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Title: Wireless Monitoring of Liver Hemodynamics In Vivo

Abstract

Liver transplants have their highest failure rate in the first two weeks following surgery. There are no devices for continuous, real-time monitoring of the graft, currently. Here, we present a continuous perfusion and oxygen consumption monitor based on photoplethysmography. The sensor is battery operated and communicates wirelessly with a data acquisition computer which provides the possibility of implantation provided sufficient miniaturization. In two in vivo porcine studies, the sensor tracked perfusion changes in hepatic tissue during vascular occlusions with a root mean square error (RMSE) of 0.125 mL/min/g of tissue. We show the possibility of using the pulsatile wave to measure the arterial oxygen saturation similar to pulse oximetry. This signal is used as a feedback to extract the venous oxygen saturation from the DC levels. Arterial and venous oxygen saturation changes were measured with an RMSE of 2.19 and 1.39% respectively when no vascular occlusions were induced. The resulting error increased to 2.82 and 3.83% when vascular occlusions were induced during hypoxia. These errors are similar to the resolution of the oximetry catheter used as a reference. This work is the first realization of a wireless perfusion and oxygenation sensor for continuous monitoring of hepatic perfusion and oxygenation changes.

Authors:
 [1];  [2];  [3];  [3];  [1];  [4]
  1. Texas A & M Univ., College Station, TX (United States). Dept. of Biomedical Engineering
  2. Univ. of Pittsburgh, PA (United States). Dept. of Surgery; Veterans Affairs Healthcare System, Pittsburgh, PA (United States)
  3. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
  4. Univ. of California, Irvine, CA (United States)
Publication Date:
Research Org.:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Org.:
National Institutes of Health (NIH)
OSTI Identifier:
1366361
Grant/Contract Number:
AC05-00OR22725; #5R01-GM077150
Resource Type:
Journal Article: Accepted Manuscript
Journal Name:
PLoS ONE
Additional Journal Information:
Journal Volume: 9; Journal Issue: 7; Journal ID: ISSN 1932-6203
Publisher:
Public Library of Science
Country of Publication:
United States
Language:
English
Subject:
60 APPLIED LIFE SCIENCES; 59 BASIC BIOLOGICAL SCIENCES; Liver; perfusion monitoring; oxygenation; wireless sensing

Citation Formats

Akl, Tony J., Wilson, Mark A., Ericson, M. Nance, Farquhar, Ethan, Cote, Gerard L., and Brody, James P. Wireless Monitoring of Liver Hemodynamics In Vivo. United States: N. p., 2014. Web. doi:10.1371/journal.pone.0102396.
Akl, Tony J., Wilson, Mark A., Ericson, M. Nance, Farquhar, Ethan, Cote, Gerard L., & Brody, James P. Wireless Monitoring of Liver Hemodynamics In Vivo. United States. doi:10.1371/journal.pone.0102396.
Akl, Tony J., Wilson, Mark A., Ericson, M. Nance, Farquhar, Ethan, Cote, Gerard L., and Brody, James P. Mon . "Wireless Monitoring of Liver Hemodynamics In Vivo". United States. doi:10.1371/journal.pone.0102396. https://www.osti.gov/servlets/purl/1366361.
@article{osti_1366361,
title = {Wireless Monitoring of Liver Hemodynamics In Vivo},
author = {Akl, Tony J. and Wilson, Mark A. and Ericson, M. Nance and Farquhar, Ethan and Cote, Gerard L. and Brody, James P.},
abstractNote = {Liver transplants have their highest failure rate in the first two weeks following surgery. There are no devices for continuous, real-time monitoring of the graft, currently. Here, we present a continuous perfusion and oxygen consumption monitor based on photoplethysmography. The sensor is battery operated and communicates wirelessly with a data acquisition computer which provides the possibility of implantation provided sufficient miniaturization. In two in vivo porcine studies, the sensor tracked perfusion changes in hepatic tissue during vascular occlusions with a root mean square error (RMSE) of 0.125 mL/min/g of tissue. We show the possibility of using the pulsatile wave to measure the arterial oxygen saturation similar to pulse oximetry. This signal is used as a feedback to extract the venous oxygen saturation from the DC levels. Arterial and venous oxygen saturation changes were measured with an RMSE of 2.19 and 1.39% respectively when no vascular occlusions were induced. The resulting error increased to 2.82 and 3.83% when vascular occlusions were induced during hypoxia. These errors are similar to the resolution of the oximetry catheter used as a reference. This work is the first realization of a wireless perfusion and oxygenation sensor for continuous monitoring of hepatic perfusion and oxygenation changes.},
doi = {10.1371/journal.pone.0102396},
journal = {PLoS ONE},
number = 7,
volume = 9,
place = {United States},
year = {Mon Jul 14 00:00:00 EDT 2014},
month = {Mon Jul 14 00:00:00 EDT 2014}
}

Journal Article:
Free Publicly Available Full Text
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Citation Metrics:
Cited by: 5works
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