Selective Feedback Control of Spastic Musculature in a Canine Model

Autor: Charles R. Davies, Kouroz Azar, Harvey M. Tucker, Gordon Jacobs, Michael Broniatowski
Rok vydání: 1992
Předmět:
Zdroj: ASAIO Journal. 38:M248-M252
ISSN: 1058-2916
DOI: 10.1097/00002480-199207000-00030
Popis: Muscular spasm, the etiology of which remains elusive, has been difficult to control. The authors, therefore, proposed selective restraint of forced contractions by a closed-loop circuit. In four dogs, the strap (n = 6) and thyroarytenoid (n = 4) muscles were submitted to tetanic contractions via bipolar supramaximal stimulation (30 Hz, 6 mA, 0.5 msec) of ansa hypoglossi and recurrent laryngeal nerves, respectively. Subsequent reduction of distance between two sonomicrometer crystals embedded into muscle was used in lieu of "spastic information" for a stimulator to deliver blocking signals through tripolar electrodes passed downstream. By modifying frequency (30-110 Hz) and current (60-95%) distribution between the central cathode and the peripheral anodes, significant relaxation (up to 100%) was recorded within "blocking windows," varying with each nerve (3-18 mA sweeps). The selective restraint of unwanted contractions, leaving "normal" subthreshold tone undisturbed, may offer a more mature approach to spastic disorders than destructive procedures, such as nerve section and its chemical counterpart, botulinum toxin injection.
Databáze: OpenAIRE