Erik Fosse

Velocity and position approximations from left ventricular 3D accelerometer data

We report on preliminary results from a study of 3 pigs using a three dimensional (3D) accelerometer on the left ventricular heart wall. Approximating velocity and position from acceleration data, we show how these typically correspond in time with the electrocardiogram (ECG) cycle. There is a short discussion focusing on the velocity approximations. By plotting the approximated position data in 3D we briefly analyze and discuss to what extent the plots might correspond to the 3D movement of a point on the epicardial surface.

Head tracking of a surgical robotic scopeholder - a user involvement test of the system

This paper addresses the concept, development and testing of a new head-tracking system and a user involvement test for comparison between the proposed system and two other control techniques to control the scope — either voice control of Aesop from ComputerMotion (ComputerMotion Inc., Goleta, California) or HeadControl of EndoAssist from Armstrong (Armstrong Healthcare Limited, High Wycombe, England). The average time to complete the task using HeadTracking in both 3D and 2D -mode was shorter than the times for the two other control modes. The average task time using HeadTracking were 39,9% shorter, using 3D with head-mounted display (HMD) and 54,1% using 2D screen compared to HeadControl with EndoAssist. These results were found to be statistical significant (p<0.05). In order for robotic devices to be introduced successfully into surgical practice, the development of transparent surgeon/machine interface is critical. This user involvement test showed that our HeadTracking system with it’s ability to follow the head movements in an intuitive manner, is transparent in functionality to the surgeons which found the system to be the best suited to control the scope in laparoscopic surgery.