Abstract:
A portable enclosure for simulating surgical conditions using endoscopic instruments. The enclosure contains a pump and fluid reservoir and a canister in which an animal or synthetic tissue sample is placed within an adjustable cavity. The pump circulates fluid to an endoscopic instrument external to the enclosure enabling an individual to practice either monopolar or bipolar instrument techniques within the cavity and under conditions that simulate real life operating conditions.

Description:
BACKGROUND INFORMATION 
     1. Field of the Invention 
     The present invention relates generally to a surgical trainer and in particular it relates to a simulator that incorporates features to simulate visual and manipulation conditions for training surgeons in surgical procedures such as endoscopy and particularly hysteroscopy. 
     2. Background of the Invention 
     New surgical instruments and techniques have been developed to make surgery less invasive to the patient thus eliminating the need to make incisions requiring lengthy healing time. Endoscopes are presently used for diagnostic purposes and therapeutic treatment of the interior of a hollow viscous. Endoscopic surgery is generally performed in the presence of a distension medium. The distension medium may be either a liquid or a gas. There are many different uses for endoscopes, and frequently the endoscope design is varied, depending on its use, to optimize the performance of the endoscope for its intended purpose. Endoscopes having integral working channels are generally employed when the body cavity may be accessed through a natural body opening. For example, a hysteroscope is used to access the intrauterine cavity of the uterus via the cervical canal, and a urethroscope is used to access the prostate gland and the bladder via the urethra. Other types of endoscopes include the upper endoscopes for examination of the esophagus, stomach and duodenum, colonoscopes for examining the colon, angioscopes for examining the blood vessels and heart, bronchoscopes for examining the bronchi, laparoscopes for examining the peritoneal cavity, arthroscopes for examining joint spaces and sigmoidoscopes for examining the rectum and sigmoid colon. 
     In operation, the surgeon is able to insert either a semi-rigid or flexible operating instrument through a working channel to perform any number of surgical procedures as viewed by the eyepiece connected to a viewing scope. Representative operating instruments include scissors, biopsy and grasping forceps, ball electrode, optical scissors and an optical punch. 
     Many endoscopic surgeries require incision and dissection of tissue using electrocauterization. The endoscopic electrocautery device may be either monopolar or bipolar in nature. 
     Surgeon training has represented a major problem encountered in the implementation of new surgical instruments and techniques. Performing delicate operations on patients without having the particular tissue or organ exposed requires unnatural hand-eye coordination. Conventional techniques for teaching endoscopic surgery procedures involve the use of animal specimens. The use of laboratory animals for surgical training, however, is very expensive and is the subject of public debate. Further, animal specimens have a short viability on the operating table, and thus provide the trainee with a limited period of time in which to practice repeated techniques. In addition, it would be preferable to have a portable trainer that can be used in a physician&#39;s office or in a clinical setting. 
     Representative training simulators are the SEMM PELVI-TRAINER and Hystero/Fallopo Trainer manufactured by Storz-Carl Storz--Endoskope. The SEMM PELVI-TRAINER simulator consists of a lower tray on which an object representing a human organ is positioned. An upper tray has puncture-simulating openings through which surgical instruments and a viewing scope are inserted. The trainee maneuvers the instrument through the opening and operates on the object. 
     U.S. Pat. No. 5,149,270 discloses an apparatus having a cavity in which an object simulating a human organ is mounted for performing the practice procedure. The cavity is closeable to outside view or access. 
     U.S. Pat. No. 5,425,644 discloses an apparatus including a frame, a pump, appropriate tubing and a reservoir containing a volume of fluid. Non-living animal tissue is joined to the tubing at the outlet side of the pump and surgical personnel are permitted to conduct surgical techniques. 
     U.S. Pat. No. 5,620,326 discloses an anatomical simulator system including a synthetic anatomical torso resting on a base. The torso includes an internal cavity and a pneumoperitoneum wall. 
     All of these systems are generally bulky and complex. 
     Thus, there is a need for a simplified and portable videoendoscopic surgical training system that accurately simulates a surgical procedure. This invention satisfies this need by providing a simple and cost effective endoscopic trainer. 
     SUMMARY OF THE INVENTION 
     The present invention relates generally to an apparatus that provides for a portable and completely self-contained training unit to practice endoscopic procedures. In one embodiment the enclosure is no larger than a carrying bag for transporting laptop computers and the interior is divided into two compartments. The first compartment houses a submersible pump and fluid reservoir and the second compartment houses a canister having a cavity that contains an animal or synthetic tissue sample. Preferably, the size of the cavity is adjustable to accept varying sizes of tissue samples. The canister also contains an access aperture to the cavity that is accessible from the exterior of the enclosure. In operation, the pump circulates fluid to a endoscopic instrument external to the enclosure thus enabling an individual to practice either monopolar or bipolar instrument techniques within the cavity that simulate real life surgical conditions. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is perspective view, opened for viewing the internal structure, of an apparatus of the present invention; 
     FIG. 2 is an elevation view of the pump and fluid reservoir of the present invention; 
     FIG. 3 is an elevation view of the operational face of an apparatus of the present invention; and 
     FIG. 4 is an assembly plan of the canister of the present invention; 
     FIG. 5 is a cut-away view of the inner canister of the present invention; 
     FIG. 6 is an elevation view of the cap adapter or the present invention, showing the internal access in phantom; and 
     FIG. 7 is a major component assembly plan of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Before explaining the present invention in detail, it should be noted that the invention is not limited in its application or use to the details of construction and arrangement of parts illustrated in the accompanying drawings and description; the illustrative embodiments of the invention may be implemented or incorporated in other embodiments, variations and modifications, and may be practiced or carried out in various ways. Furthermore, unless otherwise indicated, the terms and expressions employed herein have been chosen for the purpose of describing the illustrative embodiments of the present invention for the convenience of the reader and are not for the purpose of limiting the invention. 
     As shown in FIGS. 1 and 7, surgical training apparatus  8  includes a corrosive resistant enclosure  10 , for example fiberglass, that houses a pump assembly  11  and a canister  30  that contains an animal or synthetic tissue sample. Enclosure  10  is divided into two compartments  10   a  and  10   b,  separated by a bulkhead  10   c  that is sealed to prevent fluid leakage between the compartments. The enclosure  10  can be sized to be no larger than a carrying case for a laptop computer. Such a design facilitates the training apparatus to be easily transported and allow instrument demonstration/training within a doctor&#39;s office. 
     As shown in FIG. 2, pump assembly  11  includes a pump  12  having a pump inlet  14  and pump outlet  16 . Inlet tubing  18  is attached to inlet  14  by known means, for example, a hose clamp or press fit. Tubing  18  communicates with a fluid reservoir  20  which is adapted to receive and hold fluid  22  such as a saline, lactated ringers solution, or any electrolyte or non-electrolytic solution. Outlet tubing  24  is attached to pump outlet  16 , again by known means. Tubing  24  communicates with an outflow connector  26  attached to enclosure  10 . Outflow connector  26  fluidly communicates with the inflow port of an endoscopic instrument (not shown), as is generally known to those skilled in the art. The fluid may be used to distend the tissue cavity as is common in some endoscopic procedures. Fluid removed from the tissue sample cavity is pumped out through the endoscopic instrument through inflow connector  28  and into compartment  10   a  via hose  29 . In the preferred embodiment, pump  12  is a submersible pump, model no. 1A-MD-1 as manufactured by March Mfg. Inc. of Glenville, Ill. 
     Located in compartment  10   b  is a canister  30  for accepting animal tissue or a synthetic replication thereof. Referring to FIGS. 4 and 5, canister  30  comprises an inner housing  32 , which slidably engages an outer housing  34 . Housing  34  also threadedly couples to a seal port  38 . 
     Inner housing  32  defines an adjustable cavity  40  that accepts an animal or synthetic tissue sample. Outer housing  34  contains a bore  34   a  that accepts a plunger element  42 . Plunger  42 , combination with piston  50 , varies the volume of cavity  40  so that variably sized tissue samples may be used with the invention. Plunger  42  further provides for the electrical connections that make the instant invention capable of training personnel on monopolar electrosurgical instruments. The distal end of plunger  42  has a bore and threaded section that accept a spring  54  and contact head  56 . Spring  54  slides over a wire  52  that inserts through a center bore within plunger  42  and which is soldered to contact head  56 . During the use of monopolar electrosurgical instruments, wire  52  is connected to a grounding pad via electrical connector  80  (see FIGS.  3  and  7 ), as is well known to those skilled in the art. Piston  50  comprises a bore  50   a  at its proximal end that accepts the distal portion of plunger  42 . The distal end of piston  50  is a second bore  50   b  that accepts an electrically conducting washer  46 , preferably stainless steel that in operation contacts the tissue sample. A screw  48 , preferably, stainless steel, attaches washer  46  to plunger  50  and threadedly engages the distal end of plunger  42  and makes contact with contact head  56 . Accordingly, electrical conductivity is maintained from the wire  52  to contact head  56  to screw  48  to washer  46 . The user is able to define the volume size of cavity  40  by grabbing handle  43  and moving plunger  42  into or out from cavity  40 . O-ring  58  positioned on piston  50  provides a liquid tight fit of piston  50  within cavity  40 . Inner housing  34 , plunger  43  and piston  50  are all made out of non-electrically conducting material, preferably, plastic. 
     As shown in FIG. 4, inner housing  32  slides within outer housing  34 . Preferably, outer housing  34  is a nalgene bottle that is modified to include a cut slot and bore  35  which accepts a spring pin  35   a  located on inner housing  32  to securely fasten inner housing  32  within outer housing  34 . An O-ring  59  is included as shown in order to provide a liquid-tight seal of the housings. 
     Seal port  38  includes a connector  36 , which comprises outside threads  36   a  and inside threads  36   b,  O-rings  60 ,  62  and  66 , cap adapter  64  and cap  68 . Cap  68  is a conventional trocar seal that provides an aperture  68   a  for access to a tissue sample in cavity  40 . A useful trocar seal is the universal OneSeal reducer cap, part number 1Seal, sold by Ethicon Endo-Surgery, Inc. of Cincinnati, Ohio. 
     Connector  36  screws onto outer housing  34  via inside threads  36   b.  O-ring  60  provides for a secure, leak-free connection. FIG. 6 illustrates cap adapter  64 , which press fits within connector  36  as shown in FIG.  4 . O-ring  62  provides for a secure, leak-free connection. Cap adapter  64  defines a lip region  64   a  and a tissue attachment surface  64   b.  Cap adapter  64  also comprises slots  64   c  for accepting tab portions  68   b  of cap  68 ; tab portions  68   b  are rotated within channel  64   d  to provide a secure fit of cap  68  to cap adapter  64 . O-rings  62  and  66  provide for a secure, leak-free fit. 
     Referring to FIGS. 2 and 7, pump assembly  11  (as completely illustrated in FIG. 2) is placed within compartment  10   a,  and canister  30  is attached to housing via connector  70  threadedly connected to outside threads  36   a  as shown. Enclosure  10  may also include an adjustable vent knob  15  to allow venting of the enclosure during operation or transportation. To complete the installation tubings  24  and  29  connect to their respective connectors  26  and  28 , which are also connected to the inlet and outlet ports of an endoscopic instrument. 
     Referring also to FIGS. 4 and 6, the instrument including viewing scope and other instruments to be utilized to practice a procedure are inserted through access opening  68   a  and into cavity  40 . In one preferred embodiment, cavity  40  contains a tissue sample that is representative of a cavity of an organ, such as a uterus. A pig&#39;s bladder may be used to simulate the uterus. In addition, another piece of tissue, such as a heart muscle may be sewn within the bladder to simulate a fibroid, polyp, uterine septa or intrauterine adhesion that the surgeon is required to biopsy and/or remove. An endometrial resection may be simulated with this model. Alternatively, a synthetic tissue sample may be employed as disclosed on page 1060 of Research Disclosure, August 1999 entitled  A Synthetic Surrogate for Demonstrating the Thermal Spread of Electrosurgical and Ultrasonic Surgical Instruments.  The bladder slips around lip  64   a  and is securely fastened about attachment area  64   b  using any conventional attachment means such as a tie-wrap. During the training procedure, the bladder is out of view of the surgeon, which requires the surgeon to manipulate and use the instruments for a procedure under conditions simulating an endoscopic procedure. 
     Although the present invention has been described in detail by way of illustration and example, it should be understood that a wide range of changes and modifications could be made to the preferred embodiments described above without departing in any way from the scope and spirit of the invention. Thus, the described embodiments are to be considered in all aspects only as illustrative and not restrictive, and the scope of the invention is, therefore, indicated by the appended claims rather than the foregoing description. All changes that come within the meaning and range of equivalency of the claims are to be embraced within their scope.