Medizinische Universität Graz - Research portal
Selected Publication:
Rafolt, D; Gallasch, E.
Surface myomechanical responses recorded on a scanner galvanometer.
Med Biol Eng Comput. 2002; 40(5):594-599
Doi: 10.1007/BF02345460
Web of Science
PubMed
FullText
FullText_MUG
- Co-authors Med Uni Graz
- Gallasch Eugen
- Altmetrics:
- Dimensions Citations:
- Plum Analytics:
- Scite (citation analytics):
- Abstract:
- A moving magnet galvanometer equipped with lever and indentor was evaluated for mechanomyography (MMG). First, the precision of the galvanometer was tested on a piezo-electric disc actuator. Using a 50 mm lever, synthesised micromotions with an amplitude of 1 microm could be detected (noise level < 0.2 microm) at static indentation forces ranging from 0.1 to 2 N. Then the galvanometer was mounted on an isometric ankle dynamometer to sense calf-muscle responses (N = 6). In the first protocol, twitch contractions were elicited by electrical stimulation while the indentation force was increased. Twitch amplitudes, twitch contraction times and twitch half-relaxation times were analysed from the surface and contraction responses. With indentation force (0.1-0.5 N), the amplitude of the surface responses increased (+61%), contraction and half-relaxation times, however, were not influenced. The mean twitch contraction time from the surface responses (60 +/- 11 ms) was shorter than that from the contraction responses (115 +/- 7 ms), indicating more fast-contracting fibres under the indented area. In the second protocol, voluntary target contractions were produced, and the surface responses were simultaneously recorded on an accelerometer. After double differentiation of the galvanometer signal, both acceleration MMGs showed a high coincidence in the time and frequency domains. With an indentation force of 2 N applied on the accelerometer, the signal amplitude (-10%) and the mean frequency (-19%) decreased. A specific application of this galvanometer-dynamometer test system is the assessment of regeneration processes in paraplegics with long-term denervated muscles.
- Find related publications in this database (using NLM MeSH Indexing)
- Electric Stimulation -
- Electronics, Medical -
- Humans -
- Muscle Contraction -
- Muscle, Skeletal - physiology
- Myography - instrumentation
- Research Support, Non-U.S. Gov't - instrumentation
- Find related publications in this database (Keywords)
- mechanomyogram
- indentation sensing
- contact pressure
- isometric contraction
- electrical stimulation
- twitch response