Biomedical subjects

Weoi-Luen Chen

Publications and source records attributed to Weoi-Luen Chen.

5 recordsLinked to original sources

PubMed2005

The M3S-based electric wheelchair for the people with disabilities in Taiwan.

PURPOSE: This study aims to establish an electronic wheelchair system in Taiwan that conforms to multiple master-multiple slave (M3S) standards. The proposed system could enhance the safety and convenience of people with disabilities. MATERIAL AND METHOD: The M3S-based head-controlled electric wheelchair consists of three parts: (A) the input device, (B) the output device, and (C) the safety device. Head movement can be used as the input control to cause the tilting device to produce a corresponding level of analog voltage (backward & forward/left & right) which is then transmitted to the analogy/digital conversion module to control the output device (wheelchair's motor). Ten subjects with C5 incompleted spinal cord injury were recruited in the clinical assessment. They were randomly assigned into groups A and B. In the group A, the subjects were assigned to operate the head-controlled wheelchair system with M3S standard before operating the head-controlled wheelchair system without M3S standard. In the group B, the subjects were assigned to operate the head-controlled wheelchair system without M3S standard before operating the head-controlled wheelchair system with M3S standard. Two subjects in the group B drop off due to their personal reasons. RESULTS: The time cost for group A in completing tasks 1, 2, and 3 with the M3S and without the M3S were insignificant (p>0.05). The time cost for completing in group B was insignificant (p>0.05). Thus, the wheelchair operating time is depended on the proficiency of the subjects, not the M3S standard added. DISCUSSIONS AND CONCLUSIONS: The time cost for subjects to operate the wheelchair was determined by their proficiency, not the M3S standard control added to the system. However, the M3S-based system did realize the safety mechanism and complex auxiliary tools with and without the plug-in and play function.

Adult↗

PubMed2004

Infrared-based communication augmentation system for people with multiple disabilities.

PURPOSE: This study describes an eyeglass-type infrared-based communication board for the nonspeaking with quadriplegia. METHOD: This system is composed of four major components: a headset, an infrared transmitting module, an infrared receiving/signal-processing module, and a main controller, the Intel-8951 microprocessor. This design concept was based on the use of an infrared remote module fastened to the eyeglasses which could allow the convenient control of the input motion on the keys of a communication board, which are all modified with infrared receiving/signal-processing modules. For system evaluation, 12 subjects (all men, 21-45 years old, six normal subjects as the control group and six nonspeaking with quadriplegia as the experimental group) were recruited. RESULTS: The average accuracy of the control group and the experimental group were 93.1 +/- 4.3% and 89.7 +/- 5.5%, respectively. The average time cost of the control group and the experimental group were 78.3 +/- 8.7 s and 89.9 +/- 10.2 s, respectively. An independent t-test revealed that the differences in the average accuracy and the average time cost of the control group and the experimental group were not significant (p>0.05). CONCLUSIONS: The increase of opportunity to communicate using the infrared-based communication board would help people with multiple disabilities to socialize actively.

Adult↗

PubMed2003

The development of a knee locker with closed-loop functional electrical stimulation (FES) for hemiplegia in gait training.

PURPOSE: A knee locker with closed-loop functional electrical stimulation (FES) system has been developed to prevent the quadriceps weakness and the drop-foot of the hemiplegia during gait training. METHOD: The FES system is triggered by a footswitch on the heel of the disabled foot to stimulate the tibialis anterior muscle for dorsi-flexion and to turn-off the knee locker in the swing phase through the main controller. Besides, the footswitch on the heel of the affected-side can be used to stimulate the quadriceps and to turn-on the knee locker for quadriceps weakness in the stance phase. RESULTS: It is revealed that the mean velocity, cadence, stride length, active ankle motion range, and functional ambulation category (FAC) have improved significantly from 0.15 +/- 0.04 m sec( - 1), 43.3 +/- 15.4 steps min( - 1), 0.36 +/- 0.11 m, 15 degrees, level 2 to 0.43 +/- 0.21 m sec( - 1), 69.4 +/- 19.1 steps min( - 1), 0.73 +/- 0.17 m, 40 degrees, level 4 respectively for the patient. A paired t-test indicated that differences in the electromyography (EMG) of the tibialis anterior and the quadriceps muscles between patient's disabled (affected-side) foot and normal (unaffected-side) foot are not significant (p > 0.05) after 16 weeks of training. CONCLUSIONS: It is concluded that this new knee locker with closed-loop FES system is capable of providing the hemiplegia with restoration to regular walking after appropriate gait training.

Electric Stimulation Therapy↗

PubMed2003

A head movement image (HMI)-controlled computer mouse for people with disabilities.

PURPOSE: This study proposes image processing and microprocessor technology for use in developing a head movement image (HMI)-controlled computer mouse system for the spinal cord injured (SCI). METHOD: The system controls the movement and direction of the mouse cursor by capturing head movement images using a marker installed on the user's headset. In the clinical trial, this new mouse system was compared with an infrared-controlled mouse system on various tasks with nine subjects with SCI. RESULTS: The results were favourable to the new mouse system. The differences between the new mouse system and the infrared-controlled mouse were reaching statistical significance in each of the test situations (p<0.05). CONCLUSIONS: The HMI-controlled computer mouse improves the input speed. People with disabilities need only wear the headset and move their heads to freely control the movement of the mouse cursor.

Communication Devices for People with Disabilities↗

PubMedDate not supplied

Neural network and fuzzy control in FES-assisted locomotion for the hemiplegic.

This study is aimed at establishing a neural network and fuzzy feedback control FES system used for adjusting the optimum electrical stimulating current to control the motion of an ankle joint. The proposed method further improves the drop-foot problem existing in hemiplegia patients. The proposed system includes both hardware and software. The hardware system determines the patient's ankle joint angle using a position sensor located in the patient's affected side. This sensor stimulates the tibialis anterior with an electrical stimulator that induces the dorsiflexion action and achieves the ideal ankle joint trace motion. The software system estimates the stimulating current using a neural network. The fuzzy controller solves the nonlinear problem by compensating the motion trace errors between the neural network control and actual system. The control qualities of various controllers for four subjects were compared in the clinical test. It was found that both the root mean square error and the mean error were minimal when using the neural network and fuzzy controller. The drop-foot problem in hemiplegic's locomotion was effectively improved by incorporating the neural network and fuzzy controller with the functional electrical simulator.

Algorithms↗