494 KB17 KB198520252001Bunc, MatjažRozman, Janezštevilka:2letnik:31str. 106-109ISSN:0352-9045COBISSID:13623257URN:URN:NBN:SI:doc-IP297Y7NenStrokovno društvo za mikroelektroniko, elektronske sestavne dele in materialeInformacije MIDEMAnkle jointDogsElectric stimulation therapyfiziologijagibanjeMuscle contractionnogaopornicaOrthotic devicesElectronic brace for the measurements and eliciting of muscle contractions in a dog's ankle| Elektronska opornica za pasivno gibanje pasje noge in meritev kontrakcije v pasjem kolenskem sklepu|An experimental electronic brace, which is able to avaluate torque in the ankle joint of a dog elicited by spontaneous or stimulated muscle contraction,has been developed. The brace is aslo able to impose electrically controlled passive movements on the dog leg. Precise-passive movements, as passive external, electrically-controlled flexion or extension of the ankle ofa dog leg, are defined in as speed and angle of rotation / movement. On the other hand, switching in a certain working mode, the brace, equipped with force transducers and a goniometer, could serve for measurements of isometric (locked mode) or isotonic contractions (active mode and passive mode) of a dogleg. A range of the rotation around the ankle joint is limited between -40 and +55 degrees according to the neutral position. The calculated endurance moment of the brace is 2.41 x 10-4 kg m2 s-1, while the speed of electronically controlled movement of the brace in the passive mode is up to 78 degrees/second, respectively. In the active mode the brace is able to rotate synchronously with the dog ankle joint with a speed of up to 400 degrees/second. The maximum frequency, on activation of the tibialis anterior muscle current, when the amplitude of flexion was 50 degrees, was 7/min. In the locked mode the brace is able to measure the amplitude of force of a dog leg isometric contraction elicited by electrical stimulation. The force transducer with a natural frequency of 8 Hz and compliance of 0.4 um/g represents a very linear dependence of the output voltage upon the load with atransducer sensibility of 0,5 mV/mN at a bridge excitation voltage of 5V. Thenominal range of each transducer is 0-70 NIzdelali smo elektronsko opornico za pasjo nogo, s katere je moč meriti momente v pasjem gležnju, ki ji izzovejo mišice ob spontanem ali stimuliranem krčenju. Poleg tega je mogoče z opornico izzvati v naprej predvidene pasivne gibe pasje noge z natančno določeno hitrostjo krčenja ali raztegovanja in kotom premika opornice ter s tem na njo pritrjene pasje okončine. Razen tega lahko opornico priredimo za meritve izometrične kontrakcije (locked mode) ali pa izotonične kontrakcije (active mode) ter za prej omenjena programirana gibanja opornice (passive mode). Kot za katerega se lahko zavrti opornica opornice glede na nevtralno lego, določeno z nevtralno lego pasjega gležnja, je od -40 do 55 stopinj. Izračunani vztrajnostni moment opornice je 2.41 x 10-4 kg m2 s-1. Pri pasivnem, programiranem gibanju opornice je moč nastaviti hitrost rotacije v območju od nekaj stopinj/sek do največ 78 stopinj/sek. V aktivnem načinu pa se opornica lahko zavrti, skupaj z stimulirano pasjo nogo, s hitrostjo tudi do 400 stopinj/sek. Največja frekvenca draženja mišice tibialis anterior, pri kateri je bilo moč izvajati meritve v aktivnem načinu brez popačenja (amplitudi zasuka opornice 50 stopinj) je bila 7/min. Na opornico je bil vgrajen tudi senzor sile, katerega resonančna frekvenca je bila 8Hz, podajnost (compliance) 0.4 um/g in občutljivost 0.5 mV/mN (napajanje5V). Občutljivost je bila pri napajanju s 5V v pričakovanem področjumerjenih sil (0-70 N), povsem linearnaTEXTznanstveno časopisjejournalsSlovenian National E-content AggregatorNational and University Library of SloveniaStrokovno društvo za mikroelektroniko, elektronske sestavne dele in materiale