Journal of Computer Aided Surgery Vol.3 No.1
Abstract
Surgical sirmulation is one of interactive techniques such as a flight
simulation or a CAD (Computer Aided Design) in terms of using the same
computer graphics. However, different from above techniques, one big characteristic
of surgical simulation is to handle unfixed forms of three-dimensional
human body in which conventional computer graphics techniques are weak.
Thus surgical simulation can be done with giving changes of ones anatomical
three-dimensional forms in details. Changing with the times, the function
and quality of the surgical simulaition transited depend on an ability
of the computer itself. Sirnulated operations became sirnple to complex,
and simple model of the affected part changed to model with more cornplex
structures according the transition of its functions. By rapid improvement
of the computer system in these 10 years, we can now handle the detailed
affected model with the huge data in real time and natural operation. In
addition, as a result of an external force during the operation, transformation
of soft objects such as internal organs can be shown in real time. Moreover,
by combining with virtual reality technique, it let simulation come near
to real movements of fingers in the surgical simulation. It can give us
not only visual feedback of the simulation, but the sense oftouch of the
operation comparing to three-dimensional images. Thus, we are approaching
to real operation under the virtual space. Based on results by a team of
the authors institute, the present circumstances of development with simulation
system of the operation will be discussed. In addition, we focused on trends
of the works and development of researches for future simulation systems
of the operation which is close to advanced medical techniques, for instance,
supporting system during the operation such as Data fusion and tele-medicine
etc.
Key words :Surgical simulation, Realtime simulation, Abdominal surgery,
Model deformation, Haptic device.
Abstract
On author's investigation, 76% of neonates are born with auricular deformity.
This paper describes the spline approximation method of auricular shape
that characterizes those deforrnities and it's application to the treatment.
Contours of external auricular shape and inside fringe of helix are approximated
by B-spline function of order four based on the ear base line. The position
of control points that is coefficients of B-spline function is used as
an indicator of auricular shape. Deformities are classified into 6 groups
including normal ear and discriminant analysis is performed using the Mahalanobis
generalized distance calculated by the distribution of control points.
Also normal and abnormal rates are calculated by the component ratio of
probability of belonging to the classified group. The success ratio of
discriminant analysis and average of normal and abnormal rates are increased
by using not only control points of external shape but also those of inside
fringe of helix. The system to generate the orthosis shape for the treatment
of deformities that utilizes spline approximated auricular shape is developed.
Orthoses manufactured by the system were applied to patients and improved
deformities within a year. The transitions of auricular shape of patients
are analyzed by the position of control points and normal and abnormal
rates. The result of analyses also shows that using both control points
of extemal auricular shape and inside fringe of helix well chcracterizes
the improvement of those deformities.
Key words
Spline approximation, Auricular shape, Malformed ears, Control point. Mahalanobis generalized distance.
Abstract
A method to use pre-surgical T2-weighted magnetic resonance images (MRI)
with intra-surgical T1-weighted MRI to guide prostate biopsy is presented.
The method uses T1-weighted MRI to guide the needle through the perineum,
whilst T2-weighted MRI presented by a surgical navigation software was
used to visualize a tumor foci and sextant targets. Two feasibility studies
in an open-configuration MRI scanner indicated it is feasible to perform
sextant and targeted prostate biopsies under MRI guidance.
Key words MRI, Prostate biopsy, Navigation.
Abstract
The kinds of interface in the automation of clinical surgery were analyzed
in this study. The kinds of interface were classified into 3 kinds, that
is Vehicle-Type, Process-Type and Computer-Type according to the Kawano's
classification of man-machine interface. Vehicle type interface is defined
as the interface that is mainly controlled under the body feeling cue and
physical law such as automobile and motorcycle. Computer type interface
is defined as the interface that is mainly controlled under computer interface
in which only logical cue is used. Process type interface is defined as
the
interface in which primary parameters is main cue such as chemical plants.
ME devices in the operating room has mainly vehicle type and process type
interface, most of the surgical instruments such as electro-cautery, suturing
and anastmotic devices and ultrasonic cavitation devices were commanded
by vehicle type interface, directly controlled by body feeling cues. ME
devices of patient monitoring system and clinical laboratory consist of
mixture of process, vehicle and computer type interface. However most of
the interface of ordering and reservation system for prescription, meal
service, clinical laboratory and radiology were commanded by computer type
interface. Caution must be paid that miss-ordering into the computer type
interface can cause disadvantage directly to the patients as well as other
kinds of ME devices, so adequate protection for human error must be equipped
to the computer type interface.
Key words :Man-machine interface, Hospital automation, Endoscopic surgery.