Biomedical subjects

R M Iñigo

Publications and source records attributed to R M Iñigo.

3 recordsLinked to original sources

PubMed1993

Seat support surface optimization using force feedback.

The development, implementation and evaluation of an algorithm designed to find optimal seat support surfaces is presented. The algorithm has been developed and implemented on an active contour measurement device. The device consists of an array of positioning elements equipped with force sensors for feedback. With a patient seated on the array, the algorithm is designed to find a seat contour that optimally satisfies given performance criteria. The performance criteria are based on measured stiffness of the soft tissues. A theoretical development of the algorithm is presented along with the modifications made to the algorithm during implementation. The results from several tests using man-made test bodies and a prototype contour gage are presented to verify the algorithm's performance.

Algorithms↗

PubMed1993

A closed loop automated seating system.

This technical report presents the recent progress in the design and construction of a closed loop automated seating system. Preliminary test results are reported. The system is designed to measure seating surface forces and control the seating surface geometry of a seated human. It uses force information as feedback to determine custom seating contours which produce desired seating characteristics. Ultimately, the system is intended to be used for research studies with patients. The system consists of an electronically actuated, force-sensing seating surface which is controlled by a computer. Stepper motors are used to move force sensing probes up or down until the desired seating surface characteristic is attained. Preliminary test results are presented and analyzed. A force-equalizing control algorithm has been written and found to produce relatively uniform force distributions for soft, hemispherical loads of various weights.

Algorithms↗

PubMed1987

An adaptable optimal controller for electric wheelchairs.

A microcomputer-based optimal control system for electric wheelchairs is presented. As the weight of a wheelchair is generally small compared to that of a user, the user's actual weight can have a tremendous impact on the dynamics of the wheelchair. The velocity feedback controller presented here was designed to give an optimal response for all users by incorporating a measure of the individual user's weight into the control algorithm. This allows optimal control of the motor velocities while assuring the constant stability of the system. Control of the system is managed by a modified proportional-integral-derivative (PID) controller, and the adaptability is handled by use of variable-structure control. The factors and considerations involved in such a system are identified, as are the advantages and disadvantages of the particular control strategy used. Experimental results are presented.

Microcomputers↗