title: Model-based correction of the influence of body position on continuous segmental and hand-to-foot bioimpedance measurements.
abstract: Bioimpedance spectroscopy (BIS) is suitable for continuous monitoring of body water content. The combination of body posture and time is a well-known source of error, which limits the accuracy and therapeutic validity of BIS measurements. This study evaluates a model-based correction as a possible solution. For this purpose, an 11-cylinder model representing body impedance distribution is used. Each cylinder contains a nonlinear two-pool model to describe fluid redistribution due to changing body position and its influence on segmental and hand-to-foot (HF) bioimpedance measurements. A model-based correction of segmental (thigh) and HF measurements (Xitron Hydra 4200) in nine healthy human subjects (following a sequence of 7 min supine, 20 min standing, 40 min supine) has been evaluated. The model-based compensation algorithm represents a compromise between accuracy and simplicity, and reduces the influence of changes in body position on the measured extracellular resistance and extracellular fluid by up to 75 and 70%, respectively.
authors.affiliation: Philips Chair for Medical Information Technology (MedIT), Helmholtz-Institute for Biomedical Engineering, RWTH Aachen University, Pauwelsstrasse 20, 52074, Aachen, Germany. medrano@hia.rwth-aachen.de
authors.forename: Guillermo
authors.initials: G
authors.lastname: Medrano
authors.forename: Frank
authors.initials: F
authors.lastname: Eitner
authors.forename: Marian
authors.initials: M
authors.lastname: Walter
authors.forename: Steffen
authors.initials: S
authors.lastname: Leonhardt
mesh_terms: D000328:Adult; D000465:Algorithms; D001834:Body Water / Q000378:metabolism*; D058266:Dielectric Spectroscopy / Q000379:methods; D017097:Electric Impedance; D005260:Female; D006801:Humans; D008297:Male; D008954:Models, Biological; D008991:Monitoring, Physiologic / Q000379:methods*; D011187:Posture / Q000502:physiology; D055815:Young Adult
references.citation: Physiol Meas. 2006 Sep;27(9):921-33
references.pmid: 16868355
references.citation: Acta Physiol Scand. 1995 Oct;155(2):157-63
references.pmid: 8669288
references.citation: J Physiol. 1993 May;464:407-22
references.pmid: 8229810
references.citation: J Appl Physiol (1985). 2005 Aug;99(2):780-1
references.pmid: 16020450
references.citation: Eur J Med Res. 1999 Jul 28;4(7):264-70
references.pmid: 10425263
references.citation: Med Biol Eng Comput. 2006 Oct;44(10):873-82
references.pmid: 16964519
references.citation: IEEE Trans Biomed Eng. 2004 Jan;51(1):166-75
references.pmid: 14723506
references.citation: Am J Clin Nutr. 1996 Sep;64(3 Suppl):423S-427S
references.pmid: 8780358
references.citation: Annu Int Conf IEEE Eng Med Biol Soc. 2007;2007:3934-7
references.pmid: 18002860
references.citation: Med Biol Eng Comput. 2009 Jan;47(1):77-84
references.pmid: 18797950
references.citation: Am J Clin Nutr. 2007 Jan;85(1):80-9
references.pmid: 17209181
references.citation: Med Biol Eng Comput. 2004 May;42(3):356-65
references.pmid: 15191082
references.citation: Kidney Int. 1997 Apr;51(4):1078-87
references.pmid: 9083273
references.citation: Clin Nutr. 2003 Apr;22(2):153-7
references.pmid: 12706132
references.citation: J Appl Physiol (1985). 1998 Aug;85(2):497-504
references.pmid: 9688726
references.citation: Med Biol Eng Comput. 2009 Feb;47(2):153-63
references.pmid: 18853214
references.citation: Am J Physiol. 1986 Jan;250(1 Pt 2):H68-75
references.pmid: 3942238
references.citation: Physiol Rev. 1971 Jul;51(3):527-63
references.pmid: 4950077
references.citation: Med Biol Eng Comput. 2009 Oct;47(10):1093-102
references.pmid: 19820978
references.citation: ASAIO J. 2010 May-Jun;56(3):215-20
references.pmid: 20404719
references.citation: Med Biol Eng Comput. 2009 Dec;47(12):1265-71
references.pmid: 19888612
references.citation: Scand J Clin Lab Invest. 1982 Apr;42(2):131-8
references.pmid: 7134797
references.citation: J Med Eng Technol. 1999 Mar-Apr;23(2):45-52
references.pmid: 10356673
references.citation: Surg Gynecol Obstet. 1948 Oct;87(4):472-5
references.pmid: 18119801
references.citation: Am J Physiol. 1948 Mar 1;152(3):471-91
references.pmid: 18863145
references.citation: Acta Physiol Scand. 1993 Aug;148(4):379-85
references.pmid: 8213193