Biomedical subjects

Andrew Barriskill

Publications and source records attributed to Andrew Barriskill.

3 recordsLinked to original sources

PubMed2006

Gait event detection using linear accelerometers or angular velocity transducers in able-bodied and spinal-cord injured individuals.

We report on three different methods of gait event detection (toe-off and heel strike) using miniature linear accelerometers and angular velocity transducers in comparison to using standard pressure-sensitive foot switches. Detection was performed with normal and spinal-cord injured subjects. The detection of end contact (EC), normally toe-off, and initial contact (IC) normally, heel strike was based on either foot linear accelerations or foot sagittal angular velocity or shank sagittal angular velocity. The results showed that all three methods were as accurate as foot switches in estimating times of IC and EC for normal gait patterns. In spinal-cord injured subjects, shank angular velocity was significantly less accurate (p<0.02). We conclude that detection based on foot linear accelerations or foot angular velocity can correctly identify the timing of IC and EC events in both normal and spinal-cord injured subjects.

Acceleration↗

PubMed2006

The development, validity, and reliability of a manual muscle testing device with integrated limb position sensors.

OBJECTIVE: To report the development and validation of a new hand-held muscle strength-testing device that is integrated with orientation sensors and designed to test the strength of major muscle groups at a given limb or joint position. DESIGN: Design description and validation study. SETTING: University-based human movement facility. PARTICIPANTS: Twenty-eight able-bodied, healthy subjects. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURE: A device was developed based on a hand-held force dynamometer with integrated orientation sensors. The validity and reliability (interrater, intertrial) of 5 maximum isometric contractions of hip flexion, knee extension, and ankle plantarflexion and dorsiflexion were assessed. The results were compared with those from an isokinetic dynamometer (KinCom). RESULTS: The new manual muscle tester was highly reliable and valid in estimating muscle strength of the lower limbs. The coefficient of variation between trials of all movements was low, with a mean less than 10% (range, 3.7%-8.9%). The only significant difference in muscle strength between the new device and the isokinetic dynamometer was found for hip flexion. CONCLUSIONS: The new hand-held muscle strength tester appears to be a reliable and valid clinical assessment tool that can be used to objectively assess muscle strength at particular limb positions and/or joint angles. This feature appears to represent a technical advance in portable muscle strength devices, providing comparable information to those obtained by isokinetic dynamometers at a fraction of the cost and size. However, the device needs to be validated in clinical populations, such as patients with spinal cord injury and stroke, in order to demonstrate its general clinical utility.

Adolescent↗

PubMedDate not supplied

A portable, 8-channel transcutaneous stimulator for paraplegic muscle training and mobility--a technical note.

This paper introduces an 8-channel transcutaneous neuromuscular stimulator, called ExoStim, which was designed and developed to provide stimulation to the lower-limb muscles of spinal cord injured individuals. The intended purposes of the ExoStim were to act as a skin-surface precursor to an implantable neuromuscular stimulator for the specific tasks of increasing paralyzed leg strength and endurance, enabling the performance of basic lower-limb functional tasks, and familiarizing patients with functional electrical stimulation training. The initial design specifications included portability (approximately 500 g), battery-powered output, constant current control (0-300 mA), 8 channels of biphasic stimulation (charge-balanced, constant current), and microprocessor control of all stimulation parameters. Various tests, including output power characteristics, environmental, mechanical, and battery life, were performed on three prototype units to validate our design specifications. Having successfully passed all tests, the ExoStim is now ready to be deployed to clinical trial sites for further evaluation with spinal cord injured subjects.

Electric Stimulation Therapy↗