The number of adult patients who had an arterial switch operation has been increasing. In general, the postoperative thoracic aorta has abnormal curvature and torsion at the beginning of the ascending aorta due to geometric interferences with the pulmonary artery.Consequently, it is predicted that blood flow in the postoperative aorta becomes more complicated. However, there are few studies on blood flow field in the postoperative aorta, so CFD analysis is necessary for the better understanding. In this research, blood flow in the normal thoracic aorta and the postoperative aorta is simulated by use of incompressible Navier-Stokes equation. Each thoracic aortic model is made by medical image data, and virtual flux method is applied to calculate blood flow on Cartesian grid. It is found that secondary flows in the postoperative model are more complicated than that in the normal model. In addition, it is observed that maximal value of wall shear stress for the postoperative model is higher than that for the normal model.

View full abstract

In this study, the authors analyze the behavior of the bolus by peristalsis by simulation. The esophagus and bolus are represented by spring-mass model. Circular muscle contraction of the esophagus by peristalsis is represented by changing the natural length and the coefficient of the spring. The interaction of the bolus and esophagus is treated as contact between spheres and virtual spring and dumper are introduced to represent consistent contact. The profile of estimated elapsed time of swallowing showed qualitative matching with in vivo experiment result.

View full abstract

This paper discusses evaluation of a vision-based remote navigation system for tele-auscultation. In tele-auscultation, the doctor needs to navigate a non-clinical proxy handler of the stethoscope. The system provides doctor's navigation of the stethoscope as a graphics marker overlaid on a view of the target's chest. The system is evaluated in a simulated tele-auscultation experiment with a lung auscultation simulator. Auscultation time was reduced when the system was used. The results of conversation analysis show that the system has reduced the indication of auscultation position and position tuning. The subjects commented in the questionnaire that the system smoothened navigation and handling of the stethoscope.

View full abstract

We have developed a 6-DOF rehabilitation support robot for upper limbs and its application software. The symptom that the system aims at is cerebellar ataxia. The application software deals with a technique of physical therapy: FNF (Finger-Nose-Finger) test. We conducted some fundamental experiments using the rehabilitation system, and demonstrated the availability of the system.

View full abstract