Journal of Computer Aided Surgery Vol.2 No.3
招待講演一1
The Erlangen experience of Image Guided Surgery (IGS) consists of 514 procedures since 1995. Of these 105 were operated with the aid of Functional Neuronavigation. The simultaneous application of a state-of-the-art neuronavigation system with open MRI was realized using a ZEISS NC 4 navigation microscope in 37 cases. In this lecture we summarize our concept of IGS and focus on the latest development of neuronavigation and open-MRI as well as future aspects of high-field MRI. Intraoperative high-field MRI is the next evolution in Image Guided Surgery, however this technique will be subject to further studies regarding benefits of better resolution and possible susceptibilty artifacts.
招待講演-2
Volumetric image analysis is one of the key techniques for the computer-assisted diagnosis (CAD) in three-dimensional CT images such as spiral CT and MRI. The following three topics related to CAD and the employed techniques of volumetric image analysis will be presented. (1) Computerized Detection of Colonic Polyps Colonic polyps were detected in CT colonography data, based on the segmentation of the colonic walls and the feature analysis of volumetric curvature. By use of the feature values of volumetric curvature: shape index and curvedness, voxels of colonic polyps were identified and were distinguished from the false positive structures such as folds. (2) Computerized Detection of Pulmonary Embolism Detection of pulmonary embolism was performed in spiral CT angiography data. Thrombi in the pulmonary arteries were automatically identified based on the segmentation of pulmonary vessels and the feature analysis inside the segmented vascular volume. The main techniques used in the detection of thrombi were, local contrast analysis based on greyscale math-morphology, and multi-scale analysis of second derivatives. (3) Non-1inear Vascular Size Analysis The local size of blood vessels is an important feature for segmentation of blood vessel and for identification of adjacent structures such as pulmonary nodules. A non-linear and segmentation-free technique for vascular size determination was developed based on volume decomposition by using greyscale math-morphology. The technique was applied for the determination of local vascular size distribution inside the lungs.
招待講演-3
Our goal was to improve image guidance during minimally invasive imageguided therapy by developing an intraoperative segmentationand nonrigid registration algorithm. The algorithm was designed to allow for irnproved navigation and quantitative monitoring of treatment progress in order to reduce the time required in the operating room and to improve outcomes. The algorithm has been applied to intraoperative images from cryotherapy of the liver and fromsurgery of the brain. Empirically the algorithm has been found to be robust with respect to imaging characteristics such as noise and intensity inhomogeneity and robust with respect to parameter selection. Serial and parallel implementations of the algorithm are sufficiently fast tobe practical in the operating room.
Abstract
This paper gives a comprehensive survey of the state of the art of Computer
Aided Diagnosis (CAD) for mammography and its technical trend in the future.
Mammogram is the projected 2D image of breast and the overlapped shadows
of multiple tissues make it difficult to detect abnormalitiesfrom the complicated
background. The combination of CC and MLO views may give a clue to overeome
those diffieulties. The flat panel detector will be another factors influencing
the development of the CAD system of mammography. The performances of representative
systems and the problem to be solved for revolutionary improvement are
given.
[ABSTRACT]
We developed a prototype of optical navigator for computer-aided surgery by combining 3D position measurement techniques, digital imageprocessing, and 3D display techniques. Three normal CCDs are used in our system to detect the coordinate of operating instrument. To improve the accuracy due to the low resolution, a calculation of the image coordinate with subpixel accuracy is required, where we calculated the center, area and circularness of each spot. As another important part of CAS, the visualization of the images and operating instruments have been well considered in our system.
Keyword neuronavigator, optical localizer, computer aided surgery
Key Words
Normalization, Neural Network, Tomographic Image, Automatic registration, Norrnalization
Abstract
In this paper, we present a software tool for normalization of two-dimensional
and three dimensional image data automatically and compare the change cortical
structures in the human brain that will facilitate neuro-anatomical quantitative
analysis and permit characterization of morphometric variability across
subjects. This software tools developed under widely used Microsoft Windows
operating system. The software is called "Neuro-normalizer".
It can support both inter and intra modality normalization.
[Abstract]
CTの進化により，生体の3次元画像データは縦軸方向の分解能が向上すると共にデータ量が膨大になってきている．臨床検査においてはボリュームレンダリングによる画像観察が盛んになってきており，適切は高速性が必要となっている．ボリュームレンダリングの特徴は，各種医療検査装置から得られるスライス上の濃淡値情報を保有したまま3次元表現できることである．しかし，臨床検査で求められる画像の表示速度に対して満足なものを得るには非常に処理速度の高いコンピュータを必要としなければならないという欠点もある．弊社は米国三菱電機㈱RTVizが開発したボリュームレンダリング用アクセラレータボード「VolumePro」を利用して，フルカラー・フルスケールボリュームレンダリングをリアルタイムで実現する3次元ビューワー「INTAGE
RV」を開発した．
[Abstract]
This demonstration shows the movement of operating table controlled by
computer system. When the operating table is rotated for changing the orientation
of patient, the rotation angle are fed-back to the PC controller via A/D
converter and then to keep the position of patient to come in sight of
microscope the movement of X,Y and Z axis of the operating table will be
controlled by PC controller. The results show the effective of proposed
method with high accuracy position control.
Key Words: Cranial nerve surgery, feedback control
Abstract: A real-time surgical navigation system that superimposes the
real, intuitive 3-D image for medical diagnosis and operation was developed.
This system creates 3-D image based on the principle of integral photography,
named "Integral Videography(IV)", which can be observed following
the operator's movement of the field of vision via a half-mirror as if
they could be seen through the body. Moreover, a real-time IV algorithm
for calculating the 3-D image of surgical instruments was used for navigation
between the location of surgical instruments and the organ during the operation.
Beeause of the simplicity and the accuracy of real-time projected point
location, this system will be practically usable in the medical field.
Key Words: integral videography, real-time, surgical navigaton
[Abstract]
Most auricular deformities can be cured by mounting a suitably shaped orthoses.
To generate and evaluate the orthosis shape, three-dimensional (3D) auricular
model is necessary. The model can be constructed by matching and composing
multiple 3-D data obtained by non-contact 3-D measurement equipment. Recent
equipment can obtain not only 3-D position data but also red, green and
blue color brightness data. We have developed an automatic matching method
that utilizes the color information for composing the multiple 3-D data.
To apply the method, the auricle is painted by the striped color pattern
and the Imatching experiment that uses the color and that does not was
performed. The results show that both accuracy and processing time can
be improved by using the color information.
Key words: malformed ears, three-dimensional data, color information, automatic
matching
[Abstract] Development of the active catheter that casn change the atitude
and move in any direction in solid tissue is challenging study. In this
paper the mechanism of the catheter bending caused by the unsymmetric blade
shape at needling is investigated in order to predict and control the catheter
path. The theory of bending at needling is assumed with mechanical considering
and evaluated by comparing with experimental study.
Key Words: Active catheter, Bending, Mechanics
[ Abstract]
In high-precision surgical fields such as brain surgery, image guided navigation
system plays an important role for indicating the positional relationship
between tomograms and the actual affected parts in the patient's body, to guide surgeons to the affected part precisely. However, during neurosurgical operation, cerebrospinal fluid and brain incision cause the nonlinear transformation of the brain tissue and make it difflcult to get the correspondence between the tomograms and the brain. We propose a 3-D brain tissue displacement estimator by an iterative operation consisting of 3-D brain surface model construction based on parallax and consensus within the migratory vector group, to form a self-organizing neural network for searching the correspondent points between stereo brain surface irnages, according to the principle of competition and consensus. Recent progress of high-speed network activates the formation of load sharing facilities by organizing decentralized computer systems. Although real-time processing of 3-D surface generation is prerequisite for effective surgery, installation of high-performance computer in operating room is not practical. In this paper, we used JGN (Japan Gigabit Network) to conduct a fundamental experiment with real-time 3-D surface reconstruction facilitating the application to tele-medical treatment. Validities and further problems are also discussed.
Key Words : piecewise surface construction algorithm, 3-D brain surface
model, tele-medical treatment
[Abstract]
There is a field of Data Fusion in the medical resarch of Virtual Reality.
This field enables for surgeons to give operations, while the surgeon views
the patient's inside by the fusion of three- dimensional reconstruction
image of internal organs. Although such technology has already been used
in the surgical operations of the brain, it's not applied yet for the organs
that moves and transforms easily during the operations.. In this system,
we can observe changes of internal organs in real-time. For our study,
we choose a liver as the object, and in order to obtain changes of the
liver, we use two
types to sensor that give us changes of the liver in real-time. Then, we
made a device "Floating Window" that makes it possible to fuse
imaginary and real space without HMD (head mount display) . Using the Floating
Window, surgeons can observe inner condition of the liver immediately.
Key Words : data fusion, virtual reality, realtime imaging
[ Abstract]
Our study has been aimed at storing the three-dimensional and the four-dimensional
structure of human body into a database, and to producing of the
large-scale database of the human body that enables the utilization at
multiple remote locations. At first, detailed male and female 3D data set
was mesured bv MRI. It also extracted body surface and main organ from
these MRI data set in the region, man and woman did the surface and rendering.
The func-tion that could display the fault image ofthe neces-sary position
by choosing this as an index, of ob-serving the human body organ from the
free view-point. These database can act as a database of the human shape
in the wide field which makes not only application as a reference data
in teaching material for medical education and clinical medicine but also
human engineering.
Keywords: high dimensional database, structual da- tabase, functional database
Abstract
We have developed the skeletal-muscular system by computer graphic technique.
When we construct the realistic skeletal muscle mode1, we converted
coordinates derived from a mesh framework of a muscle into algorithms.
Using this system, we were. able to visualize the muscle activity. However,
this system has not yet allowed us enough to comprehend the connection
and interaction of human skeletal muscles. In this study, we tried to improve
this system in order to perform physical activities like the change of
the muscle's shape by contacting skeletons, and adjacent muscles, or the
restricting skins. Then, we introduced the position data, which was measured
by the optical sensor during walking to this system. As a consequence,
this system enabled us not only to grasp the interactions between the skeleton
and the muscle or between muscles themselves much better, but also to conduct
the simulation of basic motions like walking precisely.
Key words: skeletal and muscular model, physical interference, 4D analysis,
mesh
[Abstract]
The motion analysis of the muscle in the movement of a human body has been
done until now on the basis of the bio-information using observation of
body surface and electromyography. But it was difficult to recognize the
dynamic phase and combination in the operation. Therefore, the development
of the human model which combines the anatomy got from the three-dimensional
images such as CT or MRI and movement function is advanced. However, Researching
and developing of model which covered the whole-body is difficult because
of problems such as the operation quantity in adding a
model construction and a motor function. Then, our purpose is to manufacture
model over the whole-bodv constituted by skeletons and muscles using
simplified string muscle model without shape information. It became possible
to get the operation of the each muscle as a time and spatial variation
and to know quantitatively the coordination operation of the muscle.
Key Words : whole-body model, simplified string muscle model, muscle dynamics
[Abstract]
We have been developing a virtual surgery system that uses virtual reality
techniques, and it makes us possible to perform surgical maneuvers on elastic
organs. We tried to construct an elastic organ model enabling real-time
deformations without using the fi nite element methods. So, we made a method
to cre-ate an elastic organ model by the name of sphere filled model that
suited for real-time simulation and quantitative deformation. In this paper,
we would like to present the complicated incisions that approach the resection
by modifying this model and show the defor mation of the inner structures
only by sphere's behav ior. Moreover, the effect of gravity on various
ma nipulations to the modified sphere-filled model was dis cussed. By applying
this model, we will be able to perforrn realistic medical procedures.
Key Words:virtual surgery, sphere-filled model,incision.
Abstract
Learning surgical anatomy and operation of endoscope is essential for novices of endoscopic sinus surgery, because limited view of endoscope often causes disorientation. Most of surgical simulators lack the function of skill evaluation, which is indispensable for medical training. We have developed a new surgical training system for ENT surgeons. The system consists of a realistic silicone sinus model, position and force sensors to measure the behavior of surgical tools. Training experiments with ENT surgeons and novice volunteers revealed that force sensors are helpful for quantitative evaluation of skill.
Key Words: endoscopic sinus surgery, surgical training, skill evaluation
[ Abstract]
We have used computer based virtual endoscopy techniques to diagnose biliary
disease. Eight cases of the cholangiogarcinomas were investigated by virtual
endoscopy. Virtual endoscopic images were generated with Virtual Endoscopy
Software Application on UNIX workstations. We created surface-rendernd
virtual endoscopic images derived from a computer reconstruction of the
cross-sectional MRI data. Virtual choledochoscopy could provide good simulation
of endoscopy. The virtual endoscopic images were similar to surgical specimen.
Virtual choledochoscopic images of nodular type suggested elevated lesion
on the surface of the bile duct. A step down lesion on the bile duct surface
was observed by virtual endoscopy in a case of cholangiocarcinoma, which
had a ulceration on the tumor. In addition, vritual choledochoscopy gave
us infomation beyond the obstruction and visualized the reverse side view.
Virtual choledochoscopy is useful for observation of the surface of cholangiocarcinoma.
Key words: Virtual choredochoscopy, Bile duct carcinoma
Abstract
In this report, we describe an improved method for generating a virtually
stretched image of the stomach. This method requires a reference surface
that approximates the global shape of a stomach. In the previous method
[ I ], folding patterns on a virtually stretched image are not appropriately
observed, since we could not adequately stretch the reference surface due
to an incompletely removed folding patterns that are existing on the reference
surface. We propose here a new method for generating more appropriate reference
surface from which folding patterns are removed by using a image processing
technique. The proposed method was applied to four cases of 3-D abdominal
CT images, and the experimental result showed that the proposed method
could generate a stretched image of the stomach successfully.
Key Words:virtually stretched image of the stomach, reference surface,
3-D abdominal CT images
Abstract
This paper describes a method for the camera motion estimation of a real
endoscope using a virtual endoscope system. The camera motion tracking
is indispensable for an endoscope navigation system that overlays navigational
information of the virtual endoscope system on the real endoscopic image.
To improve the estimation accuracy, we use a texture mappinng of real endoscopic
images to a virtualized endoscope image. We applied the proposed method
to the video images of the real bronchoscopy and 3-D X-ray CT images. The
result showed that the method could track the camera motion of the real
endoscope correctly.
Key Words : vinual endoscopy , camera motion estimation, endoscope navigation
system
Abstract
This paper describes a method for presenting regions that the user did
not observe during a fly through in the Virtualized Endoscope Sysstem(VES).
A user can distinguish observed and unobserved regions after a fly through
by using this method. For this purpose, the method calculates triangle
patches that were displayed on the screen when we employ a surface rendring
method. In the case of the volume rendering method, we fmd voxels that
affected
the rendered image by analyzing the change of accumulated opacity values.
We applied our method to a colon region that was extracted from a real
3D X-ray CT image. The experimental results showed that the method could
display observed and unobserved regions appropriately
Key Words: Virtual Endoscope System, unobserved regions, fly through
Abstract
A retractor-type probe for monitoring the oxygenation state of the living
tissue is designed to minimize the tissue damage during brain retraction.
One optical fiber for emitting the near infrared light and three optical
fibers for detecting the scattered light are built in a retractor. The
emitted light propagates in the tissue with absorption and scattering.
The absorption of the light occurs in the endogenous chromophores in the
tissue, such as oxy-,
deoxyhemoglobin or cytochrome oxidase. The oxygen saturation was calculated from the measurement of the absorption coefficients of the brain tissue at 780, 805, 830 nm by means of spatially resolved spectroscopy. According to the measurement of the temporal profile of the oxygen saturation in human forearm, a comparison between standard probe and retractor-type probe was made. Using these two probes, the same tendency was shown in the temporal profile.
Key Words: hemoglobin, oxygenation monitor, spatially resolved spectroscopy
[Abstract]
We developed an intramedullary osteotomy device for Bone-lengthen surgery.
In Bone-lengthen surgery, bone regeneration level causes remarkable influence
on ,bc results. But bone cutting in low invasion to periosteum is impossible,
even though nutrition for bone regeneration is mainly provided by periosteum.
To alleviate this problem, we propose an easy and intuitive device for
navigation of Nd-YAG Iaser probe in cavum nedullare , and drilling assist
mechanism. We also established a new concept of osteotomy in Bone-lengthen
surgery .
Key Words, Bone-lengthen surgery , Osteotomy， Periosteum
abstract
In surgical robotics,safety issue is one of the most important aspects.Therefore,the
authors developed a fail-safemechanism or surgical system.The fail-safe
mechanism has the following characteristics:it behaves rigid under the
preset load.However,when the over-load force is applied,refuse motion starts.Multi
layer leaf spring was adopted in the developed system. The rated force
value can be controlled by changing the compression amount of the spring
.X-and Y-directional refuse motion is actuated by moment and Z-directional
one is performed by axial force.Proximity sensors are adopted to detect
diplaement of the spring..The emergency signal is sent to the controller
on over-load condition.The developed system was evaluated by the experiment.
KeyWords:Tele-surgery,Safety,Fail-safe mechanism
Abstract
Miniaturized prototype of master-slave Hyper Finger applicable for minimal
invasive surgery is developed.By using a couple for the Hyper Finger,smooth
control of the surgical tool is verified experimentally.Both feasibility
and probrems for clinical application are made clear by in vivo surgical
experiments with anesthetized pig.
[Key Words]
Hyper Finger,lapaloscopic Surgery,Minimally Invasive Surgery,Decoupled
wire Drive,Medical Robotics
[Abstract] We developed a forceps manipulator for laparoscopic surgery.
Some problems in laparoscopic surgery are irLainly due to the poor degree
of freedom (DOF) for controlling forceps and laparoscope. The forccps manipulator
we newly developed has 2 additiona} DOF of bending and has novel characteristics;
1)small diameter( c 6mm), 2) sterilizable and washable, 3) compact and
lightweight. Using this manipulator, problems in laparoscopic surgery are
clearly solved, and new standards with higher effectiveness and safety
are achieved. In this report, we present the frrst prototype of the manipulator
and the experimental results of the medical utility of the manipulator.
And we construct a new surgical manipulator system concept for laparoscopic
hepatectomy, using the forceps manipulator. The basis of this concept are
shown- in this rep ort .
Key Words: Manipulator, Forceps, Laparoscopic Surgery
Abstract
Mechanical support system is needed for minimally invasive surgery, since
it enables precise manipulation of surgical instruments beyond human ability
in a small operation space. In this approach, we are developing a micro
manipulator for neurosurgical operation support system. The micro manipulator
consists of two micro grasping manipulators, a rigid neuToendoscope, a
suction tube, and a perfusion tube. This paper reports on the micro grasping
manipulator. It has two D.O.F for bending and one D.O.F for grasping. This
prototype is 3.Imm in diameter and can bend 30 degrees in any direction.
Stainless steel wire was used to actuate the manipulator.
Key Words: Neurosurgery, Manipulator, Minimally invasive surgery
[Abstract] In the surgery for tubular organ it is more dcsirable but considered
to be impossible to remove the ksion without damaging the inner walls of
the organ. On the other hand, robot is able to continue the significantly
accurate and precise motions. It reminds us to make use of robot for the
surgery for tubular organ. We have developed a robotic device for less
invasive prostatectomy. It allows the surgeon to remove the prostatic tissue
of the sufficient volume for remedy dlrough a small hole made on the intraprostatic
mucous membrane. In this paper we examine its fundamental performance and
discuss the application of its mechanism and technique to the surgery of
artery.
Key Words: minimally invasive surgery, tubular organ, robotics.
[Abstract]
Minimally Invasive Direct Coronary Artery Bypass (MIDCAB) requires surgeons
the precision of hand skill and the mental concentration, since it needs
to work on beating hearts. We propose a surgical robot system that compensates
motions of organs during operations. The motion canceling robot system
includes three technologies; visual stabilization, motion stabilization
and master-slave. The visual stabilization provides the surgeon with the
image of stabilized target point on the monitor. The surgeon operates the
master robot referring to the stabilized image. The motion stabilization,
on the other hand, controls the slave robot being synchronized with the
heart beat. Master-slave transforms the master motion and controls the
slave robot. In this paper, we verify the effectiveness of master-slave
system with the motion cancelator.
Key Words: Medical Robot, Minimally Surgery, High Speed Camera Invasive
[Abstract] The purpose of this study is to evaluate the accuracy of femoral
cement removal using the ROBODOC system. Three cadaveric femurs and nine
sawbones were used. After a stem was implanted with cement. the stem was
extracted. Cement of the th:ree cadaveric bones and four sawbones was removed
using the ROBODOC system. Cement of the remaining five sawbones was removed
manually with an osteotome. CT images were obtained preoperatively and
postoperatively. Axial images of four levels were created. Rates of the
remaining cement, cortical over-reaming.,precise achievements of the preoperative
planning were calculated. Operation time and complication were evalutd.
Precise achievements of the preoperative planning: was 86 to 104 %. Rates
of the remaining cement, cortical over-reaming, and operation time with
the ROBODOC system was smaller than the manual, procedure. Three fractures
occurred with the manual procedure, but no fracture with the ROBODOC system.
Our results showed femoral cement removal using the ROBODOC system was
more safe, quick, and effective than the manual removal.
Key Words: femoral cement removal. ROBODOC.,accuracy evaluation
[Abstract]
We have developed a tele-echography system by using mechanism to control
angle and position of echo probe. To realize motion of examiner's hand
and arm, three dimensional rotatiqn and translation alc required. Rotational
and translational motion are made by gimbal and pantograph mechanism, respec-tively.
Construction is carefully considered not to damage human body. Since only
the tip of echo probe contacts on body surface, the mechanism never dam-age
patients. We controlled angle and position of the mechanism to capture
tube inside a phantom, which mimics human blood vessel. After confirming
va-lidity of the mechanism, we applied to human abdo-men to capture echogram
of liver and heart, not to exceed dangerous contact force, by controlling
the mechanism via network and transferring real-time echogram.
Key words: tele-echography, echo probe, contact force
[Abstract]
This paper describes a concept of a assistove health-care robot for holding
and carrying a bedridden patient. The major part of the concept is that
the robot has multi-dimensional robot arms using offset rotary joints.
The characteristics of the arrn are slender joint shape, and stick shaped
configulation. This characteristics are useful for the robot arm insertion
between a bed and patient, Pressure sense sheets are furnished to arms
for controlling arm angles to fit a patient shape at hollding action with
painless holding.
Kev Words : Offset Joint, Holding Robot Arm, Health-Care Robot
Abstract; We describe a novel robotic endoscope system. It an be used to
observe a wide area without moving or bendiug the endoscope. The system
consists of a laparoscope with zoom facility and two wedge prisms at the
tip. This new concept produces excellent characteristics as follows. Firstly,
it can change the field of view even in a small space. Secondly, it is
safe because it avoids the possibility of hitting internal organs. Finally,
because it does not require a large mechanism for manipulation of the endoscope,
it does not obstruct the surgeon's operation. During evaluation, we confirmed
that the tange of view were acceptable for clinical use.
Key Words: Endscope, Minimally invasive surgery, Medical robots
[Abstract] MR compatible endoscope is developed. In order to achieve MR
compatibility, the body consists of Bakelite to prevent static and dynamic
electromagnetic interference between MRI and the endoscope, and the CCD
unit is securely shielded to reduce noise from and to MRI. MR compatibility
of the endoscope is also evaluated by comparing with that of conventional
MRI endoscope.
Key Words: MR Compativility, Endoscope, Open MRI
[Abstract] We have developed a novel human- machine interface for controlling
a laparoscope based on the surgeon's face image processing, FAMOUS.
This system consists of a CCD camera placed just over the TV monitor, a
general PC, and a laparoscope manipulator. The surgeon's face features
are
detected in real-time from a sequence of video images taken through the CCD camera for positioning the laparoscope. Compared with the previous methods, the proposed system requires the surgeon to use neither additional hand/foot switches nor head-mounted 3D position/orientation sensing devices. This paper describes the prototype of the FAMOUS system.
Keywords: Human Interface, Laparoscopic Solo Surgery, Medical Robotics
[Abstract] Precise measurements of reference pints would be mandatory if
robotic equipments would be introduced in operation rooms. We developed
a real-time laser-pointing endoscope using an optical galvano scanner and
a 955fps high-speed camera. This system provides the scanned 3D image of
the liver and a touch screen interface so that surgeons can intuitively
indicate points of interest.
Key Words:natural 3D interface, 3D scanning, intra,-operative support
[ Abstract]
Endoscopic ultrasound (EUS) is being Increasingly used as one of the diagnostic
imaging methods for gastroenterology. However, for acquiring and evaluating
images of EUS, an observer must integrate the information of multiple serial
images to obtain a mental impression of the three dimensional anatomy.
We developed new three-dimensional EUS systems with convex scanning echoendoscopes
and three-dimensional positioning sensors to perform safely invasive procedures
with EUS. We reconstruct a three-dimensional image of a splenic vein from
270 two-dimensional serial images using with data of positioning sensors.
Then we achieved to depict an arbitrary three-dimensional splenic vein
image quickly in one esophageal varices case.
Key Words: endoscopic ultrasound, convex scanning echoendoscope, invasive
examination
[Abstract] The kinds of interface in the automation of endoscopic surgery was analized in this study.ME device in the operating room has "vehicle" and "process" type interface.Most of the ordering system has "computer" type interface. Human orientated design of the interface is important to avoid the accident due to human error.
<Abstract>
We made computer-generated Integral Photograpy (IP) images for surgical
navigation. We used this 3-D display system for surgical planning of minimally
invasive resection of the pancreas. We also generated rotating movies of
pancratic tumors with NlH Image. IP and NlH image showed 3-D anatomical
relationship between the pancreatic tumor and the main pancreatic duct.
We could determine the most suitable operative method. IP and NIH Image
were
useful for preoperative surgical planning.
Key word: Integral Photography, NIH Image, Pancreatic Tumor, Surgical Planning
Abstract: A real-time surgical navigation system that superimposes the
real, intuitive 3-D image for medical diagnosis and operation was developed.
principle of integral photography, named "Integral Videography(IV)",
which can be observed following the operator's movement of the field of
vision via a half-mirror as if they could be seen through the body. Moreover,
a real-time IV algorithm for calculating the 3-D image of surgical instruments
was used for navigation between the location of surgical instruments and
the organ during the operation. Because of the simplidty and the accuracy
of real-time projected point locaton, this system will be practically usable
in the medical field.
Key Words: integral videography, real-time, surgical navigation
Abstract
We present an augmeneted reality visualization system to assist with laparoscopic
surgery. The system uses VP-PI(Visualization using Parallel Projected Image)
method. In perspective rendering the scale of objects varies with the depth.
In laparoscopic surgery, a laparoscope camera poses ncar the operated organ,
and thus the effect of scale change is too large to be ignored. Therefore
the size recognition of internal tissues at deep point in the organ is
diflicult. The method employs a plane located on the organ's surface, and
creates an image by parallel projected rendering. That image saves the
size of objects at any depth. VPPI and augmented reality visualization
lead correct size, position and orientation of a 3-D image of organ internals
in a laparoscope scene.
Key words: computer assisted surgery, Iaparoscopic sur er au mented realit
3-D ultrasound image
Abstract
This paper discusses a robustness for estimation of nonlinear distortion
parameters. On medical applications using X-ray or endoscope images, the
evaluation or the ex-traction of nonlinear distortion is significant. For
the non-linear component estimation of distortion, some methods have been
present,ed[1] [2] [3] . Haneishi used the constraint tha,t the carastaristic
points are on a line. For stable es-timation, we use the cross-ratio as
additional constraint. We simulated these methods and evaluated the robust-ness
by using Gaussian noise.
Key words: nonliner distortion correction, radial dis-tortion, cross-ratio
[Abstract]
A digital three Dimensional (3D) ultrasound imaging system for neurosurgery
has been developed. A diagnostic ultrasound imaging system is PC-based
and its communication program makes it possible to transfer image datasets
to other computers through LAN. To acquire 3D images, we rotated the probe
and an encoder measured the accurate position of the probe. Volume data
were reconstructed from sequence of 2D images acquired during the probe
rotation. Another PC treated graphics, controlled the motor, and the image
data were transferred to the memory of it from the diagnostic ultrasound
machine. It took approximately 40 seconds from the begiming of the getting
the data, to show the volume data, and they could be treated at real time
speed because of a graphic accelerator board specialized to voxel data.
The opacity and color of volume were assigned according to their intensity
and the setting could be changed easily. It will help surgeons to understand
the condition ofthe lesion during the operation.
Key words : Neurosurgery, Ultrasound, Volume Rendering
[AbStract]
We are studying a teleoperation and communica-tion support system with
which to realize a new type of communication. This system, which uses a
Communication Terminal ( CTerm ), allows easy communication without misunderstandings
for supporting telemedical treatments at remote sites or in ambu-lance
cars. The CTerm is the core of our proposed system, and set up at a remote
site, where a patient and a emergency life guard are. A camera and a laser
pointer, that can both be rotated by the doctor using a remote control
at a hospital, are attached to the CTerm. The doctor directs the laser
pointer to a particular spot to provide clear practical instruction to
the emergency life guard at the remote site. This allows conversation between
two locations using prnouns such as "this" or"that",
and makes detailed oral explanations unnecessary. This system using the
CTerm provides smooth and easy telemedical support.
Key Words : Teleoperation, Telemedicine, Ambulance Support
[Abstract]
By the development of cone beam three-dimensional CT, it became possible
to acquire a three-dimensional image of an organism in a short time. At
the present a fourdimensional inrage can be also obtainable_ We made it
to be a purpose that enormous irLfionnation, which is included for a four-dimensional
inrage, is skill-fully sorted out and a four-dimensional image was visually
displayed. By using the data segnented in every organ, it was possible
for an observer freely switched a method for surface rendering to volume
rendering. We were able to display like the Roentgen inrage that retained
3-dimensional information using 3DMIP. As the result it became possible
by using this system to operate cutting, ejection, a clairvoyance of the
four<1imensional image on the VR space. Furthermore, in tus environment
it could be offered for an observer to image the inside of the organism.
Key Words: VlR, 4D visuahzation 3DCT
Abstract
In the knee orthopedic surgery, estimation of the three-dimensional (3-D)
position and orientation of knee prosthesis components is highly important
to validate innovative prosthesis designs and different surgical strategies.
In general, for the knee, video-fluoroscopy has been successfully used
to analyze kinematics. In the previous studies, a model-based method for
the estimation of the 3-D position and orientation of the knee prosthesis
components was presented. We implemented this method and applied it to
a simple model. We evaluated the effect of resolution of the distance map.
Key Words : knee prosthesis components, estimation of the 3-D position
and orientation, distance map
Abstract
With the advancement of interventional MR techniques, the demand of MRI
Compatible manipulator would be increasing to generate the next advanced
therapy. MRI Compatible manipulator requires non-magnetic materials, which
produces less image artifacts in the MR gantry. However, considering the
rigidity of the manipulator, the use of ferro-material is required and
consequently some image artifacts or distortion is inevitable. This studyshows
the basic phantom test to measure the image distortion caused by the manipulator,
and the correction method is described with considering the principle of
taking MR images.
Key Words: MRI compatible robots, image distortion, correction
OSADA Akiko, WASHIO Toshikatsu*, CHlNZEI Klyoyuki*, ISEKI Hiroshi** ,KOBAYASHI
Etsuko, SAKUMA Ichiro, TSUJI Takayuki, DOHI Takeyoshi
Institute of Environmental Studies, Graduate school of Frontier Sciences,
The University of Tokyo
*Mechanical Eng. Lab., MITI/Japan
**Department of Neurosurgery Neurological Institute Tokyo Women's Medical
(Abstract)
Magnetic Resonance Imaging (MRI) has been used mainly for diagnostic purpose.
But, recently with the spread of "Open MRI", it is used as a
location measuring instrument during surgical intervention. When we use
it during surgical operation, it is necessary to put the surgical instruments
and robots in
MR scanner. Therefore they have been developed to be fit to use in MR scanner
(MR compatible) in recent years. However, they have an effect on the magnetic
field. And these devices distort the static magnetic field and the gradient
magnetic field. On the other hand, it has never solved how they distort
the magnetic fields. In this study, we will visualize the magnetic field
in the imaging volume by using the FEM method, and develop the numerical
estimation method for MR compatib ility.
Key words : MRI, MR compatibility,,Magnetic field
○瀬尾信一郎,丸山隆志*,望月誠,佐久間一郎,土肥健純,伊関洋*
東京大学大学院工学系研究科
*東京女子医科大学脳神経センター脳神経外科
(Absuract)
It is sometime difficult to identify cerebral tumor among healthy tissue.Nevertheless
excessive excision is undesirable for serious danger of side effect.
This study investigates a new identiffing method of cerebral tumor lean
on 5-Aminolevulinic Acid(5-ALA).
5-ALA is of increasing interest for photodynamic therapy (PDT)for mainly
citus lesion. We considered that photodynamic of 5-ALA is usable for investigating
tumor especially celebral. For our object we challenge to develop a soecific
sergical fluoresance microscope.
Deciding optical filler cutoff wave length ,observation of fluoresance
of 5-ALA ingestioned pig has been done.Abrain contusion was createed to
observe inffamation. Inffamation gained photosencety and to observe. Resulting
data suggests 550nm of wave length to be the best for detection . However
new problem appeared.
Keywords: 5-aminolevulinic acid, celluar photodestruction, brain tumor
[Abstract]
The aim of this study was to clarify the utility of computed tomography
(CT) volumetry for size matching for living related orthotopic liver transplantation
(LROLT) with three-dimensional computed tomography (3D-CT). 3D-CT volumetry
was applied to a donor, who underwent hepatectomy for living related orthotopic
liver transplantation. 3D-CT imaging was made using the workstatron "ZIO
M900" (zio software inc., Tokyo, Japan). The 3D-CT imaging gave us
the anatomy of bifurcation of hepatic vein and the shape of the graft.
In comparison the 3D-CT with two-dimensional CT (2D-CT), the 3D-CT images
brings more exact volumetry than 2D-CT.And once 3D images were completed,
3D-CT volumetry is easier to work than 2D-CT volumetry.
3D-CT volumetry will be more exact and easier to work and recheck volumetry
after operation than conventional volumetry with 2D-CT with the advance
of technology. Therefore, 3D-CT volumetry will be useful for size matching
for LROLT.
Key Words: volumetry, surgical simulations, visualization
[Abstruct]
Liver cancers often occur frequently in cirrhotic(highly fibrotic) Iiver.
It is difficult to diagnose the liver cancer precisely before the operation
by normal CT images. We did the following examination for the purpose of
the automatic detection and diagnosis of the liver cancer. Histogram and
profile of CT value of the cases which had a hepatic resection in our facilities
was analyzed. It was conceivable that it could be the assistance of the
automatic
detection and also qualitative diagnosis of the liver tumor by making quantitative
analysis of the CT value.
Key Words:Liver tumor, MDCT, 3-D Profilmg
[Abstract]
Recent development and progress enable to perform the minimal invasive
surgery with endoscope also in Neurosurgery.Moreover the preoperative image
can be used effectively for getting suffic.ient information .However,preoperative
image can 't correspond to the changes during the operation.For that
reason,we attempt to introduce the Open-MRI which acquires some real-time
information.In this case,it is important to get essential information and
to show briefly to the surgeon.Therefore,we investigate what information
should be acquired and the way which let the surgeon to know the sutiation
of the operation,and develop+the navigation system to show some visual
information to the surgeon effectively in this study.In this report,we
describe the MRI oompatible endoscope whose head can only bend with polyurethane
tube and hard pipe.
Keyword : navigation system , neurosurgery, MRI compatible
Abstract
Intraoperative open MRI operating theater (Intelligent operating theater
i n the twenty-first century ) has the impact which changes the conven
tional neurosurgery operation. Removal rate of the malignant brain tumor
is stastically correrated with survival rate improved. Removal extent could
be surely improve up to 90-95% by the image of residural tumor with the
open MRI. Especially, it is possible that the operation staff pursues the
removal rate to 99-100% by combined use of t he real - t ime update naviga
tion which always refreshes by necessarily responding, in respect of the
image intraoperative image datum. The image picturized in multicross section
and various sequences of the intraoperative MRI supports the operation
staff by offering the accurate, objective and intraoperative i mage in
proportion to deformatlon and transfer of the brain by the operat ion.
Just, evidenced based medicine (EBM) will be brought in the operation.
The visualization of the medical Information in which that it comes out
to whom is also proven brings about advantage ( high-quality operation
) to patient and both operations staffs, and the fleld (place ) which practices
it is the intelligent operating ( theater ) in the twenty-first century.
Key words: open MRI. navigation, intraoperative imaging, neurosurgery
[Abstract]
The extent of operative removal in glioma is statistically correlated with
patient's prognosis, however, its irregular shape often cause incomplete
removal.
Various navigation systems are not useful by becoming outdated for the
brain shift. We report the development and initial experience of new "real-time"
navigation system (RTnavi) updated with intraoperative MRI. Passive navigation
system using optical tracking and software was renewed for RTnavi that
can import the DICOM formatted image data from open MRI. Fiducial markers
were implanted in the skull surrounding the craniotomy. The time for update
of image data took be]ow 10 minutes. RTnavi was useful for detecting residual
tumor and increasing removal rate without damage of normal brain. Initial
two cases of glioblastoma could be removed over 95%, without no postoperative
deflcits. RTnavi is powerful tool for sugical guidance and it would enable
us to accomplish gross total removal of glioma by reregister shifting brain.
Key Words: navigator, brain tumor, safety
Abstract
We have developed advanced technologies such as a surgical navigation system
to support surgical operation by utilizing the various information obtained
pre- and intraoperatively. We introduced an open MRI system (AIRIS II,
Hitachi Medical Co.) into an operating theater connected to high speed
computer network and a medical dat~base. The theater was designed to realize
the operation environment in the 2lst century, and named the intelligent
operating
theater. Up to now, brain surgical operation was carried out for 28 patients.
Although the open MRI system has been used for diagnostic use in
other hos pitals, the intraop erative use dramatically improved the clinical
results. The 5-gauss line is so narrow that it hardly disturbed the operation.
In addition, this in~elligent operating theater was also useful for the
practical evaluation of the medical devices and instruments under development.
Key words : open MRI, brain surgery, evaluation
[Abstract]
Radio Frequency Ablation (RFA) is a new way to treat liver tumor by inserting
the radio-wave electrode without abdominal incision. This operation is
less invasive for patient. However, it is quite difficult for surgeon to
insert the electrode to the appropriate position precisely, because the
surgeon must estimate three-dimensional geometrical situation around the
tumor and execute insertion from pre-operation images (MRI, etc.) and intra-operative
ultrasound images. To assist surgeon's operation, we propose a passive
navigator system by braking mechanism for navigation of the electrode to
the target with high accuracy. The system consist of hardware to point
the electrode on the proper position of the tumor on the coordinate system
of hardware based on information from pre-operation images.
Keyword:REA,Passive Navigator, Image Guide
[Abstract]
Radiofrequency ablation (RFA) is a new therapy for liver neoplasm by heating
surrounding area using radiofrequency energy from the inserted electrode
needle. Large tumor is usually inserted electrode multitimes because of
limited ablation area Microbabble generated after first ablation obstructs
clear observation of the tumor. We have performed RFA since 1995. The local
lecurrence rate of the hepatocellular careinoma which size was over 3 cm
in diameter was much higller than that of under 3 cm (27.3 % vs. 5.2%).
One of the reason of this high recurrence rate is the difficulty of accurate
insertion afier first ablation. Therefore navigation system is very important
for RFA electrode insertion. We used the POLARIS for optical-based tracking
system. The marker was attached to the handpiece of electrode needle, and
was tracked by the POLARIS. The position of a target and the tip of needle
were displayed on a computer monitor.
Key Words : Radiofrequency ablation, Navigation system, POLARIS
Abstract
This paper describes intraoperative simulations for the limb length and
the range of motion (ROM) adjustment in total hip relacement (THR) surgery,
and their util-ity in intraoperative planning. After implantation of the
cup and stem, final adjustments can be made t,o the limb length and ROM
by selecting the optimal combination of femoral neck and head components
from the range available in a c,hangeable modular system. The aim of this
work is t,o provide intraoperative assistance to the surgeon in selecting
the optimal component combination as well as in planning additional osteotomy
to remove unwanted bone impingements and widen the safe ROM. Using the
positions and orientations of the cup and stem intraop-eratively measured
by a combined acetabular and femur (CAF) navigation system, Iimb length
and ROM simulations are carried out for neck and head components of various
lengths and angles. These simulations provide information on limb length,
the ROM, and where in a 3D model impingements will occur for each combination
of components. The accuracy of the simulations was evaluated by comparison
with postoperative CT data for the limb length and actually measured motions
for the ROM.
Key words: computer assisted surgery, hip joint, range of motion, Iimb
length
[Abstract]
Instrumentation surgery including transpedicular screw is an indispensable
technique in recent spine surgery. However, misplacement of screws can
cause major vascular or neurological complications, and accurate placement
of screws is the essential requisite for successful surgery. In order to
avoid these complications, we develop computer navigation system using
optical 3-D Iocalizers (OPTOTl~K 3020). The purpose of this study is to
evaluate the
overall system accuracy of our navigation system. Using our navigation
system, we insert pedicle screws to 30 pedicles of plastic lumbar spine
models. Positional error is 2.24i 1.02mm . Angular error is 2.32~ 1.54
degrees. The results of this study show the accuracy of our navigation
system is sufficient for clinical application.
Key Words: computer aided surgery, pedicle screw, lumbar spines
[Abstract]
Navigation system for neurosurgery is essential for non-invasive surgery. For navigation, position of the patient must be measured. We developed a reference frame as eye glasses attached CT/MRI markers. This frame enables us to measure the patient's position and orientation simply and non-invasively. On taking CT/MRI scans, the patient wears the frame on the face. At the beginning of the surgery the patient wears the frame again. and position of markers are measured. Then we can register CT/MRI slices and the patient. Because of this frame, registration becomes simple and non-invasive. The navigation system with the frame has been used in 7 clinlcal tests, and we confirmed the effrciency of the navigation system and the frame.
Key Words: navigation, reference frame, registration
Abstract
Laparoscopic procedures assisted with computer-enhanced surgical system,da
Vinci were successfully performed in ten patients. The endoscopic procedures
performed were cholecystectomy,distal gastrectomy,ileocaecal resection,inguinal
herniorrhaphy,splenectomy,and repair of esophageal hiatal hernia. There
were no major complications. No procedures were converted to the open surgery.The
robotic surgery is feasible,but requires further prospective study to evaluate
the effectiveness and safety with the computer-enhanced surgical system.
Keywords: da Vinci, endoscopic surgery, navigation