Measurement of Electrical Signals in the Intestine Allison Redmond and Kevin Parton Advised by: Dr. Bill Richards, M.D. Dr. Alan Bradshaw, Ph.D. Dr. Scott Seidel, M.D.

Overview of Physiology Consists of ileum, jejunum, and duodenum Composed of smooth muscle Involuntary response Important to body’s uptake of nutrients and removal of wastes

Electrical Signals in the Intestine? All muscle conducts electrical impulses to be active Manifested as BER –Basic Electrical Rhythm –10-12 cycles per minute This electrical activity can be measured

Problem Intestine can be ischemic –Lack of blood flow –leads to necrosis Necrotic bowel must be removed –surrounded by “gray areas” –need to check periodically Causes need for additional surgery

Group Purpose Electrodes can be introduced –attached to recording equipment Values can be taken –propagation velocity –amplitude –frequency Can be diagnostic –extra surgeries not necessary

Our Objective Tissue Impedance can be measured –Done on surface and in body Known values not available Impedance should change with necrosis –We will test in rabbits Our hope is that this will lead to better assessment of overall function

Past Work Determine best method for investigating tissue impedance. Learn to use LR-700 AC Resistance Bridge. Call Linear Research Inc. for technical assistance.

Current Work Design connection from impedance meter to electrodes Gather materials Begin assembly Test meter accuracy on sciatic nerve of frog

Future Work Test electrodes on a rabbit to determine the correct configuration. Using our connector device, test bowel impedance of a rabbit during ischemia. If there is significant change, begin construction of a medically suitable impedance meter.