WO2004032095A1

WO2004032095A1 - Interactive medical training system and method

Info

Publication number: WO2004032095A1
Application number: PCT/CH2002/000556
Authority: WO
Inventors: Ivan Vecerina; Murielle Launay; Jurjen Zoethout
Original assignee: Xitact S.A.
Priority date: 2002-10-07
Filing date: 2002-10-07
Publication date: 2004-04-15
Also published as: EP1550099A1

Abstract

A method for training a user in a medical procedure utilizes an interactive computer system with a virtual representation of at least one organ (1) and at least one instrument (2, 3). The representation of surface area parts (4, 5, 7, 8, 9) of the virtual organ (1) to be treated are covered with graphical identification marker (14, 15A to 15C, 17). The computer system comprises a table stored in his memory comprising situations arising within the medical procedure predefined through positions of the instrument(s) (2, 3), positions of the organ(s) (1), the logical sequence of steps to be executed within said medical procedure, different aspect values for the graphical identification markers (14, 15A to 15C, 17) and assessment values for said situation. Upon interaction of the user with the at least one organ (1) and the at least one instrument (2, 3) one or more graphical identification markers (14, 15A to 15C, 17, 18A + 18B, 19) change their aspect according to the stored value in said table for the predefined situation and the corresponding assessment value is stored in a history log table within the computer system.

Description

Interactive medical training system and method

Field of the invention

The invention relates generally to an interactive medical training system.

Background of the invention

Specialized force-feedback devices are more and more proposed for medical training of surgeons, especially in view of endo- scopic interventions. Haptic interfaces accommodate the different controllers and environments.

US 6,131,097 shows a haptic/visual authoring tool comprising a disclosure of controlling an avatar interacting with a virtual object, generating responsive forces.

It is known from prior art that the user in training manipulates handles of actual endoscopic instruments in front of a box being the simulation of a torso of a patient. The images of the users actions with said instruments are shown on a video display. Said video display shows computer generated images of the instruments used and the environment (i.e. organs etc.).

US 5,791,907 discloses a method for training a user in a medical procedure utilizing an interactive computer system, said medical procedure having a plurality of steps. Following the answers of the user on specific questions of the system, the system provides an ongoing display history in connection with the correct answers and the errors.

The need remains, however, for a method and system to organize the training to guide the user and to provide a measurable result at the end of a training session, usable by the person trained and the training center.

Summary of the invention

The present invention relates on the insight that a method for training a user in a medical procedure has to divide the training session into smaller parts, that the user should be able to start every of these parts repeatedly in an environment of a perfectly completed former part, that the method has to guide the user within the different steps, and that the method has to provide an assessment at the end of a completed training session clearly showing the results and especially possible weaknesses of the user in view of further training sessions.

Preferably the result (i.e. the assessment) of a training session is available for a supervisor of the training session in connection with a stored session history to be able to evaluate the errors together with the user at any later moment .

Brief description of the drawings

Fig. 1 shows a schematic view of a virtual organ, two instruments and several graphical identification markers, Fig. 2 shows a screen display showing different steps of the training session available in connection with the simulated treatment of the organ according to Fig. 1,

Fig. 3 shows a screen display showing different sub-steps of a step according to Fig. 2, and

Fig. 4 shows a schematic view of another virtual organ with further graphical identification markers .

Detailed description of the invention

Fig. 1 shows a schematic view of an organ 1 together with two instruments 2 and 3 as it is generated on a screen visible to the user in the training session. Said representations of organ

1 and instruments 2 and 3 are virtual geometrical elements within a computer controlled virtual environment . The instruments 2 and 3 are connected through a control arrangement to physical devices, namely handles of (fake) surgical instruments, which are manipulated by the user in said training session. The background of the image according to Fig. 1 shows a virtual representation of the abdominal cavity (not shown) .

The user has to perform a surgical interaction, i.e. a simulated treatment of said organ 1. Fig. 2 shows a screen display of different steps of the training session available in connection with the simulated treatment of the organ 1 according to Fig. 1. Within the embodiment shown, and as an example, this surgical interaction may comprise: step 51: gripping' of the organ in the area 4 with instrument

2 and step 52 : setting clips in the area 5 with help of the instrument 3 , and. step 53: cutting a vessel in an area 7.

In reality this surgical operation has to be performed in a row within a preferred time limit. In the simulated environment the training is separated into different training steps 51 to 53. There are three training steps within this embodiment. The different steps 51 to 53 can be chosen independently from a menu as shown in Fig. 2. Additionally the menu comprises a step 50: information about the virtual patient, step 55: tutored intervention of all steps 51 to 53 within one step, step 56: complete "free" intervention of all steps 51 to 53 within one step, and step 57: assessment of the training session. Further steps for maintenance .of the user information, storing or retrieving parameters for the intervention (e.g. parameters of the virtual patient, surgical problems arising with said patient, etc. ) and/or storing or retrieving of different training sessions (e.g. for later assessment) may be included within the menu display and are summarized under reference numeral 58: administration.

Every of the three steps 51 to 53 is organized within sub-steps which have preferably the identical layout .within every step 51 to 53 for easy reference. Therefore, choosing one of the steps 51 to 53 on the screen leads to a new menu. In the case depicted in Fig. 3 step 52 "clipping of the organ" is the header of the menu wherein each step comprises preferably the following identical sub-steps, which can be chosen independently from the menu: sub-step 61: a prerecorded video representation of said step

51 or 52 or 53 within a real intervention, sub-step 62: a prerecorded virtual reality video representation of the intervention to be performed within said step 51 or

52 or 53 based on the structure of the virtual reality environment, sub-step 63: instructions for the intervention of said step 51 or 52 or 53, sub-step 64: a prerecorded virtual reality graphical (stills) or video representation of common errors within said step 51 or 52 or 53, which can usually be picked from a further listing submenu, sub-step 65: training session of the step in question with guidance, sub-step 66: training session of the step in question without guidance. The main advantage of this procedure is based on the insight that the user can be directed within each step and repeat the steps in which he needs the most training. This preparation together with the guidance through the below mentioned graphical codes gives a better training result. Additionally the result of the simulated intervention is stored and the evaluation is possible on parts of the intervention or the whole process .

Within every sub-step 65 the graphical representation comprises a direct correlation with the action of the instrument handled by the user. This can be shown within the embodiment of the intervention as follows .

Within the step 52 "clipping" , the user has to move the instrument 2 towards the organ 1 and grip it in an area 4 (same procedure as in the step 51 "gripping") . Then he has to hold the organ 1 in a certain position and to apply three clips in the two areas 5 (in order to enable the cutting of the vessel in step 53 "cutting" between the clips in area 7) .

Before the user has gripped the organ 1, the area within which the instrument 2 has to be applied is marked through a blue dot 14 (the area shaded in the drawing) . When the area 4 is gripped, the dot changes its color, e.g. into yellow until the user has pulled the organ 1 into the corrected position, upon which occasion the dot changes its color a further time, e.g. into green. Since the user has to hold instrument 2 throughout the step in an extended period of time, he may deviate from the correct position, and the controller changes the color from green to red, when the position is not correct anymore. A less correct position may be marked yellow. Such graphical feedback enables the user to find the correct position and the dot 14 becomes green again. The step 52 "clipping" asks the user to put three clips into predefined positions, which are marked 15A, 15B and 15C. The necessity to apply the same number of clips to the second vessel in the background is not treated within this simplified approach of the description. At the beginning only one part of area 5, i.e. the ring 15A is blue. The user virtually loads a clip 13 into instrument 3 and approaches the blue ring 15A. Upon application of the clip 13 the blue ring 15A becomes green. If the clip is misplaced, the ring may become yellow or red. Preferably the color red is associated with a hazardous situation and yellow a situation which is not correct according to the teached procedure but not "dangerous" for the virtual patient. Upon fulfillment of the first clipping action the next ring, here 15B or 15C becomes blue and the process is repeated until all clips are set. Then all areas 14, 15A to 15C which are shaded in the drawings and which should be green vanish as indication that the step is completed.

It is then subject of step 53 "cutting" to exchange instrument 3 towards scissors and to cut the vessel in area 7, which is afterwards indicated through a (separated) green ring 7.

Although the intervention of opening surface tissues in an area is not part of the menus according to Fig. 2 or Fig. 3, these further graphical indications are shown in connection with a further schematic drawing, Fig. 4.

Fig. 4 shows a schematic vie ' of another virtual organ 1 with further graphical identification markers 18A, 18B and 19. Organ 1 has a cylindrical form. In case that the user has to mark a path on the organ 1 in the area 8 through treating the surface of the organ with current, a blue line 18A is appearing on the organ. This line 18A has preferably a starting point and an end point which can be seen through enlarged dots. In case that the user marks correctly, the relevant part of the line 18A turns green. If the user burns the area or enters the instrument too deep into the organ, then beside the effect of the virtual representation showing the results of this treatment (smoke, burned points, bleeding) this part of the line turns red. When all blue parts of the line 18A had been treated, the line and the dots turns into green and the next segment 18B is lit up in blue colour. This advises the user where to continue his task until the related step is completed.

Area 19 shows a region in which the user has to open the surface within a larger area. Here the area to be opened is blue and all cut off pieces will loose there blue color and turn green. Upon completion of the task the whole area will have green borders and then the marker areas will vanish.

The concept of guidance is to project a (two-dimensional) surface area information in the area which has to be treated through the user in training. This may be a larger spot, as spot 14 for a gripping action. This may be a ring, as ring 18A for the clipping action. This may be a line or a segment of a line as lines 18A and 18B for marking or cutting purposes. Finally this can be of any geometrical form as polygon 19 which marks the area which has to be treated. The correlation between the instrument and the graphical representation is immediate and gives a direct visual assessment in the training. In case of the line it had been shown that it is possible to directly show the three states: a.) parts still to be treated are in blue b.) parts which have been correctly treated are in green and c . ) parts which has been maltreated are in red (or yellow) . Beside the possibility to show the errors in color they can also be ex- plained through text which are correlated to the errors through a suitable table. Such a direct computer calculated assessment gives the user the opportunity to correct and ameliorate his performance in one or more of the steps before trying the final (not guided) stage of the intervention.

Claims

1. Method for training a user in a medical procedure utilizing an interactive computer system with a virtual representation of at least one organ (1) and at least one instrument (2, 3) , wherein the representation of surface area parts (4, 5, 7, 8, 9) of the virtual organ (1) to be treated are covered with at least one graphical identification marker (14, 15A to 15C, 17, 18A + 18B, 19) , wherein the computer system comprises a table stored in his memory comprising situations arising within the medical procedure predefined through positions of the instrument (s) (2, 3) , positions of the organ (s) (1) , the logical sequence of steps to be executed within said medical procedure, one or more different aspect values for the one or more graphical identification markers (14, 15A to 15C, 17, 18A + 18B, 19) and one or more assessment values for said situation, wherein upon interaction of the user with the at least one organ (1) and the at least one instrument (2, 3) one or more graphical identification markers (14, 15A to 15C, 17, 18A + 18B, 19) change their aspect according to the stored value in said table for the predefined situation and the corresponding assessment value is stored in a history log table within the computer system.

2. Method according to claim 1, wherein the graphical identification marker is a spot (14) , a ring contour (15A to 15C, 17) , a line (18A + 18B) or a polygonal surface (19) .

3. Method according to claim 1 or 2 , wherein the change of aspect of a graphical identification marker is a change of color according to a color table.

4. Method according to one of claims 1 to 3, wherein the as- sessment value is correlated to a success-and-error-table comprising predefined assessment information.

5. Method according to one of claims 1 to 4 , wherein said table of situations comprise one-, two-, or three-dimensional interval values for the position of the organs (1) and instruments (2, 3) .

6. Method for training a user in a medical procedure utilizing an interactive computer system with a virtual representation of an organ (1) and at least one instrument (2, 3), said medical procedure having a plurality of steps (51, 52, 53) to be performed one after another, wherein each of the plurality of steps (51, 52, 53) is subdivided into identical sub-steps (61 to 66), wherein at least one sub-step comprises a method according to one of claims 1 to 5.

7. Method according to claim 6, wherein the sub-steps (61 to 66) comprise one or more of the following steps: a prerecorded video representation of said step (51 or 52 or 53) within a real intervention (61) , a prerecorded virtual reality video representation of the intervention to be performed within said step (51 or 52 or 53) based on the structure of the virtual reality environment (62) , instructions for the intervention of said step (51 or 52 or 53) , a prerecorded virtual reality graphical stills or video representation of common errors within said step (51 or 52 or 53) , a training session of said step (51 or 52 or 53) without guidance .

8. System for training a user in a medical procedure comprising an interactive computer system, able to create a virtual representation of at least one organ (1) and at least one instrument (2, 3), wherein the representation of surface area parts (4, 5, 7, 8, 9) of the virtual organ (1) to be treated are covered with at least one graphical identification marker (14, 15A to 15C, 17, 18A + 18B, 19), wherein the computer system comprises a table stored in his memory comprising situations arising within the medical procedure predefined through positions of the instrument (s) (2, 3), positions of the organ(s) (1), the logical sequence of steps to be executed within said medical procedure, one or more different aspect values for the one or more graphical identification markers (14, 15A to 15C, 17, 18A + 18B, 19) and one or more assessment values for said situation, wherein upon interaction of the user with the at least one organ (1) and the at least one instrument (2, 3) one or more graphical identification markers (14, 15A to 15C, 17, 18A + 18B, 19) change their aspect according to the stored value in said table for the predefined situation and the corresponding assessment value is stored in a history log table within the computer system.