WO2011117862A2 - Wearable sensors - Google Patents

Abstract

A garment having a back side and a front side, comprising means for adjusting the garment to a patient's torso, at least one array of respiratory vibration sensors connected with the back side of the garment, electronic means for reading the sensors, connected with the garment and communication means for communicating bi-directionally between the electronic means and an external electronic device.

Description

WEARABLE SENSORS

TECHNICAL FIELD

The present invention relates to a non-invasive physiologic monitoring system which includes a garment incorporating an array of sensors and communications for transmitting monitored physiological signals to a remote monitoring unit.

CROSS-REFERENCE TO RELATED PATENT APPLICATIONS

This patent application claims priority from and is related to U.S. Provisional Patent Application Serial Number 61/282,729 filed 24 March 2010, U.S. Provisional Patent Application Serial Number 61/344,279 filed 22 June 2010 and U.S. Provisional Patent Application Serial Number 61/384,337 filed 20 September 2010, these U.S. Provisional Patent Applications incorporated by reference in their entirety herein.

BACKGROUND

In the medical monitoring area, multi-channel patient monitors are currently available. These monitors are hard-wired between the patient-worn sensors and the

processing/display module. They are bulky and unsuitable for less than intensive, critical care monitoring. These bedside and console monitors offer multi-parameter sensing, but are not intended to be worn directly by the patient.

It would therefore be desirable to have a system which can be worn by the subject being monitored and which can provide alarm indications to caregivers in the immediate vicinity of the subject being monitored.

SUMMARY

According to a first aspect of the invention there is provided a garment having a back side and a front side, comprising means for adjusting the garment to a patient's torso, at least one array of respiratory vibration sensors connected with the back side of the garment, electronic means for reading the sensors, connected with the garment and

l communication means for communicating bi-directionally between the electronic means and an external electronic device.

According to a second aspect of the invention there is provided a system for evaluating a patient's physiological condition, comprising a garment having a back side and a front side, the garment comprising means for adjusting the garment to a patient's torso, respiratory vibration sensors connected with the back side of the garment, electronic means for reading the sensors, connected with the garment and communication means; and an external electronic device communicating bi-directionally with the electronic means, the external electronic device comprising a computer application program for at least one of managing and sequencing the sensors' operation.

According to a third aspect of the invention there is provided a back rest for sensing a patient's physiological condition, comprising: at least one array of respiratory vibration sensors, an inflatable air cushion for providing pressure distribution among the sensors and a rigid support having a shape to support the air cushion so as to properly receive a human back.

According to a fourth aspect of the invention there is provided a vibration sensor array comprising: a plurality of sensors constructed in a substantially flat geometry arranged with the flat side substantially perpendicular to the direction of the vibration,

wherein the sensors are encapsulated in flexible material and wherein the

encapsulated sensors are arranged in a pre-determined spatial geometry.

According to a fifth aspect of the invention there is provided a sensor for sensing vibrations, said sensor constructed of: a flat piezoelectric element, an enclosure holding the piezoelectric element generally in its perimeter, providing it the degree of freedom to vibrate in direction perpendicular to the sensor plan and a mass assembled on the surface of the Piezoelectric element.

According to a sixth aspect of the invention there is provided a sensor for sensing vibrations, the sensor constructed of: a flat piezoelectric element, an enclosure holding the piezoelectric element generally at its center, wherein at least a part of the perimeter of the piezoelectric element suspends free from mechanical contact within the

enclosure, providing it the degree of freedom to vibrate in direction perpendicular to the sensor plan. According to a seventh aspect of the invention there is provided an electronic

stethoscope comprising vibration sensors.

According to an eighth aspect of the invention there is provided a perimeter length sensor constructed of: a piezoelectric sensor, the piezoelectric sensor is attached to a surface of a structure, the structure includes elements that, when pulled, bend the section where said sensor is attached and the elements are connected to a belt-like setup wrapped around the object of which perimeter length needs to be sensed.

According to a ninth aspect of the invention there is provided a sensor for sensing vibrations, the sensor constructed of: a flat piezoelectric element and an enclosure holding the piezoelectric element in at least one section that is a relatively small part of the perimeter of said piezoelectric element.

According to a tenth aspect of the invention there is provided a system for remote auscultation comprising: a group of sensors distributed over the torso of a person, the sensors adapted to sensing the person's breathing sounds and transmitting the sounds to a remote auscultation device, wherein the auscultation device has an interface for remotely selecting a sensor and wherein the auscultation device comprises audio means for enabling the operator to listen to the sound received by the selected sensor.

BRIEF DESCRIPTION OF THE DRAWINGS

For a better understanding of the invention and to show how the same may be carried into effect, reference will now be made, purely by way of example, to the accompanying drawings.

With specific reference now to the drawings in detail, it is stressed that the particulars shown are by way of example and for purposes of illustrative discussion of the preferred embodiments of the present invention only, and are presented in the cause of providing what is believed to be the most useful and readily understood description of the principles and conceptual aspects of the invention. In this regard, no attempt is made to show structural details of the invention in more detail than is necessary for a

fundamental understanding of the invention, the description taken with the drawings making apparent to those skilled in the art how the several forms of the invention may be embodied in practice. In the accompanying drawings: Figs. 1 A and 1 B are schematic drawings of an exemplary vest as worn by the patient;

Figs. 2B through 2K are illustrative cross sections in the array at the center of a sensor;

Fig. 3 depicts an exemplary sensor array's position on the patient;

Fig. 4 depicts an exemplary conceptual layers structure of the back of the vest; Fig. 5 depicts an exemplary mode of usage of the vest;

Fig. 6 is a schematic drawing of a basic front view of the vest;

Fig. 7 is a schematic drawing of an alternative configuration of the vest;

Figs. 8A and 8B are front and top views of yet another embodiment of the vest; Figs. 9A and 9B depict yet another embodiment of respiratory measurement, using a stretchable fabric;

Figs. 10A and 10B are schematic drawings of the vest comprising additional sensors;

Fig. 11 is a schematic drawing of the vest comprising blood pressure measurement means integrated into the vest;

Fig. 12 is a schematic drawing of the back of the vest of Fig. 4, installed on chair;

Figs. 13A through 13C depict another embodiment in which each sensor is encapsulated in a thin housing;

Figs. 14A through 14C depict another embodiment of the invention, in which mass is attached to sensor surface;

Figs. 15A through 15c depict yet another embodiment of the invention, in which the Piezoelectric element is supported in the center;

Figs. 16A through 16C depict another embodiment of the invention, a novel torso perimeter;

Figs. 17A and 17B depict another embodiment of a torso perimeter;

Figs. 18A and 18B depict an alternative design of the sensor;

Figs. 19A through 19C depict a cross section of an exemplary of 2-parts sensor housings;

Figs. 20A and 20B depict another embodiment of a sensor housing; and Fig. 21 depicts another embodiment, in which the wearable sensors are configured for effective remote auscultation.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

The present invention provides a garment for the evaluation of pulmonary condition. The garment, preferably a vest (hereinafter "vest" ) but optionally a jacket or the like, includes respiratory vibration sensors, e.g. such as described in U.S. Patent No.

6,887,208 to the same assignee, said patent incorporated inhere by reference in its entirety and additional physiology condition sensors as specified below.

The vest is light-weight, easy to use, and operable by the patient without help from another person.

The vest accompanies the patient during his normal life and is easy to pack and cany with the patient's personal handbag to minimize carry-along burden during normal lifestyle.

In general, the various sensors communicate bi-directionally with any computerized device such as a Smartphone, such as Motorola Cliq, a Tablet PC such as Fujitsu LifeBook T900, a laptop computer such as IBM ThinkPad Z61m 9452, or a dedicated proprietary electronic device built for the purpose of this vest, or others, preferably wirelessly. For simplicity, all these devices will be referred to hereinafter as

"Smartphone". The Smartphone comprises a management application for managing and sequencing the various measurements and for transmitting the results to a remote server or a remote station (hereinafter: remote computer). The remote server is typically an intermediate computer between the Smartphone and the remote station. The remote station is the computer typically used by the healthcare team to examine the data measured from the patient, communicate with him through his electronic device and conduct video conferences with the patient through his electronic device or conduct alpha-numeric communications or vocal communication. The Smartphone may also be utilized for additional tasks such as aggregating data, analyzing the data, QC etc. The Smartphone may communicate the data, results and/or the analysis to a remote computer for physician evaluation and may receive physician's instructions in return. The Smartphone application may also enhance patient compliance by issuing reminders for performing measurements and communicating family members to recruit them for compliance or other support.

Figs. 1A and 1B are schematic drawings of an exemplary vest (101) as worn by the patient (100). The vest comprises shoulder straps (102) adjustable to the patient size by any means (106) known in the art and chest straps (103, 104) adjustable by means (105) to the patient's perimeter, so as to allow for positioning of the sensors relative to the patient's anatomy and allow for breathing space. An electronic enclosure (107) is mounted on the back side of the vest, comprising electronics for controlling the sensors array and optionally other sensors. The vest additionally comprises an on/off button

(108).

The vest provides the following functionality:

a. Support 2 sensor arrays, 3x6 (optional 3x7) sensors each.

i. All 36 (optional 42) sensors should maintain firm and clear contact with the skin during breathing cycles.

b. Support electronic boards.

c. Support optional sensors:

. Torso perimeter sensor

Skin surface thermometer

iii. Pulse Oximeter, such as CMS 50A fingertip Oximeter (USB connection), available from Contec Medical System Co., Inc.

(www.contecmed.com) or Onyx II Model 9560 (Bluetooth connection), available from Nonin Medical Inc.

iv. Respiration sensor, such as J&J MC3MY, available from Bio-Medical Instruments, Inc. (www.bio-medical.com).

v. ECG, such as ecg@home, available from HealthFrontier

(www. healthfrontier.com).

vi. Galvanic Skin Response (GSR) sensor, such as SH-GSR-KlT-002,

available from Shimmer (www.shimmer-research.com). vii. Fluid level (http:/ www.omnimedicalsupply.com/zoe_setup.htm). External sensors with wireless or wire connection that may connect to the Smartphone or the vest:

1. Blood pressure monitoring device, such as BP-3AG1 , available from Blood Pressure Association (www.bpassoc.org.uk).

2. Spirometer, such as SPR-BTA, available from Vernier

(www.vernier.com)

3. Respiratory peak flow meter, such as Clean Peak Flow Meter, available from ERT (www.ert.com).

4. Blood glucose monitor, such as OneTouch Delica, available from Lrfescan (www.lifescan.com)

5. Weight

6. PT/INR meter, such as Alere Hemosense INRatio2 PT/INR Meter, available from Alere (www.alere.com). d. Adjustable to a large range of patient sizes (height and weight, male and female).

e. Easily wearable by all patients who dress themselves without help.

f. Light weight to support carry-along in handbag.

g. Foldable to a thin package to support carry-along in handbag.

h. Easy to clean.

Vibration sensors geometry:

Figures 2C through 2K are illustrative cross sections in the array at the center of a sensor.

Sensor array lateral typical geometry is depicted in Fig. 2A, Fig. 2B (partial top view) and Fig 2C (sensor area cross section). The sensor array (200) in this example comprises 3x7 sensors enclosed in silicon rubber (hereinafter "silicon") molding. One such silicon is Koraform A-18 available from Alpina Technische Prudukte GmbH, Breslauer Weg 123, D-82538 Gerestried, Germany. The convex top sensor enclosure (201) is designed to contact the body surface and transfer the respiratory vibrations to the sensor. Specially designed fasteners (203) serve for fastening the sensor array to the vest fabric, preferably using embroidery. An electric connector (202) connects the sensor array to the electronic enclosure (107). Fig. 2B depicts a partial typical cross section of the sensor array (200), showing the sensor's enclosure (201), the fasteners (203), the sensors (204) embedded in the enclosure and electric wires (205) connecting the sensors to the electric connector (202). Fig. 2C depicts a typical cross section of one sensor along line A-A of Fig. 2B. The thickness of the sensor array may be under 20mm.

A sensor typically useful in a preferred embodiment is a Piezo ceramic sensor, such as OBO-TE20265-16 available from OBO PRO.2 INC, No. 224-9, Lane 105, Yung-Feng Road, PA-TE City, Taoyuan, Taiwan, R.O.C.

This type of sensor in about 0.4mm thick, which allows the wiring and entire

encapsulation to be less than 2mm thick. This can perfectly serve implementation in department such as Intensive Care Units or Emergency department, where the patient lies on a mattress and a thin sensor array introduces minimal interference and inconveniency.

Although the Piezo ceramic sensor provides reasonably good signal to background noise separation, other sensor types such as accelerometers can also be used to improve this separation at the cost of thickness. Accelerometers can also offer pre- amplification on the device level, offering the option to deliver larger signal right off the sensor and thus be less susceptible to electro-magnetic interferences (hereinafter EMI). Where with sensors like non-amplified Piezo ceramics one might need to use shielded and/or twisted-pair transmission line from the sensor to the electronics, in the case of sensors with integrated pre-amplifier non-shielded transmission lines can be used, such as flex cables or low-cost simple pair. Such MEMS accelerometers can even provide digital output virtually immune to EMI. One such example of an accelerometer is

KXP74-1050 available from Kionix, Inc., 36 Thornwood Drive, Ithaca, NY 14850, USA. A typical assembly of such a sensor is shown in Fig. 2D.The silicon encapsulation (201) encapsulates, in this example, flex cable (206) that provides the transmission lines, other lines required for the operation of sensor (208) and the contacts to the sensors and other parts as might be required (not shown in Fig 2D). A thin PCB (0.4mm) (207) or a similar material is fused to the other side of flex (206) to support two functions: (1) provide mechanical flatness to the flex cable that is required for SMT devices such as sensor (208); (2) provide a large area facing the vibration waves to accumulate the pressure over area and improve the force/mass ratio of the unit. This will result in larger acceleration of the sensor and thus better sensitivity to the vibrations signals. It would be appreciated that other electronics assembly technologies can be applied with the same motivations and results.

In Fig. 2E mesh (209) is added, covering all areas in sensor array (200) where elongation is not desired. In some embodiment elongation forces induce stress on the electrical lines encapsulated in the relatively soft silicon. The characteristic of

submission to pressure is desired to create a good acoustic contact between array

(200) and the body of the patient. Also flexibility of the silicon is desired to conform with the curvatures of the patient's body to provide for a good acoustic contact. The elongation does not contribute to the placement of the array on the body but it allows stress to be induced in the internal components, mainly wires and soldering. Mesh (209) prevents the undesired elongation while allowing the softness and flexibility of the array. One such mesh that can be used for this purpose is S/9116 available from Warwick Mills Inc., 301 Turnpike Rd., New Ipswich, NH. 03071 USA

In Fig 2F, the surface of the silicon encapsulation is flat as shown by numerical indicator (210). This is useful when the attachment to the patient skin is made using double-sided gluing sticker. Methods involving such sticker used with an acoustic array (200) are described in details in US Patent Application S/N 12/805,082 to the same assignee. It would also be appreciated that the array can be constructed completely flat as described in reference to Intensive Care Units and Emergency Departments. Although rise-up (210) adds thickness to the array, the advantage in having it is a more firm and definite acoustic contact in the correct location, right against the sensors.

In another embodiment of the invention shown in Figure 2G, the material used for the encapsulation is not homogenous. In this example volume (211) that is used to establish the contact between the sensor array and the patient can be made from medical grade material such as Silastic ® MDX4-4210, available from Dow Corning Corporation, Midland, Ml 48686-0994, USA, whereas the rest of the array volume (212) can be made from industrial grade material, thus reducing the materials cost of the complete assembly. The configuration of Fig. 2G can also be used in association with structural and acoustic considerations such as using rigid material for volume (211) to transfer motion to sensor (204), capable of moving in softer material (212).

In another embodiment of the invention shown in Fig. 2H, to allow piezoelectric sensor (204) to experience stress due to vibrations, volume (213) is selected from relatively soft material while the sensors interconnection volumes (214) are made from a more rigid material to maintain a more firm spatial geometry of the sensors array.

In the embodiment of Fig. 2J, a cap (215) made of relatively rigid material is mounted on the side of the array pointing away from the patient. This cap allows producing acoustical engagement to the patient using the method of Fig. 4 and Fig. 5 (explained below) but still maintaining a cavity (216) that prevents pressure from air-cushion (401) of Fig. 4 on material (217) encapsulating sensor (204) in the sensor area, thus allowing sensor (204) efficient dynamic mechanical response to vibration signals as required to receive the desired stress on the sensor and thus the piezoelectric signal. Air cavity (216) also functions to reduce the acoustical engagement of the encapsulating material with the pressuring agent (401 of Fig. 4 in the example of this disclosure) and thus reduce undesired penetration of external noise though the rear side of the sensors. In another embodiment of the invention, cap (215) is replaced with structure (218) of Fig. 2K. This structure is an integrated part of the encapsulation material and therefore can easily be manufactured in a simpler molding process of the array. Structure (218) acts to prevent the rear side of the sensor from being in contact with the pressuring agent (401 of Fig. 4) and thus reduces acoustical noise transfer from the rear side of the array. Sensor array positioning

Sensor arrays position on the patient is exemplified in Fig. 3, where the vest is not shown for clarity purposes. The sensor arrays (200) are positioned on both sides of the patient's (100) spine (300). Application of array to body A conceptual layers structure (400) of the back of the vest is depicted in the cross section of Fig. 4 (vest not shown for clarity), comprising a sensor array (200), an inflatable air cushion (401) for adjusting uniform pressure on each of the individual sensor encapsulation elements (201) and a rigid support (403) having the shape of the human back, to support the air cushion (401) in the right curvature.

Mode of usage is shown in Fig. 5 (vest not shown for clarity). After wearing the vest the patient (100) rests against the back of a chair (500) to provide pressure (502) that will hold the sensors in firm contact with the back of the patient. Vest configurations:

Fig. 6 is a schematic drawing of a basic front view of the vest (101), comprising two sensor arrays (200) located inside the rear side of the vest.

Fig. 7 is a schematic drawing of an alternative configuration of the vest (101), in which a replaceable fabric (700) or other material, covers the sensor arrays, allowing only the curved casing protrusions (201) to be exposed through holes in the fabric, to allow acoustic contact with the patient's skin.

Figs. 8A and 8B are front and top views, respectively, of yet another embodiment of the vest (101), comprising a perimeter sensor, e.g. a rubber variable electrical resistor (800), such as ht^:/ www.robotshop.(X)m/images-sdentific-8inch-stretch-sensor.html, connected to the vest in points (801) and (802), thus creating a smaller perimeter than the vest itself. When the vest is worn and fastened, the rubber stretches. When the patient inhales and exhales the rubber is stretched and released accordingly, creating electrical measurable changes in resistivity that enable displaying an

inspiration/expiration curve.

Figs. 9A and 9B depict yet another embodiment of respiratory measurement, using a stretchable fabric (900), such as EeonTex LM247261 , available from Eeonyx

corporation (www.eeonyx.com), that changes electrical resistivity as it stretches. The fabric may comprise a thermal sensor (901) such as thermistor, optionally in contact with the skin, for measuring skin temperature. Alternatively, the thermistor may be isolated on the external side to minimize heat conduction and thus set faster to the correct temperature. Figs. 10A and 10B are schematic drawings of the vest (101) comprising additional sensors on top of the respiratory vibration sensors.

Two ECG sensors (1001) are depicted in Fig. 10A, connected to the inner part of the shoulder straps (102). The ECG sensors may be metal sensors mounted on Styrofoam supports to ensure good contact. Additionally, a single ECG sensor may be used, that uses conductive fabric (1002), such as EeonTex 170NW-PI-15, available from Eeonyx corporation (www.eeonyx.com), instead of metal, and is also placed on Styrofoam supports to ensure good contact. Additional ECG contacts may be added.

One or two sets of acoustic sensors ( 003) may be positioned in the vest, to pick up posterior or side respiratory sounds. An additional acoustic sensor (1004) may be mounted at a position optimized for the recording of heart beat sounds. It may be used for Ejection Fraction (EF) calculations using, for example, the method described in Published PCT Application WO2009118729 to the same assignee, said application incorporated herein in its entirety.

Two galvanic contacts ( 005, 1006) may be used for measuring the fluid level

(www.omnimedicalsupply.com/zoe_setup.htm).

Prothrombin Time (PT) and International Normalized Ratio (INR), which indicate blood coagulation parameters, is a device external to the vest, working similarly to a diabetic monitoring device.

Additional galvanic contacts (1007, 1008) may be used for measuring skin conductivity, which indicates sweating level.

Fig. 11 is a schematic drawing of the vest (101) comprising blood pressure

measurement means integrated into the vest. A blood pressure inflator (1100) is combined in the vest sleeve, connected via an air tube (1 01) to an electronic interface (1102) of the measurement device. In a preferred embodiment of the invention the sleeve incorporating the inflator (1100) can be detached from the vest by means of zipper and be removed with tube (1101) and electronics interface (1102).

Fig. 12 is a schematic drawing of the back of the vest (400) of Fig. 4, now shown in a configuration without a vest. Instead, this back is installed on a chair (500), using metal construction (1202). This metal structure fits the back-rest (1201) of many chairs and is simply mounted on the back-rest of the chair. Screws (1203) and (1204) attach back (400) to metal structure (1202). Metal structure (1202) may have a vertical series of holes for screws (1203) and (1204) or a vertical slit to adjust the height of back (400) to the size of the patient and the height of back-rest (1201).

In this embodiment the patient simply sits on the chair and rests back to get in contact with the sensors. Decorative and aesthetic features can be combined with back (400) to make it more pleasant to use.

In another embodiment of the invention the Smartphone manages the complete flow of process. The Smartphone has a "Start" key, on the touch screen, which starts the measurement sequence. When the patent hits "Start", the Smartphone communicates with the electronic means to ensure all communication and functions are in a working condition. Then the Smartphone presents a message (and/or plays a sound message saying "When ready to measure lungs click "Measure Lungs"". The patient then clicks "Measure Lungs" and breaths as required. When the measuring time is up the

Smartphone displays and/or pronounces: "Measure completed. When ready to measure blood pressure click the "Start" button on the blood pressure monitor device".

After the Smartphone reads the blood pressure value it displays and/or announces the message: "Blood pressure measurement is completed"... and so on.

In another embodiment of the invention the Smartphone manages the complete flow of the process and the function of the measurement devices.

In this example a blood pressure device will be used. In the flow described above the patient has to click the "Start" button on the blood pressure monitor and thus be involved with the interface of two devices that frequently do not have the same look n' feel and occasionally do not have the same logic. In this preferable mode the blood pressure monitor is fully controlled by the Smartphone, not only for reading

measurement values but also for the "Start" command and any other function.

In this situation, in the step of measuring blood pressure, the message from the

Smartphone will be "Measure completed. When ready to measure blood pressure click the "Measure BP" button, whereas this button is on the Smartphone touch screen.

After the user click "Measure BP", the Smartphone activates the blood pressure monitor until the measurement is completed. In yet another embodiment of the invention, for certain measurements, particularly such that involve respiratory functions, the orientation of the patient might be important for a proper measurement procedure. In such a case an inclination senor (or accelerometer) is mounted in the vest, preferably at the back side between the acoustic sensors.

In one embodiment the angle of inclination may be recorded and transmitted with the data to enable the healthcare team to know the inclination of the patient during measurement and interpret the measured values accordingly.

In a second embodiment, if the inclination of the patient is out of the desired range the Smartphone advises the patent in which direction and what degree to move so as to adjust his inclination as required by the measurement.

In another embodiment of the invention the Smartphone displays a dial and scale with red range and green range. The dial points at the current inclination of the patient and by changing inclination the patient can bring the dial into the green range while having a real-time visual (or audible) feedback on the Smartphone.

The application on the Smartphone may be configured to refuse measurement if the inclination of the patient is not within the required range.

In yet another embodiment of the application, where the patient is occasionally not compliant (does not execute the physician's instructions as required) or for other reasons, the system can be configured to advise a relative or a friend of the patient, by phone or email or any other communication means, and thus get him to communicate the patient and check on him, verifying he is OK and about to conduct the monitoring process. Such a system can be configured to contact such a person using scheduled monitoring program that is programmed into the Smartphone or the remote computer. This program follows up on the schedule and patient compliance. If, for example, more than 4 hours have elapsed since the scheduled time for the patient to execute monitoring and the monitoring process has not been completed, the Smartphone or the server communicates the designated person, to his mobile phone, email, line phone or any other means and advises the person regarding the incompliance.

Reference is made now to Fig. 13A illustrating another embodiment of the invention. In this embodiment sensor (204) is not in direct contact with encapsulation material (211 ) and/or (212) as shown in Fig. 2. Instead, sensor (204) is encapsulated in a thin housing (1300) which is encapsulated in material (211) and/or (212). It is appreciated that materials (211) and (212) may be the same material. With this arrangement, the member receiving the acoustical vibrations from the encapsulating media is enclosure (1300). As a result, enclosure (1300) is displaced in a direction vertical to sensor (204) surface. Due to the inertia of sensor (204), the sensor bends and stress is generated upon its surface, whereby an electrical signal is created and is useful for measuring the acoustical vibrations.

Fig. 13B is an enlarged illustration of enclosure (1300) and sensor (204), showing how sensor (204) is suspended through its perimeter in the enclosure so that it can vibrate vertically to its surface plane. Suspension might be throughout the entire perimeter of sensor (204) or through part of the perimeter.

This arrangement can provide additional flexibility in different sensitivities according to the way sensor (204) is mounted relative to its environment (in contact with the encapsulation media or suspended off the encapsulation media.

In Fig. 13C three enclosed sensors such as the sensor of Fig. 13B are arranged on a fabric (1301). The advantage of many fabrics is low acoustic conductivity. This arrangement, therefore, supports lower cross-talk between the sensors while holding them in the matrices arrangement of Fig. 2A and Fig. 2B.

It would be appreciated that fabric layer (1301) may be replaced by other materials such as memory-foam (polyurethane with additional chemicals increasing its viscosity and density) which is often referred to as Visco-elastic polyurethane foam.

Such materials are available from http.V/viscomemoryfoammattress.com. The thickness of layer (1301) may be selected to suit the mode of use. For example, to attach the sensors to the back of a patient by pressure as described above in Fig. 5, one may use 2-5 cm Visco layer instead of the inflator layer (401) of Fig. 4.

Reference is made now to Fig. 14A illustrating another embodiment of the invention. In this embodiment a small mass (1302) is attached to sensor (204) surface. This mass increases the inertia of the center of the sensor. When enclosure (1300) vibrates in direction perpendicular to the plane of sensor (204), mass (1302) is more resistive to these vibrations due to the increased inertia. As a result the stress on sensor (204) increases and electrical signals, for a given vibration, are larger than in the configuration illustrated in Fig. 13B.

Fig. 14B illustrates even more sensitive sensor by adding an additional mass (1303) on the other side of sensor (204).

The masses of Fig. 14A and Fig. 14B can be typically designed in the range of 0.1 g to 1.0g, depending on the desired increase in sensitivity and effect on resonance frequency and frequency response.

Reference is made now to Fig. 14C, illustrating the assembly of Fig. 14B with additional two holes (1304) and (1305) in enclosure (1300). These holes allow air flow between the internal volume of the enclosure and the external environment. When enclosure (1300) moves back and forth relative to sensor (204), the enclosed volume above and under sensor (204) is changed at the vibration frequencies. This is most evident for low frequencies. As a result, the pressure above and under sensor (204) changes in a manner that resists to the vibration and therefore reduces sensitivity, especially at low frequencies. Holes (1304) and (1305) allow air flow in response to changes in volume and prevent pressure buildup.

In yet another embodiment of the invention, the Piezoelectric element may be supported in the center as shown in Fig. 15A and not at the perimeter as shown in Fig. 14A. With this arrangement, when housing (1300) vibrates, the center of Piezoelectric element (204) vibrates with the housing while the inertia of the perimeter of Piezoelectric element (204) provides for the stress exercised on the Piezoelectric element (204) to generate voltage output in response to the vibration. In this assembly the perimeter inertia can be increased by adding a mass (1501) which is shaped as a ring and is attaches to the Piezoelectric element. This structure is shown also in cross-section AA in Fig. 15B where the different elements are marked by numerical indicators in conjunction with Fig. 15A.

The main advantage of the arrangement of Fig. 15A is that it allows adding a

considerable inertia to the assembly, making the sensor even more sensitive.

Fig. 15C demonstrates that the inertia mass does not have to be a complete ring. One can add the inertia at the perimeter from a few sections of an arc of a ring (or just a few cubic-like masses). This provides for a large range of controlling the behavior of the device in the presence of vibrations.

It would be appreciated that all masses of Fig. 15A, 15B and 15C can be added also on the other side of Piezoelectric element (204).

It would also appreciated that the round shape of the Piezoelectric element is provided as an example but it is not a limiting geometry of the invention.

It would also be appreciated that the disclosed vibration sensing technology may serve a stand-alone electronic stethoscope. In this case a single module is used in

conjunction with an amplifier, analog to digital converter, signal processing board, memory and power supply such as a battery and user interface, such as 3M™

Littmann® Electronic Stethoscope Model 3200 available from Zargis Medical, Stamford, CT, USA.

In reference to Fig. 8 above, a torso perimeter sensor was described being constructed from elastic variable resistor (800). This method has the limitation of being susceptible to tear under mild stress. In another embodiment of the invention a novel torso perimeter is presented that can stand high stress and also generate its own voltage signal. This sensor is illustrated in Fig. 16A where (1601) is a Piezo-electric device such as OBO-TE20265-16 available from OBO PRO.2 INC, No. 224-9, Lane 105, Yung-Feng Road, PA-TE City, Taoyuan, Taiwan, R.O.C. Piezo-electric device (1601) is glued to the bottom plane of a structure (1603). Strips (such as any fabric strip) (1604) and (1605) are connected to the top section of the vertical side-walls of structure (1603). Electrical wires (1602) deliver the voltage generated in Piezo-electric device (1601) as a result of stress.

Fig. 16B illustrates how this assembly operates. Strips (1604) and (1605) are pulled to the sides as shown by the nearby arrows. As a result the side-walls of structure (1603) bend outwardly and the bottom part of structure (1603) bends, causing Piezo-electric element (1601) to bend as well. As a result an electrical voltage is generated on Piezoelectric element (1601) that can be measured on electrical wires (1602).

Fig. 16C illustrates how this structure is useful in measuring torso perimeter. Structure (1603) is held by strips (1604) and (1605) that are wrapped around the torso like a fastened belt. When the person of Fig. 16C breaths, the length of the perimeter of the torso changes and changes the stress imposed on strips (1604) and (1605). As a result of the stress changes structure (1603) is bending back and forth, inducing correlated stress changes on sensor (1601). These changes are measured as voltage changes in wires (1602).

It would be appreciated that the technical design of Fig.16A is provided as an example and the invention is not limited to this design. The scope of the invention refers to mechanical designs that incorporate an elastic element to which a Piezoelectric element is attached wherein the mechanical element is distorted using an element movable by breathing motion of the torso and as a result, induces stress onto the Piezoelectric element. This stress produces the voltage useful to electrically measure breathing parameters.

This general scope is demonstrated by another example of Fig. 17A and Fig. 17B. Fig. 17A is a top view of a twisted structure (1606) which has a flat central part to which a flat Piezoelectric element (1601) is attached. The right end of structure (1606) is twisted 90 degrees in one direction and the left end is twisted 90 degrees in the other direction.

The operation of this assembly is explained in reference to Fig. 17B.

Strips (1604) and (1605) are attached to each of the right and left ends of structure

(1606). By pulling these strips in opposite direction as shown by the arrows of Fig. 17B, structure (1606) is distorted and bends generally about dashed-line (1607). As a result the attached Piezoelectric element (1601) experiences stress and produces a voltage that is indicative of the force used to pull strips (1604) and (1605). When attached to a torso in the mode described in reference to Fig. 16C, the torso perimeter changes can be evaluated via this voltage.

Reference is made now to Fig. 18A where an alternative design of the sensor is presented. Fig.18A displays a housing (1300) for the piezoelectric sensor. It is designed to have 3 pedestals (1800), (1801) and (1802) that are used to hold the piezoelectric sensor in three points. This is shown in reference to Fig 18B where sensor (204) is shown to rest on the 3 pedestals (1800), (1801) and (1802). By constructing the sensor this way, using a small number of pedestals such 2, 3, 4 or 5 as examples, much of sensor (204) area can maintain flexibility and therefore good sensitivity to vibrations of housing (1300).

Weight (1303) may be added in the center of the sensor to increase the inertia of the central part of the sensor and enhance further the vibration signals transmitted via the housing (1300). This is similar to the method of Fig. 14.

After assembly of Piezoelectric element (204) in housing (1300), a round cover in the shape of a disc (not shown in Fig. 18) can be glued as a cover of the housing part (1300).

Pedestals (1800), (1801) and (1802) may be constructed of the same material as the housing and provide rigid plastic characteristics, or made from flexible material such a rubber or silicon. Piezoelectric element (204) may be glued to the pedestals by hard epoxy glue that transfers well the vibrations but limits the Piezoelectric element (204) flexibility. Piezoelectric element (204) may also be glued to the pedestals by soft glue such as silicon glue that partially reduces transfer of vibrations from housing (1300) but allows more flexibility to Piezoelectric element (204).

Fig. 19 demonstrates a cross section of an example of a 2-parts housings with a design similar to the design of the single housing part of Fig. 18.

Pedestal (1800) is visible through the cross section and pedestal (1801) is shown cut at the cross section. Similarly, pedestal (1806) of the upper housing (1900) is visible through the cross section and pedestal (1805) is shown cut at the cross section. In Fig. 19A the two parts are shown separated without a Piezo sensor.

The two parts are designed so that when they are joined together as shown in Fig. 19B with Piezoelectric senor in between, the upper pedestals meet with the lower pedestals to hold Piezoelectric sensor (204) in place. This can provide for simple and fast assembly of the Piezoelectric sensor and the housing.

Fig. 19C demonstrated an alternative to Fig. 19B by allowing some space for glue (1902) in each of the meeting points of the pedestals and Piezoelectric sensor (204). Through glue selection (soft or rigid) one can control the tradeoff between vibration transfer from the housing to Piezoelectric sensor (204) and the flexibility of Piezoelectric sensor (204). It would be appreciated that also in reference to Fig, 19 the pedestals may be constructed of different materials to control vibration transfer and flexibility of Piezoelectric sensor (204).

The housing itself for all housing examples may be constructed from typical materials for this purpose such as ABS.

Reference is made now to Fig. 20 demonstrating another embodiment of the invention. Figure 20A is a top view of the assembly of the housing and Piezoelectric sensor (204) according to this embodiment and Fig. 20B is a cross section of Fig. 20A.

In this embodiment Piezoelectric sensor (204) is held only on one side by pedestal (2001). Inertia weight (2002) is mounted opposite to the side of the pedestal. With this configuration sensitivity of the assembly to lower frequencies is improved.

Remote auscultation

Typical face to face auscultation, when a patient stands in front of the medical team person, is made by moving the stethoscope from one place to another over the torso surface of the patient to listen to different lung sections.

This is not possible with remote auscultation since the medical team person can not control the sensor placement and can not trust the patient to place it reasonably where needed. The wearable sensor array provides a distribution of sensors over the torso surface that can resolve this problem.

The wearable sensors of the present invention are also configured for effective remote auscultation as explained in reference to Fig. 2 .

The patient under examination is represented by numerical identification (2000). His torso is represented by numerical identification (2001) and his lungs are represented by numerical identification (2002).

In the example of Fig. 21 , 36 sensors (2014) are attached to the back of the patient as illustrated. The 36 sensors cover the area of both lungs and the position of each sensor relative to the assembly is known. The position of the sensor array relative to the lungs is determined using anatomical references to roughly keep the sensors in a known anatomical registration, as described in details above in reference to Fig. 1 to Fig. 12. Electrical leads provide for signal transfer from each sensor to electronics that represents any alternative such as electronics (107) of Fig. 1 B that uses wireless communication to communicate with a computer or an external communication device or it may be connected by wires (2018) to such an external device (2020) as shown in Fig. 21. The trivial implementation of such a device is a computer.

Computer (2020) is connected to the Internet (2022) which in turn, is connected to a remote computer (2024). The remote computer (2024) has screen (2026) that serves as an interface to the remote operator who performs the remote auscultation. Screen (2026) presents a display of sensors array (2028) that represents sensors array (2014) at the patient's side.

After the patient had put on the sensors and is in the position of recording as described above, and computer (2020) is connected through the Internet (preferably peer to peer). With computer (2024), remote auscultation can start.

The remote operator selects a sensor to listen to by pointing at a sensor on screen (2026) such as sensor (2030). As a result, computer (2024) sends an instruction to computer (2020) to start transmitting the sound signal from sensor (2032) which is the sensor equivalent to the sensor-representation selected by the remote operator. The audio sound that is digitized on the patient's side of the system is transmitted typically in a streaming mode over the peer-to-peer connection to computer (2024) where the incoming signal is modified into analog signals that can be sent to earphones or a loudspeaker connected to computer (2024).

The operator can then select different sensors in the same way and thus listen to any portion of the lungs without a need to move the sensor from one torso location to another as it is typically done during a face-to-face meeting but is impossible with remote auscultation having one sensor.

In another embodiment of the invention, the operator can select more than one sensor to have their signals joined together on the remote electronics (2020) and be

transmitted in the same way as one sensor.

In yet another embodiment of the invention, the transmitted auscultation data can be transmitted to more than one location, enabling two or more users to listen

simultaneously to the same patient, while the control of selecting the sensor to which they want to listen may be with any one of them or only with one of them at a given time. With this capability the remote users (that are also remote from each other) can discuss the real time breathing of a remote patient and improve the medical service as a team.

Methods to transmit the audio signal from the remote electronics (2020) to the operator's electronics (2024) in virtually real time such as peer-to-peer connection (known also as P2P) and streaming technologies are known in the art.

It would be appreciated that the geometrical arrangement of the sensors over the surface of the torso is presented hereinabove as an example for one embodiment and it is not limited to this geometry.

It would also be appreciated that the communication method presented here to provide for the sound signal to be transferred from a sensor to the operator is not limited to the embodiment presented here and that telephone lines or other media can serve the same purpose.

It would also be appreciated that the devices used in the above embodiment to support the remote sensor selection for auscultation is not limited to the devices of the presented embodiment and other devices can be used.

Claims

1. A garment having a back side and a front side, comprising:

means for adjusting the garment to a patient's torso;

at least one array of respiratory vibration sensors connected with said back side of the garment;

electronic means for reading the sensors, connected with the garment; and communication means for communicating bidirectionally between said electronic means and an external electronic device.

2. The garment of claim 1 , wherein said extemal electronic device comprises one of the group consisting of a Smartphone, a tablet PC, a laptop and a dedicated electronic device.

3. The garment of claim 1 , wherein said extemal electronic device comprises a computer application program for at least one of managing and sequencing said sensors' operation.

4. The garment of claim 3, wherein the application program in the extemal electronic device is configured to follow up on patient compliance and notify another person in case of non-compliance.

5. The garment of claim 3, wherein the application program in the external electronic device is configured to support video conference between the electronic device and a healthcare personnel computer.

6. The garment of claim 1 , wherein said communication means are wireless.

7. The garment of claim 1 , wherein the sensors are encapsulated in flexible material.

8. The garment of claim 7, wherein the skin of the patient comes in direct contact with the sensors' encapsulation.

9. The garment of claim 1 , wherein the sensors are covered by a replaceable cover.

10. The garment of claim 9, wherein the cover comprises holes.

11. The garment of claim 10, wherein the sensors are encapsulated in flexible material and wherein the holes are designed to allow the sensors' encapsulation to protrude therethrough.

12. The garment of claim 1 , additionally comprising at least one sensor for sensing other physiological conditions.

13. The garment of claim 12, wherein said additional at least one sensor is selected from the group consisting of torso perimeter sensor, skin surface thermometer, inspiration/expiration detector, ECG, skin galvanic response and fluid level detector.

14. The garment of claim 12, wherein said additional at least one sensor is

selected from the group consisting of blood pressure monitoring device, oximeter, pulse oximeter, spirometer, respiratory peak meter, glucose monitor, scales and PT/INR.

15. The garment of claim 1 , wherein the data communicated from said electronic means to said external electronic device comprises measurements data and wherein the data communicated from said external

electronic device to said electronic means comprises operation commands.

16. The garment of claim 15, wherein the electronic device controls non-autonomic functions of at least one sensing device.

17. The garment of claim 16, wherein the non-automatic functions are selected from the group consisting of turning device on, initiating measurements and turning device off.

18. The garment of claim 15, wherein said operation commands comprise at least one of managing commands and sequencing commands.

19. The garment of claim 1 , wherein the thickness of said at least one array of sensors is smaller than 20mm.

20. The garment of claim 1 , wherein the thickness of said at least one array of sensors is smaller than 2mm.

21. The garment of claim 1 , additionally comprising a cushion for providing

pressure distribution among the sensors and a rigid support to support the cushion to receive the shape of a human back.

22. The garment of claim 21 , wherein the cushion comprises an inflatable air cushion.

23. The garment of claim 21 , wherein the cushion comprises soft material.

24. The garment of claim 14, wherein the inflator of the blood pressure monitoring device is integrated with the garment in the form of an arm sleeve.

25. The device of claim 24, wherein the arm sleeve with the inflator is detachable from the garment by detaching means.

26. The garment of claim 1 , comprising means for measuring the inclination angle of the patient.

27. The garment of claim 26, comprising an electronic display indicating the inclination angle of the user.

28. The garment of claim 26, comprising an electronic device application that refuses to conduct a measurement until the patient is in a predefined inclination range.

29. A system for evaluating a patient's physiological condition, comprising:

a garment having a back side and a front side, said garment comprising:

means for adjusting the garment to a patient's torso;

respiratory vibration sensors connected with said back side of the garment;

electronic means for reading the sensors, connected with the garment;

and

communication means; and

an external electronic device communicating bi-directionally with said electronic means, said external electronic device comprising a computer application program for at least one of managing and sequencing said sensors' operation.

30. The system of claim 29, wherein the application program in the external electronic device is configured to follow up on patient compliance and notify another person in case of non-compliance.

31. The system of claim 29, wherein the application program in the external electronic device is configured to support video conference between the electronic device and a healthcare personnel computer.

32. A back rest for sensing a patient's physiological condition, comprising:

at least one array of respiratory vibration sensors;

an inflatable air cushion for providing pressure distribution among the sensors;

a rigid support having a shape to support the air cushion so as to properly receive a human back;

electronic means for reading the sensors, connected with the garment; and communication means for communicating bidirectionally between said electronic means and an external electronic device.

33. The back rest of claim 32, comprising means to fasten the back rest to a chair.

34. The back rest of claim 32, comprising means to adjust the back rest to a patient's size.

35. The garment of claim 1 , comprising at least two galvanic contacts to the skin of the patient.

36. The garment of claim 35, wherein said galvanic contacts are usable for measuring ECG.

37. The garment of claim 35, wherein said galvanic contacts are usable generally in measuring fluid level.

38. The garment of claim 35, wherein said galvanic contacts are made of metallic material.

39. The garment of claim 35, wherein said galvanic contacts are made of smart fabric.

40. The garment of claim 35, wherein said galvanic contacts are constructed on a flexible podium to provide functionality of pressing the contacts against the skin of the patient.

41. The garment of claim 40, wherein the flexible podium comprises one of Styrofoam, rubber, and silicon rubber.

42. The garment of claim 1 , wherein additional vibration sensors are positioned in the front of the garment.

43. A vibration sensor array comprising:

a plurality of sensors constructed in a substantially flat geometry arranged with the flat side substantially perpendicular to the direction of the vibration,

wherein said sensors are encapsulated in flexible material and wherein said

encapsulated sensors are arranged in a pre-determined spatial geometry.

44. The array of claim 43 whereas said sensors are piezoelectric sensors.

45. The array of claim 44, wherein the piezoelectric material is selected from the group consisting of crystal, ceramic and polymer.

46. The array of claim 44, wherein the piezoelectric material is assembled on a relatively thin supporting material.

47. The array of claim 46, wherein said supporting material comprises one of metal support and a ceramic piezoelectric material.

48. The array of claim 46, wherein said supporting material faces the vibration source.

49. The array of claim 45, wherein the piezoelectric material faces the vibration source.

50. The array of claim 44, wherein the sensors are connected to an electronic amplifier via one of a coax cable, a twisted-pair cable, a shielded pair cable and a shielded twisted pair cable.

51. The array of claim 50, wherein said connection cables are encapsulated in said flexible material.

52. The array of claim 44, wherein the sensors are connected to an electronic amplifier via one of a flex PCB and a shielded flex PCB.

53. The array of claim 52, wherein said connection cables are encapsulated in said flexible material.

54. The array of claim 44, wherein said spatial geometry is enabled by the structure of said flexible material.

55. The array of claim 44, wherein a first electronic amplifier is connected to said sensors in a relatively close proximity to said sensors.

56. The array of claim 55, wherein said a first electronic amplifier is encapsulated in said flexible material.

57. The array of claim 44, wherein a first electronic amplifier is connected to said sensors in a relatively distant location in reference to said sensors.

58. The array of claim 44, wherein said sensors are accelerometers.

59. The array of claim 58, wherein said accelerometers are mounted on a relatively light and wide area surface operative to vibrate in response to vibration waves and move the mounted accelerometer accordingly.

60. The array of claim 58, wherein said accelerometer are mounted on a flat surface PCB.

61. The array of claim 58, wherein said accelerometers are mounted in a flex PCB and the flex area under the sensor is supported by a flat element to provide the desired flatness.

62. The array of claim 58, wherein said accelerometers are built using MEMS

technology.

63. The array of claim 44, wherein each said sensor comprises a pre-amplifier.

64. The array of claim 44, wherein each said sensor comprises an analog-to-digital converter.

65. The array of claim 44, wherein the encapsulation in the near proximity of said sensor has a standoff structure on the side facing the vibration source to provide better acoustic interface contact between the vibration source and the sensor.

66. The array of claim 65, wherein said standoff structure has a convex shape.

67. The array of claim 65, wherein said standoff structure has a flat ramp shape.

68. The array of claim 44, wherein the encapsulation in the near proximity of said sensor thickness is minimized to provide an overall thin sensor array .

69. The array of claim 44, wherein a mesh of relatively low-elongation material is embedded in said encapsulation material, said mesh is operative to reduce the elongation yield of the sensors array.

70. The array of claim 69, wherein the material of the mesh is one of polyamides (Nylon) and aramid (Kevlar).

71. The array of claim 69, wherein one direction of the mesh threads is generally aligned with the direction of the long dimension of the sensor array.

72. The array of claim 69, wherein one direction of the mesh threads is generally aligned with the direction of the short dimension of the sensor array.

73. The array of claim 69, wherein the mesh is positioned between the sensors and the vibration source.

74. The array of claim 69, wherein the sensors are positioned between the mesh and the vibration source.

75. The array of claim 69, wherein at least two of said mesh layers are encapsulated in the sensor array encapsulation.

76. The array of claim 75, wherein the direction of the threads of said at least two mesh layers are arranged in directions to complement each other to minimize elongation of the assembly in the desired directions.

77. The array of claim 44, wherein the encapsulation material is not homogenous.

78. The array of claim 77, wherein encapsulation material in proximity to the sensor is different than the encapsulation material between the sensors.

79. The array of claim 78, wherein encapsulation material in proximity to the sensor is optimized to the sensing function and the encapsulation material between the sensors is optimized to the support of the spatial geometry of the sensors array.

80. The array of claim 77, wherein the encapsulation material generally between the sensors and the vibration source is different than the rest of the encapsulation material.

81. The array of claim 78, wherein encapsulation material generally between the sensors is optimized to the sensing function and the rest of the encapsulation material is optimized to the support of the spatial geometry of the sensors array.

82. The array of claim 44, wherein the sensor side opposite to the vibration source is encapsulated with material and geometry that provides for sensor dynamic mechanical distortions in response to vibrations.

83. The array of claim 82, wherein the outermost encapsulation element in the sensor area, in the side opposite to the vibration source, is hollow.

84. The array of claim 83, wherein said hollow encapsulation element is produced from a relatively rigid material.

85. The array of claim 77, wherein an encapsulation part including the surface that is in contact with the vibration source is made of medical grade material and the rest of the encapsulation is made from industrial grade material.

86. The array of claim 43, wherein a structure is positioned on the rear side of the array to reduce direct contact of the encapsulation material with the pressing means.

87. The array of claim 86, wherein said structure is a cap.

88. The array of claim 86, wherein said structure is an open elevated structure.

89. The array of claim 86, wherein said structure is an integrated section of the encapsulation.

90. The array of claim 86, wherein said structure is a separated add-on to the

encapsulation structure.

91. The array of claim 44 whereas the sensors are enclosed so as to create a gap between said sensor surface and the encapsulating material.

92. The array of claim 91 , wherein the encapsulating material is replaced by a fabric layer that holds the enclosed sensors in the desired position.

93. The array of claim 92, wherein the fabric layer is replaced by an elastic foam layer.

94. A sensor for sensing vibrations, said sensor constructed of:

a flat piezoelectric element;

an enclosure holding said piezoelectric element generally in its perimeter, providing it the degree of freedom to vibrate in direction perpendicular to the sensor plane; and a mass assembled on the surface of the piezoelectric element.

95. The sensor of claim 94, wherein one mass is added to one side of the sensor and another mass is added to the other side of the sensor.

96. The sensor of claim 94, wherein said sensor is enclosed so as to create a gap between said sensor and said enclosure and wherein said enclosure holding said piezoelectric sensor has at least one hole allowing air flow.

97. A sensor for sensing vibrations, said sensor constructed of:

a flat piezoelectric element;

an enclosure holding said piezoelectric element generally at its center, wherein at least a part of the perimeter of said piezoelectric element suspends free from mechanical contact within the enclosure, providing it the degree of freedom to vibrate in direction perpendicular to the sensor plane.

98. The sensor of claim 97, wherein a mass is added to at least a part of the said perimeter of said piezoelectric element suspending free from mechanical contact, on at least one side of the piezoelectric element plan.

99. An electronic stethoscope comprising the vibration sensors of claim 94.

100. An electronic stethoscope comprising the vibration sensors of claim 97.

101. A perimeter length sensor constructed of:

a piezoelectric sensor;

said piezoelectric sensor is attached to a surface of a structure;

said structure includes elements that, when pulled, bend the section where said sensor is attached; and

said elements are connected to a belt-like setup wrapped around the object of which perimeter length needs to be sensed.

102. The perimeter sensor of claim 101, wherein said structure comprises a bent flexible strip

103. The perimeter sensor of claim 101, wherein said structure comprises a twisted flexible strip.

104. The perimeter of claim 102, wherein said bent flexible strip is twisted in both ends in opposite direction.

105. A sensor for sensing vibrations, said sensor constructed of:

a flat piezoelectric element; and

an enclosure holding said piezoelectric element in at least one section that is a relatively small part of the perimeter of said piezoelectric element.

106. The sensor of claim 105, wherein the holding part is a pedestal made from the same material as the enclosure.

107. The sensor of claim 105, wherein the holding part is a pedestal made from flexible material.

108. The sensor of claim 106, wherein flexible glue is used to glue the sensor to said pedestals.

109. The sensor of claim 105, wherein said enclosure holding said piezoelectric element in just one section that is a relatively small part of the perimeter of said piezoelectric element.

110. The sensor of claim 109, additionally comprising inertia weight mounted generally on a perimeter section of the piezoelectric element that is on the far side from the holding location of the piezoelectric element.

111. A system for remote auscultation comprising:

a group of sensors distributed over the torso of a person, said sensors adapted to sensing said person's breathing sounds and transmitting the sounds to a remote auscultation device;

wherein said auscultation device has an interface for remotely selecting a sensor and wherein the auscultation device comprises audio means for enabling the operator to listen to the sound received by said selected sensor.

112. The system of claim 1 1, wherein said auscultation device interface is adapted to selecting a plurality of sensor and wherein the auscultation device comprises audio means for enabling

the operator to listen to the combined sound received by said selected sensors.

113. The system of claim 111, wherein the system includes more than one auscultation device that receives signals from said sensors.

114. The system of claim 113, wherein any of the operators can select the sensors to listen to.

115. The system of claim 111, wherein the group of sensors is arranges in a wearable device used to place the sensors on the torso of said person.