Abstract:
A cardiopulmonary resuscitation device includes a case having an extension portion extending therefrom. In operation, the user places the case across the chest of a person being given CPR, and presses the case into the person&#39;s chest, applying uniform force in according to a rhythm guided by audible and/or visual feedback. The cardiopulmonary resuscitation device includes a control circuit having a display screen, and a distance sensor apparatus operatively coupled to the control circuit. The distance sensor apparatus is carried by the extension portion which can be situated over the edge of the person, and provides a sensor signal to the control circuit in response to movement of the case. The display screen displays a distance and rate that the case has been moved during CPR, and both an audible sound and visual light are emitted each time the device is applied properly to the person receiving CPR. The device is automatically activated once a certain amount force is applied to the case.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates generally to an artificial resuscitation device. 
     2. Description of the Related Art 
     Cardiopulmonary resuscitation (CPR) is an emergency procedure that involves the compression and decompression of the thoracic cavity in response to pressure applied to the sternum. CPR is typically performed in many different emergency situations, such as when a person is experiencing circulatory arrest (i.e. cardiac arrest) and respiratory arrest (e.g. drowning). 
     It is known that most people who receive CPR outside of a hospital do not survive. For example, recent statistics indicate that only about 8% of people who receive CPR outside of a hospital survive. Conversely, about 88% of those who receive CPR at a hospital do survive. One reason people do not survive when receiving CPR outside of a hospital is that the CPR is not performed correctly. In some instances, the pressure applied during compression is not applied evenly. The applied pressure often will not compress the entire thoracic cavity to get adequate pumping started. Instead, the applied pressure is applied as a sharp force to the sternum. The sternum must also be compressed/decompressed at an optimal distance and rate. The chances of a successful resuscitation are greatly reduced if the chest is compressed too deeply or in too shallow a manner. Further, in an emergency situation, people would greatly benefit from a device that is simple to use and quickly guides them through the steps necessary to successfully perform CPR. Hence, it would be desirable to provide an alternative to conventional manual CPR techniques that particularly non-medical personnel can perform properly so as to increase the likelihood of surviving. 
     BRIEF SUMMARY OF THE INVENTION 
     The present invention is directed to a cardiopulmonary resuscitation device which aids in the performance of CPR. The novel features of the invention are set forth with particularity in the appended claims. The invention will be best understood from the following description when read in conjunction with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       It should be noted that like reference characters are used throughout the several views of the drawings. 
         FIG. 1  is a perspective view of a cardiopulmonary resuscitation device. 
         FIG. 2  is side view of the cardiopulmonary resuscitation device of  FIG. 1 . 
         FIG. 3  is an opposed side view of the cardiopulmonary resuscitation device of  FIG. 1 . 
         FIG. 4  is perspective view of the inside of the cardiopulmonary resuscitation device of  FIG. 1  showing a circuit board, which carries control circuitry, and a distance sensor apparatus in communication therewith. 
         FIG. 5  is a block diagram of one embodiment of the cardiopulmonary resuscitation device of  FIG. 1  showing the control circuitry and distance sensor of  FIG. 4 . 
         FIG. 6 a    is a side view of one embodiment of the control circuitry and circuit board of  FIGS. 4 and 5 . 
         FIG. 6 b    is a circuit diagram of a first portion of the control circuitry of  FIGS. 4, 5, and 6   a , wherein the first portion includes a microcontroller and display screen. 
         FIG. 6 c    is a circuit diagram of a second portion of the control circuitry of  FIGS. 4, 5 , and  6   a , wherein the second portion includes a first converter and first biasing circuit, which provide a first reference potential. 
         FIG. 6 d    is a circuit diagram of a third portion of the control circuitry of  FIGS. 4, 5, and 6   a , wherein the second portion includes a second converter and second biasing circuit, which provide a second reference potential. 
         FIG. 7  is a perspective view of the circuit board and control circuitry of  FIG. 4 . 
         FIG. 8  is an opposed perspective view of the circuit board and control circuitry of  FIG. 4 . 
         FIG. 9  is a perspective view of the distance sensor apparatus of  FIG. 4 . 
         FIG. 10  is an opposed perspective view of the distance sensor apparatus of  FIG. 4 . 
         FIG. 11  is a front view of the cardiopulmonary resuscitation device of  FIG. 1  being operated by a user when performing CPR on a patient. 
         FIG. 12 a    is a side view of the cardiopulmonary resuscitation device in a direction shown in  FIG. 11 . 
         FIG. 12 b    is a partial view of the cardiopulmonary resuscitation device in a region shown in  FIG. 11 . 
         FIG. 13 a    is a side view of the cardiopulmonary resuscitation device in the direction shown in  FIG. 11 . 
         FIG. 13 b    is a partial view of the cardiopulmonary resuscitation device in the region shown in  FIG. 11 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIG. 1  is a perspective view of a cardiopulmonary resuscitation device  100 .  FIG. 2  is side view of the cardiopulmonary resuscitation device  100  of  FIG. 1 , and  FIG. 3  is an opposed side view of the cardiopulmonary resuscitation device  100  of  FIG. 1 . In this embodiment, the cardiopulmonary resuscitation device  100  includes a cover  102  and case  106 , which are coupled together in a repeatably removeable manner. In this embodiment, the case  102  includes a gripping portion  107 , which facilitates the ability to hold the cardiopulmonary resuscitation device  100  with hands. 
     As shown in  FIG. 2 , the cardiopulmonary resuscitation device  100  has is shaped to have opposed lengthened sides  154  and  155 , and opposed shortened sides  156  and  157 . A length axis  103  and width axis  105  are shown in  FIG. 2  for reference purposes only. The length axis extends between the shortened sides  156  and  157 , and the width axis extends between the opposed lengthened sides  154  and  155 . It should be noted that a lengthened side is longer than the shortened side, and a shortened side is shorter than the lengthened side. The lengthened sides  154  and  155  can have many different lengths. In some embodiments, the lengthened sides  154  and  155  are less than about eighteen inches. In some embodiments, the lengthened sides  154  and  155  are between about eight inches and eighteen inches. In general, the lengthened sides  154  and  155  are chosen to have lengths that match the chest width of a typical human. 
     The cover  102  and case  106  can include many different types of material, such as plastic. In some embodiments, the cardiopulmonary resuscitation device  100  includes a backing of resilient material, such as foam. The backing of resilient material can be positioned at many different locations, such as on the cover  102  and/or case  106 . 
     In this embodiment, the cardiopulmonary resuscitation device  100  includes an extension portion  109 , wherein the extension portion  109  includes portions of the cover  102  and case  106 . In particular, the extension portion  109  includes a cover extension portion  104 , wherein the cover extension portion  104  is included with the cover  102 . Further, the extension portion  109  includes a case extension portion  108 , wherein the case extension portion  108  is included with the case  106 . The extension portion  109  provides the cardiopulmonary resuscitation device  100  with an L-shape. The extension portion  109  extends in a direction substantially away from the length axis  103 . The extension portion  109  extends in the same substantial direction as the width axis  105 . In this embodiment, the extension portion  109  extends from proximate to the intersection of the lengthened side  155  and the shortened side  157 . It should be noted, however, that the extension portion  109  can extend from other portions, such as the intersection of the lengthened side  154  and the shortened side  157 . 
     In this embodiment, and as shown in  FIGS. 1 and 2 , the cardiopulmonary resuscitation device  100  includes a display screen  116 , which extends through the cover  102 . Display screen  116  will be discussed in more detail below with  FIGS. 5, 6, 7 and 8 . The display screen  116  is carried by a circuit board  110  ( FIGS. 4, 6, 7, and 8 ). The display screen  116  is for displaying information regarding the operation of the cardiopulmonary resuscitation device  100 . 
     In this embodiment, and as shown in  FIGS. 1 and 2 , the cardiopulmonary resuscitation device  100  includes a pressure switch  142 , which is disposed inside the case  106 . The pressure switch  142  will be discussed in more detail below with  FIGS. 5 and 8 . The pressure switch  142  can be of many different types, such as a force sensing resistor. The resistance of the force sensing resistor changes in response to an applied force. 
     In this embodiment, and as shown in  FIGS. 1 and 2 , the cardiopulmonary resuscitation device  100  includes a luminaire  144 , which extends through the cover  102 . The luminaire  144  is useful to provide the user of the cardiopulmonary resuscitation device  100  with a visual indication that the sternum is being compressed and decompressed the desired distance. The luminaire  144  will be discussed in more detail below with  FIGS. 5 and 8 . 
     In some embodiments, the cardiopulmonary resuscitation device  100  includes a luminaire  143 , which extends through the cover  102 . The luminaire  143  can provide the visual indication that the sternum is being compressed and decompressed the desired distance. In some embodiments, the luminaire  144  indicates when the device is on or off, and the luminaire  143  provide the visual indication that the sternum is being compressed and decompressed the desired distance. 
     In this embodiment, and as shown in  FIG. 3 , the cardiopulmonary resuscitation device  100  includes a distance sensor apparatus  160 , which extends through the case  106 . The distance sensor apparatus  160  will be discussed in more detail below with  FIGS. 4, 5, 9, and 10 . The distance sensor apparatus  160  includes a receive sensor  166  and transmit sensor  167 , which extend through the case  106 . In particular, the receive and transmit sensors  166  and  167  extend through the case extension portion  108 . The receive and transmit sensors  166  and  167  can extend through the case  106  in many different ways. In this embodiment, the receive and transmit sensors  166  and  167  extend through corresponding openings of the case  106 . In general, the receive and transmit sensors  166  and  167  extend through at least one opening of the case  106 . It should be noted that the opening(s) through which the receive and transmit sensors  166  and  167  are opposed to the opening through which the display screen  116  extends ( FIGS. 1 and 2 ). In this way, the display screen  116  and distance sensor apparatus  160  face opposed directions. 
       FIG. 4  is perspective view of the inside of the cardiopulmonary resuscitation device  100  of  FIG. 1  with the cover  102  removed from the case  106 . In this embodiment, the cardiopulmonary resuscitation device  100  includes the circuit board  110 , which is carried by the case  106 . The circuit board  110  carries the control circuitry  112 , which controls the operation of the cardiopulmonary resuscitation device  100 . It should be noted that the display screen  116  is positioned on the opposite side of the circuit board  110  in  FIG. 4 , as is shown in  FIGS. 7 and 8 . 
     The devices included with the control circuitry  112  will be discussed in more detail below. In this embodiment, the control circuitry  112  includes a microcontroller  114 , which controls the operation of the cardiopulmonary resuscitation device  100 . The control circuitry  112  includes a sound device  117 , which is operatively coupled to the microcontroller  114 . As will be discussed in more detail below, the sound device  117  provides a sound indication in response to receiving a sound signal S Sound  ( FIG. 5 ) from the microcontroller  114 . In this embodiment, the sound indication corresponds to an audible sound. The audible sound is within a frequency range of human hearing. The microcontroller  114  provides the sound signal S Sound  in response to movement of the cardiopulmonary resuscitation device  100 . The sound signal S Sound  is useful to provide the user of the cardiopulmonary resuscitation device  100  with an audible indication that the sternum is being compressed and decompressed the desired distance. In an embodiment, the signal S Sound  will also indicate that the desired distance was not reached. This might happen if the compression/decompression was done in either too shallow a manner or was done too deeply. In this case, the signal S Sound  can be used to generate a different sound altogether to indicate an improper action. Thus, the person performing CPR is provided auditory feedback as to whether the CPR is being done correctly or incorrectly. It should be noted that, in some embodiments, the luminaire  144  operates in response to receiving the sound signal S Sound . This feature is useful so that the luminaire  144  operates when the sound device  117  operates. The luminaire  144  is provided power so it is capable of operating when the pressure switch  142  has an activated condition, as will be discussed in more detail below. 
     The cardiopulmonary resuscitation device  100  includes a battery  118 , which is carried by the case  106  and positioned proximate to the circuit board  110 . The battery  118  provides power to the control circuitry  112  through a battery cable  119 , as will be discussed below with  FIG. 7 . 
     As mentioned above, the cardiopulmonary resuscitation device  100  includes the distance sensor apparatus  160 . The distance sensor apparatus  160  is carried by the case  106 , as shown in  FIG. 4 . In particular, the distance sensor apparatus  160  is carried by the case extension portion  108 . The distance sensor apparatus  160  is positioned between the case extension portion  108  and the cover extension portion  104 . The distance sensor apparatus  160  is connected to the control circuitry  112  through a sensor cable  146 , as will be discussed below with  FIGS. 9 and 10 . 
       FIG. 5  is a block diagram of one embodiment of the cardiopulmonary resuscitation device  100  of  FIG. 1 . As mentioned above, the cardiopulmonary resuscitation device  100  includes the sound device  117  operatively coupled to the microcontroller  114 . The sound device  117  provides the sound indication in response to receiving the sound signal S Sound  from the microcontroller  114 . The microcontroller  114  provides the sound signal S Sound  to the sound device  117  in response to movement of the cardiopulmonary resuscitation device  100 , as will be discussed in more detail below. 
     In this embodiment, the cardiopulmonary resuscitation device  100  includes the luminaire  143  operatively coupled to the microcontroller  114 . The luminaire  143  provides the visual indication in response to receiving the light signal S Light  from the microcontroller  114 . The microcontroller  114  provides the light signal S Light  to the luminaire  143  in response to movement of the cardiopulmonary resuscitation device  100 , as will be discussed in more detail below. It should be noted that, in some embodiments, the light signal S Light  is provided by the sound device  117  so that the sound indication and visual indication are provided a substantially the same time. 
     In this embodiment, the display screen  116  is operatively coupled to the microcontroller  114  through a display channel  111  so that a display signal S Display  flows therebetween. The display signal S Display  includes information it is desired to display on display screen  116 , as will be discussed in more detail below. 
     As mentioned above, the cardiopulmonary resuscitation device  100  includes the pressure switch  142 . In this embodiment, the pressure switch  142  is connected directly to the circuit board  110 , and the battery cable connector  140  is connected to the battery cable  119  ( FIG. 4 ) in a repeatably removeable manner. The battery  118  ( FIG. 4 ) provides a power signal S Power  to the battery cable connector  140  through the battery cable  119 . 
     In this embodiment, the cardiopulmonary resuscitation device  100  includes biasing circuits  122  and  132  operatively coupled to the pressure switch  142 . The pressure switch  142  is repeatably moveable between activated and deactivated conditions. In the activated condition, the pressure switch  142  allows the power signal S Power  to flow to the biasing circuits  122  and  132 . In the deactivated condition, the pressure switch  142  does not allow the power signal S Power  to flow to the biasing circuits  122  and  132 . In some embodiments, the pressure switch  142  moves from the deactivated condition to the activated condition in response to a force applied to the cardiopulmonary resuscitation device  100 . In this embodiment, the cardiopulmonary resuscitation device  100  remains in the activated condition for a predetermined amount of time. 
     In this embodiment, the biasing circuit  122  is in communication with a converter  120 , wherein the converter  120  is in communication with the display screen  116 . The biasing circuit  122  and converter  120  provide a potential difference V 2  to the display screen  116  when the pressure switch  142  is in the activated condition. The biasing circuit  122  and converter  120  do not provide the potential difference V 2  to the display screen  116  when the pressure switch  142  is in the deactivated condition. In this way, the display screen  116 , biasing circuit  122  and converter  120  are operatively coupled to the pressure switch  142 . 
     Further, the biasing circuit  132  is in communication with a converter  130 , wherein the converter  130  is in communication with the microcontroller  114 . The biasing circuit  132  and converter  130  provide a potential difference V 1  to the microcontroller  114  when the pressure switch  142  is in the activated condition. The biasing circuit  132  and converter  130  do not provide the potential difference V 1  to the microcontroller  114  when the pressure switch  142  is in the deactivated condition. In this way, the microcontroller  114 , biasing circuit  132  and converter  130  are operatively coupled to the pressure switch  142 . 
     The cardiopulmonary resuscitation device  100  includes the distance sensor apparatus  160 , which is connected to the control circuitry  112  through the sensor cable  146 . As will be discussed in more detail below, a sensor signal S Sensor  flows between the distance sensor apparatus  160  and control circuitry  112 . In particular, the sensor signal S Sensor  flows between the distance sensor apparatus  160  and microcontroller  114 . The sensor signal S Sensor  is provided in response to movement of the cardiopulmonary resuscitation device  100 . The sensor signal S Sensor  includes information corresponding to a distance that the cardiopulmonary resuscitation device  100  has moved. 
     In this embodiment, the sensor cable  146  is connected to sensor cable connectors  147  and  148  at opposed ends, wherein the sensor cable connector  147  is connected to the distance sensor apparatus  160  in a repeatably removeable manner. The control circuitry  112  includes a sensor cable connector  141  carried by the circuit board  110  ( FIG. 6 a   ). The sensor cable connector  148  is connected to the sensor cable connector  141  in a repeatably removeable manner. The control circuitry  112  is in communication with the distance sensor apparatus  160  so the sensor signal S Sensor  can flow therebetween. In particular, the microcontroller  114  is in communication with the distance sensor apparatus  160  through the sensor cable  146  and sensor cable connectors  147 ,  148 , and  141 . The microcontroller  114  is in communication with the distance sensor apparatus  160  so the sensor signal S Sensor  can flow therebetween. In this way, the control circuitry  112  is in communication with the distance sensor apparatus  160 . 
       FIG. 6 a    is a side view of one embodiment of the control circuitry  112  carried by the circuit board  110  ( FIG. 4 ). The circuit board  110  can be of many different types of circuit boards. In this embodiment, the circuit board  110  is a printed circuit board. As will be discussed in more detail below with the circuit diagrams of  FIGS. 6 b , 6 c , and 6 d   , the control circuitry  112  includes a plurality of electrical components. The electrical components include conductive pins and/or terminals that extend through openings of the circuit board  110 , and are soldered thereto. The pins and terminals are connected together so that the electrical components operate as a circuit. 
     The electrical components of the control circuitry  112  can be of many different types. For example, the electrical components of the control circuitry  112  include a resistor. The resistor can be of many different types, such as a through-hole and surface mounted resistor. The electrical components of the control circuitry  112  include a capacitor. The capacitor can be of many different types, such as an electrolytic capacitor. Electrolytic capacitors are provided by many different companies, such as Nichicon, which provides the UWT1E100MCL1GB and UWT1E220MCL1GB aluminum electrolytic capacitors. The electrical components of the control circuitry  112  includes an inductor. The inductor can be of many different types, such as a wire wound inductor. Wire wound inductors are provided by many different companies, such as ABRACON Corporation, which provides the AISC-1210HS wire wound inductor. Taiyo Yuden provides the CB2518T331K wire wound inductor. The electrical components of the control circuitry  112  include a diode. The diode can be of many different types, such as a Schottky barrier rectifier. VISHAY Intertechnology provides the SS1P3L and SS1P4L surface mounted Schottky barrier rectifiers. The electrical components of the control circuitry  112  include a connector, such as connectors  140  and  141 . The connector can be of many different types of connectors, such as a PCB header. PCB headers are provided by many different companies, such as MOLEX, which provides the 35312 Series of pitch headers. 
       FIG. 6 b    is a circuit diagram of a first portion of the control circuitry  112  of  FIGS. 4 and 6   a . In this embodiment, the control circuitry includes the microcontroller  114 . The microcontroller  114  can be of many different types of microcontrollers. In this embodiment, the microcontroller  114  is a TEXAS INSTRUMENTS MSP430G2 Mixed Signal Microcontroller. A pin  10  of the microcontroller  114  is connected to the reference potential V 1  through a resistor  150   a . A pin  1  of the microcontroller  114  is connected to the reference potential V 1 , and a pin  14  of the microcontroller  114  is connected to the current return  145 . Pins  1  and  14  of the microcontroller  114  are in communication with each other through a capacitor  152   a . A pin  3  of the microcontroller  114  is connected to a first pin of the sensor cable connector  141  through a resistor  150   e . It should be noted that the sensor signal S Sensor  flows through the resistor  150   a  between the first terminal of the sensor cable connector  141  and pin  3  of the microcontroller  114 . Second and third pins of the sensor cable connector  141  are connected to the reference potential V 2  and current return  145 , respectively. 
     A pin  4  of the microcontroller  114  is connected to a control terminal of a transistor  115 . The transistor  115  can be of many different types. In this embodiment, the transistor  115  is an NPN transistor, which is provided by NXP as model number PDTD123Y. A first terminal of the transistor  115  is connected to the current return  145 . 
     The control circuitry  112  includes the sound device  117 . The sound device  117  can be of many different types. In this embodiment, the sound device  117  is a magnetic buzzer, which is provided by KOBITONE Audio Company as part number 254-EMB105-RO. The sound device  117  includes a first pin connected to the reference potential V 2 , and a second pin connected to a second terminal of the transistor  115 . In this embodiment, the control circuitry  112  includes the luminaire  143 . The luminaire  143  can be of many different types, such as a light emitting diode. 
     The control circuit  112  includes the display screen  116 . The display screen  116  can be of many different types. In this embodiment, the display screen  116  is a NHD-0116AZ-FL-YBW liquid crystal display screen, which is provided by Newhaven Display International. The second pin of the sound device  117  is connected to a negative pin of the display screen. The control circuit  112  includes a resistor  150   d , which is connected between the reference potential V 2  and a positive pin of the display screen  116 . Pins  6 ,  7 ,  8 , and  9  of the microcontroller  114  are connected to pins  11 ,  12 ,  13 , and  14 , respectively, of the display screen  116 . It should be noted that the connection between the pins  6 ,  7 ,  8 , and  9  of the microcontroller  114  and the pins  11 ,  12 ,  13 , and  14  of the display screen  114  form the display channel  111  ( FIG. 5 ) through which the display signal S Display  flows. As will be discussed in more detail below, the display signal S Display  can include many different types of information, such as distance and/or rate information. 
     The control circuitry  112  includes a resistor  150   c  with a first terminal connected to the current return  145 , and a second terminal connected to a pin  3  of the display screen  116 . The second terminal of the resistor  150   c  is connected to a first pin of a resistor  150   b . A second pin of the resistor  150   b  is connected to the reference potential V 2 . Pins  1  and  5  of the display screen are connected to the current return  145  and to a first terminal of a capacitor  152   b . A second terminal of the capacitor  152   b  is connected to the reference potential V 2 , and to a pin  2  of the display screen  116 . 
     As discussed above with  FIG. 5 , the reference potential V 1  of  FIG. 6 b    is provided by the converter  120  and biasing circuit  122 . Further, the reference potential V 2  of  FIG. 6 b    is provided by the converter  130  and biasing circuit  132 . One embodiment of a circuit that provides the reference potential V 1  is shown in  FIG. 6 c   , and one embodiment of a circuit that provides the reference potential V 2  is shown in  FIG. 6   d.    
       FIG. 6 c    is a circuit diagram of a second portion of the control circuitry  112  of  FIGS. 4 and 6   a , wherein the second portion includes the converter  120  and biasing circuit  122 . The converter  120  can be of many different types. In this embodiment, the converter  120  is an asynchronous DC-DC buck converter manufactured by BCD Semiconductor Manufacturing Limited as model number AP3211. 
     In this embodiment, the control circuitry  112  includes the battery cable connector  140 . A first terminal of the battery cable connector  140  is connected to a first terminal of the pressure switch  142 , and a second terminal of the battery cable connector  140  is connected to the current return  145 . The pressure switch  142  is shown in  FIGS. 1, 2, 5 and 8 . 
     In this embodiment, the biasing circuit  122  includes a capacitor  125   a  with a first terminal connected to the second terminal of the pressure switch  142 , and a second terminal connected to the current return  145 . The biasing circuit  122  includes an inductor  128   a  with a first terminal connected to the first terminal of the capacitor  125   a , and a second terminal connected to a first terminal of a capacitor  125   b . A second terminal of the capacitor  125   b  is connected to the current return  145 . 
     In this embodiment, the biasing circuit  122  includes a resistor  126   a  with a first terminal connected to the first terminal of the capacitor  125   b  and a second terminal connected to a first terminal of a resistor  126   b . A second terminal of the resister  126   b  is connected to the current return  145 . The biasing circuit  122  includes a capacitor  125   c  with a first terminal connected to the first terminal of the resistor  126   a  and a second terminal connected to the current return  145 . The converter  120  includes a pin  4  connected to the first terminal of the capacitor  125   c , and a GND terminal connected to the current return  145 . 
     In this embodiment, the biasing circuit  122  includes a capacitor  125   d  with first and second terminals connected to pin  1  and  6  of the converter  120 , respectively. The biasing circuit  122  includes a diode  129  with first and second terminals connected to the pin  6  of the converter  120  and the current return  145 , respectively. The biasing circuit  122  includes an inductor  128   b  with a first terminal connected to the pin  6  of the converter  120 , and a second terminal connected to a first terminal of a resistor  126   c . The second terminal of the resistor  126   c  is connected to a pin  3  of the converter  120 , and to a first terminal of a resistor  126   d . A second terminal of the resistor  126   d  is connected to the current return  145 . The biasing circuit  122  includes a capacitor  125   e  with a first terminal connected to the second terminal of the inductor  128   b , and a second terminal connected to the current return  145 . It should be noted that the second portion of the control circuitry  112  of  FIG. 6 c    provides the reference potential V 1  at the first terminal of the capacitor  125   e.    
       FIG. 6 d    is a circuit diagram of a third portion of the control circuitry  112  of  FIGS. 4 and 6   a , wherein the third portion includes the converter  130  and biasing circuit  132 . The converter  130  can be of many different types. In this embodiment, the converter  130  is an asynchronous DC-DC buck converter manufactured by BCD Semiconductor Manufacturing Limited as model number AP3211. 
     In this embodiment, the biasing circuit  132  includes a capacitor  135   a  with a first terminal connected to the second terminal of the pressure switch  142 , and a second terminal connected to the current return  145 . The first terminal of the capacitor  135   a  is connected to a pin  4  of the converter  130 . A GND pin of the converter  130  is connected to the current return  145 . 
     In this embodiment, the biasing circuit  132  includes a capacitor  135   b  with first and second terminals connected to pin  1  and  6  of the converter  130 , respectively. The biasing circuit  132  includes a diode  139  with first and second terminals connected to the pin  6  of the converter  130  and the current return  145 , respectively. The biasing circuit  132  includes an inductor  138  with a first terminal connected to the pin  6  of the converter  130 , and a second terminal connected to a first terminal of a resistor  136   a . A second terminal of the resistor  136   a  is connected to a pin  3  of the converter  130 , and to a first terminal of a resistor  136   b . A second terminal of the resistor  136   b  is connected to the current return  145 . The biasing circuit  132  includes a capacitor  135   c  with a first terminal connected to the second terminal of the inductor  138 , and a second terminal connected to the current return  145 . It should be noted that the third portion of the control circuitry  112  of  FIG. 6 d    provides the reference potential V 2  at the first terminal of the capacitor  135   c.    
       FIG. 7  is a perspective view of the circuit board  110  and control circuitry  112  of  FIG. 4 , and  FIG. 8  is an opposed perspective view of the circuit board and control circuitry  112  of  FIG. 4 . As mentioned above, the circuit board  110  carries the control circuitry  112  and display screen  116 . The control circuitry  112  is connected to the display screen  116 , and controls the operation of the display screen  116 . 
     In this embodiment, the control circuitry  112  is connected to the battery  118  through the battery cable  119  ( FIG. 4 ). In this embodiment, a battery cable connector  113  is connected to the battery cable  119 , wherein the battery cable connector  113  is repeatably moveable between connected and disconnected conditions with the battery cable connector  140 . The battery cable connector  140  is discussed in more detail above with  FIGS. 5, 6   a , and  6   c . The battery  118  ( FIG. 4 ) provides the power signal S Power  ( FIGS. 5, 6   c , and  6   d ) to the battery cable connector  140  ( FIGS. 5, 6   a ,  6   b , and  6   c ) through the battery cable  119  and battery cable connector  113 . 
     As mentioned above, the distance sensor apparatus  160  ( FIG. 4 ) is connected to the control circuitry  112  through the sensor cable  146 . The distance sensor apparatus  160  can be connected to the control circuitry  112  in many different ways. In this embodiment, a sensor cable connector  148  is connected to the sensor cable  146 , wherein the sensor cable connector  148  is repeatably moveable between connected and disconnected conditions with the sensor cable connector  141  ( FIGS. 5, 6   a , and  6   b ). The sensor signal S Sensor  flows between the distance sensor apparatus  160  and the control circuitry  112  when the sensor cable connector  148  is connected to the sensor cable connector  141 . In particular, the sensor signal S Sensor  flows between the distance sensor apparatus  160  and microcontroller  114  through the sensor cable  146 , and sensor cable connectors  141  and  148 . The sensor signal S Sensor  flows between the sensor cable connector  141  and the microcontroller  114 , as shown in  FIG. 6   b.    
     In this embodiment, the control circuitry  112  includes the pressure switch  142  ( FIGS. 1, 2, 5, 8 ). As discussed in more detail above, with  FIG. 5 , the pressure switch  142  turns the cardiopulmonary resuscitation device  100  to the activated condition in response to a force applied thereto. In the on and off positions, the display screen  116  is in an on and off condition, respectively. Further, in the on and off positions, the control circuitry  112  is in an on and off condition, respectively. 
     In this embodiment, the control circuitry includes the luminaire  144  ( FIG. 8 ). The luminaire  144  can be of many different types of lights, such as a light emitting diode. Light emitting diodes are provided by many different manufacturers, such as CREE and Philips. Visual Communications Company (VCC) provides the VAOL-3GWY4 Superbright LED lamp. The luminaire  144  can provide many different colors of illumination, such as white, red, green, and blue, among others. It should be noted that a lens can be positioned proximate to the luminaire  144 . The lens can be of many different types, such as a Fresnel lens. The lens is useful to focus the light provided by the luminaire  144 . The lens is also useful to hold the luminaire  144  to the cardiopulmonary resuscitation device  100 . As will be discussed in more detail below, the luminaire  144  is useful to provide the user of the cardiopulmonary resuscitation device  100  with a visual indication that the sternum is being compressed and decompressed the desired distance. 
       FIG. 9  is a perspective view of a distance sensor apparatus  160  of  FIG. 4 , and  FIG. 10  is an opposed perspective view of the distance sensor apparatus  160  of  FIG. 3 . The distance sensor apparatus  160  can be of many different types. In this embodiment, the distance sensor apparatus  160  is an ultrasonic distance sensor. There are many different ultrasonic distance sensors that can be used, such as the PING))) ultrasonic distance sensor, which is provided by PARALAX as model number 28015. 
     In this embodiment, the distance sensor apparatus  160  includes a circuit board  164 , which carries distance sensor circuitry  162  ( FIG. 10 ). The transmit and receive sensors  166  and  167  are carried by the circuit board  164  and operatively coupled to the distance sensor circuitry  162 . As mentioned above, the distance sensor apparatus  160  is connected to the sensor cable  146 . The distance sensor apparatus  160  can be connected to the sensor cable  146  in many different ways. In this embodiment, the distance sensor apparatus  160  includes a sensor cable connector  168 , which is carried by the circuit board  164  and connected to the distance sensor circuitry  162 . As mentioned above with  FIG. 5 , the sensor cable connector  147  is connected to the sensor cable  146 . The sensor cable connector  147  is repeatably moveable between connected and disconnected conditions with the sensor cable connector  168 . The sensor signal S Sensor  is allowed to flow through the sensor cable  146  when the sensor cable connector  147  is connected to the sensor cable  146 . 
     As mentioned above, one reason people do not survive when receiving CPR outside of a hospital is because the CPR is not performed correctly. The operation of the cardiopulmonary resuscitation device  100  will now be discussed to illustrate how it facilitates the correct performance of CPR. 
       FIG. 11  is a front view of the cardiopulmonary resuscitation device  100  being operated by a user when performing CPR on a patient  170 , wherein the patient is supported by a support surface  171  (e.g., a floor or ground). It should be noted that the pressure switch  142  turns the cardiopulmonary resuscitation device  100  to the activated condition in response to the user applying the force thereto. The luminaire  144  moves from the deactivated condition to the activated condition in response to the user applying the force thereto. In particular, the force is applied to the cover  102 . Further, it should be noted that transmit and receive sensors  166  and  167  are shown in phantom in  FIG. 11 . 
     In this embodiment, the cardiopulmonary resuscitation device  100  is positioned on the chest  172  of the patient  170 . In particular, the cardiopulmonary resuscitation device  100  is positioned on the chest  172  of the patient  170  so the case  106  extends across a sternum  174  of the patient  170 . It should be noted that the chest  172  is typically resilient, so it moves back into shape after being compressed. In this way, chest  172  forms a resilient surface. 
     In this embodiment, the cardiopulmonary resuscitation device  100  is positioned on the chest  172  of the patient  170  so the extension portion  109  extends away from the chest  172 . In particular, the cardiopulmonary resuscitation device  100  is positioned on the chest  172  of the patient  170  so the extension portion  109  extends away from the sternum  174 . The extension portion  109  extends away from the sternum  174  and over a shoulder  173  of the patient  170 . The extension portion  109  extends over the shoulder  173  so that the distance sensor apparatus  160  faces the support surface  171 . In particular, the extension portion  109  extends over the shoulder  173  so that the transmit sensor  166  and receive sensor  167  face the support surface  171 . The extension portion  109  extends away from the chest  172  so the distance sensor apparatus  160  is held away from the chest  172 . 
       FIG. 12 a    is a side view of the cardiopulmonary resuscitation device  100  in a direction  176  of  FIG. 11 , and  FIG. 12 b    is a partial view of the cardiopulmonary resuscitation device  100  in a region  177  of  FIG. 11 . The cardiopulmonary resuscitation device  100  is shown positioned on the chest  172  in  FIG. 12 a    in the same orientation shown in  FIG. 11 . It should be noted that the shortened side  157  is shown when looking in the direction  176 . Further, it should be noted that the transmit and receive sensors  166  and  167  are shown in phantom in  FIG. 12 a   . As will be discussed in more detail below, the transmit and receive sensors provide an ultrasonic pulse S Ultrasonic  and echo pulse S Echo , respectively. 
     As will be discussed in more detail below, it is desirable to move the chest  172  between uncompressed and compressed positions in a repeatable manner. The uncompressed position is denoted as Position  1 , and the compressed position is denoted as Position  2 . Hence, it is desirable to move the chest  172  between the Positions  1  and  2  in a repeatable manner. The distance between Positions  1  and  2  is denoted as a distance D 1 . Further, the distance between the Position  1  and the support surface  171  is denoted as a distance D 2 . 
     In  FIG. 12 b   , the position of the cardiopulmonary resuscitation device  100  is displayed by the display screen  116 . For simplicity and illustrative purposes, the position of the cardiopulmonary resuscitation device  100  at Position  1  is displayed as “0 cm” by the display screen  116 . As will be discussed in more detail below, the display screen will display a distance value corresponding to distance D 1  when the cardiopulmonary resuscitation device  100  at Position  2 . It should be noted that at Position  1 , the luminaire  143  does not provide light, and the sound device  117  does not provide the sound indication. It should also be noted that the distance value is provided to the display screen  116  with the display signal S Display . 
     In this embodiment, the display screen  116  displays information corresponding to the rate in which the chest  172  is moving between the compressed and uncompressed positions. The information corresponding to the rate in which the chest  172  is being compressed and uncompressed is displayed in units of counts per minute (cpm). It should be noted that information corresponding to the rate is provided to the display screen  116  with the display signal S Display . In  FIG. 12 b   , the counts per minute is being displayed as “0 cpm” for simplicity and illustrative purposes. Hence, information corresponding to “0 cpm” is provided to the display screen  116  with the display signal S Display . 
     In operation, and as shown in  FIG. 12 a   , a force  178  is applied to the cardiopulmonary resuscitation device  100  and, in response, the cardiopulmonary resuscitation device  100  moves from the deactivated condition to the activated condition. In some embodiments, the cardiopulmonary resuscitation device  100  remains in the activated condition for a predetermined amount of time in response to the force  178  being applied thereto. The force  178  is applied to the cardiopulmonary resuscitation device  100  so that the chest  172  moves from the uncompressed position at Position  1  to the compressed position at Position  2  in response. In particular, the force  178  is applied to the cover  102  and case  106 . The force  178  is typically applied using the hands (not shown) of the user of the cardiopulmonary resuscitation device  100 . 
     It should be noted that the force  178  is applied more evenly across the chest  172  and sternum  174  because the cardiopulmonary resuscitation device  100  is positioned as shown in  FIG. 11 . Recent medical studies show that applying the force  178  across the chest  172  and sternum  174  increases the likelihood that the patient  170  will survive. In particular, the force  178  is distributed along the length axis  103  ( FIG. 2 ). It is believed that distributing the force  178  along the length axis  103  increases the likelihood that the patient  170  will survive. 
       FIG. 13 a    is a side view of the cardiopulmonary resuscitation device  100  in the direction  176  of  FIG. 11 , and  FIG. 13 b    is a partial view of the cardiopulmonary resuscitation device  100  in the region  177  of  FIG. 11 . The cardiopulmonary resuscitation device  100  is shown positioned on the chest  172  in  FIG. 13 a    in the same orientation shown in  FIG. 11 . It should be noted that the shortened side  157  is shown when looking in the direction  176 . Further, it should be noted that the transmit and receive sensors  166  and  167  are shown in phantom in  FIG. 13   a.    
     In operation, the distance sensor apparatus  160  provides the ultrasonic pulse S Ultrasonic  towards the support surface  171  with the transmit sensor  166 , and the distance sensor apparatus  160  receives the echo pulse S Echo  with the receive sensor  167  in response. It should be noted that the echo pulse S Echo  corresponds to the ultrasonic pulse S Ultrasonic  being reflected by the support surface  171 . The distance sensor apparatus  160  provides the ultrasonic pulse S Ultrasonic  and receives the echo pulse S Echo  in response to the cardiopulmonary resuscitation device  100  being moved between Positions  1  and  2 . 
     The sensor signal S Sensor  is provided to the microcontroller  114  by the distance sensor apparatus  160  in response to the ultrasonic pulse S Ultrasonic  being transmitted. The sensor signal S Sensor  is terminated in response to the echo pulse S Echo  being received by the receive sensor  167 . The width of the echo pulse S Echo  corresponds to the distance D 2  the ultrasonic pulse traveled. Information corresponding to the width of the echo pulse S Echo  is provided to the control circuitry  112  with the sensor signal S Sensor . In particular, information corresponding to the width of the echo pulse S Echo  is provided to the microcontroller  114  with the sensor signal S Sensor  ( FIGS. 5, 6   b , and  7 ). The microcontroller  114  determines the distance D 1  by determining the width of the echo pulse S Echo . Information corresponding to the distance D 1  is provided to the display screen  116  by the microcontroller  114  through the display channel  111  ( FIGS. 5 and 6   b ). It should be noted that information corresponding to the distance D 1  is provided to the display screen  116  with the display signal S Display . 
     As shown in  FIG. 13 a   , the cardiopulmonary resuscitation device  100  has moved from the Position  1  to Position  2 , which corresponds to a movement of the distance D 1 . Hence, the display screen  116  displays a distance value corresponding to distance D 1 . In  FIG. 13 b   , the distance value is chosen to be “5 cm” because recent medical studies show that this is the optimum compression distance for CPR. Information corresponding to “5 cm” is provided to the display screen  116  in the display signal S Display . It should be noted that the distance value can have many other values that depend on the distance D 1  between Positions  1  and  2 . The display screen  116  will display the distance that the cardiopulmonary resuscitation device  100  has moved during CPR so that the user will know how far the chest  172  has been compressed. It is believed that the distance value of about 5 centimeters is desired to increase the likelihood that the patient  170  will survive CPR. 
     It should be noted that at Position  2 , the luminaire  143  does provide light, and the sound device  117  does provide sound the sound indication. In this way, the cardiopulmonary resuscitation device  100  provides a visual and audio indication that the chest  172  has been compressed a desired amount. Further, the cardiopulmonary resuscitation device  100  does not provide the visual and audio indication if the chest  172  has not been compressed the desired amount. In response to the visual and audio indication, the user removes the force  178  so that the chest  172  moves from Position  2  to Position  1 . The movement of the chest  172  from Position  2  to Position  1  is indicated by a force  179 . It should be noted that the force  179  can be from the resiliency of the chest  172 . 
     It should be noted that the display screen  116  displays distance values between Position  1  and Position  2  while the cardiopulmonary resuscitation device  100  is moving therebetween. Hence, in the example above, the display screen  116  will display “2.5 cm” when the cardiopulmonary resuscitation device  100  is halfway between Positions  1  and  2 . In this way, the display screen  116  displays an intermediate distance value. It should be noted that information corresponding to the intermediate distance values is provided to the display screen  116  with the display signal S Display . 
     As mentioned above, the display screen  116  displays information corresponding to the rate in which the chest  172  is being compressed and uncompressed. In  FIG. 13 b   , the counts per minute is being displayed as “100 cpm” for simplicity and illustrative purposes. Recent medical studies show that the rate value of about 100 cpm is desired to increase the likelihood that the patient  170  will survive CPR. In this way, the cardiopulmonary resuscitation device  100  provides the user with information corresponding to the rate of compressions. It should be noted that information corresponding to “100 cpm” is provided to the display screen  116  with the display signal S Display . 
     Hence, the invention provides a cardiopulmonary resuscitation device which facilitates the ability of the user to correctly perform CPR on a patient. The cardiopulmonary resuscitation device provides a visual indication that CPR is being performed at a desired rate of compressions and decompressions. Further, the cardiopulmonary resuscitation device provides visual and audio indications that the chest of the patient has been compressed by a desired amount. The cardiopulmonary resuscitation device is also shaped so that the force applied to the chest of the patient is applied more evenly, so that the entirety of the thoracic cavity is compressed and not just one sharp point. These features of the cardiopulmonary resuscitation device allow the user to increase the likelihood that the patient will survive CPR. 
     The embodiments of the invention described herein are exemplary and numerous modifications, variations and rearrangements can be readily envisioned to achieve substantially equivalent results, all of which are intended to be embraced within the spirit and scope of the invention as defined in the appended claims.