a vest that can be worn around a person's torso. Multiple sensors are mounted to the vest, wherein the multiple sensors detect vibrations generated within the body by the artificial heart valve. Multiple vibration-generating actuators are mounted to the vest. A first sensor of the multiple sensors is positioned near a first vibration-generating actuator of the multiple vibration-generating actuators to form a sensor / actuator group.

[0007] In some embodiments, a method for reducing vibrations perceived by a person as attributable to an artificial heart valve involves providing a setting vest that can be worn around a person's torso. The setting vest has a first plurality of sensors and a first plurality of vibration-generating actuators that can be repositioned on the setting vest. A calibration session is performed to customize the placement of the first plurality of sensors and the first plurality of vibration-generating actuators on the setting vest. The vest is provided to a person, the vest having a second plurality of sensors and a second plurality of vibration-generating actuators mounted on the vest according to the placement from the calibration session. At least one of the second plurality of sensors is positioned near at least one of the second plurality of vibration-generating actuators to form a sensor / actuator group. Attached Figure Description

[0008] Figure 1 is an example of a phonocardiogram known in the art.

[0009] Figure 2 It is a schematic side view of a cross-section of a human chest with a vibration damping device according to some implementation schemes.

[0010] Figure 3A An isometric view of a vibration damping device according to some embodiments is shown.

[0011] Figure 3B An isometric view of another vibration damping device according to some embodiments is shown.

[0012] Figure 4A This is a diagram of a vibration suppression device based on some implementation schemes.

[0013] Figure 4B This is an illustration of a vest designed according to some implementation plans.

[0014] Figure 5 This is a schematic diagram of a vibration suppression system on the human body based on some implementation schemes.

[0015] Figure 6 This is a block diagram of the electronic components of a vibration suppression system based on some implementation schemes.

[0016] Figure 7 The vibration cancellation waveforms are shown according to some implementation schemes.

[0017] Figure 8 This is a block diagram of a vibration suppression system based on some implementation schemes.

[0018] Figure 9 This is a flowchart of a method for reducing vibrations perceived by a person attributable to an artificial heart valve, according to some implementation schemes. Detailed Implementation

[0019] Many people suffer from heart or heart valve problems that lead to surgery and replacement of their natural aortic or mitral valve. Several types of artificial heart valves exist; some are mechanical, while others are made of tissue (human donor or animal tissue). However, all of these artificial valves, whether mechanical or tissue, generate unwanted vibrations throughout the chest cavity as the heart pumps blood. These vibrations propagate through the bone structure and chest tissue.

[0020] The systems and methods disclosed herein relate to vibration damping devices worn on the exterior of a person's torso to significantly attenuate vibrations perceived by the patient as being attributable to an artificial heart valve. Vibrations may include tactile sensations felt by the patient as well as audible noises heard by the patient. The vibration damping device takes the form of a chest cover worn by the patient, the chest cover having sensors positioned around the patient's torso. The chest cover may be, for example, in the form of a vest. Sensors within the vest read vibrations generated by the heart valve on the outer side of the chest. In some embodiments, the sensors are located in the same position as vibration-generating actuators in a group, such that the anti-vibration signal of a particular actuator is based on the signal sensed by the sensor paired with it. These sensor / actuator groups advantageously provide more accurate noise cancellation compared to single noise cancellation generated for the entire system. Such noise may include audible and / or inaudible signals. The sensors and actuators may be placed in locations on the vest tailored to the individual patient.

[0021] In some implementations, the vibration suppression system of this disclosure uniquely learns the vibration characteristics of an individual's heart valve and tailors vibration cancellation signals to significantly reduce the effects of those vibrations. Such systems include electronics and a microcontroller that use real-time data from sensors and a specially designed adaptive software algorithm to predict the next vibration pulse. The electronics drive a vibration-generating actuator, also located on the vest, to counteract vibrations from the artificial heart valve within the patient's body. The system senses, learns, adapts, predicts, and generates anti-vibration pulses to significantly attenuate sensed internal vibrations. A uniquely designed signal cancellation method is used for algorithmic calibration of the sensors for each patient to address inter-patient variability.

[0022] In this disclosure, vibration suppression may be referred to as anti-vibration, vibration cancellation, noise cancellation, or noise suppression. The signal generated by the vibration-generating actuator may be referred to as a vibration, pulse, or wave. Vibration suppression should refer to reducing the vibration perceived by the patient, such as substantially or significantly reducing, attenuating, eliminating, or canceling the vibration to a level acceptable to the patient.

[0023] Figure 1 shows a typical heart sound diagram 100 measured by a sensing device on the chest. A heart sound typically consists of at least two pulses—S1, caused by the closure of the mitral and tricuspid valves at the beginning of systole, and S2, caused by the closure of the aortic and pulmonary valves at the end of systole. The respective two cycles are shown in Figure 1, labeled S1-1, S2-1, S1-2, and S2-2, and close-up views of each are also shown. Pulses generated by artificial valves are similar to those seen in Figure 1. As vibrations generated by artificial valves travel through the chest cavity, they are picked up by nerve endings and subsequently felt by the patient, which in many cases can lead to anxiety and insomnia. Vibrations generated by artificial valves can exhibit patient-to-patient variability, such as waveform, frequency, and / or amplitude. This variability depends on each patient's internal bone and tissue structure, density, and other factors, making it difficult to characterize vibrations in a universal way. Furthermore, individual vibrations can vary throughout the day, for example, due to physical activity, stress, or sleep. Individual vibrations can also change over time, due to factors such as aging, weight loss or gain, or changes in health status. Therefore, characterizing human heart sounds is very complex.

[0024] Figure 2 This is a schematic cross-sectional view of the human torso (200°), illustrating the anatomical aspects that vary from individual to individual and affect the generation and transmission of vibrational signals within the human body. Figure 2 The diagram illustrates skin 210, soft tissue 220, heart 230, bones 240a and 240b, and nerve endings 250. Bones 240a are shown in longitudinal views, such as representing the spine, while bones 240b are shown in cross-sections, such as ribs. The size, location, density, and other aspects of these anatomical features vary from patient to patient, leading to complexities in generating noise cancellation signals that cannot be addressed using conventional techniques. For example, a patient's weight, body mass, and muscle tension will affect how vibrations propagate through their chest cavity.

[0025] The initial source of the noise vibration to be addressed in this disclosure is the artificial heart valve 260. Even when the same type of valve is implanted in two different patients, the generated vibrations will differ between the two patients due to their individual physiology. The transmission of vibrations through the body will also differ between the two patients. The noise vibrations travel through soft tissues 220 (muscle, fat, etc.) to bones 240a, 240b and skin 210. Nerve endings 250 in many parts of the body pick up the vibrations and send signals to the brain. Depending on the location of the bone within the soft tissue, the type of soft tissue present (e.g., the ratio of muscle to fat), and the location and number of nerve endings, the perception of vibration will differ among different patients. To address these vibrational sounds and bodily sensations, this disclosure describes a vibration suppression device 270 worn on the patient's chest. The vibration suppression device 270 senses and analyzes the heart sounds generated by the patient and analyzes and generates anti-vibration signals to significantly reduce the artificial heart valve sounds perceived by the patient. The vibration suppression device 270 is advantageously adapted to individuals with different anatomical structures by enabling customized sensor placement within the vest. Device 270 also continuously monitors and adapts to the patient’s cardiac signals, such as by using algorithms to predictively analyze and generate anti-vibration signals.

[0026] The system should be primarily described in the form of a vest worn on a person's chest, such as under their clothing in direct contact with the skin. However, the wearable device of this disclosure can be constructed in other forms, such as a strap, belt, or band covering at least a portion of the chest above the heart region. The embodiments referred to as "vest" in this disclosure should also apply to these other configurations.

[0027] Figure 3A An example of a vest 300 according to some embodiments is shown, which includes components of a vibration damping system. The vest 300 has a main portion 310 that at least covers the area above the patient's heart. For example, the main portion 310 may at least cover the chest area or ribcage, or it may cover the entire torso, such as from the shoulders to the waist. In the example shown, the vest 300 includes shoulder straps 320 to help prevent the vest 300 from slipping off the patient. However, in other embodiments, the straps 320 are not required, such that the device only includes the main portion 310, as... Figure 3B The vest 300 is shown with chest strap 301. Different versions of the vest 300 may be available for men and women, such as with different size ranges, silhouettes, or styles (e.g., a wider strap 320 for men compared to women). Both the vest 300 and chest strap 301 have an adjustment mechanism 330 to allow for size adjustment to secure around the patient's torso. The adjustment mechanism 330 is positioned on the user's back. The adjustment mechanism 330... Figure 3A In the example, it is shown as a hook-and-eye closure, and in Figure 3BThe fastener is exemplified as a hook and loop fastener. In other embodiments, the adjustment mechanism 330 may be, for example, a buckle, button, strap, and / or other device with a slider / adjuster. The main portion 310 is made of a soft material that the wearer finds comfortable, such as natural or synthetic fabrics. In some embodiments, the material may be an elastic fabric to allow it to stretch and contract with the expansion and contraction of the user's chest. In some embodiments, the material of the main portion 310 may be selected as a material that substantially isolates vibration signals from propagating laterally along the vest 300 or chest strap 301.

[0028] Figure 4A This is a schematic diagram illustrating an exemplary arrangement of components according to an embodiment within the main portion of a vest 400. For simplicity, only the front section of the vest 400 is shown. Multiple sensors 410 and vibration-generating actuators 420 are positioned at different locations along the vest 400 to process heart sound signals from the user's chest. The vibration-generating actuators 420 generate anti-vibration signals; that is, vibrations that attenuate or reduce the perceived noise of the artificial heart valve by the patient. Compared to using a single sensor and actuator, using multiple sensors 410 and actuators 420 in the system (e.g., at least two sensors and at least two vibration-generating actuators) improves the accuracy and sensitivity of the detected signals and enables more complete vibration attenuation.

[0029] One or more sensors 410 may be located near each vibration generating actuator 420, and they work together to form a sensor / actuator group 430. In these sensor / actuator groups 430, each vibration generating actuator 420 may generate an attenuated signal corresponding to a vibration sensed by the sensor 410 near its location. That is, a first sensor 410 of a plurality of sensors may be located near a first vibration generating actuator 420 of a plurality of vibration generating actuators to form a sensor / actuator group 430. In the sensor / actuator group 430, an anti-vibration signal generated by the system (e.g., a controller) for the first vibration generating actuator corresponds to the vibration detected by the first sensor. For example, a controller may be instructed or programmed to receive and transmit data from / to sensors and actuators to associate the group of sensors and actuators with each other. The sensor / actuator group 430 may include, for example, one sensor 410 and one actuator 420, or one or more sensors 410 and one or more actuators 420. In some implementations, two or more sensors 410 are placed at a distance from each other, such that the gradient of the amplitude of the vibration sensed by the two or more sensors 410 can be determined. In one example using a piezoelectric sensor and a vibration generating actuator, the sensor 410 and the actuator 420 are each about 1 / 2 inch square and are placed adjacent to or very close to each other.

[0030] A sensor / actuator assembly in which an anti-vibration actuator generates a signal based on vibrations sensed near its location is advantageous because the vibrations will vary in direction relative to the heart. According to some embodiments, the sensor / actuator assembly 430 advantageously enables the actuator 420 to specifically target vibrations sensed at said particular location. The sensor / actuator assembly 430 is distributed across the patient's chest, wherein the number of sensor / actuator assemblies 430 and the spacing between them can be determined by factors such as bone mineral density, rib structure, and / or body fat percentage. For example, heavier individuals or individuals with a higher body fat percentage may require more sensors and / or smaller spacing between sensors compared to those who are thinner or have a lower body fat percentage. In another example, a women's vest may be designed with different sensor spacing and placement than a men's vest to accommodate anatomical differences between women and men in the chest region. Figure 4A As shown, the sensor / actuator group 430 can be arranged in various orientations, spacings, and relative arrangements to each other based on noise interference assessed for a specific patient. Figure 4A As also illustrated, some sensors 410 and actuators 420 may be positioned separately from each other (i.e., not in groups) to provide additional sensing data or provide vibration resistance signals based on multiple sensors from different locations.

[0031] Figure 4B An embodiment of the main portion 401 of a "setting" vest for customizing the placement of sensors and actuators on an individual patient is shown. Vest 401 includes adjustable features (e.g., Figures 3A to 3B The adjustable feature (adjustment mechanism 330) is used to fit the vest snugly against the patient so that vibrations can be properly sensed from and transmitted to the patient. The vest 401 has a test surface 460 for attaching and determining the optimal placement of the sensor 410 and actuator 420 during a setup session (also referred to herein as a calibration session or calibration phase). The test surface 460 may include multiple connection points for releasably mounting the sensor and actuator to the vest. In some embodiments, the test surface may include a flexible circuit board and / or wiring harness. The test surface 460 may be located on the inner surface of the vest 401, facing the patient, for direct contact with the patient's body. The test surface 460 may be configured as a sheet above the working area of ​​the vest 401, or a strip or sheet smaller than the entire working area and placed in different areas of the vest.

[0032] The test surface 460 and / or vest material may be configured with fasteners (e.g., hooks, clips, adhesive strips) to which the sensor 410, actuator 420, and / or sensor / actuator assembly 430 are attached. Embodiments may also include compartments that can hold the sensor / actuator assembly 430. The fasteners and / or compartments allow the sensors and actuators to be repositioned on the vest for individual-specific placement. In some embodiments, the test surface 460 may include location markers—on Figure 4B The location markers, shown as a grid, are printed or drawn on the test surface 460 to serve as reference points for the test positions of the sensor 410 and actuator 420 (e.g., individually or in pairs as sensor / actuator group 430).

[0033] During the setup session, sensors 410 and actuators 420 can be moved, reoriented, and otherwise repositioned and adjusted to determine the location where the patient is experiencing a heart valve signal with the highest signal amplitude. In some examples, the heart valve signal includes audible and / or inaudible signals (e.g., vibration and / or noise). The number and type of sensors and actuators can be varied during the setup session to achieve patient-acceptable noise reduction results. In some embodiments, two or more of sensors 410 are operable to provide an amplitude gradient of the heart valve signal to quickly determine the location where the patient is experiencing a heart valve signal with the highest signal amplitude. In some embodiments, the gradient of the heart valve signal in a specific area can be measured using multiple sensors temporarily placed in that area to guide the direction of sensor movement for better signal reception. Once an acceptable placement of the sensors and actuators is achieved using the setup vest, a custom vest can be fabricated for the patient, with the sensors and actuators mounted to the vest in the positions determined during the calibration session.

[0034] Figure 4A and Figure 4B A battery 440 (e.g., a thin lithium-ion button cell) is also shown, which powers the sensor 410, the vibration-generating actuator 420, and electronics 450 that process signals to and from the sensor 410 and the vibration-generating actuator 420. In some embodiments, a wireless charger 445 is used to charge the battery 440. In some embodiments, the electronics 450 may be housed on a flexible electronic board for wearer comfort. In other embodiments, the electronics 450 and / or the battery 440 may communicate electrically and signal-wise with the sensor 410 and the vibration-generating actuator 420, but may not be mechanically fixed to the vest.

[0035] Implementations may include minimizing the size of battery 440 for user comfort. Battery size can be minimized, for example, by providing a power-saving mode to conserve battery usage and / or by reducing the power consumption of electronic devices 450 to provide longer battery life. A power-saving mode may involve taking measurements less frequently, or operating certain sensors and vibration-generating actuators at less frequent measurement or actuation rates in areas where heart sound disturbances are not as pronounced as in other areas. In some implementations, the system may have a sleep mode for when the patient is asleep, where the microcontroller maintains a decay level comfortable for the user, but does not perform continuous monitoring and calculation of future heart sounds (thus conserving battery life) because the patient is asleep and not physically active. In one implementation, the system may be programmed to switch to sleep mode at a certain time during the night. In another implementation, the system may communicate with an external monitor (e.g., the patient's smartwatch or sleep monitor) that detects when the patient falls asleep and subsequently instructs the vibration suppression system to switch to sleep mode.

[0036] In one implementation, the device for reducing vibrations perceived by a person as attributable to the artificial heart valve is a vest that can be worn around a person's torso. Multiple sensors are mounted to the vest, wherein the multiple sensors detect vibrations generated within the body by the artificial heart valve. Multiple vibration-generating actuators are mounted to the vest. A first sensor of the multiple sensors is positioned near a first vibration-generating actuator of the multiple vibration-generating actuators to form a sensor / actuator group.

[0037] Figure 5 A block diagram of a device 500 for suppressing vibrations generated by an artificial internal device within a patient's body, according to some embodiments, is shown. Device 500 is a chest cover, such as a vest, worn by a user. Device 500 includes a vibration sensor 510 for detecting vibrations generated by the internal artificial device (shown herein as a mechanical aortic valve 560) and a vibration generating actuator 520 for generating vibration-canceling waves. Device 500 also includes a wireless rechargeable battery system 540 and electronic equipment 550. Electronic equipment 550 may include, for example, a microcontroller, an analog-to-digital converter, a digital-to-analog converter, etc. Wi-Fi connectivity, amplifier, and memory.

[0038] exist Figure 5In this device, when the heart pumps blood and activates the aortic valve 560, the movement of the valve 562 generates vibrations. These vibrations are transmitted through the valve body 564 and subsequently through the patient's bone structure 570 and the tissues of the chest cavity. These vibrations are picked up by numerous nerve endings 580, and the vibration sensation is then transmitted to the patient's brain. Using the vibration suppression device 500 of this disclosure, several vibration sensors 510 placed externally at multiple locations on the chest also pick up these vibrations. An actuator 520 generates signals to reduce the vibrations perceived by the patient, thereby improving comfort and quality of life.

[0039] Figure 6 This is a block diagram of a vibration suppression system 600 according to some embodiments. The system includes devices such as a vest or other chest cover worn by a patient, wherein the wearable device includes a vibration sensor 610, a vibration generating actuator 620, a battery 640, a battery charger 645 (e.g., a wireless charger), and electronics 650. The vibration generating actuator 620 generates anti-vibration signals to attenuate or reduce artificial heart valve noise perceived by the patient. Electronics 650 includes an analog-to-digital converter 652, a controller 654 (e.g., a microcontroller), and a digital-to-analog converter 656. Electronics 650 may also include a wireless transmission system 670 on the same or separate circuit board as other electronics. In some embodiments, the vibration suppression system 600 communicates with a computing device 660, such as an external computer server or a cloud-based computing system.

[0040] Wireless transmission system 670 is used to transmit and receive stored and real-time data from vibration sensor 610, controller 654, and vibration generating actuator 620 to computing device 660 via Bluetooth or Wi-Fi. Data can be collected during the initial patient calibration phase and / or from continuous patient monitoring to inform the readjustment of parameters in algorithm 655, which may be, for example, a learning adaptive prediction (LAP) algorithm. Exemplary parameters that can be known by algorithm 655 include characteristics of cardiac pulses (e.g., waveform shape, time interval between S1 and S2, amplitude of S1 and S2, spectral (spectral) content of S1 and S2 pulses) and the weights of those characteristics.

[0041] A rechargeable battery 640 powers components within the wearable vest. In some embodiments, a battery charger 645 wirelessly recharges the battery 640. In some embodiments, the battery charger 645 may include a physical connector for recharging the battery 640 via a plug-in charger. Information regarding battery charge levels and / or system status can be provided to the patient via a mobile application or computer.

[0042] During use, heart sounds and vibrations 680 are detected by vibration sensors 610 in a chest vest. Analog signals 681 from vibration sensors 610 are transmitted to an analog-to-digital converter 652, which then sends digital data 682 to a controller 654. The digital data 682 is analyzed in real time by the controller 654, and an algorithm 655 within the controller 654 generates an anti-vibration digital sequence 684. The controller 654 is operable to receive signals representing detected vibrations from multiple sensors and is operable to generate anti-vibration signals that substantially attenuate the detected vibrations. In some embodiments, algorithm 655 is a LAP algorithm that predicts the next vibration the patient will experience and generates the anti-vibration digital sequence 684 to attenuate those signals. Aspects of the predicted vibration may include waveform, frequency, amplitude, pulse duration, time between pulses, and / or delay in pulse occurrence. The anti-vibration digital sequence 684 is converted to an analog signal 686 via a digital-to-analog converter 656, as appropriate. An anti-vibration analog signal 686 or an anti-vibration digital sequence 684 is applied to drive a vibration generating actuator 620, which generates a vibration cancellation anti-vibration signal 688 toward the chest and / or other directions as needed.

[0043] Sensor 610 is operable to detect mechanical vibrations and / or audible noise and provide a signal representing them to analog-to-digital converter 652. Sensor 610 may include, but is not limited to, an electrocardiogram (ECG) sensor, a piezoelectric sensor, a microelectromechanical system (MEMS), an accelerometer, a displacement sensor, a velocity sensor, a pressure sensor, and / or a microphone. Vibration generating actuator 620 is operable to receive digital or analog signals and generate mechanical vibrations corresponding to the received signals. Vibration generating actuator 620 may include, but is not limited to, tactile actuators (e.g., piezoelectric actuators, linear resonant actuators, and eccentric rotating mass actuators) and / or non-tactile actuators, such as speakers or microphones.

[0044] The sensor 610 and vibration-generating actuator 620 can be of the same type and / or size throughout the vest, or they can be of multiple types and / or sizes. Because vibrations propagate in all directions, using sensors and vibration-generating actuators of different types and / or locations on the chest strap can more effectively eliminate the vibrations felt by the patient compared to a single sensor and actuator.

[0045] Sensor 610 can be used to detect audible clicking sounds heard by a patient (or someone near the patient) and tactile vibrations felt by the patient. Sensor types used to sense acoustic sounds include microphones, such as contact microphones (e.g., piezoelectric-based) and microelectromechanical (MEMS) microphones. In some embodiments, the sensor can be configured to detect frequencies within the human audible range (e.g., 20 Hz to 20 kHz) and below that range. For example, the sensor may include a microphone that responds in the sub-audio (i.e., infrasound) range below 20 Hz. Although the patient may not hear infrasound, this information can help the LAP algorithm predict future vibrations. Sensor types used to pick up physical vibrations include accelerometers, such as triaxial accelerometers and piezoelectric MEMS accelerometers. Readings from the acoustic and tactile vibration sensors can be used in conjunction with each other to enhance the identification of noise signals. For example, the loudness of an audible clicking sound from a heart valve may be less than that of other present sounds, and therefore tactile vibration readings can be used to verify which signals detected by the acoustic sensors are caused by the heart valve.

[0046] The sensor 610 was also selected to have low latency and a faster response rate compared to the cardiac noise frequency of interest. A sensor with a sufficient acoustic overload point (AOP) was chosen so that the amplitude of the signal sensed by the sensor would not overload the microphone.

[0047] Various actuators 620 can be used to address vibrational noise perceived by the patient's hearing and tactile noise felt by the patient through their body (e.g., bone, soft tissue). In some embodiments, actuators 620 and sensors 610 can be used as part of a feedforward or feedback vibration and / or audible noise cancellation topology. In an example of a speaker used as an actuator in a feedforward topology, such a speaker can be positioned outward from the patient's face to cancel audible heart valve clicks emanating from the patient's body. A sensor (e.g., a microphone) for picking up audible clicks from the artificial heart valve can be paired with a speaker used as an anti-vibration actuator, where the microphone is positioned such that it detects audible noise leaving the vest. In contrast, sensors 610 (e.g., microphones) and actuators 620 can be placed as close as possible to the noise / vibration source, such as close to the patient's skin, adjacent to the location on the vest where a specific sensor picks up the sound to be canceled. A feedback speaker generates sound entering the body to cancel vibrations from the source (heart valve).

[0048] In some embodiments, multiple sensors and multiple vibration-generating actuators are releasably mounted to the vest, thereby enabling adjustment of the position of the multiple sensors and multiple vibration-generating actuators. In some embodiments, the multiple sensors and multiple vibration-generating actuators are mounted in a position customized for an individual patient. The multiple sensors may include accelerometers, microphones, acoustic sensors, and / or tactile vibration sensors. The multiple vibration-generating actuators may include tactile actuators or non-tactile actuators such as feedforward microphones.

[0049] Figure 7 An exemplary phonocardiogram of the original vibration 710 (waves S1-S2) detected by a sensor is shown. Anti-vibration signals 720 (anti-vibration waves S1' and S2') are applied by an actuator in response to the original vibration. A combined signal 730, generated by the original vibration 710 added to the anti-vibration signal 720, reduces the vibration to a threshold acceptable to the patient or a level at which the patient does not notice the vibration. In some embodiments, the anti-vibration signal 720 eliminates or significantly reduces vibration signals detected at different nerve endings in the chest cavity as it travels through the pleural cavity. In other embodiments, the anti-vibration signal 720 travels through the air to eliminate noise signals heard by the patient.

[0050] In the implementation scheme, the learning algorithm of this disclosure can analyze not only vibrations that disturb the user, but also the patient's normal heart rhythm to improve the accuracy of predicting future cardiac signals. For example, the algorithm can analyze the blood intake portion of each cardiac cycle to achieve advance estimation and reduce processing delay. The algorithm can also learn indicators before an individual patient's heart rate increases or decreases, which can also achieve more accurate estimation and reduce processing delay.

[0051] Figure 8 This is a block diagram of an exemplary system 800 for reducing the sound of an artificial heart valve perceived by a patient, according to some embodiments. The system includes a wearable device 805 (e.g., a chest vest) and a user interface device 850. The user interface device 850 is a board peripheral device from the wearable device 805 and may be an electronic device such as a personal computer or mobile phone. The user interface device 850 has a user application 852 that allows a user (e.g., a physician, technician, or patient) to calibrate the wearable device 805 for an individual patient. The calibration or setup session can be performed, for example, in a doctor's office or laboratory.

[0052] In some implementations, algorithm 855 receives an analog or digital representation of signals associated with the artificial heart valve (e.g., electrical signals, vibrations, and / or audible noise), determines individual signals for each individual actuator to maximize the attenuation level of vibration and noise perceived by the patient (e.g., by generating cancellation signals that are out of phase with the vibrations or audible noise), and generates analog or digital signals or instructions to control each actuator such that the actuator produces noise or vibration that substantially attenuates the signals associated with the artificial heart valve. The attenuation amount can be set according to the patient's tolerance for noise and vibration interference, such as a desired reduction of at least 2 dB of perceived noise, such as at least 3 dB, at least 4 dB, or at least 6 dB. In some implementations, the algorithm can target achieving at least a minimum attenuation amount (e.g., at least 3 dB or at least 4 dB) regardless of the user's preference.

[0053] In some embodiments, the algorithm implements classical or modern control strategies known in the art for active vibration control (AVC). In some embodiments, algorithm 855 implements a proportional-integral-derivative (PID) control algorithm. In some embodiments, algorithm 855 implements a model predictive control (MPC) algorithm. In some embodiments, a heart-associated electrical signal (e.g., ECG) is used to determine when the signal associated with the artificial heart valve is transmitted and / or will be transmitted. In some embodiments, algorithm 855 includes a learning adaptive prediction (LAP) algorithm 855 that uses artificial intelligence to learn the vibration characteristics of an individual wearing the device and then predicts future vibrations based on those characteristics. In some embodiments, the LAP algorithm is a specially designed prediction algorithm that uses an analog or digital representation of a previously received signal associated with the artificial heart valve to predict future characteristics of the signal associated with the artificial heart valve, such as amplitude, frequency content, and periodicity.

[0054] The user interface device 850 enables the user to input and store biometric inputs 854 into the system. During a setup session, which can be the patient's initial setup or a periodic recalibration session, the user creates a profile including various user biometric inputs 854. Biometric inputs 854 may include information such as height, weight, gender, and age, which can be used as parameters for algorithm 855 and / or via the user interface device 850 to select a pre-trained model 856 for use with the LAP algorithm of algorithm 855. The pre-trained model 856 can be obtained from a cloud processor (e.g., Figure 6 The computer device 660) or the selection built into the user application 852 can be retrieved.

[0055] In an implementation that uses the LAP algorithm as part of algorithm 855, the next step is to run a calibration process on top of the pre-trained model 856 or the initial LAP algorithm of algorithm 855, taking input from the vibration sensor array 810 on the wearable device 805.

[0056] Wearable device 805 (e.g., vest 401) includes multiple locations for sensors 810 and actuators 830. In some embodiments, a computer database or algorithm may suggest an initial positional map of sensors 810 and actuators 830 on wearable device 805 based on the patient's anatomy and their biometric input 854. The computer database or algorithm may also suggest the number and type of sensors 810 and actuators 830 to be used. During the calibration phase, in addition to those measurements from wearable device 805, auxiliary sensors 820 may be used for auxiliary measurements. Auxiliary sensors 820 may include a heart rate sensor for measuring heart rate and / or a blood pressure monitor for measuring blood pressure. In some embodiments, a tracked-motion electrocardiogram (ECG) may be performed, and calibration readings are recorded during the trial, allowing the LAP algorithm of algorithm 855 to learn how the patient's specific body structures (e.g., bone structure, bone density, fat percentage, fat distribution in the chest, muscle mass) affect the vibrations generated by the artificial heart valve during physical activity. Readings can also be collected in static modes, such as in different body positions while the patient is sleeping, as vibrations are often most bothersome to patients during sleep. Calibration sessions can be used to locate the sensor positions where the strongest vibration signals are detected, especially when the patient is lying down. The calibration phase can also involve using subjective input from the patient to learn a threshold for the vibration amplitude that bothers them.

[0057] Once the optimal positions of the sensors and actuators have been determined based on calibration tests, custom-made vests for the patient are ordered based on the placement determined during the calibration phase. In the custom-made vest, the sensors (among multiple sensors) and actuators (among multiple vibration-generating actuators) are mounted on the vest in positions based at least in part on measurements taken and other parameters collected during the calibration phase. Similarly, the type and number of sensors and actuators used in the custom-made vest are based on assessments conducted during the calibration phase.

[0058] Calibration phases can be performed multiple times during a patient's continued use of the vest. For example, a calibration phase can be performed for a patient during the initial session using the setup vest. Calibration can also be performed when a patient first uses the custom vest to check if it functions as planned. Calibration can also be performed periodically, such as every few months, to further fine-tune the learning algorithm (in addition to ongoing adjustments to the learning algorithm) and / or to see if changes in the patient's health or other conditions have affected how the vest meets the patient's needs. In some implementations, measurements taken during the calibration phase can be used to determine or readjust the placement of sensors and actuators on the vest, replace sensors and / or actuators with different types of sensors and actuators, or make software adjustments.

[0059] During normal use, the chest vest senses vibrations at multiple points around the wearer's chest. Personalized models are implemented for each actuator for each patient based on the sensor placement on the wearable device and the patient's bone and tissue structure to ensure optimal attenuation. In some embodiments, the LAP algorithm of algorithm 855 predicts future vibrations, such as intensity, nature (e.g., waveform shape), frequency, and / or delay and / or the timing of the next pulse, and programs the vibration-generating actuator 830 to generate attenuation pulses. Sensor 810 continuously collects sensor readings and applies continuously retrained algorithm 855 to output an optimal model for predicting the next vibration pulse. In some embodiments, continuous measurements by sensor 810 are performed at a rate greater than the rate at which the phonocardiogram signal travels through bone and tissue and at a rate greater than the maximum frequency associated with the phonocardiogram signal. For example, for a typical cardiac vibration signal with a 1-2 kHz spectrum, the measurement algorithm of this embodiment may utilize a sampling rate at least twice the maximum frequency and / or bandwidth of the spectrum.

[0060] The LAP algorithm in the microcontroller continuously monitors and measures vibrations and nearby sounds during use to attempt and predict the next vibration pulse and corresponding cancellation strategy for the actuator. The system can utilize pattern recognition algorithms and machine learning. The system is constructed with low latency, where the microcontroller loops at a very high speed, enabling signal processing much faster than the frequency period of interest.

[0061] In some implementations, a linear regression-based model can be used to generate the vibration-damping actuator waveform output required to attenuate vibrations such as those felt at nerve endings in a patient. Some implementations may utilize the Darmois-Skitovich theorem, which characterizes a Gaussian distribution by the independence of two linear forms from independent random variables. The Darmois-Skitovich theorem has been used in the communications industry to effectively invert communication channels without using pilot signals and by radiologists in an attempt to make interventional tissue noise essentially transparent.

[0062] In various embodiments, a system for reducing vibrations perceived by a person as attributable to an artificial heart valve includes: a vest wearable around a person's torso; a plurality of sensors mounted to the vest; a plurality of vibration-generating actuators mounted to the vest; and a controller. The plurality of sensors detect vibrations generated within the human body by the artificial heart valve. The controller is operable to receive signals representing the detected vibrations from the plurality of sensors, and the controller is operable to generate an anti-vibration signal that reduces, for example, substantially attenuates, the detected vibrations. A first sensor of the plurality of sensors is positioned near a first vibration-generating actuator of the plurality of vibration-generating actuators to form a sensor / actuator group. In the sensor / actuator group, the anti-vibration signal generated by the controller for the first vibration-generating actuator corresponds to the vibration detected by the first sensor.

[0063] In some embodiments, the controller has an algorithm that predicts future vibrations from the artificial heart valve in response to detected vibrations from multiple sensors, and wherein the controller generates anti-vibration signals for multiple vibration generators based on the predictions. In some embodiments, multiple sensors continuously detect vibrations, and the controller adaptively adjusts the algorithm based on the vibration monitoring detected by the multiple sensors. In some embodiments, the algorithm includes parameters initially set during a calibration phase, and these parameters include measurements of heart rate, blood pressure, or patient body structure. The patient's body structure may include body fat percentage, bone structure, and bone mineral density. Multiple sensors are mounted in positions on a vest based on measurements from the calibration phase.

[0064] In some embodiments, the system includes a user interface device that communicates with a controller. In some embodiments, the multiple sensors include accelerometers or microphones. In some embodiments, the multiple sensors include acoustic sensors and tactile vibration sensors. In some embodiments, the multiple vibration generating actuators include tactile actuators or non-tactile actuators. In some embodiments, the multiple vibration generating actuators include a loudspeaker in a feedforward topology.

[0065] Figure 9This is a flowchart 900 illustrating a method for reducing vibrations perceived by a person as attributable to an artificial heart valve. Step 910 involves providing a setup vest, wearable around a person's torso, the setup vest having a first plurality of sensors and a first plurality of vibration-generating actuators repositionable on the setup vest. In step 920, a calibration session is performed to customize the placement of the first plurality of sensors and the first plurality of vibration-generating actuators on the setup vest. In step 930, a customized vest is provided to the person, the vest having a second plurality of sensors and a second plurality of vibration-generating actuators mounted on the vest according to the placement from the calibration session. The vest of step 930 is thus advantageously customized for the individual patient's anatomy and response to perceived vibrations. At least one of the second plurality of sensors is positioned near at least one of the second plurality of vibration-generating actuators to form a sensor / actuator group.

[0066] The implementation also includes a step 940 of providing a controller operable to receive signals representing detected vibrations generated by the artificial heart valve from a plurality of sensors. The controller is operable to generate an anti-vibration signal that reduces, for example, substantially attenuates, the detected vibrations. In the sensor / actuator group, the anti-vibration signal generated by the controller for at least one vibration-generating actuator corresponds to sensor readings from at least one sensor. In some embodiments of flowchart 900, the controller has an algorithm for predicting future vibrations from the artificial heart valve in response to sensor readings generated by a second plurality of sensors. In some embodiments, the controller adaptively adjusts the algorithm based on vibration monitoring detected by the second plurality of sensors. In some embodiments, the system includes a user interface device communicating with the controller. In some embodiments, the plurality of sensors include accelerometers or microphones. In some embodiments, the plurality of sensors include acoustic sensors and tactile vibration sensors. In some embodiments, the plurality of vibration-generating actuators include tactile actuators or non-tactile actuators. In some embodiments, the plurality of vibration-generating actuators include speakers in a feedforward topology.

[0067] Reference has been made in detail to embodiments of the disclosed invention, one or more examples of which are illustrated in the accompanying drawings. Each example has been provided by way of explanation of the technology, not as a limitation thereof. In fact, although the specification has been described in detail with respect to specific embodiments of the invention, it will be understood that modifications, variations, and equivalent embodiments of these embodiments will readily occur to those skilled in the art upon gaining an understanding of the foregoing. For example, a feature illustrated or described as part of one embodiment may be used with another embodiment to produce yet another embodiment. Therefore, this subject matter is intended to cover all such modifications and variations within the scope of the appended claims and their equivalents. These and other modifications and variations of the invention may be practiced by those skilled in the art without departing from the scope of the invention (which is set forth more specifically in the appended claims). Furthermore, those skilled in the art will understand that the foregoing description is merely exemplary and is not intended to limit the invention.

Claims

1. A system for reducing vibrations perceived by a person as originating from an artificial heart valve, the system comprising: A vest that can be worn around the person's torso; Multiple sensors are mounted to the vest, wherein the multiple sensors detect vibrations generated by the artificial heart valve; Multiple vibration generating actuators are mounted on the vest; as well as A controller operable to receive signals of detected vibrations from the plurality of sensors, wherein the controller is operable to generate an anti-vibration signal that reduces the detected vibrations. The first sensor of the plurality of sensors is positioned near the first vibration generating actuator of the plurality of vibration generating actuators to form a sensor / actuator group; In the sensor / actuator group, the anti-vibration signal generated by the controller for the first vibration generator corresponds to the vibration detected by the first sensor; and The controller has an algorithm for predicting future vibrations from the artificial heart valve in response to detected vibrations from the plurality of sensors, and the controller generates the anti-vibration signal for the plurality of vibration generators based on the prediction.

2. The system as claimed in claim 1, wherein: The multiple sensors continuously detect the vibration; and The controller adaptively adjusts the algorithm based on the vibration monitoring detected by the plurality of sensors.

3. The system as claimed in claim 1, wherein: The algorithm includes parameters initially set during the calibration phase; and The parameters include measurements of heart rate, blood pressure, or patient body structure.

4. The system of claim 3, wherein the patient's body structure includes fat percentage, bone structure, and bone density.

5. The system of claim 3, wherein the plurality of sensors are mounted in positions on the vest based on the measurement results from the calibration phase.

6. The system of claim 1, further comprising: A user interface device that communicates with the controller.

7. The system of claim 1, wherein the plurality of sensors include an accelerometer or a microphone.

8. The system of claim 1, wherein the plurality of vibration generating actuators include tactile actuators.

9. The system of claim 1, wherein the plurality of vibration generating actuators include a loudspeaker in a feedforward topology.

10. The system of claim 1, wherein the plurality of sensors includes an acoustic sensor and a tactile vibration sensor.

11. The system of claim 1, wherein the plurality of sensors and the plurality of vibration generating actuators are releasably mounted to the vest such that the positions of the plurality of sensors and the plurality of vibration generating actuators can be adjusted.

12. The system of claim 1, wherein the plurality of sensors includes a feedforward microphone.

13. The system of claim 1, wherein the plurality of vibration generating actuators include non-tactile actuators.

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