JPH08280710A - Real time medical device,and method to support operator to perform medical procedure on patient - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a real-time display system so that an operator can view both internal and external structures in real-time. SOLUTION: An interactive display system overlaps images of internal structures on a semi-transparent screen 250. Through the semi-transparent screen 250, a surgeon views a patient during a medical procedure. The images for overlapping are obtained from an image derived from an imaging system. An invasive device 3 is also tracked and displayed on the semi-transparent screen 250. A ray extending through the invasive device 3 can be displayed, too. The image is combined together with a patient 1 viewed from the surgeon, and displayed in real-time during a medical procedure. This allows the surgeon to view internal and external structures, the relation between them, and the proposed passage of the invasive device 3, and accordingly adjust the procedure.

Description

Detailed Description of the Invention

[0001]

[Relationship with Related Applications] The United States patent application, which forms the basis of the priority claim under the Paris Convention of this application, was Jun. 21, 1993.
Filed on the date of C.L.Dumlin, Earl Dee Darrow, W. J. Adams (CL
Dumoulin, R .; D. Darrow, W.C. J. A
US patent application Ser. No. 08 / 078,335
No. (corresponding to Japanese Patent Application No. 6-135286), “Display system for enhancing visualization of body structure during medical procedure”
(A Display System For Enh
ancing Visualization Of B
ody Structures During Med
It is a partial continuation application of the ICC (Procedures). This application is filed with the applicant's ref. No. RD-24,025 (corresponding to Japanese Patent Application No. 7-297965), "Interactive three-dimensional pointing device" (An Intera
ctive Three-dimensional (3
D) Pointing Device), and 19
Chris Naphis, Tim Keriher, Harvey Klein, Bill Laurensen, David Altberg, Ron Kikinis, Robert Darrow and Charles Dumlin, filed April 20, 1993.
Nafis, Tim Kelliher, Harvey
Cine, Bill Lorensen, David
Altobelli, Ron Kikinis, Ro
bert Draw and Charles D
U.S. patent application Ser. No. 08/049,
No. 913 (corresponding to Japanese Patent Application No. 6-523167), “Computer for enhancing visualization of body structure during surgery.
Graphics and Live Video Systems "(Co
mputer Graphic and Live V
video System for Enhance
Visualization of Body Str
related to the Duties Surgery). Both of these applications are hereby incorporated by reference and are assigned to the assignee of the present invention.

This application is also filed on December 23, 1991 by William E. Lorensen, Harvey.
E. Klein, Bruce Theta and Siegwald Rutke (William E. Lorensen, H
arvey E. Cline, Bruce Teete
r and Siegwalt Ludke) U.S. patent application Ser. No. 07 / 812,394, "System for displaying cubic cuts on the surface of a cubic model".
(System For Displaying Sol
id Cuts For Surfaces of S
(Old Models), Harvey E. Klein, William E. Laurensen and Siegwald Rutke (Harv) filed December 23, 1991.
ey E.E. Cline, William E. Lore
US patent application Ser. No. 07 / 812,479 by Nsen and Siegwalt Ludke, "Creation of Solid Models by the Span Method Using Divided Cubes" (So
lid Models Generation By
Span Method Using Divin
G. Cubes), and Harvey E. Klein, William E. Lorensen and Siegwald Rutke, filed on December 23, 1991.
y E. Cline, William E. Loren
US patent application Ser. No. 07 / 812,395 by Sen and Siegwalt Ludke, “Apparatus and method for displaying surgical cuts in a three-dimensional model”.
(Apparatus and Method For
Displaying Surgical Cuts
in Three-Dimensional Mod
els). All of which are hereby incorporated by reference and are assigned to the assignee of the present invention.

[0003]

FIELD OF THE INVENTION The present invention relates to a system for assisting a physician, such as a surgeon, in visualizing anatomy during a medical procedure, and more particularly to a practitioner, both internal and external. It relates to a system that allows real-time viewing of anatomical structures.

[0004]

2. Description of the Prior Art Currently, during surgery and during other medical procedures such as endoscopy, biopsy and transplantation, physicians are required to take several static radiographic images of a patient in the operating room. I see. These are usually magnetic resonance (MR (magneti)
c), computed tomography (CT (computed tomography))
y)), a transparent film rendering of a normal X-ray or ultrasound image. Since these images are two-dimensional still images, the physician must determine from the two-dimensional image he is looking at the actual three-dimensional (3D) position and shape of the desired internal structure inside the patient. The surgeon conceptually constructs a three-dimensional model of internal structures and correlates these internal structures with the external structures visible to the patient that he must cut. This is often difficult. This is because the scale and orientation of the two-dimensional image may differ from what the surgeon is looking at, and the surgeon may not be able to see both the patient and medical diagnostic images at the same time.

Another technique used to position internal structures during surgery is known as tactile surgery. For this, we use the articles "CO ₂ laser and CT acquisition database" by BCA Cal, PJ Kelly and SJ Goas published in iTriple Transactions on Biomedical Engineering. Interactive Tactile Surgery System for Removal of Intracranial Tumors "(" Interactiv
e Stereotactic Surgical S
ysystem for the Removal of
Intracranial Tumors Utili
zing the CO ₂ Laserand CT-D
erected Database "by BAK
all, P.A. J. Kelly and S. J. Goe
rss, IEEE Transactions on
Biomedical Engineering, v
ol. BME-32, no. 2, pp. 112-11
6, 1985), and B. A. Kal, PJ Kelly, and S. J. Goas's article "Comprehensive Computer-Aided Data Collection and Treatment Planning and Interactive Surgery" in Medical Imaging. Compr
hensive Computer-Assist
d Data Collection Treatme
nt Planning and Interaction
ve Surgery ”by BA Kall,
P. J. Kelly and S. J. Goerss,
Medical Imaging, vol. 767,
pp. 509-514, 1987).
In this approach, a rigid mechanical frame is attached to the patient prior to the CT or MR procedure. The frame and its landmarks can be seen in the resulting image.
The mechanism of the frame positions the probe at a specific location within the image. The drawbacks of this approach are that the frame limits the access to the patient and that the image is a non-patient still image if the patient moves during surgery.

[0006] The third method used for positioning the internal structure is EM Freets, JW Straw vane, published by Eye Triple E Transactions on Biomedical Engineering. J. F. Hatch and D. W. Roberts, "A Frameless Tactile Surgery Microscope for Neurosurgery"("A Frameless Ster").
eotaxic Operating Microsc
ope for Neurosurgery “by
E. FIG. M. Friets, J.M. W. Strohbehn,
J. F. Hatch and D.M. W. Robert
s, IEEE Transactions on B
iomedical Engineering, vo
l. 36, no. 6, pp. 608-617, June
1989).

A three-dimensional model of the anatomy can be created from data in different medical imaging formats, as described in the applications listed in the "Relationship to Related Applications" section above. These applications describe the creation and manipulation of a model of the patient's internal structure and the delivery of an image of the selected structure in the desired orientation to the operator. With these, the internal structure can be visualized as a three-dimensional model.

Presently, a system for assisting a physician in surgery and other medical procedures that interactively displays a computer-generated representation of the internal structure in the correct relationship to the external structure of the patient to provide a real-world view of the invasive device. What is needed is a system that allows visualization of routes and virtual routes.

[0009]

OBJECTS OF THE INVENTION One object of the present invention is to perform surgery by simultaneously superimposing images of the internal structure on the external structure, regardless of whether the patient changes its position or the operator changes its viewing angle. It is to provide a support system. Another object of the present invention is to provide an interactive system having the same scale on top of an external structure and displaying the desired internal structure viewed from the same directional angle.

Another object of the present invention is to provide a surgeon with a head-up display of radiographic images overlaid on the patient's external structure within the surgeon's field of view without the use of cumbersome headgear. is there. Another object of the present invention is to provide a display system integrated with an invasive device to provide a visible image of the invasive device to the internal structure of a subject.

[0011]

SUMMARY OF THE INVENTION A real-time surgical device for displaying interactive internal and external images of a patient allows an operator to simultaneously view an exposed surface of the patient and a computer generated image of the internal structure of the patient. It uses a semi-transparent display screen that makes it possible. Invasion
e) A symbol representing the device is superimposed on the computer-generated image at the correct displayed position for both the internal structure and the external image.

Medical imaging equipment or computer-aided design (CAD)
system) provides the workstation with three-dimensional (3D) imaging data of the internal structure of the patient.
The three-dimensional position and orientation of the patient, the translucent screen, the operator's eyes, and the invasive device to be inserted into the patient are monitored in real time. The workstation creates 3D computer-generated models of the patient's internal structure, and these 3D computer-generated models
The medical imaging device can be operated without further need. By interactively redirecting and scaling the two-dimensional computer-generated image of the model,
The display of the computer-generated image on the translucent display matches the operator-visible image of the patient through the translucent screen.

The features of the invention believed to be novel are:
Details are set forth in the claims. However, the structure and operation method of the present invention, and the objects and advantages of the present invention other than the above can be best understood by the following description with reference to the drawings.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. 1, a subject to be subjected to a medical procedure such as an operation, that is, a patient 1, is a medical imaging apparatus 10.
Scanned by. The medical imaging apparatus 10 is a magnetic resonance (MR) imaging apparatus capable of creating multidimensional volumetric data, for example, three-dimensional (3D) data from an internal structure of a patient, a computer axial tomography. (CAT
(Computed axial tomograph
y)) device, body-emission tomography (PET (po)
sitron emission tomograph
y)) device or similar imaging device. After imaging, the device 10 supplies volumetric data to the model workstation 100. Once the volumetric data is provided to the model workstation 100, the imaging device 10 is no longer needed. This is important. This is because some medical procedures do not have to be performed with the patient within range of the imaging device. The fact that the patient has to be placed within the range of the imaging device can be an obstacle in the case of MR imaging. In an alternative embodiment, the imaging device 10 can be used interactively during a medical procedure. The model workstation 100 stores the volumetric data and creates a computer-generated model from the data that can be scaled, rotated, and other operations. The imaging device 10 is no longer needed.

An operator 350, eg, a doctor or medical assistant, monitors the patient 1. A translucent screen 250 is inserted between the patient 1 and the operator 350. Operator 350,
A tracking device 50 for monitoring and tracking the translucent screen 250 and the patient 1 has a position and a direction of the operator 350, the subject 1, the translucent screen 250 and the invasive device 3, that is, a roll α, a pitch. (Pitch) θ and yaw (φ) φ are measured. Installation of Ascension Technology Corporation dated July 5, 1992 Introduction to "Flock of Birds", pages 1-3, Appendix 1-8
Page 9 and Appendix 3, page 93 ("The Flock of
Birds ”Installation and
Operation Guide, Ascensio
n Technology Corporation,
Jul 5, 1992, in the Intr
oduction pp. 1-3, Appendix
1, p. 89 and Appendix 3, p. 9
As described in 3), the tracking device 50 can be a tracking device with 6 degrees of freedom.

The patient 1 has an origin (x, y,
z) = (0,0,0). Therefore,
All positions for patient 1 are simply (x, y, z) positions. The position and orientation of the patient 1, the translucent screen 250 and the operator 350 are interactively provided to the model workstation 100 by the tracking device 50.
In other embodiments, the position and orientation can also be manually supplied to the model workstation (s).

Model workstation 100 processes the three-dimensional volumetric data it receives and creates a selected rendering of the data. One rendering method measures the surface between different types of tissue. Next, the connectivity of similar types of tissues adjacent to each other is measured. Tissue type discrimination based on the nature of the signal in the 3D image data is based on segmenta.
known as When three-dimensional (3D) volumetric data is sorted into internal structures, each internal structure can be treated by the model workstation 100 as a separate solid. The model workstation manipulates these images in the desired manner by selectively displaying desired internal structures, color-coding the structures, and cutting, rotating, and translating the internal structures to model the model work. A visible image is provided to the operator moving the station 100.

An alternative rendering method that produces a two-dimensional projection of selected features in a three-dimensional dataset is described in 19
US Pat. No. 5,233,2 granted Aug. 3, 1993
No. 99, SP Souza, W. J. Adams and C. El Dumlin (SP Souz)
a, W. J. Adams and C.I. L. Dumous
Lin) "Projection Method for Generating Two-Dimensional Images from Three-Dimensional Data" (Projection Meth
ods for Producing Two-Dim
Ensional Images from Thre
e-Dimensional Data). For example, two-dimensional projection angiography can be extracted from three-dimensional phase contrast or time-of-flight magnetic resonance angiography. Several projection algorithms are possible.
These projection algorithms detect the maximum pixel intensity along a selected projection ray through the three-dimensional data, measure the average pixel intensity of the selected projection rays, and measure all pixels along the selected projection ray. Includes standard deviation measurements.

The model workstation 100 receives input data from the workstation view input device 60 and from the position and orientation tracker 50 to select the orientation in which the internal structure of the patient 1 is displayed. The workstation view input device 60 can be a computer pointer (pointing) device such as a mouse or trackball, or any input device that indicates the plane to which the image should be cut and the viewing angle and scale. The model workstation 100 is operated by the operator 35.
Synthesize an interactive computer-generated image of the internal structure of patient 1 that is consistent with 0 real-time viewing scenes. The symbol generator 5 generates a symbol indicating the position and direction of the invasion device 3. Alternatively, a ray extending from the invasive device 3 may be drawn to indicate the current planned route of the invasive device 3.

The interactive computer-generated image can be converted from a computer monitor signal, such as an RGB computer monitor signal, into a video format depending on the required display format of the translucent screen 250. This conversion is done by passing the interactive computer-generated image through a scan converter 192 (shown in phantom). The computer generated image is provided to a translucent screen 250 sandwiched between the patient 1 and the operator 350. The translucent screen 250 provides the desired mixing of the external structure of the patient 1 as seen by the operator 350 and the computer generated image from the model workstation 100. The translucent screen 250 can receive input signals from an operator, such as via the workstation view input device 60. This includes the transparency of each image,
Or any of a variety of other special effects can be included. One of the most useful special effects is the moving window. The movable window is another image overlaid with 0% transparency (100% opacity). When the window image is an image of the internal structure overlaid on the external structure,
This creates a phantom of the external structure cut out in the window, exposing the underlying internal structure. Other conventional video special effects can also be used. Translucent screen 2
50 allows the operator 350 to see both internal and external structures simultaneously. Even if the patient moves during the medical procedure, the resulting scene seen by the operator 350 is
Is an interactive real-time image of. Since the internal structure and the relationship of the internal structure to the exposed external structure are displayed simultaneously, the surgeon using the present invention recognizes a very accurate indication of where to cut the external structure. Thus, a desired internal structure is reached while avoiding a significant internal structure.

FIG. 2 illustrates an alternative embodiment of the present invention. In this example, operator 350 receives a stereoscopic view of the internal and external structures of patient 1. Operator 3
Since each of the 50 eyes is oriented differently to the patient, each eye is provided with a different view. Tracking device 5
0 indicates the positions (x1, y) of the first and second eyes of the operator 350, the patient 1, the semitransparent screen 250, and the invasive device 3.
, Z1) and direction angles (α1, φ1, θ1). The position and orientation of the operator's second eye is determined by the tracking device 50.
Can be measured independently. Alternatively, the position and orientation of the first eye can be used to calculate the position and orientation of the second eye. These positions and orientations are provided to the first model workstation 100a and the second model workstation 100b. model·
The workstations 100a and 100b are operated by the operator 3
Positions (x1, y1, z1) and directions (α1, φ1, θ1) corresponding to the respective 50 eye views,
And the positions (x2, y2, z2) and (α2, φ2, θ
In step 2), create right and left computer graphic images respectively.

The symbol generator 5 receives the position and orientation of the invasive device 3 and displays the symbol at the appropriate position and orientation of the translucent screen 250. The symbol may be extended by a ray indicating the planned path of the invasion device 3. Workstation view input device 60 and imaging device 10
Control signals from both can be sent to the first model workstation 100a. The first model workstation 100a is connected to the second model workstation 100a via the communication path 140.
Control signals can be propagated to the model workstation 100b, or alternatively, the control signals can be sent directly to both model workstations.

When required by the translucent screen 250, the left and right computer-generated images associated with the left and right views, respectively, are converted to a video format. This conversion involves scan converters 192a and 19a.
2b (shown in phantom) and scan converter 192
a and 192b send the converted computer-generated signal to sequencer 198. The sequencer 198 is a videotape recording, editing and displaying of field sequential stereoscopic motion images and videos by M. Starks, published by Stereoscopic Displays and Applications Proceedings SPII. A low cost portable device to do ”(“ Portabl
e, Low Cost Devices for V
videotaping, Editing, and D
Displaying Field Sequential
Stereoscopic Motion Pict
ures and Video ”by M. Star
ks, Stereoscopic Displays
and Applications Proc. SP
IE Vol. 1256, pp. 266-271, 19
It can be a conventional video sequencer as described in 90).

Sequencer 198 sends the left computer-generated image to semi-transparent screen 250. Sequencer 1
98 then sends the right computer-generated image to the translucent screen 250. The sequencer 198 synchronously switches between the left view and the right view many times per second. By time-multiplexing the images displayed on the semi-transparent screen 250, images for the left and right eyes of the operator are created alternately. The stereoscopic viewer 252 is the sequencer 19
In synchronism with 8, it operates to block the visual acuity of the left or right eye of the operator. This allows the opposite eye to see the image on the translucent screen 250 at the moment, and so on for the opposite right or left eye. This allows the operator 350 to see the left image with the left eye while the right eye is not seeing anything, and the right image with the right eye while the left eye is not seeing anything, which can be quickly It can be performed continuously. As a result, a three-dimensional illusion is created, and a dimension for recognizing the depth when viewing the image displayed on the semitransparent screen 250 is added. Depth perception is very useful in surgery. This is because recognizing depth adds dimensions that help visually locate the structure. This is especially important in complex and delicate surgery.

For both embodiments of the invention, the computer image must be aligned with the external structure seen by the operator 350. Rotating, translating, and scaling the computer-generated image with manual input from an operator to match the computer-generated image with the scene seen through the translucent screen, or using the tracking device 50 to set initial parameters. The initial setting can be performed.

Once the three-dimensional model and the visible image of the patient 1 are aligned, the tracking device 50 keeps the viewing angle and field of view constant. This allows real-time interactive synchronization between the operator's view of patient 1 and the computer-generated image. Since the image of each internal structure can be classified into a stereoscopic image, this image can be operated as a stereoscopic image. In the case of patient structure, the surgeon can obtain data from the patient by medical imaging and then plan the surgery by manipulating the model to plan for the desired outcome prior to the surgery. This is common in complex reconstructive surgery. Once a plan has been determined, this plan can be stored and replayed during surgery. The image of the internal structure is interactively oriented and scaled to match the actual patient.

The user uses the workstation view input device 60 of FIGS. 1 and 2 to select a plane to cut the structure of the model, a three-dimensional direction of the model, and a workstation view. Select the screen cut plane that defines the area. The model workstation has a clipping circuit to determine points in the model cut plane, a rotation circuit to rotate the points and the normal vector, a classification processor, and the direction of the normal vector at each point. Shading circuit that determines shading based on In addition, a screen clipping circuit can be used to determine points within the area defined by the screen cut plane. The model workstation may also include display circuitry for generating a video signal. This video signal is
When propagated to a suitable display device, it produces images of multiple surfaces lying in the desired display area and screen cut plane.

In the case of a thorough surgery, such as a resection surgery, or a major trauma, there is little structure left to properly determine what the normal tissue is. In these cases, an additional model workstation could be used to store a model of normal structure. This model of normal structure, mixed with other displayed images, serves as a guide for reconstructive surgery. This can be embodied by an additional workstation or model control panel.

In this embodiment of the invention, a semi-transparent screen 250 is inserted between the operator 350 and the patient 1. The screen 250 can be composed of a liquid crystal display, or the screen 250 can be composed of a partially silvered mirror that reflects the image from the video monitor. The semi-transparent screen 250 can be configured as a relatively large device whose dimensions are approximately equal to the dimensions of the region of interest of the patient 1. Or instead,
The translucent screen 250 can be of small size, placed relatively close to the operator's eyes and incorporated into headgear or eyewear.

In one embodiment of the invention, the translucent screen is attached to the movable arm 7. The movable arm 7 allows the screen to be arranged at any position between the patient 1 and the operator 350. This allows the use of the present invention which is not possible with a display device worn on the head. For example, if the translucent screen 250 is formed of a material that is a writable surface, the operator 350 may use ink markers to draw or annotate the area of interest (eg, the location of the incision). Yes, these can be seen by others nearby.

Another use of the invention not possible with head-mounted display devices is to use the position and orientation of the display screen to determine the image displayed on the screen. The input device 60 can then be used to adjust the depth of the image plane inside the patient. Therefore, it can be used to scan the patient for internal structures to determine if the planned path of the invasive device is correct.

Optionally, an invasive positioner 9 holding an invasive device is added to the system. This is also tracked by the tracking means 50 and the position and orientation of the invasive device is monitored and fed to the model workstation. Preferred points to track are the endpoints and at least one other point of the invasive positioner 9, which ascertains the orientation as well as the position of the invasive device.

While we have described in detail some presently preferred embodiments of the novel visualization system, many modifications and variations will occur to those skilled in the art. Therefore, it should be understood that the appended claims are intended to cover all such modifications and variations that fall within the spirit of the invention.

[Brief description of drawings]

FIG. 1 is a schematic block diagram of a first embodiment of a medical display device according to the present invention.

FIG. 2 is a schematic block diagram of a second embodiment of the medical display device according to the present invention.

[Explanation of symbols]

1 patient 3 invasive device 5 symbol generator 7 movable arm 10 medical imaging device 50 tracking device 100, 100a, 100b model workstation 250 semi-transparent screen 252 stereoscopic viewer 350 operator

Continuation of front page (51) Int.Cl. ⁶ Identification number Office reference number FI Technical indication location G03B 42/02 A61B 5/05 380 (72) Inventor William John Adams Clifton Park, New York, United States , Valdepenas Lane, number 6

Claims (10)

[Claims] 1. A real-time medical device for displaying to an operator an interactive image of a patient's internal structure consistent with the operator's view of the patient, comprising: (a) presenting a given image through the screen. A translucent screen with adjustable transparency so that it appears superimposed on the visible structure; and (b) the operator and the patient so that the operator can view the patient through the translucent screen. A mechanical arm for holding the translucent screen in a selected position between: (c) a tracking device for repeatedly measuring the position and orientation of the operator, the patient and the translucent screen, (d) It is connected to a tracking device and receives the position and orientation and from the set of stored imaging data the operator, the patient and the translucent screen. Real-time medical device that includes a workstation the image of the relative position and direction consistent with internal structure formed on the translucent screen. 2. The real-time medical device of claim 1, further comprising a medical imaging system that determines a set of three-dimensional imaging data of the patient's internal structure. 3. (a) an invasive device having a position and a direction tracked by the tracking device; and (b) a symbol indicating the position and the direction of the invasive device is superimposed on the semitransparent screen. The real-time medical device according to claim 1, further comprising symbol generation means. 4. The symbol generating means further comprises means for displaying a ray indicating the current orientation of the invasive device and the planned path of the invasive device to the internal structure of the patient. Real-time medical device. 5. The tracking device determines a first position and a direction and a second position and direction corresponding to each eye of the operator, and the workstation determines the first position and direction. An image associated with position and orientation is formed, and (a) a second workstation for forming a second image of the internal structure of the patient from the imaging data when viewed from the second position and orientation. And (b) stereoscopic display means synchronized with the semi-transparent screen, wherein only one eye of the operator can see the semi-transparent screen when the first computer-generated image is displayed. And allowing the other eye of the operator to see the translucent screen when the second computer-generated image is being displayed, whereby the exterior of the patient is exposed. Real-time medical device of claim 1 further comprising a stereoscopic display means for simulating a three-dimensional image of superimposed inner structure on the concrete. 6. The real-time medical device according to claim 1, wherein the translucent screen has a surface comprised of a material that can be written and erased on it. 7. A method for assisting an operator in performing a medical procedure on a patient, comprising: (a) obtaining multidimensional medical imaging data from internal structure of the patient; and (b) the operator. And (c) selecting a position and orientation between the patient and the patient, and (c) selecting the position and orientation so that the operator can view the patient through a self-supporting semi-transparent screen. Positioning the transparent screen, (d) measuring the position (x, y, z) and the direction angle (α, φ, θ) of the patient, the operator and the semi-transparent screen; (e) Forming a computer-generated image of the internal structure that matches the measured position (x, y, z) and orientation angle (α, φ, θ) from the medical imaging data; and (f) the medical procedure. At the operator Displaying the computer-generated image at the desired transparency on the translucent screen so as to create an illusion of internal structure overlaid on the patient to assist in performing a medical procedure on the patient. How to assist an operator to carry out. 8. The method of claim 7, wherein the step of acquiring multidimensional medical imaging data is performed in real time by a medical imaging system. 9. The step of forming the computer image includes: (a) forming from the medical imaging data a pair of computer-generated stereoscopic images of the internal structure that match the measured position and orientation angle. And (b) the translucent so as to form a stereoscopic illusion of internal structure superimposed on the patient to assist the operator in the medical procedure. A method as claimed in claim 7 including the step of displaying the pair of computer generated images with desired transparency on a screen. 10. The operation of claim 7, further comprising adjusting the distance and direction angle of the left computer-generated image and the right computer-generated image to correspond to the view of the patient by the operator. To help the person.