Patent Abstract:
A protective case for enveloping a smartphone incorporates at least one sensor for detecting stimuli arriving from outside of the smartphone. The case and the phone form an integral unit that possess extra features than the phone alone wouldn&#39;t have. The sensor is supplemented by a signal conditioning and interface electronic circuit for communicating the sensed information to the smartphone inner processor. The communication is via a wired connection to the smartphone&#39;s connector or wireless via a radio waves or optical link. For expanding versatility of the smartphone, the sensors may be adapted for detecting non-contact temperature, light, ultrasonic, smell, material composition, human vital signs, and other signals.

Full Description:
[0001]    This application claims the priority of a provisional U.S. patent application Ser. No. 61/737,739 filed on 15 Dec., 2012. The disclosure of the prior related application is hereby fully incorporated by reference herein. 
     
    
     FIELD OF INVENTION 
       [0002]    This invention relates to mobile communication devices, more specifically to accessories for handheld smartphones. 
       DESCRIPTION OF PRIOR ART 
       [0003]    Smart telephones became more and more versatile. Nowadays in their versatility, smart telephones resemble a Swiss Army Knife—a multi-function and multi-purpose item. Most wireless communication devices (cellular or mobile telephones, e.g.) incorporate additional non-communication features, such as imaging (photo and video), personal planners, games, navigation, etc. There are numerous inventions that attempt to include more features for measurement and/or monitoring external signals such as temperature and air pressure. An example is the electromagnetic radiation sensors as taught by the U.S. Pat. No. 8,275,413 issued to Fraden et al. and incorporated herein as reference. Especially of interest for practical applications are medical uses of the smartphones for patient monitoring, self-diagnostic and treatment. 
         [0004]    For a chemical analysis and material composition a mass-spectrometry can be employed. A recent advancement in the MEMS technology allowed a construction a miniature sensor responsive to a single molecule as described in A. K. Naik et al. “Towards single-molecule nanomechanical mass spectrometry”.  Nat. Nanotechnol.  4, 445-450 (2009). This chip can be incorporated in a mobile communication device or a carrying case. 
         [0005]    Certain medical monitoring detectors can be imbedded directly into a smartphone and become an integral part of such. Yet, many more shouldn&#39;t be integrated into mobile communication devices (smart phones, e.g.) for various reasons. The key reason why all smartphones should not comprise a multitude imbedded sensors is a pure practicality. At least in a foreseeable future, many sensors would take a valuable space and increase cost—often this makes not much sense for a generic smartphone that is intended for a general population. Being “smart’ is good and beneficial, but being “too smart” is not always useful. For example, an air pressure or noncontact infrared temperature measurements may be very useful features during activities of certain phone owners (in a work place, hospital, travel, e.g.), yet they would not be needed at all for many other users that are not engaged in such activities. Incorporating monitors and sensors into smartphones while technically feasible, would increase cost, cause larger overall dimensions and reduce reliability. Further, numerous smartphone models being already in service, can&#39;t be retrofitted for adding the extra sensing features. One approach to this issue would be a use of an external attachment to a conventional telephone. However, such attachments may not be convenient for carrying around (and most consumers would never do that), are relatively bulky and require extra efforts for attaching and maintenance. Another and more practical approach is to imbed additional sensors and detectors into a conventional everyday accessory that is routinely used with a smartphone. Such a commonly used accessory is a protective jacket or case that envelops the exterior surface of a phone and absorbs impact forces if dropped on a floor. Most of such covers are designed just for a mechanical protection of the phone. However, the phone covers that in addition to their protective properties incorporate extra electronic circuitry are known in art and exemplified herein by the following. The U.S. Pat. No. 5,517,683 issued to Collett teaches an extension system that implements the additional electronic functions in a case attachable to an external surface of the cellular phone to form a physically integral unit with a connector to couple the extension electronics to the cellular phone electronics. U.S. Pat. No. 8,086,285 issued to McNamara et al. teaches a sound enhancing feature in a protective case. A phone case with electrical lights is taught by the U.S. Publication No. 20120302294 issued to Hammond et al. The U.S. Publication No. 20120285847 issued to Ollson teaches use of an electronic devices inside a protective case. U.S. Publication No. 20120088558 issued to Song et al. teaches an extra battery incorporated inside a protective case. A US company AliveCor (www.alivecor.com) developed the ECG screening monitor incorporated into a protective smartphone jacket. All foregoing patents, publications and the company are incorporated herewith as references. These devices and other inventions on record and known commercial products fail to address sensing a variety of external signals by a smartphone protective case. 
         [0000]    Generally, there are two types of sensors that can be either imbedded into a smartphone or protective jacket. The sensors of the first type are responsive to external electrical signals, like voltage or charge, as exemplified by the above referenced the ECG screening monitor from AliveCor. The second type sensors are responsive to non-electrical external stimuli, for instance: pressure, chemical composition, temperature, light, as exemplified by the above referenced U.S. Pat. No. 8,275,413. The latter sensor type is characterized by a complex sensor design comprising at least one transducer of non-electrical energy to electrical signal, for example, a thermopile that converts the absorbed infrared light to heat, then coverts heat to electrical signal. 
         [0006]    Thus, it is an object of the present invention to provide a protective cover for a smartphone that incorporates additional sensors and/or actuators. 
         [0007]    It is another object of the present invention to increase versatility of a smartphone by adding sensors for electromagnetic radiation, chemical composition, ECG, pressure and other external factors of either electrical or non-electrical in nature. 
         [0008]    And another goal of the invention is to develop a smartphone protective cover that can sense ECG signals with no physical contact with the patient body. 
         [0009]    Further and additional objects and goals are apparent from the following discussion of the present invention and the preferred embodiments. 
       SUMMARY OF THE INVENTION 
       [0010]    A protective case for holding a smartphone incorporates at least one sensor for detecting signals caused by the stimuli external to the smartphone. The stimuli may be electrical or non-electrical. The case and the phone form an integral unit that possess the sensing features that the phone alone doesn&#39;t have. The sensor is supplemented by a signal conditioning and interface electronic circuit for communicating the sensed information to the inner processor of the smartphone. The communication may be via a wired connection to the smartphone connector or wirelessly via a radio wave or optical link. For expanding versatility of a smartphone, specific sensors imbedded into a protective sensing case may be adapted for detecting non-contact temperature, light, ECG, smell, chemical composition, ultrasonic and other external stimuli. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0011]      FIG. 1  illustrates isometric views of the back and front sides of a sensing case; 
           [0012]      FIG. 2  is an illustration of a coupling of an internal connector to a sensing module; 
           [0013]      FIG. 3  presents a diagrammatical view of mutual dispositions of the components; 
           [0014]      FIG. 4  shows a top positioning of a sensing module; 
           [0015]      FIG. 5  is a block-diagram of a module for sensing thermal radiation; 
           [0016]      FIG. 6  is a block diagram of a sensing case for sensing thermal radiation and ECG; 
           [0017]      FIG. 7  is a cross-sectional view of a capacitive dry ECG electrode; 
           [0018]      FIG. 8  illustrates a ground electrode; 
           [0019]      FIG. 9  illustrates an isometric view of a smartphone case with a removable top; 
           [0020]      FIG. 10  is an isometric view of a case with a folding flap, containing a sensor; 
           [0021]      FIG. 11  is a case with a feedback component; 
           [0022]      FIG. 12  illustrates incorporation of a optical sensor into a phone case; 
           [0023]      FIG. 13  shows a sensor protected by a lid. 
       
    
    
       [0024]      
         [0000]    
       
         
               
             
               
               
             
           
               
                   
               
               
                 Parts List for FIGS. 1-13 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 1 
                 back side 
               
               
                 2 
                 front side 
               
               
                 3 
                 camera opening 
               
               
                 4 
                 back wall exterior 
               
               
                 5 
                 back wall interior 
               
               
                 6 
                 connector 
               
               
                 7 
                 IR sensor lens 
               
               
                 8 
                 side extension 
               
               
                 9 
                 module 
               
               
                 10 
                 wiring harness 
               
               
                 11 
                 upper part 
               
               
                 12 
                 receptacle 
               
               
                 13 
                 slots 
               
               
                 14 
                 flat battery 
               
               
                 15 
                 smartphone 
               
               
                 16 
                 phone connector 
               
               
                 17 
                 link 
               
               
                 18 
                 ECG converter 
               
               
                 19 
                 openings 
               
               
                 20 
                 top extension 
               
               
                 21 
                 sensing jacket (case) 
               
               
                 22 
                 thermopile detector 
               
               
                 23 
                 signal conditioner 
               
               
                 24 
                 encoder 
               
               
                 25 
                 back wall 
               
               
                 26 
                 first ECG electrode 
               
               
                 27 
                 second ECG electrode 
               
               
                 28 
                 amplifier 
               
               
                 29 
                 signal conditioner 
               
               
                 30 
                 signal converter 
               
               
                 31 
                 electrode plate 
               
               
                 32 
                 isolator 
               
               
                 33 
                 follower 
               
               
                 34 
                 driven shield 
               
               
                 35 
                 electrode housing 
               
               
                 36 
                 follower output 
               
               
                 37 
                 bottom part 
               
               
                 38 
                 upper part 
               
               
                 39 
                 coupler one 
               
               
                 40 
                 coupler two 
               
               
                 41 
                 joint 
               
               
                 42 
                 back case 
               
               
                 43 
                 flap 
               
               
                 44 
                 flap thickness 
               
               
                 45 
                 pivot 
               
               
                 46 
                 mating portion 
               
               
                 47 
                 ground electrode 
               
               
                 48 
                 ground amplifier 
               
               
                 49 
                 output means 
               
               
                 50 
                 sensor 
               
               
                 51 
                 lid 
               
               
                 52 
                 axis 
               
               
                 53 
                 directions 
               
               
                 54 
                 wireless module 
               
               
                 55 
                 1 st  LED 
               
               
                 56 
                 2 nd  LED 
               
               
                 57 
                 photo detector 
               
               
                 58 
                 filter 
               
               
                   
               
             
          
         
       
     
       DESCRIPTION OF PREFERRED EMBODIMENTS 
       [0025]    In the following description, the words “smartphone”, “cell phone”, “phone” and “mobile communications device” are used interchangeably and generally have the same meaning. Likewise, words “case”, “cover” and “jacket” refer to the same item. 
         [0026]      FIG. 1  illustrates the back,  1 , and front,  2 , sides of a protective case,  21 , for holding a mobile communication device (a smartphone, e.g.). The case is designed for a snag fit over the exterior of a phone and not to interfere with its normal functions. Toward this goal, the case,  21 , has one or more slots and openings,  13  and  19 , for the phone controls, switches, microphone/speaker, etc. To protect the phone against damage, if dropped, the case is fabricated of an impact resistant and stress absorbent material. Example are polyurethane, phenolics and polycarbonate. Such materials are well known in art and not described herein. A front side of the case,  21 , is open for providing an access to the phone display and controls, while the rear side preferably (but not necessarily) is protected by a wall having the back side,  4 , and front side,  5 . The connector,  6 , may be incorporated inside the case,  21 , for coupling to the inner electronic components and battery of the smartphone. On the upper side of the case, there is a side extension,  8 , for housing certain components that will be described below. A shape and location of the side extension,  8 , is arbitrary and depends on the ergonomic, esthetic and engineering requirements to the device. 
         [0027]      FIG. 2  shows the case,  21 , that inside the side extension,  8 , incorporates a module,  9 , that may comprise one or more sensors of the external stimuli and supporting electronic circuits to perform additional functions for the phone. Examples of such components are: a thermopile detector for sensing thermal (infrared) radiation, air pressure sensor, UV light detector, signal converter, electromagnetic field detector, blood pulse oximeter, blood glucose meter, detector of a chemical composition, and many others. A spectrum of the electromagnetic field may range from UV to long waves to static electrical and magnetic fields. The module,  9 , communicates with the smartphone (not shown in  FIG. 2 ) through the connector,  6 , that is attached to the module via a wiring harness,  10 , such as a flexible circuit board, e.g. The connector,  6 , may be directly attached to a receptacle,  12 , that allows electrical connection of the smartphone to a peripheral equipment, for example, a battery charger or computer. Optionally, an additional battery,  14 , may be incorporated inside the case,  21 , for example, inside the back wall,  25 . 
         [0028]    Before operation, smartphone,  15 , in positioned inside the case,  21 , with the phone inner connector,  16 , being coupled to the case connector,  6 , as illustrated in  FIG. 3 . For clarity only, the smartphone,  15 , is shown outside of the case,  21  while the coupling is shown by a broken line,  17 . 
         [0029]    Alternatively, the smartphone,  15 , may communicate with the module,  9 , by a wireless means, for example by using a bidirectional radiofrequency or optical coupling. In that case, the module,  9 , and smartphone,  15 , must incorporate the appropriate coupling components that are well known in art and thus not described here. As a result, the connector,  6 , and the wiring harness,  10 , will not be required for a wireless communication between the case and the smartphone. 
         [0030]    Optionally, module,  9 , may be positioned in other areas of the case,  21 , for example, inside the back wall,  25 , or at the upper part,  11 , as shown in  FIG. 4 . The latter placement will require a top extension,  20 . Positioning of the module,  9 , (or  10 ) depends on particular applications. For example, for a noncontact temperature measurement, lens,  7 , of the IR detector should be positioned close to the digital camera lens protruding through the opening,  3 . 
         [0031]    If the jacket comprises a module that for operation requires certain disposable or reusable components, the jacket my be appended with a pocket for storing such components (not shown). An example is a set of disposable test strips for a glucometer. Likewise, certain actuators, either manual or electrical, also can be imbedded into the jacket. An example is a piercing blade (a blood lancet) for puncturing the patient skin to obtain a blood sample for a glucometer. 
         [0032]    Most of the sensors imbedded into the case,  21 , can&#39;t be directly coupled to the connector,  6 , and thus require intermediate (interface) electronic circuits, such as signal conditioners, amplifiers, analog-to-digital converters, encoders, etc. As an illustration,  FIG. 5  shows module,  9 , incorporating the thermopile detector,  22 , with the infrared lens,  7 . The detector receives the incoming IR radiation and converts it into electric voltage that is fed to the signal conditioner,  23 , that in turn is connected to the encoder,  24 . Typically, the signal conditioner,  23 , is comprised of an amplifier and filter, while the encoder,  24 , is comprised of an analog-to-digital converter and a code adapter for matching a signal format in wiring harness,  10 , with the signal format compatible with a particular model of a smartphone for which the case,  21 , is intended. The sensor (a thermopile, e.g.) not necessarily should be part of the module,  9 . For practical reasons, it may be external to the module, comprising a signal conditioning, encoding and communicating functions. 
         [0033]    In this example of  FIG. 5 , a non-electrical stimulus (IR radiation) is converted by a thermopile detector,  22 , first to heat and subsequently heat is converted to a small electrical voltage that is substantially proportional to the intensity of IR radiation received by the detector,  22 . In other embodiments, a stimulus may be of an electrical nature, for example, electro-cardiographic (ECG) voltage naturally appearing over the patient&#39;s chest. 
         [0034]    To illustrate operation of a sensor responsive to the ECG electrical stimuli,  FIG. 6  shows the case,  21 , that on the back wall exterior,  4 , incorporates three non-contact ECG electrodes,  26 ,  27  and  47 . The electrodes may be simple metal plates or they can be designed in a more complex form as shown below. For clarity, module,  9 , and the electrodes are shown as removed from the case,  21 , although in reality they are incorporated into the case. Note that more than one type of sensors may be incorporated into the same case,  21 . This is illustrated by a thermopile detector,  22 , (for thermal radiation) being part of the module,  9 , with the IR lens,  7 , protruding through the case,  21 . The thermopile detector is in addition to the ECG electrodes and electronics. 
         [0035]    Electrical signals from the ECG electrodes are amplified by the amplifier,  28 , processed by the signal conditioner,  29  and converted to a digital format by the signal converter,  30 . The same converter may be used to convert signals from the thermopile detector,  22 . The digital signals pass to the connector,  6 , and subsequently appear at receptacle,  12 , for connecting to the external peripheral devices, if needed for calibration, e.g. 
         [0036]    During operation, the non-contact active electrodes  26  and  27  and the ground electrode,  47 , are pressed against the patient chest. Here term “non-contact” means that the conductive portions of the electrodes make no direct electrically conductive contact with the patient skin. Fundamentals of such an electrode system can be found in: Yu M. Chi et al. “Wireless Non-contact Cardiac and Neural Monitoring.”  Wireless Health  2010, Oct. 5-7, 2010, San Diego, USA. 
         [0037]    A more detailed schematic of an active non-contact capacitive electrode ( 26  or  27 ) is illustrated in  FIG. 7 . Word “active” here means having an imbedded electronic circuit. The electrode is comprised of an electrode plate,  31 , that is made of a conductive material (metal or conductive polymer, e.g.), isolator,  32 , voltage follower,  33 , driven shield,  34 , and the electrode housing,  35 . Note that isolator,  32 , should be thin (on the range of 1-10 mkm) and composed of an electrically non-conductive material having as high dielectric constant as practical, preferably more than 20. A high dielectric constant increases a capacitance between the patient skin (not shown) and the electrode plate,  31 , thus improving quality of the recorded ECG signals at the lower part of the frequency spectrum. Examples of suitable materials for the isolator,  32 , are certain ceramics, such as titanium dioxide (rutile) deposited on the electrode plate,  31 . Thus, the electrode plate,  31 , and isolator,  32 , forms a unitary two-layer structure. Input of the voltage follower,  33 , is connected to the electrode plate,  31 , while the follower&#39;s output,  36 , is connected to the electrically conductive driven shield,  34 , and preferably to the electrode housing,  35 , which also should be made of the electrically conductive material. The voltage follower,  33 , has a very high input impedance on the order of several Gigohm and a very low output impedance in the ohm range. This assures a to sufficiently low cut-off frequency of the electrode and lower interferences. Note that driven shield,  34 , is well isolated from the electrode plate,  31 , but both are at substantially the same voltage (potential), thanks to a unity gain of the voltage follower,  33 . “Substantial” here means be within 1% from one another. As a result, any stray capacitance between the driven shield and electrode plate becomes immaterial and makes no effect on the recorded signal. 
         [0038]    A capacitance between the electrode plate,  31 , and the patient body provides a capacitive coupling for the ECG varying voltage. A voltage difference between the electrodes,  26  and  27 , is amplified and in a digital format is fed to the smartphone inner electronics for processing. Note that the ground electrode,  47 , is driven by a ground amplifier,  48 . The ground electrode construction is shown in  FIG. 8 . Like an active electrode of  FIG. 7 , it also contains a conductive electrode plate,  21 , and insulator,  32 . 
         [0039]    Note that thanks to very high input impedance of the voltage follower,  33 , it may take a long time for an ECG signal to settle down for a normal recording after the case,  21 , being placed onto the patient chest. This transition time can be significantly reduced by a momentary shorting together the electrode plates,  21 , of both active electrodes,  26  and  27 , to the electrode plate of the ground electrode,  47 . This can be accomplished by a set of additional solid-state switches that are not shown in the drawings because details of the capacitive electrode design go beyond the scope of this disclosure. 
         [0040]    Even though the mobile communication device (smartphone, e.g.) usually has a means for communication with the user, it may be beneficial to supplement the sensing case,  21 , with an additional output means,  49  ( FIG. 11 ), comprising one or more of the following: LCD, LED, speaker, vibrator. One example of the functionality of such an output means is providing a feedback to the user in case when communication with the smartphone can&#39;t be established. 
         [0041]    Case,  21 , can be designed in many modifications without departing from the key principles and spirit disclosed herein. As an illustration,  FIGS. 9 and 10  illustrate two other embodiments of the invention. The embodiment of  FIG. 9  shows a two-part case,  21 , comprising the bottom part,  37  and the upper part,  38 , where one part is fully detachable from another. During operation, both parts are slid over the smartphone housing and joined together. A sensor (or several sensors) can be positioned either in one part or both parts. If necessary, to assure continuity of the wiring harness,  10 , at a mating portion,  46 , of the case,  12 , a coupler one,  39 , is mated with a coupler two,  40 . The couplers are the interconnecting devices. Note that the receptacle,  12 , may be separated from connector,  6 , and linked to it by an electrical joint,  41 . The embodiment of  FIG. 10  also shows a two-part case,  21 , where both parts are joined together and can mutually rotate around pivot,  45 . The back case,  42 , envelops a portion of the body of a smartphone,  15 , while flap,  43 , may carry one or more sensors as illustrated by an optical sensor having the IR lens,  7 . The receptacle,  12 , may be located on the either part of the case, like on the flap,  43 , as shown in  FIG. 10 . The flap thickness,  44 , should be sufficient for housing all needed sensors and supporting electronic components. 
         [0042]      FIG. 12  illustrates another embodiment of this invention comprising an optical sensor,  50 . Note that the optical sensor can have a multitude configurations and applications and may operate in various portions of the optical spectral range—from UV to far infrared. As an example,  FIG. 12  shows an optical sensor,  50 , adapted for measuring percentage of a human hemoglobin oxygenation by a method of a pulse oxymetry. It incorporates a near IR light emitting diode−1 st  LED,  55 , a red light−2 nd  LED,  56 , and a photo detector,  57 . These components are protected by an optical filter,  58 , that is transparent in the near IR and red portions of the light spectrum. For measuring a hemoglobin oxygenation, the filter,  58 , is pressed against a portion of the patient body, a finger tip, e.g. The method of pulse oxymetry is well known in art and thus not further described herein. Note that in this illustration, the case,  21 , has no wired connection to a mobile communication device, but is connected to it via a wireless module,  54  (a “Bluetooth”, e.g.). Since there is no wired connection to a mobile communication device, electric power to the components incorporated into the case,  21 , may be provided by a flat battery,  14 , imbedded into the back wall,  25 . 
         [0043]    An optical sensor as described herein can be adapted for monitoring a heart rate of a human or animal subject by detecting a variable (modulated) light by the photo detector,  57 . Alternatively, a heart rate me be computed from an R-wave of the ECG signal as detected by the embodiment shown in  FIG. 6 . 
         [0044]    Some sensors after being incorporated into case,  21 , may be quite delicate, thus requiring an additional protection from environment. This can be accomplished by appending case,  21 , with a protective lid,  51 , shown in  FIG. 13 . The lid,  52 , can swing in directions,  53 , around axis,  52  to an open and closed positions. If needed, the lid,  52 , may incorporate certain additional components, like a photo detector, e.g. (not shown in  FIG. 13 ). 
         [0045]    While the present invention has been illustrated by description of various preferred embodiments and while these embodiments have been described in some detail, it is not the intention of the Applicant to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications will readily appear to those skilled in the art. The various features of the invention may be used alone or in numerous combinations depending on the needs and preferences of the user. This has been a description of the present invention, along with the preferred methods of practicing the present invention as currently known. However, the invention itself should only be defined by the appended claims.

Technology Classification (CPC): 7