title: Monitoring and regulating latissimus dorsi muscle performance for circulatory assist.
abstract: The purposes of this study were monitoring and regulating latissimus dorsi muscle (LDM) performance with muscle internal pressure and thickness, and with burst stimulation parameters, respectively. The unconditioned LDM flap of a pig was connected to a measurement system to examine force and contraction length. Internal pressure was measured using a catheter pressure transducer with a fluid-filled balloon inserted into the muscle, and correlated linearly with force during both contraction and relaxation. During contraction, thickness change correlated linearly with contraction length and the area enclosed within an internal pressure-thickness curve, and the X-axis was correlated linearly with muscle work. Stroke work increased incrementally according to the pulse width up to 6.72 msec or burst rate up to 120 Hz, and then plateaued at 240 Hz. The authors conclude that muscle work during contraction could be monitored with internal pressure and thickness, and that stroke work could be regulated with pulse width or burst rate.
authors.affiliation: First Department of Surgery, Gifu University School of Medicine, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Takagi
authors.forename: H
authors.initials: H
authors.lastname: Hirose
authors.forename: E
authors.initials: E
authors.lastname: Sasaki
authors.forename: M
authors.initials: M
authors.lastname: Imaizumi
authors.forename: T
authors.initials: T
authors.lastname: Hirota
authors.forename: M
authors.initials: M
authors.lastname: Bando
authors.forename: Y
authors.initials: Y
authors.lastname: Furuzawa
authors.forename: S
authors.initials: S
authors.lastname: Murakawa
authors.forename: Y
authors.initials: Y
authors.lastname: Mori
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D018421:Cardiomyoplasty; D002404:Catheterization; D004558:Electric Stimulation; D009119:Muscle Contraction / Q000502:physiology; D009126:Muscle Relaxation / Q000502:physiology; D018482:Muscle, Skeletal / Q000502:physiology*; D011312:Pressure; D013552:Swine