Patent Publication Number: US-2023148421-A1

Title: Medical treatment simulation devices

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a Divisional application of U.S. patent application Ser. No. 16/693,833, filed Nov. 25, 2019 (status: allowed), which is a Divisional application of U.S. patent application Ser. No. 15/527,173, filed May 16, 2017 (U.S. Pat. No. 10,540,911, issued Jan. 21, 2020), which is a U.S. National Phase Application of PCT International Application PCT/US2015/060889, filed Nov. 16, 2015, which claims priority to U.S. Patent Application No. 62/080,439, filed Nov. 17, 2014; to U.S. Patent Application No. 62/080,440, filed Nov. 17, 2014; to U.S. Patent Application No. 62/080,444, filed Nov. 17, 2014; to U.S. Patent Application No. 62/081,042, filed Nov. 18, 2014; to U.S. Patent Application No. 62/128,100, filed Mar. 4, 2015; and to U.S. Patent Application No. 62/145,018, filed Apr. 9, 2015, the contents of each of which are incorporated herein by reference in their entirety. U.S. patent application Ser. No. 15/527,173 is also a Continuation-in-Part of U.S. patent application Ser. No. 14/496,396, filed Sep. 25, 2014 and a Continuation-in-Part of U.S. patent application Ser. No. 14/466,027, filed Aug. 22, 2014, the contents of each of which are incorporated herein by reference in their entirety for all purposes. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates generally to medical simulations, and more particularly, to simulation devices for training care providers to provide medical treatment. 
     BACKGROUND OF THE INVENTION 
     Conventionally, the training process for nursing or medical students related to patient care and treatment may employ mannequins that do not provide realistic patient feedback. This lack of feedback makes it difficult for nursing or medical students to gain the education needed to perform proper medical treatments or care when working with actual patients. Accordingly, improved systems and devices are desired for training medical care providers to provide treatment. 
     SUMMARY OF THE INVENTION 
     Aspects of the present invention are medical treatment simulation systems and devices. 
     In accordance with one aspect of the present invention, an intravenous treatment simulation device is disclosed. The intravenous treatment simulation device includes an overlay, at least one tube, a reservoir, and a processor. The overlay is configured to be secured to a subject. The overlay has a needle-resistant inner layer and at least one conductive layer positioned outside of the needle resistant inner layer. The at least one tube is positioned within the overlay beneath the at least one conductive layer. The reservoir is adapted to store a fluid. The reservoir is coupled to provide the fluid to the at least one tube. The processor is coupled to the at least one conductive layer. The processor is configured to detect an insertion of a needle through the at least one conductive layer and generate a signal upon the detection of the insertion of the needle. 
     In accordance with another aspect of the present invention, a catheter treatment simulation device is disclosed. The catheter treatment simulation device includes an overlay, a tube, a sensor, a reservoir, a valve, and a processor. The overlay is configured to be secured to a subject. The overlay comprises an opening sized to receive a catheter. The tube is coupled with the opening in the overlay. The sensor is coupled to the tube. The sensor is operable to detect an insertion of the catheter into the tube. The reservoir is adapted to store a fluid. The reservoir is coupled to provide the fluid to the tube. The valve is positioned to control a flow of the fluid between the reservoir and the tube. The processor is coupled to the sensor. The processor is configured to detect the insertion of the catheter into the tube beyond a predetermined threshold and to open the valve upon the detection of the insertion of the catheter into the tube beyond the predetermined threshold. 
     In accordance with yet another aspect of the present invention, a defibrillation treatment simulation device is disclosed. The defibrillation treatment simulation device includes a housing, a display coupled to the housing, one or more input devices coupled to the housing, and a processor within the housing. The display is operable to display an image to a user. The one or more input devices are operable by the user to simulate applying a defibrillation signal to a subject. The processor is programmed to generate a signal to the user that the defibrillation signal has been applied to the subject and to display a simulated patient heart rhythm on the display. 
     In accordance with still another aspect of the present invention, a thoracic treatment simulation device is disclosed. The thoracic treatment simulation device includes an overlay, a reservoir, a motor, and a processor. The overlay is configured to be secured to a subject. The overlay covers at least a portion of a torso of the subject and comprises an opening. The reservoir is coupled with the opening. The motor is coupled to the reservoir. The motor is operable to periodically pump air into and out of the reservoir via the opening. The processor is coupled to the motor. The processor is configured to operate the motor to pump the air into and out of the reservoir in accordance with a simulated breathing pattern of the subject. 
     In accordance with yet another aspect of the present invention, a device for facilitating simulating performance of medical procedure on a live subject is disclosed. The device includes an overlay, a simulated treatment structure, at least one feedback device, and at least one processor. The overlay is configured to be secured to the live subject and to cover at least a portion of a body of the live subject. The simulated treatment structure is configured to simulate a structure associated with the medical procedure. The at least one feedback device is configured to provide a feedback signal to the live subject. The at least one processor is connected to the simulated treatment structure and the at least one feedback device. The processor is programmed to operate the feedback device to provide the feedback signal based upon input generated from interaction between a treatment provider and the simulated treatment structure. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention is best understood from the following detailed description when read in connection with the accompanying drawings, with like elements having the same reference numerals. When a plurality of similar elements are present, a single reference numeral may be assigned to the plurality of similar elements with a small letter designation referring to specific elements. When referring to the elements collectively or to a non-specific one or more of the elements, the small letter designation may be dropped. This emphasizes that according to common practice, the various features of the drawings are not drawn to scale unless otherwise indicated. On the contrary, the dimensions of the various features may be expanded or reduced for clarity. Included in the drawings are the following figures: 
         FIG.  1    is an image illustrating an exemplary medical treatment simulation device in accordance with aspects of the present invention; 
         FIG.  2    is a diagram illustrating an exemplary sensor layout of the medical treatment simulation device of  FIG.  1    relative to a human subject; 
         FIG.  3    is a diagram illustrating an exemplary audio feedback layout of the medical treatment simulation device of  FIG.  1    relative to a human subject; 
         FIG.  4    is an image illustrating an exemplary tracheostomy structure and sensor layout of the medical treatment simulation device of  FIG.  1   ; 
         FIG.  5    is an image illustrating an alternative exemplary tracheostomy structure and sensor layout of the medical treatment simulation device of  FIG.  1   ; 
         FIGS.  6 A and  6 B  are diagrams illustrating an exemplary surface layer of the medical of the medical treatment simulation device of  FIG.  1   ; 
         FIG.  7    is a diagram illustrating an exemplary fluid feedback system of the medical treatment simulation device of  FIG.  1   ; and 
         FIG.  8    is a diagram illustrating an exemplary intravenous treatment simulation device in accordance with aspects of the present invention; 
         FIG.  9    is a diagram illustrating a cross-section of an overlay of the intravenous treatment simulation device of  FIG.  8   ; 
         FIG.  10    is a diagram illustrating a fluid flow path of the intravenous treatment simulation device of  FIG.  8   ; 
         FIG.  11    is a diagram illustrating an exemplary catheter treatment simulation device in accordance with aspects of the present invention; 
         FIG.  12    is an image illustrating genitalia of the exemplary catheter treatment simulation device of  FIG.  11   ; 
         FIGS.  13 A and  13 B  are diagrams illustrating a force sensor of the exemplary catheter treatment simulation device of  FIG.  11    in uncompressed and compressed configurations, respectively; 
         FIG.  14    is a diagram illustrating an exemplary defibrillation treatment simulation device in accordance with aspects of the present invention; 
         FIG.  15    is a diagram illustrating an exemplary thoracic treatment simulation device in accordance with aspects of the present invention; 
         FIG.  16    is an image illustrating an overlay of the thoracic treatment simulation device of  FIG.  15   ; and 
         FIG.  17    is an image illustrating a pressure unit of the thoracic treatment simulation device of  FIG.  15   . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Aspects of the invention are described herein with reference to simulating specific medical treatments. However, it will be understood by one of ordinary skill in the art that the exemplary devices described herein may be used to simulate treatment of a variety of medical conditions, and is not limited to any particular treatment disclosed herein. Other medical treatments suitable for simulation with the disclosed devices will be known to one of ordinary skill in the art from the description herein. 
     The exemplary devices disclosed herein may be particularly suitable for providing an enhanced level of feedback to the medical care provider relative to conventional training devices. Audio and/or haptic feedback may be provided to the care provider during treatment in order to reinforce proper techniques. Likewise, this feedback may be provided to correct treatment errors that the care provider may otherwise struggled to detect during the simulated treatment. The provision of feedback using the exemplary devices of the present invention may desirably improve the ability of medical care providers to comfortably and effectively treat patients. 
     Exemplary Tracheostomy Treatment Simulation Device 
     With reference to the drawings,  FIG.  1    illustrates an exemplary medical treatment simulation device  100  in accordance with aspects of the present invention. Device  100  is usable to train medical care providers to treat tracheostomy patients. In general, device  100  includes an overlay  110 , a tracheostomy structure  120 , one or more tubes  130 , at least one sensor  140 , and at least one feedback device  150 . Additional details of device  100  are described below. 
     Overlay  110  is configured to be secured to a subject who is playing the role of the patient. When secured to the subject, overlay  110  is configured to cover the subject&#39;s neck and upper torso. In an exemplary embodiment, overlay  110  is shaped like a patient&#39;s neck and upper torso, as shown in  FIGS.  1 - 3   . Shaping overlay  110  as described above desirably limits the size of overlay  110 , and allows the profile of overlay  110  to closely conform to the body of the subject, thereby allowing the subject to portray a tracheostomy patient. 
     Overlay  110  may be formed from multiple pieces that connect to define an enclosure for the components of device  100 . In an exemplary embodiment, overlay  110  is a housing formed from a front shell  112   a  and a rear shell  112   b , as shown in  FIG.  1   .  FIG.  1    shows the inside surfaces of both front shell  112   a  and rear shell  112   b . Front shell  112   a  is configured to be removably connected to rear shell  112   b  to form overlay  110 . Shells  112   a  and  112   b  may be attached, for example, by straps, buttons, snaps, or any other structures known in the art. In an exemplary embodiment, shells  112   a  and  112   b  are attached via snaps  114  provided at the upper and lower ends of the shells  112   a  and  112   b.    
     In an exemplary embodiment, overlay  110  may be formed from three separate components designed to best simulate the body of a tracheostomy patient. The pieces include the attachable hard shells  112   a  and  112   b , a soft and pliable front surface material intended to simulate the patient&#39;s skin (“artificial skin”), and a soft back surface material for providing comfort to the subject wearing overlay  110 . The operational components of device  100  (e.g. sensors and feedback devices) are provided within the hard shells of overlay  110 , which thereby provides protection for these components and helps conceal wiring and other items. 
     An exemplary embodiment of the artificial skin layer  180  is shown in  FIGS.  6 A and  6 B . The artificial skin layer  180  may include sound dampening material  181  in order to dampen sounds generated within overlay  110 , as will be discussed below in greater detail. The artificial skin may further provide layers of materials on the outside of one or both of hard shells  112   a  and  112   b  for simulating the patient&#39;s body. In an exemplary embodiment, the layers of material include memory foam  182 , PVC  183 , and a nylon elastane layer  184 . Alternatively, the artificial skin may comprise silicone, with an interior layer of memory foam positioned adjacent the subject&#39;s body for comfort. It will be understood that the selection, order, and thickness of layers of artificial skin layer  180  shown in  FIG.  6 B  is provided for the purpose of illustration, and is not intended to be limiting. Other suitable materials for use in simulating a patient&#39;s skin will be generally known to one of ordinary skill in the art from the description herein. 
     The layers of artificial skin  180  may be attached to the edges of the hard shells of overlay  110  via one or more attachment mechanisms. Suitable attachment mechanisms include, for example, hook-and-loop fasteners  185 , anchors  186 , adhesives, or double-sided tape  187 , as shown in  FIG.  6 A . Other suitable attachment mechanisms will be known to one of ordinary skill in the art from the description herein. 
     Rear shell  112   b  further includes a plurality of straps  116  for securing overlay  110  to a subject. In an exemplary embodiment, rear shell  112   b  includes a pair of straps configured to encircle the subject&#39;s shoulders, as shown in  FIG.  1   . Straps  116  are usable to secure device  100  to the subject during the simulated treatment. Rear shell  112   b  may further include a foam layer on the rear thereof, in order to improve the comfort of the subject wearing overlay  110 . 
     It will be understood by one of ordinary skill in the art that rear shell  112   b  may be omitted. In such an embodiment, straps may extend from front shell  112   a , and the interior components of overlay  110  may all be coupled to front shell  112   a.    
     Tracheostomy structure  120  is provided on overlay  110 . Structure  120  is designed to simulate the structures implanted in an actual tracheostomy patient. Accordingly, structure  120  is provided on the neck portion of overlay  110 . In an exemplary embodiment, structure  120  includes a tracheostomy faceplate  122 , and a tracheostomy tube  124  attached thereto. A suitable tracheostomy structure  120  for use with the present invention is provided in  FIG.  4    for the purpose of illustration. 
     While in this embodiment structure  120  relates to tracheostomy treatment, it will be understood that the invention is not so limited. Other suitable structures for simulating medical treatments will be known to one of ordinary skill in the art from the description herein. 
     Tubes  130  are positioned within overlay  110 , and connected to tracheostomy structure  120 . Tubes  130  are designed to simulate the airways of an actual tracheostomy patient. Accordingly, tubes  130  have a shape and size corresponding to the bronchial tubes of a patient. In an exemplary embodiment, tubes  130  include a first length of tubing  132  leading to a bifurcation  134 , and a pair of tubes  136   a  and  136   b  extending from the bifurcation. An exemplary layout of tubes  130  within overlay  110  is shown by diagram in  FIGS.  2  and  3   . During the simulated medical treatment, the care provider may be asked to insert a suction tube through tracheostomy structure  120  and into tubes  130 , in order to simulate drainage of a patient&#39;s lungs  130 . 
     Sensor  140  is coupled to tracheostomy structure  120 . Sensor  140  detects any manipulation of tracheostomy structure  120  during the simulated treatment of the subject. Examples of manipulations of tracheostomy structure  120  are set forth below. 
     In one exemplary embodiment, the sensor includes a normal force sensor  140   a . In this embodiment, sensor  140   a  is configured to detect a force on tracheostomy structure  120  during the simulated treatment. The force may be a force normal to the tracheostomy structure (e.g., normal to tracheostomy faceplate  122  in  FIG.  4   ). Sensor  140   a  may be an electrical force sensor positioned behind tracheostomy faceplate  122  and configured to detect a normal force on tracheostomy faceplate  122 , as shown in  FIG.  4   . In actual tracheostomy patients, excessive force on a tracheostomy faceplate (e.g., a normal force in excess of 2 lbs.) can be a source of discomfort. Accordingly, the detection of force on tracheostomy structure  120  may be desirable in order train care providers to limit excessive force on structure  120  and prevent discomfort in actual patients. 
     In the above embodiment, the force sensors used are force-sensitive resistors (FSRs). FSRs are dynamic resistors that have nearly infinite resistance when no force is applied. The resistivity of the FSR decreases, non-linearly, as the force applied increases. In this embodiment, the voltage measured across the sensor may be converted into a detection of an applied force on tracheostomy structure  120 . 
     In another exemplary embodiment, the sensor includes a rotation sensor  140   b . In this embodiment, one or more force sensors  140   b  are configured to detect a rotation of tracheostomy structure  120  during the simulated treatment. The rotation of tracheostomy structure  120  may be an axial rotation of tracheostomy faceplate  122 , as shown by a block arrow in  FIG.  4   . Sensor  140   b  may include a pair of force sensors positioned on opposed rotatable projections behind tracheostomy faceplate  122 , as shown in  FIG.  4   , such that rotation of the faceplate  122  in either direction provides a force on the adjacent force sensor. The amount of rotation of the tracheostomy faceplate  122  may be measured by determining the corresponding force detected by sensor  140   b  (which increases in a determinable manner as rotational displacement increases). In actual tracheostomy patients, as with force, excessive rotation of a tracheostomy faceplate (e.g., an axial rotation in excess of 4 degrees) can also be a source of discomfort. Accordingly, the detection of rotation of tracheostomy structure  120  may be desirable in order train care providers to limit excessive rotation on structure  120  and prevent discomfort in actual patients. 
     In another exemplary embodiment, the sensor includes a spring-based sensor  140   c . In this embodiment, the spring-based sensor  140   c  is configured to detect a force on tracheostomy structure  120  during the simulated treatment. The force may be a force normal to the tracheostomy structure (e.g., normal to tracheostomy faceplate  122  in  FIG.  5   ). Sensor  140   c  may be a mechanical force sensor that is configured to detect a normal force on tracheostomy faceplate  122  as that force is transmitted through a spring  141  coupled to tracheostomy faceplate  122 , as shown in  FIG.  5   . For example, the sensor may include an electric circuit that is kept open by a spring having a spring constant that corresponds to the response of a human throat. When the force threshold is exceeded, the circuit closes, thereby signaling excessive force received by the tracheostomy structure  120 . Coupling of tracheostomy structure  120  to a spring-based sensor as shown in  FIG.  5    may be desirable in order to provide realistic movement of tracheostomy structure  120  during the simulated treatment by the care provider. 
     The spring-based sensor  140   c  may further include a circuit that is adapted to be closed during excessive force on tracheostomy structure  120 . In an exemplary embodiment, the spring-based sensor  140   c  includes circuit contacts that are spaced a predetermined distance apart by spring  141 . When an excessive force is applied to tracheostomy faceplate  122  (for example), spring  141  is compressed, and the circuit contacts are closed. Closing of the circuit contacts may function to automatically operate one or more feedback device  150 , so that feedback is provided as soon as the excessive force is detected. 
     In addition to providing one or more sensors  140  coupled to tracheostomy structure  120 , device  100  may further include one or more sensors  142  coupled to tubes  130 . In an exemplary embodiment, sensor  142  is a force sensor coupled to tubes  130  to detect any contact between an inserted suction tube and the inner wall of tubes  130  during the simulated treatment. In a particularly preferred embodiment, sensor  142  is a force sensor coupled to the bifurcation  134  of tubes  130  to detect contact with the bifurcation  134 , where contact with the bifurcation  134  is determined to be any force above a predetermined amount (e.g., in excess of 0.5 lbs.). In actual tracheostomy patients, such contact with the patient&#39;s bronchial tubes can cause irritation. Accordingly, the detection of contact on bifurcation  134  may be desirable in order train care providers to limit such contact and provide effective treatment to tracheostomy patients. 
     The above examples of types and locations of sensors  140  are provided for the purposes of illustration, and are not intended to be limiting. It will be understood that any combination of the disclosed sensors may be used, and that additional types and locations of sensors may be used, without departing from the scope of the invention. Other possible sensors for use in device  100  would be known to one of ordinary skill in the art. 
     Feedback device  150  is also coupled to overlay  110 . Feedback device  150  is configured to provide feedback to the user of device  100  (i.e. the care provider) based on the manipulation detected by sensor  140 . Feedback may be provided when the manipulation detected by sensor  140  exceeds a predetermined threshold. For example, feedback may be provided to the user when the force on tracheostomy structure  120  exceeds a predetermined limit, or when tracheostomy structure  120  is rotated more than a predetermined amount. Additionally, feedback may be provided to the user when contact of tubes  130  is detected. 
     In an exemplary embodiment, feedback device  150  is a vibrating motor. The vibrating motor creates a vibration of overlay  110  that can be felt by the user during the simulated treatment of the subject. Suitable vibrating motors for use as feedback device  150  include, for example, a shaftless vibration motor provided by Precision Microdrives (Model 310-101; Size 10 mm). 
     In another exemplary embodiment, feedback device  150  is an audible alarm. The alarm generates a sound that can be heard by the user during the simulated treatment of the subject. Suitable loudspeakers for use as the audible alarm will be known to one of ordinary skill in the art from the description herein. Other feedback devices, or combinations thereof, will be known to one of ordinary skill in the art from the description herein. 
     In addition to or alternatively to providing feedback to the care provider, feedback device  150  may also provide feedback to the subject wearing device  100 . In an exemplary embodiment, feedback devices  150  may be coupled to straps  116  of overlay  110 , in order to provide feedback (e.g., vibration feedback) only to the subject, as shown in  FIG.  1   . Such feedback may be used as a signal to cause the subject to respond to the simulated treatment in a predetermined way, without directly indicating to the care provider that improper or undesirable treatment has been provided. 
     Where multiple sensors  140  are employed by device  100 , it may be desirable to provide different types of feedback dependent on the information being detected. For example, device  100  may be configured to provide vibration feedback when excessive force or rotation is provided on tracheostomy structure  120 , and may be configured to provide audible feedback when contact occurs in tubes  130 . 
     In an exemplary embodiment, each sensor employed by device  100  may have its own feedback device  150  provided in a particular location or type (e.g., in each strap  116 ), in order for the user and/or the subject to determine which sensor has been triggered during the simulated treatment. For example, sensor(s)  140  for the tracheostomy structure  120  may include a feedback device  150  in the left strap  116 , and sensor  142  for the tubes  130  may include a feedback device  150  in the right strap  116 . Other possible combinations of sensor detection and feedback will be apparent to one of ordinary skill in the art from the description herein. 
     Device  100  is not limited to the above-described components, but can include alternate or additional components as would be understood to one of ordinary skill in the art in view of the examples below. 
     For example, device  100  may include a microcontroller  160 . In an exemplary embodiment, microcontroller  160  is connected in communication with sensors  140  and feedback device  150 . Microcontroller  160  processes the information detected by sensors  140 , and determines whether the sensed manipulations (force, rotation, etc.) exceed predetermined thresholds stored by microcontroller  160 . If microcontroller  160  determines that any threshold is exceeded, it sends signals to operate feedback device  150  to provide feedback to the user of device  100 . 
     For another example, device  100  may include one or more speakers  170 . Speakers  170  are positioned within overlay  110 , and are configured to emit sounds during the simulated treatment of the subject. The care provider may be trained to listen for sounds (e.g., noises within a patient&#39;s lungs) during the treatment being provided. Accordingly, device  100  may include a plurality of speakers positioned within overlay  110  in locations corresponding to the areas at which the care provider is trained to listen. 
     An exemplary layout of speakers  170  is provided in  FIG.  3   . Suitable loudspeakers for use as speaker  170  include, for example, a miniature speaker provided by Visaton (Model: K 28 WP; Size: 8 ohm 2.3 cm). In this embodiment, simulated lung sounds can be auscultated in four anatomically correct regions of the overlay  110  corresponding to anterior thorax locations, in order to simulate medical conditions such as pneumonia, mucus build up in the upper airway necessitating tracheal suctioning, wheezing (constriction of the air passages in the lungs) necessitating simulated aerosolized medication administration, and finally normal lung sounds indicating treatment choice was effective. Additionally, the layout of speakers  170  could include a rear surface corresponding to the posterior thorax, in order to allow posterior lung auscultation in 4-8 lung fields and include the same options for lung sounds mentioned above. 
     Speakers  170  emit simulated patient sounds that the care provider would expect to hear from a patient during treatment corresponding to different medical conditions of the patient, as set forth above. Preferably, these sounds are quiet enough that they are inaudible to the care provider without the use of a stethoscope. 
     Speakers  170  may be connected with one or more microcontrollers  172  for controlling the sounds emitted therefrom, as shown in  FIGS.  1  and  3   . Microcontrollers  172  may be located with overlay  110 , or may be provided remote from overlay  110 . Likewise, the connection between speakers  170  and microcontrollers  172  may be wireless or wired. In an exemplary embodiment, a trainer of the care provider may control the sounds emitted from speakers  170  during the simulated medical treatment. This control may include the ability to control when speakers  170  emit sound, which speakers  170  emit sounds, what sounds are emitted, and how loud those sounds are emitted. Alternatively, microcontroller  160  may control the sounds emitted from speakers  170  in addition to the operation of feedback device  150 . 
     For yet another example, device  100  may include an option to simulate secretions in the airway during treatment. During actual medical treatment of a tracheostomy patient, it is possible for mucus to build up in the patient&#39;s bronchial tubes/upper airway. Such buildup may requirement suctioning or tracheostomy care to provide a realistic feel while suctioning. Accordingly, as shown in  FIG.  7   , device  100  may include one or more reservoirs  190  adapted to store fluid having a viscosity corresponding to the mucus found in a patient. Each of these reservoirs may include one or more valves  192  adapted to release the fluid in the one or more tubes  130 . The reservoirs fluid may be released into the tubes  130  by gravity feed, or reservoirs  190  may further include one or more actuators or pumps (such as peristaltic pumps, not shown) for pushing fluid into tubes  130  during the simulated treatment of the patient. Suitable pumps and valves for use in fluid reservoirs will be known to one of ordinary skill in the art from the description herein. 
     Reservoirs  190  containing simulated mucus may be controlled through substantially the same systems as discussed above with respect to speakers  170 . For example, the valves  192  of reservoirs  190  may be electrically coupled to and controlled by microcontroller  160  in a predetermined fashion during the course of a simulated treatment, as shown in  FIG.  7   . Alternatively, a trainer of the care provider may control the release of fluid from reservoirs during the simulated medical treatment using one or more microcontrollers that are wired or wirelessly connected to the fluid reservoirs. 
     Exemplary Intravenous Treatment Simulation Device 
       FIGS.  8 - 10    illustrate an exemplary intravenous treatment simulation device  200  in accordance with aspects of the present invention. Device  200  is usable to train medical care providers to perform intravenous treatments. In general, device  200  includes an overlay  210 , at least one tube  220 , a reservoir  230 , and a processor  240 . Additional details of device  200  are described below. 
     Overlay  210  is configured to be secured to a subject who is playing the role of the patient. In an exemplary embodiment, overlay  210  is adapted to be worn around the subject&#39;s arm, as shown in  FIG.  8   . Preferably, overlay  210  can be slid onto the subject&#39;s arm in one or more pieces. Overlay  210  desirably has a thin profile, to allow overlay  210  to closely conform to the shape of the subject&#39;s arm. 
     Overlay  210  is formed from multiple layers. As shown in  FIG.  9   , overlay  210  includes a needle-resistant inner layer  212 , a middle layer  214 , and at least one conductive layer  216  positioned outside of inner layer  212  and middle layer  214  (relative to the subject&#39;s arm). The layers of overlay  210  are selected to promote simulation of the intravenous treatment while providing protection to the subject wearing device  200 . Additional details regarding the layers of overlay  210  are set forth below. 
     Needle-resistant inner layer  212  prevents the subject from being inadvertently stuck with a needle during simulation of the intravenous treatment. Needle-resistant inner layer  212  may be formed from any flexible fabric or material that exhibits high resistance to needle penetration. In an exemplary embodiment, inner layer  212  is formed from SUPERFABRIC® brand materials provided by HexArmor. Alternatively, inner layer  212  may be formed from small rigid plates that flexibly overlap along the contour of the subject&#39;s arm. Other suitable materials for forming needle-resistant inner layer  212  will be known to one of ordinary skill in the art from the description herein. 
     Inner layer  212  may be continuous, or may be formed from patches of material positioned in locations where the intravenous treatment is expected to occur. Where inner layer  212  is not continuous, it may be coupled to a base layer  211  to provide a structure for the separate pieces that form inner layer  212 . Base layer  211  may be formed from a material that contours to the subject&#39;s arm, such as SPANDEX®. 
     Middle layer  214  is positioned between the needle-resistant inner layer  212  and the outer conductive layer  216 . Middle layer  214  stabilizes the tube  220  of device  200 . Middle layer  214  may have a thickness selected based on a diameter of tube  220 , such as a thickness between ½ the diameter of tube  220  up to a thickness greater than the diameter of tube  220 , so that tube  220  can be at least partially or fully embedded or covered by the material of middle layer  214 . To this end, middle layer  214  may have one or more channels defined therein for receiving tube  220 . In an exemplary embodiment, middle layer  214  is formed from silicone rubber. Other suitable materials for forming middle layer  214  will be known to one of ordinary skill in the art from the description herein. 
     Conductive layer  216  is positioned outside of inner layer  212  and middle layer  214 . Conductive layer  216  enables device  200  to determine when a needle has been inserted into device  200 , as will be discussed below. Conductive layer  216  may be formed from any flexible conductive material or fabric. In an exemplary embodiment, conductive layer  216  is formed from a fabric containing a plurality of conductive filaments therein. Other suitable conductive fabrics will be known to one of ordinary skill in the art from the description herein. 
     Overlay  210  may further include an artificial skin layer  218  outside of conductive layer  216 . Skin layer  218  is formed from a material selected to simulate the look and feel of a patient&#39;s skin, such as silicone. Other suitable materials will be known to one of ordinary skill in the art from the description herein. 
     In an exemplary embodiment, conductive layer  216  and skin layer  218  are removable from middle layer  214  during or following use of device  200 . This may be preferable in order to allow tube  220  to be removed from middle layer  214  for cleaning or replacement. 
     Tube  220  is positioned within overlay  210  beneath conductive layer  216 . In an exemplary embodiment, tube  220  is at least partially embedded in middle layer  214  in order to prevent movement of tube  220  within overlay  210 . Tube  220  receives simulated blood during the simulated intravenous treatment. Tube  220  is formed from a material such as silicone that allows a needle to penetrate tube  220  during the simulated treatment. Tube  220  desirably stretches along a substantial length of overlay  210  (e.g., from the user&#39;s wrist to above the user&#39;s elbow), in order to provide multiple different needle insertion sites along the subject&#39;s arm. 
     Tube  220  is connected at one end to reservoir  230 . Reservoir  230  is adapted to store a fluid. In operation, reservoir  230  stores simulated blood during the simulated intravenous treatment. The simulated blood may be, for example, formed from a combination of water and one or more viscous gels, lubricants, or dyes to achieve the desired amount of flow and color to simulate blood. Reservoir  230  is coupled to tube  220  in order to provide the simulated blood to tube  220 . 
     In an exemplary embodiment, reservoir  230  is part of a syringe pump, as shown in  FIG.  10   . The syringe pump is adapted to apply pressure to the fluid in reservoir  230  in order to cause the fluid to flow into and through tube  220 . The syringe pump may further apply pressure so that the fluid in tube  220  is under pressure during the simulated intravenous treatment. The fluid may be maintained under pressure through the use of one or more valves  232 , as shown in  FIG.  10   . While a syringe pump is shown in  FIG.  10   , it will be understood that other structures may be utilized in connection with reservoir  230  to cause fluid to flow into and through tube  220 . Such structures include, for example, hand pumps or peristaltic pumps. 
     Tube  220  may be connected at its other end to collector  234 . Collector  234  collects the simulated blood that has flown through tube  220 . Collector  234  may include a one-way valve to prevent fluid in collector  234  to flow back into tube  220 . Collector  234  may include one or more drainage outlets  236  to allow drainage of the fluid in collector  234 . In order to drain tube  220 , pressure may be applied from the syringe pump when no fluid is stored in reservoir  230 , in order to force air into tube  220  and cause any remaining fluid in tube  220  to be pumped into collector  234 . 
     The connections between tube  220 , reservoir  230 , and collector  234  may be internal or external to overlay  210 . In an exemplary embodiment, reservoir  230  and collector  234  are external to overlay  210  in order to provide simplified control over the pumping of fluid out of reservoir  230  and/or the draining of fluid from collector  234 . In this embodiment, tube  220  exits overlay  210  (e.g., near the subject&#39;s should/armpit, as shown in  FIG.  8   ) in order to be connected with reservoir  230  and collector  234 . 
     Processor  240  is coupled to conductive layer  216 . By detecting signals from conductive layer  216 , processor  240  is configured to detect an insertion of a needle through conductive layer  216  during the simulated intravenous treatment. Suitable processors for use as processor  240  include, for example, ARDUINO® processors. Other suitable processing elements will be known to those of ordinary skill in the art. 
     An exemplary operation of processor  240  in detecting a needle insertion is described below. Conductive layer  216  has a predetermined electrical resistance, which may be monitored by processor  240  by the application of a small voltage across conductive layer  216 . During insertion of a needle, the conductive fibers in layer  216  may be moved or displaced due to contact with the needle. This contact with the needle changes the electrical resistance of conductive layer  216  in a manner which may be detected by processor  240 . Processor  240  may therefore sense a change in electrical resistance of conductive layer  216  in order to detect the insertion of the needle. 
     Alternatively, processor  240  may employ another method of detection in embodiments that include multiple conductive layers  216 . In such embodiments, the multiple conductive layers  216  may be separated by an insulating layer (such as a silicone rubber layer). During insertion of a metal needle, the needle creates a short circuit between the conductive layers  216 . Processor  240  may detect this short circuit by application of a small voltage to one of the conductive layers  216 . Processor  240  may therefore sense a short circuit between multiple conductive layers  216  in order to detect the insertion of the needle. 
     Regardless of the method of detection, processor  240  is further configured to generate a signal upon detection of the insertion of the needle. This signal is provided to the subject wearing device  200 , in order to prompt the subject to simulate or act in the role of a patient who has been stuck with a needle. The actions or statements performed by the subject may be predetermined by the subject or by one or more persons responsible for the simulation. 
     In an exemplary embodiment, processor  240  is electrically connected to a feedback device  250 . Feedback device  250  may be any of the devices discussed above with respect to feedback device  150 . In a preferred embodiment, feedback device  250  is a tactile signal generator, such as a vibrating motor. In this embodiment, processor  240  is configured to actuate the vibrating motor to provide a tactile signal to the subject upon detection of the insertion of the needle. This signal is preferably provided in real time, so that the subject can simulate the role of the patient as the needle is inserted into device  200 . 
     Processor  240  may be positioned with overlay  210 , or may be external to overlay  210 . In either embodiment, processor  240  may include one or more wires  242  for connection with conductive layer  216  and/or feedback device  250 . Feedback device  250  may preferably be positioned away from overlay  210 , so that the user performing the simulated intravenous treatment cannot tell that a tactile signal has been provided to the subject. In an exemplary embodiment, feedback device  250  may be coupled to the subject&#39;s torso or opposite arm, and may receive signals from processor  240  through one or more wires exiting overlay  210  adjacent the subject&#39;s shoulder or armpit. 
     Exemplary Catheter Treatment Simulation Device 
       FIGS.  11 - 13    illustrate an exemplary catheter treatment simulation device  300  in accordance with aspects of the present invention. Device  300  is usable to train medical care providers to perform catheterization treatments, such as urinary catheterization. In general, device  300  includes an overlay  310 , a tube  320 , a reservoir  330 , a sensor  340 , a valve  350 , and a processor  360 . Additional details of device  300  are described below. 
     Overlay  310  is configured to be secured to a subject who is playing the role of the patient. In an exemplary embodiment, overlay  310  is adapted to be worn to cover the lower portion of the subject&#39;s torso, as shown in  FIG.  11   . Overlay  310  desirably has a thin profile, to allow overlay  310  to closely conform to the shape of the subject. Overlay  310  may include any of the layers described above with respect to overlays  110  and  210  in order to better simulate the appearance and feel of a patient. 
     Where device  300  is intended to simulate urinary catheterization, at least a portion  311  of overlay  310  is shaped to simulate genitalia of the subject. An exemplary portion of overlay  310  shaped to correspond to the genitalia of a male subject is shown in  FIG.  12   . This portion of overlay  310  includes an opening  312  sized to receive a catheter during the simulated catheterization. 
     Tube  320  is coupled with the opening  312  in overlay  310 . Tube  320  receives the catheter during the simulated catheterization. Tube  320  is formed from a material such as silicone that allows it to flex and expand during the simulated treatment. 
     Tube  320  is connected at one end to reservoir  330 . Reservoir  330  is adapted to store a fluid. In operation, reservoir  330  stores simulated urine during the simulated catheterization. The simulated urine may be, for example, formed from a combination of water and one or more viscous gels, lubricants, or dyes to achieve the desired amount of flow and color to simulate urine. 
     Reservoir  330  is coupled to tube  320  in order to provide the simulated urine to tube  320 . In an exemplary embodiment, reservoir  330  is coupled to a compartment  332  in communication with tube  320 . 
     In a preferred embodiment, reservoir  330  is positioned immediate beneath an outer surface of overlay  310  adjacent the portion shaped to simulate genitalia. In this region, reservoir  330  may simulate the subject&#39;s bladder. This may desirably enable the user performing the simulated catheterization to palpate or scan reservoir  330  to determine that reservoir  330  contains fluid, and that the subject should be catheterized. 
     Sensor  340  is coupled to tube  320 . Sensor  340  may be positioned within compartment  332 , e.g., in a path of insertion of the catheter. Sensor  340  is operable to detect insertion of the catheter. Sensor  340  communicates with processor  360  to determine when the catheter has been inserted beyond a predetermined threshold. The predetermined threshold may, for example, be based on a distance of insertion of the catheter or a force of insertion exerted by the catheter. 
     In an exemplary embodiment, sensor  340  senses a force exerted by the catheter during insertion. In this embodiment, sensor  340  is in force communication with a plate  342  positioned to be contacted by the catheter during insertion, as shown in  FIGS.  13 A and  13 B . Plate  342  may be coupled to a spring  344 , and is moved linearly against the biasing force of spring  344  by the catheter during insertion. The base of spring  344  may then be coupled to sensor  340 . During insertion, sensor  340  detects the force on plate  342  via the compression of spring  344 , and transmits the detected force to processor  360 . The predetermined force may be, for example, an amount of force necessary to cause a catheter to enter a human bladder during conventional catheterization. 
     In an alternative embodiment, sensor  340  senses when the catheter has been inserted a predetermined distance. In this embodiment, sensor  340  may comprise an optical or light sensor configured to detect when the catheter has reached a predetermined position within tube  320 . The predetermined positioned may be, for example, an area of connection between tube  320  and reservoir  330  or compartment  332 . Sensor  340  may then send a signal to processor  360  when the catheter has been inserted to the predetermined distance. 
     In another alternative embodiment, sensor  340  detects a change in the diameter of tube  320  to determine when the catheter has been inserted. Sensor  340  may detect the change in diameter at opening  312  to detect initial insertion, or may detect the change in diameter at a predetermined point along tube  320 , such as the area of connection between tube  320  and reservoir  330 . Sensor  340  may detect the change in diameter of tube  320  using one or more flex sensors positioned contacting the outer circumference of tube  320 . Sensor  340  may then send a signal to processor  360  when the catheter has been inserted. 
     Valve  350  is positioned to control a flow of the fluid between reservoir  330  and tube  320 . Valve  350  may be positioned within either tube  320  or reservoir  330 , or may be positioned within a separate tube or other structure connecting reservoir  330  and tube  320 . Valve  350  is in communication with processor  360 , such that valve can be actuated (opened or closed) by processor  360 . In an exemplary embodiment, valve  350  is a twist valve. 
     When valve  350  is opened, fluid flows out of reservoir  330  toward tube  320 . The fluid may flow through valve  350  under the force of gravity, or under pressure. In an exemplary embodiment, device  300  includes a pressurizing element  334  coupled to reservoir  330  to propel the fluid within reservoir  330  through valve  350  toward tube  320 . The fluid flows from reservoir  330  into compartment  332 . As fluid fills compartment  332 , it begins to enter the catheter under pressure from gravity and/or a pressurizing element. The fluid then flows out of device  300  within the catheter as part of the simulated catheterization treatment. Suitable elements for use as pressurizing element  334  include, for example, peristaltic pumps and/or syringe pumps. 
     In addition to valve  350 , device  300  may also include a separate valve for reservoir  330  in order to prevent leakage from reservoir  330  within overlay  310 . In this embodiment, reservoir  330  may be configured to be removed from overlay  310 , e.g., for thorough cleaning and drying. 
     Processor  360  is coupled to sensor  340 . Processor  360  is configured to detect when the catheter has been inserted into tube  320  beyond the predetermined threshold (e.g., the force or distance thresholds described above). Processor  360  is further configured to actuate valve  350  to allow fluid out of reservoir  330  and into the catheter when processor  360  detects insertion of the catheter beyond the predetermined threshold, as described above. Where valve  350  is a twist valve, processor  360  may operate a motor  352  configure to twist the valve between opened and closed positions. 
     Processor  360  is further configured to generate a signal upon detection of the insertion of the catheter beyond the predetermined threshold. This signal is provided to the subject wearing device  300 , in order to prompt the subject to simulate or act in the role of a patient being catheterized. The actions or statements performed by the subject may be predetermined by the subject or by one or more persons responsible for the simulation. 
     In an exemplary embodiment, processor  360  is electrically connected to a feedback device  370 . Feedback device  370  may be any of the devices discussed above with respect to feedback devices  150  and  250 . In a preferred embodiment, feedback device  370  is a tactile signal generator, such as a vibrating motor coupled to the subject in a position where the subject can feel the vibration, such as within overlay  310 . In this embodiment, processor  360  is configured to actuate the vibrating motor to provide a tactile signal to the subject upon detection of the insertion of the catheter beyond the predetermined distance. This signal is preferably provided in real time, so that the subject can simulate the role of the patient, e.g., upon initial insertion of the catheter into tube  320 , or upon flow of the fluid from reservoir  330  into the catheter. 
     Exemplary Defibrillation Treatment Simulation Device 
       FIG.  14    illustrates an exemplary defibrillation treatment simulation device  400  in accordance with aspects of the present invention. Device  400  is usable to train medical care providers to perform defibrillation treatments. In general, device  400  includes a housing  410 , a display  420 , one or more input devices  430 , and a processor  440 . Additional details of device  400  are described below. 
     Housing  410  houses the components of device  400 . In order to provide a realistic simulation, housing  410  has a shape, size, and appearance corresponding to a conventional defibrillator. Housing  410  may be formed from a top portion  412   a  and a bottom portion  412   b . Housing  410  may be configured to be plugged into a standard power outlet in order to power the components of device  400 . 
     In an exemplary embodiment, housing  410  matches the appearance of a CODEMASTER™  100  defibrillator, provided by Hewlett Packard. Other suitable defibrillators for use in modeling housing  410  will be known to one of ordinary skill in the art from the description herein. 
     Display  420  is coupled to housing  410 . Display  420  displays an image to a user, such as information about a defibrillation treatment or the status of a patient. Display  420  is positioned in a display opening  422  in housing  410 . Like housing  410 , display  420  has a shape, size, and appearance corresponding to a conventional display for a defibrillator. The selection of display  420  may be based on the type of defibrillator modeled by housing  410 . Suitable displays include, for example, liquid crystal displays, light-emitting diode displays, or other visual displays known to those of ordinary skill in the art. 
     Input devices  430  are provided on housing  410 . Input devices  430  enable the user to input signals, instructions, or information into device  400 . Input devices  430  may be buttons, knobs, dials, keys, switches, or other structures enabling the input of information. Like display  420 , input devices have a shape, size, and appearance corresponding to the input devices on a conventional defibrillator. The selection of input devices  430  may be based on the type of defibrillator modeled by housing  410 . 
     Input devices  430  are operable by the user to simulate applying a defibrillation signal to the subject. Conventional defibrillators include input devices (such as knobs or switches) which, when actuated by the user, cause the defibrillator to apply electrical energy to one or more electrodes attached to a patient. Device  400  includes input devices  430  which, when actuated by the user, cause device  400  to simulate the application of such a defibrillation signal. Such input devices  430  may include a dial for controlling a power of the simulated defibrillation signal, and a button  432  for simulating application of the defibrillation signal. Device  400  does not, however, actually apply a defibrillation signal. Device  400  may simulate the application of a defibrillation signal by providing simulated feedback to the user, or by signaling the subject to provide simulated feedback to the user, as will be discussed in greater detail below. 
     Processor  440  is provided within housing  410  in communication with display  420  and input devices  430 . Processor  440  is programmed to generate a signal to the user that a defibrillation signal has been applied to the subject. In an exemplary embodiment, input devices  430  include a button  432  operable by the user to simulate applying the defibrillation signal to the subject. In this embodiment, processor  440  is programmed to generate a beeping sound (e.g., using one or more speakers) to signal to the user that a defibrillation signal has been applied to the subject. 
     In an exemplary embodiment, processor  440  is electrically connected to a feedback device  450 . Feedback device  450  may be any of the devices discussed above with respect to feedback devices  150  and  250 . In a preferred embodiment, feedback device  450  is a tactile signal generator, such as a vibrating motor coupled to the subject in a position where the subject can feel the vibration. In this embodiment, processor  440  is configured to actuate the vibrating motor to provide a tactile signal to the subject in response to the user actuating the input device  430  to simulate the application of a defibrillation signal to the subject. This signal is preferably provided in real time, so that the subject can simulate the role of a patient experiencing a defibrillation signal in response to the user actuating the appropriate input device  430 . 
     In a preferred embodiment, device  400  includes a plurality of patches  460  configured to be connected to the subject. Each patch  460  is coupled to a portion  462  on the outside of housing  410  via a respective wire. Patches  460  are structured to simulate the electrodes that are attached to a patient during defibrillation. To this end, patches  460  may include an adhesive portion for adhering directly to the subject or indirectly, e.g. via one or more layers of clothing or via an overlay. One or more of the patches  460  may include a feedback device  450 . 
     In addition to the above functions, patches  460  may be utilized in certain additional ways. For example, patches  460  may include electrodes for wired coupling with processor  440  in order to detect/display the subject&#39;s actual heart rhythm. Such information may be useful for simulating the subject&#39;s healthy heart rhythm following the simulated defibrillation. Alternatively, patches  460  may be configured to provide feedback regarding the correct positioning of patches on the subject or on an overlay. For example, in connection with one of the overlays described herein, patches  460  may provide a vibratory or audible signal if they are not positioned in the correct position on the overlay. Such positioning may be detected using known electrical or magnetic sensors for contact with or detection of one or more structures on patch  460 . 
     Processor  440  is further programmed to display a heart rhythm of the subject on display  420 . The heart rhythm may be the subject&#39;s actual heart rhythm, or may be a simulated heart rhythm. In an exemplary embodiment, device  400  further includes a memory in communication with processor  440 . The memory stores one or more simulated patient heart rhythms for displaying by processor  440  on display  420 . The stored patient heart rhythms may include unhealthy heart rhythms (such as ventricular tachycardia or ventricular fibrillation) for display prior to simulating application of the defibrillation signal, and may include healthy, normal heart rhythms for display following the simulated application of the defibrillation signal. 
     Processor  440  may further be configured for wireless communication with one or more computing devices external to housing  410 . In an exemplary embodiment, processor  440  includes a wireless transceiver  442  for communication with an external computing device. The display of heart rhythms or the simulated application of a defibrillation signal may be selected, controlled, or triggered wirelessly via the external computing device. Additionally, the actuation of feedback device  450  may be controlled or triggered wirelessly via an external computing device. This set-up may enable an instructor to control the progress and performance of the simulated defibrillation treatment. 
     Exemplary Thoracic Treatment Simulation Device 
       FIGS.  15 - 17    illustrate an exemplary thoracic treatment simulation device  500  in accordance with aspects of the present invention. Device  500  is usable to train medical care providers to perform thoracic treatments such as chest drainage. In general, device  500  includes an overlay  510 , a pressure unit  520 , and a processor  550 . Additional details of device  500  are described below. 
     Overlay  510  is configured to be secured to a subject who is playing the role of the patient. In an exemplary embodiment, overlay  510  is adapted to cover at least a portion of the subject&#39;s torso, as shown in  FIG.  15   . Overlay  510  desirably has a thin profile, to allow overlay  510  to closely conform to the shape of the subject&#39;s chest. Overlay  510  may include any of the layers described above with respect to overlays  110  and  210  in order to better simulate the appearance and feel of a patient. 
     In order to better simulate the torso of a patient in need of chest drainage, the surface of overlay  510  is shaped to simulate the contour of the subject&#39;s chest, including the subject&#39;s ribs. As shown in  FIG.  16   , overlay  510  includes an opening  512 . Opening  512  is sized to be connected with a drainage tube from a conventional chest drainage system, such as those sold by Atrium Medical Corporation of Hudson, N.H. 
     Pressure unit  520  is in fluid flow communication with opening  512  of overlay  510 . Pressure unit  520  may be formed within overlay  510 , or may be external to overlay  510 . In an exemplary embodiment, pressure unit  520  is provided in a housing  521  external to overlay  510  and connected to opening  512  via a tube  522 , as shown in  FIG.  15   . Tube  522  enters overlay  510  via an area adjacent the subject&#39;s armpit, and connects with opening  512  from the interior side of overlay  510 . Pressure unit  520  may be provided, for example, underneath a pillow used by the subject, in order to conceal pressure unit  520  from the medical care provider. In general, pressure unit  520  includes a reservoir  530  and a motor  540 . Pressure unit  520  may further include one or more power sources  524  for powering motor  540 . Additional details of pressure unit  520  are provided below. 
     Reservoir  530  is coupled for fluid flow with opening  512 , e.g. via tube  522 . In operation, reservoir  530  stores air that moves into and out of reservoir  530  to simulate respiratory air during simulated breathing of the subject during the simulated thoracic treatment. In an exemplary embodiment, reservoir  530  is part of a syringe pump, as shown in  FIG.  17   . The syringe pump includes a plunger  532  for applying pressure to the air in reservoir  530  in order to simulate the subject&#39;s breathing and cause air to flow into and out of reservoir  530 . 
     Motor  540  is coupled to reservoir  530 . Motor  540  is operable to periodically pump air into and out of reservoir  530 . In the embodiment in which reservoir  530  is a syringe pump, motor  540  includes a rod  542  and adaptor  544  for coupling motor  540  to the plunger  532  of the syringe pump. Motor  540  pumps air into and out of reservoir  530  by periodically moving the plunger of the syringe pump to change the size of reservoir  530 . Motor  540  pumps air into and out of reservoir  530  at a frequency designed to simulate the breathing of the subject, as will be described below. In an exemplary embodiment, motor  540  is a stepper motor. Other suitable motors  540  for use in connection with reservoir  530  will be known to one of ordinary skill in the art from the description herein. 
     Processor  550  is coupled to motor  540 . Processor  550  is configured to operate motor  540  in order to pump the air into and out of reservoir  530  in accordance with a simulated breathing pattern of the subject. In particular, processor  550  may operate motor  540  to pump air into reservoir  530  to simulate the subject inspiring, and to pump air out of reservoir  530  to simulate the subject expiring. 
     By periodically alternating between these two actions, motor  540  may simulate a breathing rhythm of the subject with air flows into and out of reservoir  530 . These breathing patterns may be monitored by a medical care provider performing the simulated thoracic treatment by monitoring air flow into and out of opening  512 . Such monitoring may be used to train the medical care provider to detect symptoms in thoracic patients, such as difficulty breathing or thoracic air leak. 
     The breathing pattern simulated by motor  540  and processor  550  may be the subject&#39;s actual breathing pattern, or may be a simulated breathing pattern. In one exemplary embodiment, device  500  includes at least one sensor  560  coupled to overlay  510 . Sensor  560  is configured to sense an actual breathing pattern of the subject. Sensor  560  communicates the sensed actual breathing pattern to processor  550 . Processor  550  is then configured to operate motor  540  to pump air into and out of reservoir  530  in real time with the sensed actual breathing pattern. 
     In an exemplary embodiment, sensor  560  comprises a stretchable resistor wrapped around at least a portion of the subject&#39;s torso. The resistor acts as a potentiometer. As the resistor expands and contracts in time with the subject&#39;s breathing, the resistance of the stretchable resistor changes. The resistor expands as the subject&#39;s chest expands during inspiration, and contracts as the subject&#39;s chest contracts during expiration. This allows processor  550  to sense the breathing pattern of the subject in time with the changing resistance of sensor  560 . 
     In an alternative exemplary embodiment, device  500  further includes a memory in communication with processor  550 . The memory stores one or more simulated breathing patterns for use by processor  550  in operating motor  540 . The stored breathing patterns may include unhealthy breathing patterns (such as from patient&#39;s suffering from a thoracic air leak), and may include healthy, normal breathing patterns. 
     Processor  550  may be positioned with overlay  510 , or may be external to overlay  510 , such as within pressure unit  520 . In either embodiment, processor  550  may include one or more wires  552  for connection with motor  540  and/or sensor  560 . Processor  550  may further be configured to provide feedback to the subject. For example, an instructor may provide a signal to processor  550 , in order to cause processor  550  to actuate one or more feedback devices to prompt the subject to adopt a predetermined breathing pattern, or alter their current breathing pattern in a predetermined fashion. Such feedback could be provided to the subject using any of the structures described herein. 
     Combined and Other Medical Treatment Simulation Devices 
     While a number of separate medical treatment simulation devices are described herein, it will be understood to one of ordinary skill in the art that two or more of the exemplary devices described herein may be combined in a single device. For example, the tracheostomy treatment device  100  may be formed as a single device with either the intravenous treatment device  200  and/or the catheter treatment device  300 . In these combinations, the overlay may be expanded to include all of the necessary components for simulating the associated medical treatments. Moreover, a full-body overlay be may created by combining the disclosed devices, in order to enable the performance of a plurality of different simulated medical treatments. 
     Although the invention is illustrated and described herein with reference to specific embodiments, the invention is not intended to be limited to the details shown. Rather, various modifications may be made in the details within the scope and range of equivalents of the claims and without departing from the invention.