Journal of Computer Aided Surgery Vol.2No.1
Abstract
Technical aspects ofc omputer−assisted magnetic resonance（MR）image−guided surgery are discussed with highlighted applications・.The applications presented with clinical feasibility studies include multi−modality image registration for prostate cancer biopsy，organ deformation tracking for craniotomy，thermal monitoring fori nterstitial laser ablation therapy of brain tumor．A preliminary study of MR−compatible surgical manipulator is also reported．The clinical feasibility study of computer−assisted MR−guided surgery suggested the its potential contribution to accuracy，less−invasiveness，efficacy in surgical procedures．
Keywords
Magnetic Resonance Imaging，Computer，Image−guided surgery，Interstitial Laser Thermal Therapy，Deformation，Surgical Robot，Muluti−modality registration．
Abstraet
We developed intraoperative 3-dimensional（3D）echoic image using the information of 2−djmentional echo and image analyzing system（SAS−200）.The principle of SAS-200 is that magnetic field sensor，which is setting on echoic probe，recognize the position of the probe as 3D coordinate．This method was adopted to the patients with liver tumors and the donors for living−related liver transplantation．Using this method，the relation between a main tumor and feeding vessels was visualized as 3D−US image． A 3D−US imagewas useful to make an accurate navigation for liver surgery．
Keywords
Hepatocellular carcinoma，3−dimensional（3D）ultrasonography，Tumor vessels．
Abstract
Several types of supporting systems for surgical planning have been
reported．This paper describes a new surgical supportingdevice which features
image superimposition uslng a half-mirror．By using the device，graphic
image of inter−nal organs can be superimposed on the patient’s live image．In
order that the device allows users to move around，the position of the
user toward the patient was measured consecutively by a small CCD camera
placed on the top of a head mounted display（HMD）．The CCD camera imaged
a patient model with pre−arranged markers on its surface and the position
of the model was measured with the accuracy of around 0．5cm by an image
processing software.Based on this positional data，threed imensional model
data were processed on a workstation to produce graphic image for superimposition.The
image was presented to the user through the HMD which features the“see−through”function．The
error in navigation by the devicewas found to be as large as 1cm，particularly
at the peripheral view field，and this problem must be solved in the future
study．
Keywords
Image superimposition，Head mounted display，Image measurement，Virtual reality modeling language．
Abstract
Until recently，we have only inferred the movement of each skeletal
muscle from electromyogram measurements （EMG），anatomical information，and
observations of the human body surface．However，under the present circumstances
it is problematic to comprehend the connection and interaction between
the human skeleton and skeletal muscles or between human skeletal muscles
themselves. Thus we aimed to develop a method to quantitatively visualizethese
interactions in space and time sequential domains by utilizing computer
graphic techniques.First，each human skeleton and muscle model was reconstructed
from MRI data sets.Second，cordinates derived ftom a mesh frame work of
a muscle were converted into algorithm．This algorithm reduced all coordinates
of the muscle framework while maintaining the original muscle shape．Afterwards，we
were able to construct a realistic skeletal muscle model．This muscle model
can contract or extend while avojding the bone or adjacent skeletal muscle
by taking physical interferenceinto account.We also made a series of skeletal
muscle models foreach bone．As a result，we couldo bserve the activity
and contribution of each muscle in bone movement.In the future，by applying
this system we will be able to monitor the movements of peopIewith physical
disorders．
Keywords
Skeletal and muscular model，Real−time，4D analysis，Mesh．