Micro-Motion Sensing System

 

Author: WIN Tun Latt
Last Update: Dec 2008

 

PROJECT DESCRIPTION:

Abstract

We are developing a system that can detect micro level motion of a microsurgical instrument in real time using a cost-effective method. The objective of developing the system is to aid in trainings of new surgeons, evaluate internal sensing accuracy as well as effectiveness of feedback control of Intelligent Handheld Instrument, and reveal more discoveries about tremor nature of human's hand.

 

Introduction

Currently, there is no system that can detect 5 DOF motion of a microsurgical instrument in micro level. The objective of this research project is to design and develop a complete system that can sense positions and orientations (5 DOF) of a microsurgical tool in real time. The current system can detect only positions of the tool's tip. Moreover, the system needs to use a 5 mm diameter ball at the tip of the instrument to improve the reflection of IR light to the detectors. The present of the ball makes the surgeon difficult to trace and track the target at all positions. Our new system will eliminate all the difficulties of tracing and tracking the target by using two light sources and three Position Sensitive Detectors (PSD).

 

Methodology

We propose to use PSDs instead of using very expensive high resolution, high speed cameras for the sake of being able to use in many areas. Three PSDs will be used to detect 5 DOF motion of a microsurgical instrument.

Two PSDs will be positioned vertical to the working surface and perpendicular to each other. They will provide 3D position information of the instrument's tip. Another PSD will be placed just below and horizontally to the working surface. The bottom PSD together with a Red Light shinning through the instrument's tip will provide additional information about the angle's of the instrument.

Although we will be using a reflective ball at the tip of the instrument, the use of red light will eliminate the difficulty of seeing the target at all positions and orientations. The on-off time of the two light sources will be controlled properly so that they will not affect each other.

 

Advantages

Upon successful implementation of this system, many findings and discoveries can be made.

This system can be used in trainings of new surgeons. The instructor surgeons can see trainees' performance in either real time or after the surgery, and appropriate and effective instructions can be given to the trainees. Moreover, trainees' performance improvement based on different training approaches can be recorded and the best training approach can be chosen.

The effectiveness of the some suggested medicine that are said to improve surgery could be evaluated objectively. The cost of this system will be affordable to be used in many kinds of micro motion level research.

Surveys on the difference in amount of tremor among young and old people, fresh and tired people, male and female, etc can be carried out and new findings and discoveries can be made.

The accuracy of internal sensing of instrument's motion with accelerometers and gyroscopes can be evaluated using the system. Moreover, the effectiveness of piezoelectric control of the instrument can be evaluated as well.

 

Related Projects

• Virtual Reality Microsurgery Training
  Eileen Su (Visiting Ph.D. student)

 

GRANT:

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PERSONNEL:

 

PUBLICATIONS:

Refereed Conference:

1. W. T. Latt, U. X. Tan, C. Y. Shee, and W. T. Ang, "Handling Light Disturbances in a Micro Motion Sensing System and Investigation of the System Performance," in Proc. IEEE RAS/EMBS Intl. Conf. on Biomedical Robotics and Biomechatronics, Oct 2008, pp. 463 - 468.
2. W. T. Latt, E. S. Ananda, S. C. L. Ong, K. C. Veluvolu, C. Y. Shee, and W. T. Ang, "Design and Implementation of a Two Degree-of-freedom Micromanipulation Assessment System," in Proc. IEEE Intl. Conf. EMBS, Aug 2008, pp. 5640 - 5643.
3. W. T. Latt, U. X. Tan, F. Widjaja, C. Y. Shee, and W. T. Ang, "A Study of a Hand-held Instrument's Angular Motion due to Physiological Tremor in Micromanipulation Tasks," in Proc. IEEE Intl. Conf. EMBS, Aug 2008, pp. 1952 - 1955.
4. W. T. Latt, U. X. Tan, K. C. Veluvolu, J. K. D. Lin, C. Y. Shee, and W. T. Ang, "System to Assess Accuracy of Micromanipulation," in Proc. Intl. Conf. IEEE Engineering in Medicine and Biology Society, Aug. 2007, pp. 5743 - 5746.
5. T. L. Win, U. X. Tan, C. Y. Shee, and W. T. Ang, "Design and Calibration of an Optical Micro Motion Sensing System for Micromanipulation Tasks," in Proc. IEEE Intl. Conf. Robot. Automat., Apr. 2007, pp. 3383 - 3388.