WO1996016389A1 - Medical procedure simulator - Google Patents

Abstract

An interactive medical procedure simulation system having a mannequin (21) with life-like qualities of appearance, feel and touch. The mannequin is equipped with one or more trocars (23, 24) into which there are selectively inserted simulations of conventional medical procedure tools (25, 26) for diagnosis and treatment. Provision is made for creating and displaying (30) seamless representations or realistic real-life internal landscapes which are changeable to track changes in positions of simulated endoscopes and medical tools. Realism is enhanced through the use of pneumatically operated force feedback so as to enhance realistic feel for simulated procedures including tugging, tearing, cutting, clipping, stapling, pulling, pushing, grasping and probing.

Description

MEDICAL PROCEDURE SIMULATOR This invention relates to medical procedure simulation systems and more particularly to simulation systems that may be used in training physicians and other medical personnel in instrument manipulation and other techniques involved in laproscopic, endoscopic and other minimally invasive procedures used in surgical treatments.

BACKGROUND OF THE INVENTION Minimally invasive surgery and procedures often involve more precise manipulation of tools and instruments than open incision surgery since the point of manipulation (which is external) often is relatively remote from the tissue being examined or treated the latter, of course, being internal. Thus, manual feel, cause and effect are not instructively intertwined, for the point at which manipulation of the medical instrument occurs is located a substantial distance from the point of contact or observation within the patient, thus imparting a level of remoteness and indirection which requires a particularly high level of skill by the medical practitioner. For these reasons, the training of practitioners using live human subjects is more dangerous in that errors and mistakes are much more difficult to correct or overcome.

Although training on animal subjects such as pigs is helpful, it is of limited availability. Furthermore, practice on live subjects does not offer repeatable or "staged" situations for iterative practice. Accordingly, simulator systems with lifelike characteristics become highly desirable.

A useful and practical simulation system for minimally invasive surgical techniques should: (1) Define an environment in which activities are to be simulated, the allowable limits within which changes in that environment are controlled, and the movement of maneuverable bodies therein;

(2) Define allowable movements of manipulated "instruments" and provide physical constancy;

(3) Determine the position within or relative to the defined environment of manipulated "instruments";

(4) Provide one or more sensory (tactile, aural, and visual) simulation stimuli to the user with any change in the position determined in (3) above within the confines defined by (l) and (2) above; and

(5) Re-define (1) and (2) above if change limits are exceeded.

In a complete system, there should first be presented to the user a simulation of the external appearance of the subject, i.e., a physical simulation of the human torso simulating as nearly as possible the colored skin surface texture, and the under skin muscle, bone and body cavity feel. Also presented should be simulated instrument handle portions that should be of the same configuration as actual instrument handles and controls. These handles optionally may be equipped with appropriate instrumentation as necessary or desirable and may already be in position protruding from the simulated torso when the user is familiar with the initial insertion and location techniques of the instruments.

The only view and feel of the interior working area that a surgeon is provided in actual surgery is through a television monitor and tactile physical feedback through the instrument handles he is manipulating. The interior simulations need not be provided by interior physical reproductions or even physical analogs but are adaptable to synthetic sensations electronically produced or controlled in response to manipulation of the simulated instrument handles and controls.

For tactile response simulation, defining digital data for one or more instruments to be used including their dimensions, movement limits and active functions such as grasp, clamp, cut and other manipulative functions may be stored in high speed accessible electronic memory. Environment-defining digital data for areas of use immediately surrounding the defined instruments such as "clear" areas, objects (organs, etc.), position, shape and texture and their give and resilience and movement-resistant forces and interactive connections with other objects likewise may be stored in high speed accessible electronic memory.

Simulation for visual displays may comprise "multilayer" background "landscape" video information that may be actual photographic data digitized and stored in laser disc, electronic or other memory. The multilayer arrangement provides means to provide a sense of depth in the two- dimensional display through relative movement and interaction with computer graphic anatomical objects in the layers, such as organs. Additional stored visual data is required to provide visual representation of the immediate work area, e.g., the internal landscape, for the surgeon, including specific organs and anatomy to be worked on. This data, likewise may be wholly photographic data or partially photographic data such as tissue textures, stored in digital form.

The manipulatable visual information may be provided through a process of computer animation whereby data from "position" sensors and realistic defining photographic data is used to create and present visual and tactile representations showing the actions and movement of the "unseen" portions of the simulated instruments being manipulated by the simulator user.

Additionally, computer animation may be used to create and present a visual representation of the "focus" organ or anatomical region to be manipulated and operated on by the user through the simulated instruments and to show the results on that "focus" region of the instrument manipulation using data from the instrument position sensors and defining data of the anatomical region. To complete the simulation, data processing elements may be used to provide interactions necessary to coordinate the tactile and visual feedbacks and presentations to the simulation user for the real time simulation of an actual surgical operation or other procedure under the control of the user. Thus, the present invention is directed to that portion of such a simulator that provides real life and real time simulation of a variety of minimally invasive surgical procedures.

BRIEF SUMMARY OF THE INVENTION The improved simulation system according to the invention hereof provides a simulation environment which includes real¬ time video, scopes, surgical and therapeutic instruments, foot pedals for cautery and fluoroscopy and realistic torsos that house both sophisticated sensors for scopes and changeable instruments, and tactile force feedback providing realistic feel when instruments are manipulated and contact body parts. In so doing, it utilizes a plurality of coordinated inexpensive off-the-shelf computers interconnected into a network. Interconnected with the computers are high capacity memories adapted for storing a myriad of different anatomical "pavilions" (i.e., areas of the body that allow remote procedures) . Each of these anatomical pavilions is likewise extendible to a number of minimally invasive procedures, diagnostic and therapeutic, for which anatomical landscapes, virtual organs and a variety of instruments may be created in virtual reality. Thus, the computers provide a basic computer platform that can also be used for multimedia training in auxiliary subject areas. These areas include Endoscopic Retrograde Cholangiopancreatography (ERCP) for viewing internal bile and pancreatic ducts and Sphincterotomy for cutting and widening bile and pancreatic ducts for better drainage or stone removal; Laparoscopic Surgical Skills and landscapes for the lungs, the heart, the abdominal cavity, reproductive organs, arthroscopic surgical areas such as the shoulder, eye surgeries, ear, nose and throat procedures and neuroscopic procedures.

The system according to the invention additionally embodies realistic real-time representations of organ movement and response to tugging, pulling, cutting and the like.

Coupled therewith are life-like real-time representations of the surrounding environments (landscapes) in high resolution such that when the need arises for magnification, it can be readily provided (within normal ranges) without undue loss of fidelity. In addition there is included a provision for selection of any of a wide variety of pathological conditions that can be selected and included in a simulated real-time and life-like procedure.

Although certain of the foregoing appear to be advances over known systems, another advance is the provision of realistic tactile force feedback in coordinated combination with the realistic landscapes and instrument simulations. Thus, there is imparted to instrument manipulation a realistic real-life and real-time simulation of forces to which the instrument would be subjected in actual manipulation and surgery. To accomplish this there are provided a sophisticated dynamics model based on underlying physics that defines the shape and other characteristics of organs and other relevant portions of the landscape so that forces on impact, collision, contact cutting and the like are faithfully developed and transmitted to the handles or other portions of the instruments being manipulated by the user.

To further enhance the life-like qualities of the system, mannequins are provided with realistically appearing and feeling exterior surfaces as well as with underlying characteristics such as rib cages and hip bone representations, thus facilitating inspection, location of incisions, and other procedures normally followed by surgeons and assistants in performing actual procedures.

Also included within the system is optional recording of steps performed in practice surgery together with expert feedback that is provided to evaluate the performance, point out performance areas that are generally approved or otherwise acceptable as well as those that are deemed invalid. It also can identify those that are acceptable but subject to improvement. All of the foregoing are provided within a system that requires computational support costing only a small fraction of that of heretofore known proposals. Accordingly, the present system provides an enhanced level of life-like virtual simulation that includes real time realism in patient simulation including realistic landscapes, physical character including tactile force feedback, selectable multiple patient simulations, and selectable simulated procedures. OBJECTS AND FEATURES OF THE INVENTION It is one general object of the invention to improve medical procedure simulation systems. It is another object of the invention to reduce costs of such systems.

It is yet another object of the invention to increase versatility in such systems.

It is still another object of the invention to increase speed of operation in such systems to near real time.

It is yet another object of the invention to provide for ready extension and adaptation of such systems to additional pathologies and procedures.

It is yet a further object of the invention to enhance the life-like qualities of selectable mannequins for use in such systems.

Accordingly, in accordance with one feature of the invention, a plurality of off-the-shelf inexpensive computers are employed in interactive relationship, thereby reducing cost, enhancing speed of operation and enhancing flexibility and extendibility.

In accordance with another feature of the invention, physical qualities and characteristics of relevant parts of simulated patient internal landscapes are modeled and stored within physical characteristics memories, thus enhancing ready and realistic modeling and real-time display of such internal landscapes.

In accordance with yet another feature of the invention, a variety of landscape pavilions are made selectable by the system user, thereby enhancing versatility and extending the range of useful simulations.

In accordance with still another feature of the invention, a variety of simulated pathologies are made selectable by the system user, thereby extending the range of pathological simulations.

In accordance with yet another feature of the invention, landscapes of a variety of different patients are made selectable by the system user, thereby extending the range of patients that may be simulated.

In accordance with still another feature of the invention, a variety of selectable instruments and controls are included and are conditioned to provide.geometric proportionality, force and velocity in real time, thus contributing to faithful simulation.

In accordance with yet a further feature of the invention, provision is made for simultaneous utilization of a plurality of instruments, thus extending versatility. In accordance with still a further feature of the invention, the plurality of instruments are conditioned to provide multiplicitous actions, thus further contributing to system usefulness.

In accordance with yet an additional feature of the invention, physical modeling of human organs and landscapes is predicated on a tessellated mesh/deformable spring model, thus facilitating processing, manipulation and display thereof. In accordance with still one further feature of the invention, minute regions of landscape physical representations are processed as minute polygons and digitized, thereby facilitating storage and processing. In accordance with yet one further feature of the invention, realistic tactile force feedback is provided in real time to the system user, thus providing a realistic feel to procedures such as tugging, tearing, cutting, clipping, stapling, pulling, pushing, grasping and probing. In accordance with still one further feature of the invention, a plurality of realistic mannequins are included and are provided with simulated rib cages, hip bones and other characteristics to help medical personnel in locating desired positions both within and on the mannequin surfaces. In accordance with yet one additional feature of the invention, a hierarchy of "school solutions" are stored within the system; and surgical procedures are compared therewith to identify actions that might endanger a live patient as well as to display recommended procedures, to score and record surgical performance.

These and other objects and features of the invention will be apparent from the following description, by way of example of a preferred embodiment, with reference to the drawing. BRIEF DESCRIPTION OF THE DRAWING Figure 1 is a depiction of the prior art as represented by United States Patent 4,907,973;

Figure 2 is a general depiction of a simulator system embodying the principles of the invention;

Figure 3 is simple depiction of the simulator system hereof; Figure 4 is a simplified functional overview of the simulator system hereof;

Figure 5 is a diagram illustrating the multiple computer, distributed processing according to the invention;

Figure 6 is a diagram illustrating system operation when selection of skills practice is made;

Figure 7 is a diagram illustrating system operation when selection of diagnostics is made;

Figure 8 is an illustration depicting the presence and effect of an instrument within a simulated selected organ; Figure 9 is an illustration depicting simulation of the rebound effect that occurs when an instrument contacts a resilient body organ;

Figure 10 is a diagram illustrating division of a single triangular facet into three new facets when a facet is sliced edge to edge.

Figure 11 is a diagram illustrating division of a single triangular facet into four new facets when a facet is sliced from an edge to the interior.

Figure 12 is a diagram illustrating division of a single triangular facet into five new facets when a facet is sliced from a location within its interior to another location within its interior; and

Figure 13 is a diagram illustrating division of a single triangular facet into two new facets when a facet is sliced from an apex point to an edge.

DEFINITIONS Before proceeding with a detailed description of the invention, reference is made to the following terms for which the associated definitions are set out for use in understanding the embodiment hereinafter described and for use in defining the scope of the appended claims:

Deformable Spring Model means the representation of a three dimensional structure composed of verticies interconnected by bonds to form a matrix wherein each bond may stretch or compress according to dynamic principles of physics, reacting to external forces applied to it directly or through interconnections of verticies to other bonds previously acted upon by forces interacting upon them.

Dynamics Engine means processing equipment and the associated body of data and instructions generated responsive to signals received from one or more trocar sensors and internal body sensors for producing electrical indicia activating and producing visual and tactile sensations that would be experienced by a user (such as a surgeon) when closely simulating a real life procedure of the type selected by the user and with a real instrument manipulated in a manner simulated by the selected implement. Graphics Engine means a converter which is responsive to electrical indicia from a Dynamics Engine for producing internal landscape representing electrical data.

Lattice means an internal representation of tissue being modeled by the system. Selected Simulation Instrument means a representation of a specific real-world instrument which has been selected by the simulator user for a specific simulation purpose. For example, to cut tissue, the user would select a scissors, which would be represented within the simulation by turning a switch, dial, or other device to select "scissors", and the appropriate electronic signals would be generated forthwith. Simulation Control Computer means a computer providing simulation control for various devices used in the simulation system hereof, and it provides a platform for the state model and other programming. In the preferred embodiment, computers such as the Intel Corporation "Pentium" are used.

State Engine means an electronic operation of an electronic representation of various states which collectively constitute a simulation control function. The switching from one active state to another, and processing of transitional functions is the "electronic operation". Tessellated Mesh means the representation of a surface as composed of polygons with a regular pattern of vertex sharing used to improve efficiency.

Tissue Modelling Computer means a high speed computation and graphics generation engine used for such tasks as operating the dynamics engine and the diagnostic display. In the preferred embodiment, a computer such as the DEC Alpha is used.

Vignette means a brief incident or scene.

DESCRIPTION OF A PREFERRED EMBODIMENT

Now turning to the drawing, and more particularly Figure 1 thereof, it will be seen to be a representation of the prior art as set forth in the aforementioned United States Patent 4,907,973. A mock endoscope 11 is inserted within model 12 by user 13. Within model 12 there are a plurality of sensors (not shown) that respond to the position of the tip (not shown) of the endoscope 11 and which transmit corresponding signals via conventional transmission linkages 14 to computer 15. Computer 15 responds thereto by accessing storage 16 via conventional transmission linkage 17 to retrieve from conventional storage 16 a plurality of electrical indicia representing the view which would be observed from the relative location of the endoscope tip during a real operation. Such indicia are conducted to video display 18 by conventional connections represented by arrow 19.

As is known to those skilled in the art, currently available rapid-access storage media are capable of handling hundreds of megabytes of information and can easily store the large quantity of data required to provide the images needed to simulate real investigative or surgical procedures. Accordingly, storage 16 may be any one of several suitable alternative storage media such as a high capability optical disc.

Since movement of the endoscope is sensed by the aforementioned sensors, movement results in a corresponding change in the image shown on the screen 18 of the video device. Thus, a complete cycle is developed from hand-action 20 to resultant image 18 to new hand-action to another essentially instantly changed image, with computer 15 translating each variation in the mock endoscope to the precise image which would be viewed in real operation. Accordingly, there is portrayed for the user a realistic visual representation of the internal landscape that would be seen if a real-life procedure were being performed.

Moving beyond the prior art, reference is made to Figure 2 which presents an overview of the invention hereof. There, is portrayed a user 13 positioned alongside a mannequin 21 having a trunk portion 22 in which there are positioned a pair of trocars 23 and 24 within which there are mounted a pair of instruments 25 and 26. Instruments 25 and 26 are equipped with manipulating handle portions 27 and 28 which are included to facilitate manipulation by an operator such as 13. At this point, it should be noted that although a pair of trocars and associated implement are portrayed, the principles of the invention are also readily applicable where only one trocar and associated implement are provided or where several are provided.

Also depicted in figure 2 are a video display 30, a plurality of interactive computers represented by block 31, high capacity memory storage 32 for landscape and other system storage, and tactile force feedback circuits and storage 33. As previously mentioned, these are combined, functionally interrelated and connected as represented by arrows 34a-34e. Some of these arrows are shown as being double-headed and pointing essentially in opposite direction so as to represent the interchange of information and bi-directionality rather than unidirectionality.

Turning now to Figure 3, it will be seen to schematically portray in greater detail selected parts represented in Figure 2. There, in Figure 3 are the display(s) 40 which may be either a single monitor provided with single or split screens, or a plurality of monitors for simultaneously presenting several system parameters. Display(s) 40 are connected to electronics 41 via path 42, and electronics 41 are connected to gimballed assemblies 43 and 44 of left and right trocars 45 and 46 via paths 47 and 48. As will be observed from the description below, it is through these gimballed assemblies 43 and 44 that tactile force feedback forces are applied to left and right instruments 49 and 50.

Also depicted in Figure 3 is instrument panel 51 which is provided for additional display and control, including holes

52a-52k which are provided for holstering implements when they are not in use, and selector switches 53 and 54 which are included to provide for selection of procedures and instruments to be simulated from among a plurality of such procedures and related instruments. Also depicted are optional foot pedals 55 and 56 through which foot-operated actions can be simulated.

Before leaving Figure 3, it should be recalled that there are provided a plurality of sensors within the cavity 57 of mannequin 21. Certain of these sensors 58 are represented by the rectangular region at the bottom of cavity 57 and sense lateral movement of the ends 49a and 50a of implements 49 and 50. Others are represented by sensors 59 and 60 which sense movement along the linear axes of instruments 49 and 50. Electrical indicia produced by these sensors is utilized as described in the aforementioned co-pending application to produce the aforementioned tactile force feedback.

Now turning to Figure 4, it will be observed to present a general overview of the preferred system according to the invention. There are seen a conventional touch screen 64 that preferably is included as a part of the display 40 of Figure 3. The output of the touch screen 64 is denominated "user input" and is communicated as illustrated by arrow 65 to the simulation coordinator 66 which, in accordance with the foregoing description, comprises a plurality of interactive computers. As mentioned previously, there are associated with the trocars a plurality of control and sensing elements. These are represented by the trocar controller polygon 67 from which sensor electrical output indicia are communicated as shown by extended arrow 68 to dynamics engine 69. The dynamics engine is, as defined above, a body of data and instructions responsive to signals received from the trocar sensors and internal body sensors for producing physical sensations to a user closely simulating that which would appear to a surgeon when conducting a real life procedure of the type selected by the system user and with a real instrument manipulated in a manner simulated by the selected simulation implement. As will be evident from the foregoing description and from reference to Figure 4, such electrical indicia are communicated via display path 70 to Graphics Engine 71 where there are produced the corresponding graphics which are displayed on display 40 (Figure 3) .

As previously mentioned, in the preferred embodiment hereof, there are a plurality of interconnected and interactive computers and sensors that develop and control flow of needed electrical indicia within the system.

Simulator Control & User-World Interaction bi-directional arrow 72 represents such sensor action, user/operator interaction and computer control.

Extending to the right of simulation coordinator box 66 lies simulator control arrow 73 which represents flow of electrical control and information indicia, preferably in digital data form, to and from a video controller 74, memory laser disc or other high capacity memory 75, video overlay 76 and audio controller 77. Feedback type signals representing tactile force feedback are represented by block 78 and are described in detail in the above-identified co-pending United States Patent Application Serial No. 08/355,612 filed on December 14, 1994.

In operation, the system user (such as user/operator 13 of Figures 1 and 2) selects the type of simulation to be performed together with the type of instrument to be employed. As mentioned above, this is preferably accomplished by appropriately positioning selector switches 53/54 of Figure 3 (represented by arrow 65 in figure 4) . However, such can be readily performed by touching selection areas on a conventional touch screen such as touch screen 64 of Figure 4. After such selection has been made, simulation coordination and control occur and condition the accessing of dynamics engine 69 to produce corresponding landscape and control signals.

It will be recalled that one of the features of the invention is the utilization of a plurality of interconnected and interactive computers to speed operations, add flexibility and reduce cost. Such a plurality of computers is depicted in Figure 5. There are shown a state of the art simulation control computer configured as master computer 80. Master computer 80 includes: (a) an input/output and an interface for receiving and transmitting signals to the mannequin 21 (Figure 2) ; (b) a conference server; and (c) startup software.

Computer 80 is interconnected with three slave computers 81, 82, 83, and with independent computer 84 via communication bus 85.

Slave 81 is another state of the art simulation control computer which includes: (a) an application interface; (b) a play video sequence; (c) a state engine; (d) a video switch; and (e) the system video overlay. Slave 82 is a tissue modelling computer which processes and controls systems dynamics and the aforementioned graphics display. Slave 83 is a small general purpose computer denominated Audio/Video

Computer in figure 5 that processes and controls electrical indicia for the aforementioned touch screen and for a sound track in systems in which accompanying audio indicia are desired. Independent Video Computer 84 is another small general purpose computer which processes and controls electrical indicia for the aforementioned display video and the display overlays. Interactive interconnections between these computers is represented by communications bus 85 through which control indicia and data are communicated. In considering the roles of the foregoing computers, it may be helpful to consider that the concept of using multiple visual planes to display the simulation imagery, three are identified in this preferred embodiment. The "Graphics Display" is of the dynamics engine generated model; the "Display Video" is of the background plane; and the "Display Overlays" is layered on top of both of the foregoing. Now turning to Figure 6, it will be seen to depict system setup and selection process to ready the simulator for use in skills practice. Block 100 represents the system initialization in which, after being turned on, the aforementioned selection is made to use both trocars 23 and 24 (Figure 2) of the mannequin 21. Both trocars are manually reset (Figure 3) , and then either the aforementioned touch screen 64 (Figure 4) is touched or an optional conventional switch or other control is manipulated to make a selection 101 as between skills practice and diagnostics.. It may be helpful to keep in mind that, as mentioned above. Figure 6 depicts system operation when skills practice is selected, whereas Figure 7 depicts system operation when the selection is for diagnostic simulation. Therefore, system operation proceeds as by arrow 102 to rectangle 103 which represents patient mobilization and exposure. It also represents skills practice procedures such as ligation, dividing and joining which may be specifically selected; and it also includes the provision for random system selection of procedures represented by the legend "Surprise Me" on a section within the rectangle. Of course, provision is also made for return to previous menus as represented by the legend "Previous Menu". Each of these in turn is further detailed as noted below.

Next considering the category of mobilization, system operation proceeds as by arrow 104 to block 105 which portrays by examples of Mobilizations 1, 2 and 3, the selectability of any one of a variety of desired mobilizations. Moreover, provision is also made for random selections that may be made by the system if so indicated by the user. After mobilization, system operation proceeds as by arrow 106 to block 107 which represents skills menu 107 and the main system menu as well as observation and skills practice. Arrow 108 connected to oval "A" represents a path for return to the main menu which is represented by block 101.

As will be evident to those skilled in the art, a skills menu identifies those skills which the system is adapted to allow a user to practice. These may include any of a wide variety such as ligature, hernia repair, tubal ligation and duct exploration. A menu including such skills is presented on monitor display (30 in Figure 2, 40 in Figure 3) for user selection. As mentioned above, the disclosure of United States Patent 4,907,973 is incorporated herein by reference, such patent describing menus and other general characteristics of a related system in greater detail. Reference, accordingly, is made to that patent for more detailed information relating to menus, video display monitors and related matters.

Further reference to Figure 6 reveals lines 110 and 111 extending between block 107 and "Observe Video" block 112. These lines signify the communication of electrical indicia to displays such as those mentioned above as represented by "Observe Video" block 112. An additional line 113 extending between block 107 and "Simulation" block 114 represent the interchange of electrical indicia as procedure simulation proceeds. Arrow 115 extending between block 107 and "Touch Screen to Begin" block 116 represents communication of electrical indicia to condition the touch screen and ready it to accept user readiness for the procedure to get under way. After the user has instructed the simulation to proceed by appropriately touching the touch screen (as described above) , system operation progresses as represented by arrow 117, whereupon a simulation 114 of the selected procedure occurs. From time to time, as steps in such selected procedure are completed, indicia are presented on the system display instructing the user to initiate further operation by touching the screen. This is represented by arrow 118 extending between "Simulation" block 114 and "Touch Screen To Continue" block 119. System operation then resumes as represented by arrow 120 which connects to information/instruction interchange path 106.

If, instead of mobilization (block 105), an exposure (block 121) is desired, selection of exposure is made as at block 103, and the system proceeds as by arrow 122 to "Expo- sure" block 121 which is similar to block 105; and system operation then proceeds as previously described with respect to mobilization, indicia being conducted through informa- tion/instruction interchange path 106 to block 107 and thence to blocks 112, 114, 116 and 119. Correspondingly, if at block 103, selection of ligation is made, then the system proceeds as by arrow 123 to "Ligation" block 124 where user selection of a particular type of ligation, or random selection, is made. System operation then proceeds as previously described with respect to mobilization and exposure, indicia being conducted through information/instruction interchange path 106 to block 107 and thence to blocks 112, 114, 116 and 119. Other procedures and skills are selectable as represented by Joining and Division blocks 125 and 126. Selection of these procedures from the menu of block 103 is represented by arrows 127 and 128; and system operation after such selection pro¬ ceeds as by information/instruction interchange path 106 to block 107 and thence to blocks 112, 114, 116 and 119 as de¬ scribed above.

Now turning to Figure 7, it will be seen to illustrate the setup and selection process to ready the simulator for diagnostics practice use. There, block 100 (previously de- scribed with respect to Figure 6) is shown; and system opera¬ tion for Figure 7 proceeds as when diagnostic practice rather than skills practice selected.

As will be observed, when diagnostics are selected as represented by block 101, the system is conditioned as indi- cated by arrow 130 to display on the aforementioned monitor displays a message (block 131) "Please (1) Set the switch to the one hold manikin; (2) Put the trocar in its reset posi- tion; and then (3) Touch the screen to continue." After these steps have been performed by the system user, an option is provided (block 132) for the user to select as between normal and pathological conditions, whereupon the system proceeds as represented either by arrow 133 to normal simulation block 135 or arrow 134 to pathology simulation 136. If selection of normal simulation is made as represented by arrow 133, then normal diagnostic simulation proceeds and the aforementioned presentation of simulated landscape views of selected internal scenes is that of a normal patient. As mentioned previously, manipulation of the simulated viewing instrument through the selected trocar is sensed by the related sensors to condition other parts of the system (e.g., the dynamics engine, land¬ scape memories) to provide life-like representations of rele- vant simulated patient internal landscapes. After a predeter¬ mined time interval as represented by line and arrow 137, the system proceeds as by block 138 to provide for user selection of further normal simulations or return to the main menu. Selection of further normal simulations by Touch to Continue puts the system on path and arrow 139 to provide for further simulations. If, on the other hand, selection is made to return to the main menu (Touch for Main Menu) , then the system proceeds as represented by path/arrow 140 to path node design¬ ators "A" and path 141 to the point in system operation repre- sented by path 142 so that another selection as between normal and pathology may be made as represented by block 132.

If instead of selecting normal diagnostics as at block 132, the system user selects pathology, the system operation proceeds as represented by arrow 134 to pathological simula¬ tion 136. There, selection of a particular type of pathology may be made or, alternatively, the system may be instructed to randomly present one of a number of stored pathologies.

Simulation then proceeds via "Timeout" line and arrow 143, block 144 and path/arrow 145 to simulation 136, similar to the path described for line and arrow 137, block 138 and path/arrow 139, except that now the landscapes that are por- trayed are pathological rather than normal. When selection is made to return to the main menu, then the system proceeds as represented by path/arrow 146 and connected "A" designator and path 141 to path 142 so that another selection as between normal and pathology may be made as represented by block 132. As will be evident to those skilled in the art, one of the objectives of including diagnostic skills practice is to permit the user to correctly identify the presented pathology. Thus, within systems memory there may be included an identifi¬ cation of the pathological condition that is depicted in the displayed simulated landscape, and provision may be included for the system user to identify his selection either by touch¬ ing the touch screen of the aforementioned display in the appropriate location, by keyboard entry or other known tech¬ niques. If such identification is correct, then system opera- tion proceeds as by "successful" path/arrow 147 to block

"Touch Screen to Continue" block 148 where the system user is provided the choice of continuing the search or a different pathology as represented by path/arrow 149, connected "A" designator path 141 and path 142.

If rather than being successful in diagnosis of the pathology, the user is mistaken, then the system proceeds as by "Unsuccessful" path/arrow 150 to block 151 at which the option is provided for the user to return to a previous menu via path/arrow 152 and connected "A" designator 141 path, or to keep looking (try again) as represented by path/arrow 153.

Returning now to block 132, it will be observed that it is interconnected by path/arrow 154 to block 155 representing provision for user change of subject as between a plurality of differing cases, i.e., types of simulated pathologies/patient- s. Such change of patients/pathologies is represented by path/arrow 156 denoting a return of system operation (with the change of patient/pathology) to operation represented at and after block 132. If, on the other hand, it is desired to return operation of the system to the state represented by block 100, then, at user selection, the system proceeds as represented by "double touch" path/arrow 157 to the initial screen 100.

As previously mentioned one of the features of the inven¬ tion hereof is the combination and interaction of tactile force feedback with the remaining elements of the system. Figure 8 illustrates some of the considerations involved in providing faithful simulations of forces that would actually be encountered in conducting a real-life procedure. Thus, in Figure 8, there is depicted a simulation of a body organ 160. As is well known to those skilled in the art, all internal body organs are relatively soft compared with metallic instru¬ ments such as instrument 161; and the organs tend to "give" with a degree of resistance when subjected to forces thereup¬ on. Thus, organs tend to flex when forces are applied thereto by contact with an instrument. In addition, and since organs are loosely tied down, they also tend to move in three dimen¬ sional space. If the organ is tubular (as shown) , and if it is pushed by a rod-like instrument as at contact point 162, the organ will initially provide contact feedback, then flex away offering increasing resistive force and then returning to its previous position when free to do so. It has been found that the result may be an oscillation if the instrument re- mains close by but within the normal extension range of the organ. Such oscillation results, in part, from a periodic accumulation of elastic forces within the simulation of the organ. Collisions occur between objects in simulation (e.g., as between an instrument and an organ) . When it is likely that a collision may occur, the simulator attempts to deter¬ mine whether they in fact did occur. This is done by a tech¬ nique which determines whether any of the facets of the organ tissue have been penetrated by the instrument. If a collision has been detected, then it is resolved. This done much as shown in Figure 9 where the tissue is moved away from the instrument, causing the organ to compress so long as contact is made. It is at the point where the organ is compressed that force feedback signals are generated. The natural ten¬ dency of the organ is to resume its normal shape. As such, the force vectors generated reflect that tendency exactly until the organ has achieved its normal shape. A model of such contact and rebound effect is illustrated in Figure 9.

There, a tubular-like implement is represented by rectan¬ gle 163, and a series of successive positions of part of an organ are represented by circles and oval 164a-164g. These successive positions are simulations of movement of the rod- shaped instrument with respect to time arrow 165. As rod 161 is moves in contact with organ 160 as at location 162 and the organ flexes (as represented by positions 164a-164d, the organ is deformed (as represented by the oval shape of 164d) and due to its elasticity, it then rebounds as represented by succes- sive states 164e-164g.

In view of the foregoing, provision is made for prevent¬ ing the otherwise occurring oscillations so that simulated tactile force feedback faithfully represents that which would be encountered in real-life procedures. In order to provide faithful internal landscapes repre¬ senting simulations of procedures such as the cutting, abrad¬ ing, or joining of body tissue, an internal model is employed utilizing mesh representations. Thus, in accordance with the preferred embodiment and as defined above, a lattice is an internal representation of tissue being modeled by the system.

For the purpose of this description, and to facilitate under-standing of Figures 10-13, it may be considered that each lattice is made up of atoms which have mass and can be connected to each other by elastic bonds. Three atoms joined in a triangle by three bonds can have an associated, visible facet. Tissue surfaces, then, are represented by a mesh of triangular facets, with bonds along the edges of the facets and atoms at their corners. Extra bonds and atoms can provide additional invisible structure.

During a simulation, a lattice can interact with simulat- ed rigid bodies. Rigid bodies, such as the simulated instru¬ ments employed in the system, are considered as being made of components with fixed size and shape. These components can move with respect to each other, and the whole rigid body can be positioned by external stimuli and/or interactions with the lattice. The system checks to see if any rigid bodies have collided with facets, calls collision-handler routines which can modify and apply forces to the lattices, accelerates the atoms according to the forces on them, and conditions the facets to their new states. Lattices are included in vignettes which in turn are stored in the above-mentioned memory. When a vignette is recalled from memory, it includes its lattices, such as that which is illustrated in Figure 10. It also contains vignette parameter information such as lattice volume, density, surface area and mass per unit area. The system then initializes the atoms in the lattice, transforming their coordinates so that the visualization of the model overlays the background in the same place when displayed on the display screen regardless of eye point position or orientation. Information identifying the lattice bonds are, of course, also included.

In processing lattice information, only atoms are consid- ered to have mass. Each atom initially is assigned zero mass, and creating a facet adds mass to each of its atoms. The amount of mass to be distributed to the atoms is the product of the facet rest area and the lattice mass per unit area; and one third of such mass is assigned to each of the facet*s three atoms.

Provision is made through a main dynamics loop for pro¬ cessing vignette data. Such dynamics loop contains an inner loop and an outer loop. The outer loop reads control and trocar-position sockets (as described above) , responds to keyboard commands and processes what it reads from the sock¬ ets. If a vignette is loaded and running, the outer loop also runs the inner loop and performs several additional steps such as rendering the model and transmitting force feedback and filter output. The inner loop applies forces to and moves the lattice. An "iterations count" is included within vignette control to set how many times the inner loop runs for each pass through the outer loop.

In operation, the inner loop zeros the accumulated force on each atom, resets a flag indicating whether an atom has received force from a collision with a rigid body and calcu¬ lates normals for the facets and atoms. The inner loop then calls for a calculation of the length of each bond and the resulting force to be applied to the atoms of the bond. The bond with the most force on it is the one that is broken upon instrument contact provided the force on the bond exceeds its yield strength. This is done by creating tears from the midpoint of the bond to the opposite atoms of the bond facets, preferably one at a time. The bond forces are then applied to the atoms of each bond, and the effect of gravity is applied to each atom.

After a check for collisions (as hereinafter described) , the inner loop calls for an acceleration of each non-station¬ ary atom according to its accumulated force, the dampening by a global friction factor of the simulated velocity of every non-stationary atom, the limiting of simulated speed of atoms which are moving excessively quickly, and the movement to of each relevant atom to its next position. At the same time, compensation is provided for varying speeds of simulator system operation by introducing a factor related to the aver¬ age duration of an iteration of the inner loop measured during the previous iteration of the outer loop. One additional operation performed by the inner loop is sensing of atoms that should be split into two or more result¬ ing from such actions as the breaking of nearby bonds or specific types of slicing. Thus, if an atom has four or more bonds which have not been involved in slicing and border only one facet, the atom is split with one group of contiguous facets remaining connected to the original atom and each remaining group of contiguous facets being connected to a newly created atom.

Collision handling is performed for each rigid body in turn. Each rigid body can interact with the lattice and with other rigid bodies. To facilitate identification of those facets or bonds that might interact with each rigid body, a calculation is made of the distance of each atom from a plane occupied by the rigid body. Those which either cross the plane or come close enough to be of interest are then marked. A collision handler list is provided to record and pro- vide a set of functions which can include pre- and post-pro¬ cessing, interaction with facets, bonds or atoms, and handling collisions with other rigid bodies. Such is called up by the system as needed to provide collision handler information. This is used when applying force to facets such as the hemi- sphere, cylinder and grab handlers. These apply forces to a point on the facet by apportioning the force to the atoms of that facet according to the position on the facet of the point. In subsequent iterations of the inner loop, the forces from the collisions propagate to neighboring atoms. Where closure is desired, a knit collision handler is employed to permanently close the end of a tube after the walls of the tube have been pressed together. The knit colli¬ sion handler knits together sets of atoms by adding new bonds and/or by resizing existing ones. Each atom then qualified to be knit is joined by a bond to every other qualified atom, and each of the knit atoms remains in roughly the same physical position relative to the others. As mentioned above, the lattice data structure keeps track of the number of atoms, bonds and facets in the lattice and includes identifiers linking such information with linked atom, bond and facet lists that are included in the storage described above. It also includes values derived from vi¬ gnette parameters such as the spring constant-rest length product, maximum spring constant and the mass per unit area of the model.

In addition to the above, provision is also made for en- abling existing tears to widen by finding, in selected circum¬ stances, a different bond to tear. If a proposed tear bond has the end of a tear at either of its atoms, the existing tear may propagate through the atom instead of the proposed tear bond breaking and forming a new tear. If two or more of the bonds connected to an atom on the proposed tear bond were formed by tearing (i.e., the atom is at the end of an existing tear) , the system examines other bonds to tear. As possible replacements for the proposed tear bond, the system considers a bond in each facet attached to either end of the proposed bond. Only one bond in each facet, the one opposite the proposed tear bond/s end atom, is considered. Facets formed by existing tears or containing the proposed tear bond are not considered. The qualified replacement bond (if one exists) most parallel to the proposed bond is selected. If a replace- ment bond is found, the atom at the end of the old tear will have two more tear bonds going to it and will qualify to be split into two atoms. Thus, the tear will have propagated through the atom.

Selected lattices contain a plurality of roughly parallel paths running along the surface from one end to another; and each atom and bond with facets can be part of one numbered path. When every path has been cut, a "cut complete" signal is produced and is processed to denote that the cut has been completed.

Now considering the facets, for the purpose of this system, all facet forces and masses are distributed to the atoms of the facet. When a force is applied to a point on a facet, the force is distributed among the atoms of the facet as described above. Also as described above, the mass attrib¬ uted to the facet is distributed to its three atoms. Provi¬ sion is also made for avoiding the creation of small facets in size below a predetermined value so as to prevent undue slow¬ ing of system operation.

With the foregoing general background in mind, reference is now directed to Figure 10 which illustrates division of a single triangular facet into three new facets when a facet is sliced edge to edge. There, the original facet is a triangle which was composed of the three sides marked: (1) new bonds [0] and new bonds [1] ; (2) new bonds [2] and new bonds [3] ; and (3) original bond before slicing and creation of the new bonds and new atoms. These were continuous and joined togeth- er without the separation 169. Old atoms 170, 171 and 172 are located at the three apexes of the original facet as shown. When it was desired to slice the original facet from edge to edge as shown, thus providing separation 169, two of the old bonds were divided in two to produce new bonds [0], [1], [2], and [3], new bonds [4], [5], and [6] were produced, and new atoms [0], [1], [2] and [3] were created and positioned as shown. Thus, the single original triangular facet was divided into three new triangular facets [0], [1] and [2] as shown.

It should be observed that for the purposes of this description, all facets are triangular in shape; and as cut¬ ting, joining and other procedures occur, triangular facets are merged or separated to form new triangular facets, some of which may be associated together so as to form quadrilaterals or other polygons as represented by the space bounded by the original bond and new bonds [1], [3] and [5].

Turning now to Figure 11, it will be seen to depict division of a single triangular facet into three new facets when a facet is sliced from an edge to the interior. In the original triangular facet which is shown as an essentially equilateral triangle bounded by old atoms 170, 171 and 172, a cut from the lower edge (the line extending horizontally between old atoms 171 and 172) to a location marked by new atom [2] results in the creation and positioning of new atoms [0], [1] and [2] as well as the creation of new bonds [0], [1], [2], [3], [4], [5], and [6]. This, in turn results in the creation of new facets [0], [1], [2], and [3]. As mentioned above, Figure 12 is seen to depict division of a single triangular facet into five new facets when a facet is sliced from a location within its interior to another location within its interior. In the original triangular facet which is shown as an essentially equilateral triangle bounded by old atoms 170, 171 and 172, an interior cut results in the creation and positioning of new atoms [0], and [1] as well as the creation of new bonds [0], [1], [2], [3], [4], [5], and [6] . This, in turn results in the creation of new facets [0], [1], [2], [3] and [4].

Figure 13 is a diagram illustrating division of a single triangular facet into two new facets when a facet is sliced from an apex point to an edge. In the original triangular facet which again is shown as an essentially equilateral triangle bounded by old atoms 170, 171 and 172, a cut from the lower edge (the line extending horizontally between old atoms 171 and 172) to the apex location marked by.old atom 170 results in the creation and positioning of new atoms [0] and [1] as well as the creation of new bonds [0], [1], [2] and [3]. This, in turn results in the creation of new facets [0] and [1] .

The simulation of organs through the utilization of vi- gnettes comprised of a plurality of triangular facets facili¬ tates the processing of electrical indicia representing such facets and vignettes, thus further facilitating the production of other indicia representing tactile forces simulating those that would be encountered in carrying out a corresponding real-life procedure.

It will now be evident that there has been described herein, an improved medical procedure simulator that is versa- tile, provides life-like tactile force feedback and that is cost-effective to produce and use, thus contributing to its attractiveness and desirability.

Although the inventions hereof have been described by way of a preferred embodiment, it will be evident that other adaptations and modifications may be employed without depart¬ ing from the spirit and scope thereof. For example, other models could be employed that utilize other than triangular configurations. The terms and expressions employed herein have been used as terms of description and not of limitation; and thus, there is no intent of excluding equivalents, but on the contrary it is intended to cover any and all equivalents that may be employed without departing from the spirit and scope of the invention.

Claims

Waτ is Claimed is:

1. A medical procedure simulation system comprising:

(a) a physical model providing a visual and sensory simulation of that exterior portion of a human torso ordinari¬ ly encountered by medical personnel in administering to a human patient the actual procedure to be simulated by said system, said model having a plurality of sensors and implement manipulators;

(b) at least one medical instrument simulator implement comprising a shaft and simulated manual controls closely resembling a true medical instrument of the type used in said actual procedure to be simulated, said model and said at least one simulator implement being adapted for said implement to be inserted into said model and maneuvered in a lifelike manner to simulate maneuvers of an actual instrument in a true proce- dure, said plurality of sensors being so arranged relative to said at least one simulator implement when inserted in said model as to produce a plurality of electrical signals provid¬ ing essentially continuous indication of the physical position and condition an actual instrument of the type being simulated by said simulator implement would have assumed if manipulated in the same manner as said simulator implement, said implement manipulators being so arranged within said model relative to at least one simulator implement when inserted in said model as to produce in response electrical drive signals derived in response to said plurality of electrical signals from said sensors impinging forces on said simulator implement closely simulating forces as would impinge on a true instrument of the type simulated if maneuvered similarly during a true medical procedure of the type being simulated;

(c) a visual landscape library of electronically select- able human internal body scenes for depicting smoothly chang¬ ing vistas to simulate medical internal camera output for electrical display;

(d) a display means to display visual output selected from said library; and (e) a signal generator responsive to said plurality of signals produced by said sensors to produce controlled signals to select and display on said display means scenes from said landscape library to provide near real time simulation of the visual monitor display provided during the performance of the true medical procedure being simulated by said system.

2. A medical procedure simulation system according to claim 1 wherein said plurality of sensors are positioned within said model.

3. A medical procedure simulation system according to claim l wherein said plurality of implement manipulators are positioned within said model.

4. A medical procedure simulation system according to claim l wherein said plurality of sensors and implement manip¬ ulators are positioned within said model.

5. A medical procedure simulation system according to Claim 1 wherein said signal generator further provides visual simulation of said at least one medical instrument, said generator being responsive to sensor signals generated in response to manipulation of said at least one medical instru¬ ment.

6. A medical procedure simulation system according to Claim 1 wherein said signal generator further provides visual simulation of a body part responsive to an interaction with a medical instrument simulated by said simulator implement.

7. A medical procedure simulation system according to Claim 1 further including a library of various instrument simulations selectable for use with a plurality of simulator instruments.

8. A medical procedure simulation system according to Claim 1 wherein said signal generator further provides visual simulation of said at least one medical instrument, said generator being responsive to sensor signals generated in response to manipulation of said at least one medical instru¬ ment, said system further providing visual simulation of a body part responsive to an interaction with a medical instru¬ ment simulated by said simulator implement.

9. A medical procedure simulation system according to Claim 1 in which said implement manipulators are of the fluid- ics type.

10. A medical procedure simulation system according to Claim 1 in which said implement manipulators are of the pneu¬ matic type.

11. A medical procedure simulation system according to Claim 1 in which said implement manipulators comprise force feedback members communicating life-like forces to said at least one medical instrument simulator implement.

12. A medical procedure simulation system according to Claim 11 in which said implement manipulators are of the pneumatic type.

13. A medical procedure simulation system according to Claim 1 further including electrically programmable processors interconnected with predetermined ones of said plurality of sensors for processing said plurality of electrical signals.

14. A medical procedure simulation system according to Claim 13 further including means for electrically programming said programmable processors.

15. A medical procedure simulation system according to Claim 1 further including a plurality of interconnected task- dedicated and general task programmable processors responsive to said plurality of electrical signals from said plurality of sensors for producing control and operating signals to said system.

16. A medical procedure simulation system according to Claim 1 further including a plurality of interconnected task- dedicated and general task programmable processors responsive to said plurality of electrical signals from said plurality of sensors for producing control and operating signals to said system for producing near (virtual) real time sensory and visual simulation of the procedure being simulated to the user of said simulation system.

17. A medical procedure simulation system according to Claim 1 further including a plurality of interconnected task- dedicated and general task programmable processors responsive to said plurality of electrical signals from said plurality of sensors for producing control and operating signals to said implement manipulators, library and visual display.

18. A medical procedure simulation system according to Claim 1 further including a plurality of interconnected task- dedicated and general task programmable processors responsive to said plurality of electrical signals from said plurality of sensors for producing control and operating signals to said implement manipulators, library and visual display for produc¬ ing near (virtual) real time sensory and visual simulation of the procedure being simulated to the user of said simulation system.

19. A medical procedure simulation system according to Claim 7 further including a plurality of interconnected task- dedicated and general task programmable processors responsive to said plurality of electrical signals from said plurality of sensors for producing control and operating signals to said implement manipulators, libraries and visual display.

20. A medical procedure simulation system according to Claim 7 further including a plurality of interconnected task- dedicated and general task programmable processors responsive to said plurality of electrical signals from said plurality of sensors for producing control and operating signals to said implement manipulators, libraries and visual display for producing near (virtual) real time sensory and visual simula¬ tion of the procedure being simulated to the user of said simulation system.

21. The method of simulating a medical procedure com¬ prising:

(a) providing a physical model having a visual and sensory simulation of that exterior portion of a human torso ordinarily encountered by medical personnel in administering to a human patient the actual procedure to be simulated by said system;

(b) disposing a plurality of sensors and implement manipulators at said model; (c) providing at least one medical instrument simulator implement comprising a shaft and simulated manual controls closely resembling a true medical instrument of the type used in said actual procedure to be simulated, said model and said at least one simulator implement being adapted for said i ple- ment to be inserted into said model and maneuvered in a life¬ like manner to simulate maneuvers of an actual instrument in a true procedure, said plurality of sensors being so arranged relative to said at least one simulator implement when insert¬ ed in said model as to produce a plurality of electrical signals providing essentially continuous indication of the physical position and condition an actual instrument of the type being simulated by said simulator implement would have assumed if manipulated in the same manner as said simulator implement, (d) arranging said implement manipulators within said model relative to at least one simulator implement when in¬ serted in said model as to produce in response electrical drive signals derived in response to said plurality of elec¬ trical signals from said sensors impinging forces on said simulator implement closely simulating forces as would impinge on a true instrument of the type simulated if maneuvered similarly during a true medical procedure of the type being simulated;

(e) providing a visual landscape library of electroni¬ cally selectable human internal body scenes for depicting smoothly changing vistas to simulate medical internal camera output for electrical display;

(f) providing a display to display visual output select¬ ed from said library; and

(g) providing a signal generator responsive to said plurality of signals produced by said sensors to produce controlled signals for selectively displaying on said display scenes from said landscape library to provide near real time simulation of the visual monitor display provided during the performance of the true medical procedure being simulated by said system.

22. A method of simulating a medical procedure according to claim 21 further including positioning at least some of said sensors within said model.

23. A method of simulating a medical procedure according to claim 21 further including positioning at least some of said implement manipulators within said model.

24. A method of simulating a medical procedure according to Claim 21 further including positioning at least some of said plurality of sensors and implement manipulators within said model.

25. A method of simulating a medical procedure according to Claim 21 further including conditioning said signal genera¬ tor to provide visual simulation of said at least one medical instrument, and making said generator responsive to sensor signals generated in response to manipulation of said at least one medical instrument.

26. A method of simulating a medical procedure according to Claim 21 further including conditioning said signal genera¬ tor to provide visual simulation of a body part responsive to an interaction with a medical instrument simulated by said simulator implement.

27. A method of simulating a medical procedure according to Claim 21 further including providing a library of various instrument simulations selectable for use with a plurality of simulator instruments.

28. A method of simulating a medical procedure according to Claim 21 further including conditioning said signal genera¬ tor to provide visual simulation of said at least one medical instrument, and causing said generator to respond to sensor signals generated in response to manipulation of said at least one medical instrument, said system further providing visual simulation of a body part responsive to an interaction with a medical instrument simulated by said simulator implement.

29. A method of simulating a medical procedure according to Claim 21 further including rendering said implement manipu¬ lators fluid responsive.

30. A method of simulating a medical procedure according to Claim 21 further including rendering said implement manipu¬ lators pneumatically responsive.

31. A method of simulating a medical procedure according to Claim 21 further including conditioning said implement manipulators to include force feedback members communicating life-like forces to said at least one medical instrument simulator implement.

32. A method of simulating a medical procedure according to Claim 31 further including rendering said implement manipu¬ lators pneumatically responsive.

33. A method of simulating a medical procedure according to Claim 21 including providing electrically programmable processors and interconnecting said processors with predeter¬ mined ones of said plurality of sensors for processing said plurality of electrical signals.

34. A method of simulating a medical procedure according to Claim 33 further including electrically programming said programmable processors.

35. A method of simulating a medical procedure according to Claim 21 further including providing and connecting a plurality of task-dedicated and general task programmable processors and conditioning said processors, to respond to said plurality of electrical signals from said plurality of sensors for producing control and operating signals to said system.

36. A method of simulating a medical procedure according to Claim 21 further including providing and connecting a plurality of task-dedicated and general task programmable processors and conditioning said processors to respond to said plurality of electrical signals from said plurality of sensors for producing control and operating signals to said system and for producing near (virtual) real time sensory and visual simulation of the procedure being simulated to the user of said simulation system.

37. A method of simulating a medical procedure according to Claim 21 further including providing and connecting a plurality of task-dedicated and general task programmable processors and conditioning said processors to respond to said plurality of electrical signals from said plurality of sensors for producing control and operating signals to said implement manipulators, library and visual display.

38. A method of simulating a medical procedure according to Claim 21 further including providing and connecting a plurality of task-dedicated and general task programmable processors and conditioning said processors to respond to said plurality of electrical signals from said plurality of sensors for producing control and operating signals to said implement manipulators, library and visual display for producing near (virtual) real time sensory and visual simulation of the procedure being simulated to the user of said simulation system.

39. A method of simulating a medical procedure according to Claim 27 further including providing and connecting a plurality of task-dedicated and general task programmable processors and conditioning said processors to respond to said plurality of electrical signals from said plurality of sensors for producing control and operating signals to said implement manipulators, libraries and visual display.

40. A method of simulating a medical procedure according to Claim 27 further including providing and connecting a plurality of task-dedicated and general task programmable processors and conditioning said processors to respond to said plurality of electrical signals from said plurality of sensors for producing control and operating signals to said implement manipulators, libraries and visual display for producing near (virtual) real time sensory and visual simulation of the procedure being simulated to the user of said simulation system.

41. An investigative medical system comprising in combi¬ nation:

(a) a physical model representing physically and spa¬ tially at least that portion of a patient on which a selected medical procedure is to be performed;

(b) at least one implement representing a medical proce¬ dural tool normally employed in conducting said selected medical procedure;

(c) moving means for moving and controlling said imple- ment within said model;

(d) first memory means for storing data representing the internal landscape of said at least that portion of said patient;

(e) means interconnected with said moving means and responsive to the position of said implement for producing and displaying a visual presentation of that portion of said internal landscape representing the region adjacent the active portion of said implement; and

(f) force imparting means interconnected with said physical model and responsive to said position of said imple¬ ment for producing and imparting to said at least one imple¬ ment forces representing realistic forces encountered by said implement in conducting actual medical procedures.

42. An investigative medical system according to Claim

41 wherein said physical model comprises a life-like manne¬ quin.

43. An investigative medical system according to Claim

42 further including a swivelable trocar mounted within an exterior surface portion of said mannequin.

44. An investigative medical system according to Claim 41 wherein said moving means includes a trocar.

45. An investigative medical system according to Claim 44 wherein said trocar is swivelably mounted within an exteri¬ or surface portion of said mannequin.

46. An investigative medical system according to Claim 44 wherein said trocar includes a plurality of sensors for sensing movement of said implement.

47. An investigative medical system according to Claim 44 wherein said trocar includes three dimensional sensing means for sensing three dimensional movement of said imple¬ ment.

48. An investigative medical system according to Claim

47 in which said three dimensional sensing means includes means for sensing movement of said implement along a principal axis of said implement.

49. An investigative medical system according to Claim

48 in which said sensing means further includes means for measuring movement of said implement along said principal axis of said implement.

50. An investigative medical system according to Claim

49 further including a plurality of bar codes positioned in operative association with said implement and sensed by said sensing means for measuring said movement of said implement along said principal axis of said implement.

51. An investigative medical system according to Claim 41 wherein said force-imparting means includes a plurality of lattices.

52. An investigative medical system according to Claim 41 wherein said lattices represent simulated tissue.

53. An investigative medical system according to Claim 41 wherein said force imparting means includes a force-impart¬ ing donut mounted about said implement.

5 . An investigative medical system according to Claim 41 wherein said force imparting means includes a spring opera- tively associated with said implement for imparting resilient forces thereto.

55. An investigative medical system according to Claim 41 wherein said force imparting means includes a force-impart¬ ing donut mounted about said implement and a spring operative- ly associated with said donut and said implement for imparting resilient forces thereto.

56. An investigative medical system according to Claim 51 wherein lattices are represented by atoms and elastic bonds.

57. An investigative medical system according to Claim

56 wherein said lattices comprise facets comprised of said atoms and said elastic bonds.

58. An investigative medical system according to Claim

57 wherein said atoms and said elastic bonds are configured into triangles each comprising three facets.