In Vivo Inductive Phase Shift Measurements to Detect Intraperitoneal Fluid

• Published in: IEEE transactions on biomedical engineering Vol. 54; no. 5; pp. 953 - 956
• Main Authors: Gonzalez, Csar A., Horowitz, Liana, Rubinsky, Boris
• Format: Journal Article
• Language: English
• Published: United States IEEE 01.05.2007; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Abdomen; Animals; Bioelectric phenomena; Bleeding; Body Fluids - physiology; Body Weight; Computer Simulation; Electric Impedance; Electric variables measurement; Electromagnetic measurements; Electromagnetic Phenomena - methods; Electrophysiology - methods; Frequency measurement; In vivo; induction; Infusion Pumps; Infusions, Parenteral; intraperitoneal; Isotonic Solutions - chemistry; magnetic; Male; Models, Theoretical; Phase detection; Phase measurement; phase shift; Rats; Rats, Sprague-Dawley; Sodium Chloride - administration & dosage; Sodium Chloride - chemistry; Spectroscopy; Spectrum Analysis - instrumentation; Spectrum Analysis - methods; Tomography
• ISSN: 0018-9294; 1558-2531
• DOI: 10.1109/TBME.2006.889183

Four different volumes of physiological saline were infused into the abdominal cavity of rats and the resulting inductive phase shift in the bulk of the abdomen was measured with a noncontact electrical induction system, built to measure phase shift in the bulk of the body in the frequency range from 1 MHz to 8.5 MHz. This experimental study shows that inductive bulk measurements of phase shift have the potential to detect changes in intraperitoneal fluid in vivo with measurements made at frequencies higher than approximately 1 MHz. The experiments also show that the bulk phase shift increases as a function of frequency and fluid volume in a way that is qualitatively consistent with earlier theoretical predictions