Comparison of Wired and Wireless Bio-Electrical Impedance Fluid Status Monitoring Devices and Validation to Body Mass and Urine Specific Gravity Changes Following Mild Dehydration
Abstract
Dehydration is a major health and performance risk in military operations and there is a need for rapid, non-invasive and early detection. A fluid status assessment method, ZOE2, is FDA approved for fluid status monitoring. The ZOE2 measures thoracic bio-electrical impedance. A new wireless version of the ZOE2, the ZOE wireless (ZOEW), has been developed and proposed for assessment of fluid status in the field. Some investigations have reported impedance as a valid measure of hydration status in clinical or controlled settings. However, there is speculation as to the utility of bio-electrical impedance post-exercise or in a field setting. The objectives of this study were fourfold: 1) to compare biological measurements of the new ZOEW monitor with the FDA approved and patented ZOE2 monitor currently being used in the healthcare market; 2) to assess the test-retest reliability of the ZOEW monitor; 3) to compare the sensitivity and validity of the ZOEW monitor and the ZOE2 monitor to assess mild hydration status changes post-exercise in a field setting; 4) to assess the usability of the ZOEW monitor. Thirty-two participants from the USAFA Wrestling Team were recruited. Nude body weight, urine specific gravity, ZOE2 and ZOEW measurements were taken before and after a typical 90- minute wrestling practice session. Usability was tested when participants were asked to complete a survey to assess perceptions of ease of use. Similar values were obtained from the ZOE2 and ZOEW monitors. Although both body weight and urine specific gravity changes were significantly different from pre- to post-practice indicating mild dehydration, no significant differences were detected between pre- to post-practice for the ZOE2 or ZOEW device. Bio-electrical impedance, as measured by the ZOEW monitor and the ZOE2 monitor in this study, does not appear to be a valid measure of mild, post-exercise hydration status change as compared to body weight and urine specific gravity.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 18, 2008
- Accession Number
- ADA477629
Entities
People
- Al Wile
- Brandon Doan
- Eric Kozlowski
- Mary Terry
- Michael C Brothers
- Rebecca Mclean
Organizations
- United States Air Force Academy