Journal of Computer Aided Surgery Vol.2 No.4
Abstract
A real-time surgical navigation system that superimposes the real, intuitive
3D image for medical diagnosis and operation was developed. This system
creates 3D image based on the principle of integral photography, named
"Integral Videography", 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
3D image of surgical instruments was used for registration between the
location of surgical instruments and the organ during the operation. The
experimental results of sticking a point location and avoiding dangerous
area show the errors ofthis navigation system were in the range of 2-3mm.
Because of the simplicity and the accuracy of real-time projected point
location, this system will be practically usable in the medical field.
Key words
3D, Integral photography, Real-time, Surgical navigation.
Abstract
Using a patient's 3D dataset obtaine.d from CT or MRI, our virtual reality
system can perform surgical simulations in 3D virtual space. Many researchers
utilized more costly organ models which used a finite element method (FEM)
or the spring-damper model. However, in order to adapt this system to a
PC, we employed the more economical method which created the realtime organ
transformations necessary for an authentic simulation. As a result our
system can perform incisions on a 3D image of a patient's body surface
and internal organs in the manner of realtime simulation.
Key words
Surgical simulation, Realtime simulation, Abdominal surgery, Soft tissue.
Abstract
We proposed and developed the prototype of a master-slave-type 4 D.O.F.
pair of surgical forceps with force sensors. By using two types of servo
forceps, the smooth control ofthe forceps was verified experimentally.
Moreover feasibility for clinical application was made clear by in vivo
experiment.
Key words
Minimal invasive surgery. Remote surgery, Unilateral servo. Laparoscopic surgery, Servo forceps
Abstract
Most malformed ears of neonates can be treated by mounting a suitably shaped
orthosis. However, it needs much experience to make a orthosis that produces
adequate corrective force. Especially, excessive force may cause a decubituslike
inflammation on the auricle. We are studying computer aided treatment system
to support the orthosis design. And we have already developed fundamental
design and manufacturing system. This paper describes automatic orthosis
shape modification method to prevent the excessive contact force using
three dimensional finite element analysis. In each insertion step of incremental
method, contact force of every nodal point of the orthosis is calculated.
The shape is modified by canceling the insertion of nodal point where excessive
contact force is produced. The result of the simulation shows that the
maximum contact force was reduced to one third by the modified shape. Orthoses
of original shape and the modified shape by the method are manufactured.
Also, two types of force sensor systems using silicon tube and strain gage
are constructed. They use phenomena that air flow in the tube decreases
and the strain gage is deformed when they are pressed. The thickness of
tube sensor is 0.5mm and that of strain gage sensor is 0.2mm. Orthoses
on which sensors are mounted are inserted into a testee's auricle and the
contact force is measured. The results of both sensors showed that the
force produced by the orthosis of modified shape was approximately half
of original shape.
Key words
Computer aided treatment, Malformed ears, Orthosis, Finite element analysis.