Accession Number : AD0439353


Title :   THORACIC CAGE IMPEDANCE MEASUREMENTS. TISSUE RESISTIVITY IN VIVO AND TRANSTHORACIC IMPEDANCE AT 100 KC


Corporate Author : MINNESOTA UNIV MINNEAPOLIS


Personal Author(s) : Kinnen, Edwin ; Kubicek, William ; Hill, P ; Turton, G


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/439353.pdf


Report Date : Mar 1964


Pagination or Media Count : 21


Abstract : Average volume resistivities for thoracic tissues at an exciting frequency of 100 kc. are required for studies of the current flux paths in transthoracic impedance plethysmography. By using a uniquly designed probe and anesthetized dogs, an average tissue resistivity was found for skeletal muscle to be approximately 400 ohm cm; heart muscle, 450 ohm cm; lung tissue, 1,200 to 1,500 ohm cm; kidney and liver, 600 ohm cm; fat, 1,000 to 2,000 ohm cm; and for whole canine blood, 150 ohm cm at a hematocrit of 45. With the exception of whole blood, all values varied significantly between dogs and between individual readings. The values for lung and liver tissues and for fat were noted to have particularly large variations between readings and between animals. Canine skeletal muscle tissue had a linear electrical resistivity characteristic for excitation current densities up to 80 ma./sq cm. Representative normal, human skin on the bicepts was shown to contribute approximately 4.5 x 10 to the minus 3rd power of electrode surface area in series with the transthoracic impedance, with possible modifications required for electrode geometry and electrode paste. (Author)


Descriptors :   *THROAT , FREQUENCY , ELECTRODES , GEOMETRY , MUSCLES , SKIN(ANATOMY) , DOGS


Subject Categories : Anatomy and Physiology


Distribution Statement : APPROVED FOR PUBLIC RELEASE