Patent Publication Number: US-2022225934-A1

Title: Adjustable non-invasive wearable monitoring device

Description:
FIELD OF THE INVENTION 
     The present invention generally relates to a non-invasive wearable monitoring device. More particularly, the present invention relates to an adjustable non-invasive wearable monitoring device. 
     BACKGROUND OF THE INVENTION 
     A wearable monitoring device for non-invasive monitoring of a physiological property of a user includes one or more sensors and a wearable element configured to attach the one or more sensors to the body of the user. Most commonly used wearable monitoring devices are smart watches having a heartbeat monitoring sensor and/or a blood oxygen saturation monitoring sensor. In these sensors the user adjusts the smart watches strap according to his/her own personal convenience. Therefore, some users may adjust the sensor on their hand wrist tighter than others. 
     When measuring physiological properties such as heartbeat and oxygen saturation, the accuracy of the measurements is not sensitive to the amount of tightening of the wearable monitoring devices. However, when using a wearable monitoring device for non-invasive monitoring of other properties, a different approach must be taken. Measuring the chemical composition of the blood (e.g., the sugar levels, cholesterol levels, etc.), electrical conductivity and dehydration of the skin (e.g., measured by bio-impedance sensor), materials in the interstitial fluid such as glucose, and the like may include receiving from the tissue relatively weak measured signals. These week signals may require higher measuring sensitivity. In order to accurately measure a signal indicative of the chemical composition of the blood, or other relatively weak signals, the non-invasive sensor sending and receiving the signal should be attached to the skin of the user while avoiding over-tightening that may affect the blood flow in blood vessels beneath the skin or under-tightening that may affect the accuracy of the measurement. 
     Therefore, wearable monitoring devices for non-invasive measuring of the chemical composition of the blood may include a mechanism configured to adjust a location of a sensing element of the wearable monitoring device and/or the pressure the sensing element applies on the skin as to avoid over tightening of the device. Furthermore, such a mechanism may further be configured to send an alert to the user&#39;s computing device in case of over/under tightening. 
     SUMMARY OF THE INVENTION 
     Some aspects of the invention may be directed to a wearable monitoring device. In some embodiments, the wearable monitoring device may include: a housing, opened from at least one side; a sensing unit attached to a movable plate; and a controller. In some embodiments, the movable plate is connected to one or more spring-like elements, allowing the movable plate to move with respect to the housing so that when the one or more spring-like elements are extended, the sensing unit protrudes from the open side of the housing and when the one or more spring-like elements are compressed the sensing unit and the movable plate are retracted towards an internal space in the housing. 
     In some embodiments, the wearable monitoring device may further include: at least one displacement sensor for measuring the displacement of the movable plate with respect to a predefined location in the housing. In some embodiments, the controller may be configured to send an alert, to an external computing device, when the displacement is one of: above a first threshold value or under a second threshold value. In some embodiments, a first alert may include instructions for a user to at least one of: adjust the placement of the device and release a tightening of straps included in the device. In some embodiments, a second alert may include instructions for a user to at least one of: adjust the placement of the device, and slightly tightening of straps included in the device. 
     In some embodiments, the housing is configured to hold the sensing unit and the movable plate. In some embodiments, the wearable monitoring device may further include: an additional housing for holding at least one of: the controller and an additional sensing element. In some embodiments, the housing further holds the controller. In some embodiments, the controller comprises a processor and a communication module for communicating with the external computing device. In some embodiments, the spring-like element is one of: coil spring, volute spring, tension spring, leaf spring and an element made from an elastic material. 
     In some embodiments, the at least one displacement sensor is at least one of: a sensing element comprising a light source and a light sensor, a force sensing resistor, a strain gauge and a piezoelectric sensor. In some embodiments, the sensing unit may include: at least one light source; and at least one light sensor. In some embodiments, the sensing unit may be configured to apply a predefined pressure on surface of a monitored user&#39;s body, wherein the predefined pressure is a function of a spring coefficient of the one or more spring-like units. In some embodiments, the spring coefficient of the one or more spring-like units is selected such that the predefined pressure attaches the sensing unit to the surface of the monitored user&#39;s body while avoiding blocking blood flow in blood vessels located beneath the surface. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The subject matter regarded as the invention is particularly pointed out and distinctly claimed in the concluding portion of the specification. The invention, however, both as to organization and method of operation, together with objects, features, and advantages thereof, may best be understood by reference to the following detailed description when read with the accompanying drawings in which: 
         FIG. 1  shows an illustration of a wearable monitoring device according to some embodiment of the invention; 
         FIG. 2  shows an illustration of a wearable monitoring device having a single housing according to some embodiment of the invention; 
         FIG. 3  shows an illustration of a wearable monitoring device having two housings according to some embodiment of the invention; and 
         FIG. 4  shows an illustration of an example for displacement sensor according to some embodiments of the invention. 
     
    
    
     It will be appreciated that for simplicity and clarity of illustration, elements shown in the figures have not necessarily been drawn to scale. For example, the dimensions of some of the elements may be exaggerated relative to other elements for clarity. Further, where considered appropriate, reference numerals may be repeated among the figures to indicate corresponding or analogous elements. 
     DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION 
     In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the invention. However, it will be understood by those skilled in the art that the present invention may be practiced without these specific details. In other instances, well-known methods, procedures, and components, modules, units and/or circuits have not been described in detail so as not to obscure the invention. Some features or elements described with respect to one embodiment may be combined with features or elements described with respect to other embodiments. For the sake of clarity, discussion of same or similar features or elements may not be repeated. 
     Although embodiments of the invention are not limited in this regard, discussions utilizing terms such as, for example, “processing”, “computing”, “calculating”, “determining”, “establishing”, “analyzing”, “checking”, or the like, may refer to operation(s) and/or process(es) of a computer, a computing platform, a computing system, or other electronic computing device, that manipulates and/or transforms data represented as physical (e.g., electronic) quantities within the computer&#39;s registers and/or memories into other data similarly represented as physical quantities within the computer&#39;s registers and/or memories or other information non-transitory storage medium that may store instructions to perform operations and/or processes. Although embodiments of the invention are not limited in this regard, the terms “plurality” and “a plurality” as used herein may include, for example, “multiple” or “two or more”. The terms “plurality” or “a plurality” may be used throughout the specification to describe two or more components, devices, elements, units, parameters, or the like. The term set when used herein may include one or more items. Unless explicitly stated, the method embodiments described herein are not constrained to a particular order or sequence. Additionally, some of the described method embodiments or elements thereof can occur or be performed simultaneously, at the same point in time, or concurrently. 
     Some aspects of the invention may be related to a wearable monitoring device for non-invasively measuring and monitoring of a physiological condition, for example, the chemical composition of the blood. The non-invasive monitoring device may use a sensing unit that may include at least one light emitting source configured to emit light beams towards a user&#39;s skin and to measure the returned light with at least one light sensor. In some embodiments, the sensing unit may be coupled to a controller and the returned light may be analyzed in order to determine the level of at least one compound/component (e.g., sugar, cholesterol, etc.) in the blood and/or any layer of the skin. 
     In some embodiments, to ensure that the sensing element measures the level of at least one compound/component in the blood accurately, the sensing element may by attached to the skin of the user, for example, attached to the inner wrist, while avoiding partial blocking of the blood flow in the blood vessel beneath the skin. Such a partial blocking may be caused by over tightening of the strap(s), holding the wearable monitoring device around the wrist. As used herein, over tightening may be defined as applying pressure on the skin that is greater than the blood pressure in the wrist vessels. Therefore, a non-invasive monitoring device according to embodiments of the invention may include a mechanism that may prevent the over tightening and/or may alert the user if such an over or under tightening occurs. 
     As oppose to prior art wearable monitoring devices, such as, smart watches, in order to properly work, a devise according to embodiment of the invention may be controllably tightened to the inner wrist. Prior art wearable monitoring devices are configured to work even when loosely attached to the wrist. A user using these prior art wearable monitoring devices can select how tight he/she wants to close the straps of the devise. The smart watches will monitor the user&#39;s heartbeats and/or oxygen saturation regardless of the amount of tightening provided by the user. 
     Reference is made to  FIG. 1 , which is an illustration of a non-invasive monitoring device according to some embodiments of the invention. A non-invasive monitoring device  100  may include a housing  110  opened from at least one side  112 , a sensing unit  120  attached to a movable plate  130  and a controller  140  coupled to sensing unit  120 . In some embodiments, non-invasive monitoring device  100  may further include a displacement sensor  150  for measuring the displacement of movable plate  130  with respect to a predefined location  118  in housing  110 . In some embodiments, device  100  may further include a battery  160  for providing electric power to various components of device  100 . 
     In some embodiments, non-invasive monitoring device  100  may be configured to be worn around the wrist of the user, thus device  100  may further include a strap  102  and/or  104  (illustrated in  FIGS. 2 and 3 ). In some embodiments, housing  110  and straps  102  and  104  may be shaped such that when worn by a user, sensing unit  120  is in contact with the user&#39;s skin, for example, sensing unit  120  may be configured to be in contact with the inner wrist of the user, when device  100  is worn by the user. 
     In some embodiments, sensing unit  120  may include at least one light source, for example, a light emitting diode (LED) configured to emit light at at least one predetermined spectral wavelength band. In some embodiments, sensing unit  120  may include at least one light sensor configured to measure at least one property of the light scattered back from a tissue of the user. The property may be at least one of: the intensity of the scattered light, a phase shift between the emitted and the scattered light, the wavelength of the scattered light and the like. 
     In some embodiments, movable plate  130  may be or may include any suitable material having stuffiest rigidity as to avoid any flexing of movable plate  130  during the movement of movable plate  130 . For example, movable plate  130  may be made of metal (e.g., aluminum alloy, stainless steel, etc.), a rigid polymer (e.g., polystyrene (PS), polypropylene (PP) below the glass transition temperature, and the like). 
     In some embodiments, movable plate  130  may be connected to one or more spring-like elements  132  allowing the movable plate to move with respect to housing  110  so that when the spring-like elements are extended, sensing unit  120  protrudes from open side  112  of housing  110 . In some embodiments, when the one or more spring-like elements  132  are compressed sensing unit  120  and movable plate  130  are retracted towards an internal space in housing  110 . In some embodiments, one or more spring like elements  132  may include any element having elastic spring-like properties. For example, one or more spring like elements  132  may be selected from a group consisting of: coil spring, volute spring, tension spring, leaf spring, an element made from an elastic material and the like. 
     In some embodiments, housing  110  may further include a seal  114  for sealing opening  112 , thus protecting sensing element  120  from moisture or any other environmental effects. Seal  114  may be made from any elastic material (e.g., rubber) configured to seal opening  112  and element  120  while allowing sensing element  120  to move with the movement of movable plate  130 . 
     In some embodiments, sensing unit  120  may be configured to apply a predefined pressure on surface (e.g., skin surface) of a monitored user&#39;s body (e.g., the skin of the inner wrist). Such predefined pressure may be a function of a spring coefficient of one or more spring-like elements  132 . In some embodiments, the spring coefficient of one or more spring-like elements  132  may be selected such that the predefined pressure attaches sensing unit  120  to the surface of the monitored user&#39;s body while avoiding blocking blood flow in blood vessels located beneath the surface. 
     In some embodiments, controller  140  may include a memory and a processor for executing instructions stored in the memory, for example, instructions to control sensing unit  120  to measure a chemical composition of the blood or skin (such as, glucose in the interstitial fluid such as). In some embodiments, controller  140  may further include a communication module for communicating with an external computing device, for example, a user device, such as, a smartphone, a tablet, a laptop and the like. 
     In some embodiments, displacement sensor  150  for measuring the displacement of movable plate  130  with respect to predefined location  118  in housing  110  may include any sensor suitable for detecting such a displacement. In some embodiments, displacement sensor  150  may be attached to movable plate  130 . An example, for such a sensor, that includes a light source and a light sensor is given in  FIG. 4 . Other examples, for such sensor may include one of: a force sensing resistor, a strain gauge, a piezoelectric sensor and the like. In some embodiments, to avoid over-tightening controller  140  may be configured to send an over-tightening alert, to an external computing device (e.g., the user device), when the displacement is above a first threshold value. In some embodiments, to avoid under-tightening (e.g., when spring-like elements are completely loos and movable plate, having for example, a displacement under a second threshold value (e.g., zero)), controller  140  may be configured to send an under-tightening alert. 
     For example, when one or more spring-like elements  132  are compressed and sensing unit  120  and movable plate  130  are retracted towards an internal space in housing  110 , displacement sensor  150  may detect the displacement of movable plate  130 . If the displacement is above the threshold value, for example, when one or more spring-like elements  132  are fully compressed, controller  140  may send the first alert to a user device. In some embodiments, when one or more spring-like elements  132  are fully compressed, sensing unit  120  may be over-tightened or over-pressed against the surface of the monitored user&#39;s body. In such case, the first alert may include instructions for a user to release the tightening of the device and/or adjust the placement of device  100 , for example, by slightly releasing straps  102  and/or  104 , illustrated in  FIGS. 2 and 3 . 
     In another example, when one or more spring-like elements  132  are almost completely loos and sensing unit  120  and movable plate  130  are extract outward from internal space in housing  110 , displacement sensor  150  may detect the displacement of movable plate  130 . If the displacement is below a threshold value, for example, zero displacement, controller  160  may sent the second alert that may include instructions for a user to slightly increase the tightening of the device. 
     Reference is now made to  FIG. 2  which is an illustration of a wearable monitoring device having a single housing according to some embodiment of the invention. Housing  110  of a non-invasive wearable monitoring device  100 A may be configured to hold sensing unit  120  and movable plate  130  (not illustrated). In some embodiments, housing  110  may further be configured to hold controller  140 . In some embodiments, housing  110  of device  100 A may be configured to hold all the controllable elements of device  100 A, movable plate  130  and one or more spring-like elements  132 . 
     In some embodiments, non-invasive wearable monitoring device  100 A may further include straps  102  and/or  104  for holding device  100 A around the wrist of the user. In some embodiments, sensing unit  120  may be located in housing  110  as to allow sensing unit  120  to be attached to the inner portion of the wrist of the user when straps  102  and  104  are tightened around the wrist. In some embodiments, housing  110  may further holds battery  160 , illustrated in  FIG. 1 . In some embodiments, housing  110  and straps  102  and/or  104  may be designed to hold device  100 A against other parts of the user&#39;s body. 
     Reference is now made to  FIG. 3  which is an illustration of a wearable monitoring device having two housings according to some embodiment of the invention. A non-invasive wearable monitoring device  100 B may include a first housing  110  for holding sensing unit  120  and movable plate  130  (not illustrated) and a second housing  116  for holding controller  140  and battery  160  (not illustrated). In some embodiments, second housing  116  may further hold another sensing element (not illustrated) that may be similar to sensing element  120  or may be different from sensing element  120 . In some embodiments, the other sensing element may be attached to another movable plate  130  that may be connected to additional one or more spring-like elements  132  allowing the other movable plate to move with respect to housing  116 . In some embodiments, second housing  116  may further include another displacement sensor  150 . 
     In some embodiments, first strap  102  may connect housing  110  to housing  116  as to form a single inseparable element. In some embodiments, first strap  102  may include internal communication lines and power lines for connecting the electronic components of housing  110  and the electronic components housing  116  to each other, for example, connecting controller  130  and battery  160  to sensing unit  120  and displacement sensor  150 . In some embodiments, sensing unit  120  may be located in housing  110  as to allow sensing unit  120  to be attached to the inner portion of the wrist of the user when straps  102  and  104  are tightened around the wrist. In some embodiments, housings  110  and  116  and straps  102  and/or  104  may be designed to hold device  100 B against other parts of the user&#39;s body. 
     Reference is now made to  FIG. 4  which is an illustration of an example of displacement sensor  150 . Displacement sensor  150  may include a light source  152  and a light sensor  154  both being attached to movable plate  130 , illustrated in  FIG. 1 . When assembled in housing  110 , illustrated in  FIG. 1 , light source  152  may emit light towards location  118  in housing  110 , Location  118  (illustrated in  FIG. 1 ) may be a location opposite to the opening  112  in housing  110 . In some embodiments, light sensor  154  may receive back light reflected from location  118 . In some embodiments, controller  140  may calculate the displacement (e.g., the distance or change in distance) of movable plate  130  from location  118 , as disclosed, for example, with respect to the disclosure of  FIG. 4 . In some embodiments, measuring the displacement of movable plate  130  may use as an indirect way for measuring the pressure applied to sensing element  120  (e.g., by user&#39;s body surface). 
     While certain features of the invention have been illustrated and described herein, many modifications, substitutions, changes, and equivalents may occur to those skilled in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the invention. 
     Various embodiments have been presented. Each of these embodiments may of course include features from other embodiments presented, and embodiments not specifically described may include various features described herein.