title: A ventricular assist device powered by conditioned skeletal muscle.
abstract: BACKGROUND
  We are developing and testing a new ventricular assist device (VAD) to be powered by conditioned skeletal muscle.
  
  
  METHODS
  To evaluate the VAD hardware and to develop a muscle training regimen, 8 calves have been used in studies in which the right latissimus dorsi muscle was employed. The experiments were carried out to an approximately 4-month duration.
  
  
  RESULTS
  There was significant conversion of type II (fast twitch) to type I (slow twitch) muscle fibers. This did not correlate well, however, with device performance. The device stroke volumes ranged from approximately 17 to 90 cc. This variability of outcome occurred despite the fact that identical hardware, surgical procedures, and training regimens were employed.
  
  
  CONCLUSIONS
  The results from the first eight studies lead us to speculate that perfusion may be important even when the muscle is working at pressures much lower than systemic blood pressure levels. In an attempt to augment tissue perfusion, we plan to investigate thermally induced angiogenesis as a possible mechanism for increasing blood flow to the tissue.
authors.affiliation: Whalen Biomedical Laboratories, Somerville, Massachusetts 02143, USA. rlwhalen@ix.netcom.com
authors.forename: R L
authors.initials: RL
authors.lastname: Whalen
authors.forename: C L
authors.initials: CL
authors.lastname: Richards
authors.forename: G W
authors.initials: GW
authors.lastname: Lim
authors.forename: C W
authors.initials: CW
authors.lastname: Sherman
authors.forename: J C
authors.initials: JC
authors.lastname: Norman
authors.forename: G B
authors.initials: GB
authors.lastname: Bearnson
authors.forename: G L
authors.initials: GL
authors.lastname: Burns
authors.forename: D B
authors.initials: DB
authors.lastname: Olsen
mesh_terms: D000818:Animals; D002417:Cattle; D004558:Electric Stimulation; D004867:Equipment Design; D006353:Heart-Assist Devices; D006801:Humans; D009119:Muscle Contraction / Q000502:physiology*; D018482:Muscle, Skeletal / Q000473:pathology / Q000503:physiopathology*; D013318:Stroke Volume