Journal of Computer Aided Surgery Vol.7 No.4
J JSCAS vol.7, No.4, pp.535-545, 2005
Abstract
For medical stereoscopic imaging, the usefulness of the presentation of depth information and the issues of
picture quality and fatigue have been discussed. We used a laparoscope that allows switchover between
two-dimension (2D) display and three-dimension (3D) display, and compared execution time and accuracy in
three kinds of tasks ? a pegboard, incision, and suturing ? under the 2D and 3D conditions conducted for one
hour in total. To avoid the effect of fatigue and order effect to the utmost, an interval of two weeks or more was
placed between both experiments. A total of 12 subjects showed higher speed when using the 3D display than
the 2D display in all three tasks and, simultaneously, improvement in execution time as a result of order effect.
Improvement of task accuracy using 3D display was found in the pegboard task. Large individual variations in
execution time were also found. We conclude that the current stereoscopic endoscopes can improve
performance of surgical manipulations, but its effect varies from task to task.
Key words
Stereoscopic endoscope, Binocular parallax, Task performance, Order effect.
J JSCAS vol.7, No.4, pp.547-557, 2005
Abstract
This paper describes a method for estimating three dimensional (3D) positions and orientations of vertebrae together
with the load working on the vertebral bodies from a sequence of human images taken by a video camera based on a 3D
whole body mode and a 3D spine model. In this method, we first obtain the neck and waist postures, the centers of masses of
the head, trunk, and arms by fitting the 3D whole body model to an input human image. Then the 3D spine model is
deformed so that it satisfies equilibrium of the force working on the vertebrae caused by the springs which approximate
intervertebral discs. After determining the spine posture, the load working on the top surfaces of the vertebral bodies is
calculated based on the centers of masses and the weights of the body parts. The experimental results based on one real MR
image dataset showed that our method estimated the vertebra positions within the positional shifts of 6.2 mm and the
rotational variation of 3.1 degrees. We also confirmed that our method estimated the spine posture and calculated the force
working on the top surface of the lumbar vertebra ‘L5’ from the real human video images reasonably.
Key words
3D Spine model, 3D whole body model, Posture estimation, Model fitting, Statics.
J JSCAS vol.7, No.4, pp.559-565, 2005
This research aims to produce an intelligent surgical robot, incorporating the following three techniques, A: visual feedback B: force control C: organ-model base control. This research uses a robot model and a liver for the target object to evaluate organ-model base control. For the purpose of organ-model base control, three experiments were conducted to evaluate the physical properties of the liver for robot control. A dynamic viscoelastic test was then carried out to show the dynamic properties of the liver in the form of a differential equation. The nonlinearity of the liver was supported by the creep test. In addition, the liver model was validated using a constant strain rate test.
Key words
Liver, Modeling, Physical Properties, Intelligent control.
J JSCAS vol.7, No.4, pp.567-575, 2005
Abstract: N/A now
J JSCAS vol.7, No.4, pp.577-585, 2005
Abstract: N/A now
J JSCAS vol.7, No.4, pp.587-592, 2005
Abstract
This paper presents a three-dimensional microfluidic network made of thin mesoporous biodegradable polymer
membrane, which realizes rapid transfer of liquid and gas between inside and outside of the microchannel. This is a first
prototype of the “artificial blood capillary device” we have proposed to regenerate large tissues and organs in vitro. Here,
we prepared porous poly-lactic acid membrane using spincoating following phase separation, and examined the relation of
solution composition to pore size and density. We checked the permeability of the prepared membrane for three different
dyes which have varying molecular weight. We also investigated the biocompatibility of the membrane by culturing human
endothelial cells on the membrane. At last, we successfully fabricated a microfluidic network using membrane micro
embossing (MeME) process, and confirmed the size-selective transfer of micro-beads through the microchannel walls.
Key words
Tissue engineering, Membrane, Microchannel, Capillary, Porous.