Submitted on October 1, 2004
Accepted on February 22, 2005
Variants of the Tissue-Sensor Array Window Chamber
Milan T Makale1, Peter C Chen1, and David A Gough1*
1 Bioengineering, University of California San Diego, La Jolla, California, USA
* To whom correspondence should be addressed. E-mail: dgough{at}bioeng.ucsd.edu.
Sensors are being developed that can be implanted in tissues for continuous monitoring of oxygen, glucose and other metabolites. However, there have been difficulties in inferring metabolite concentrations in blood from the signals of tissue sensors due to the properties of tissues at the implant site and local physiologic phenomena that can affect sensor responses. A multi-sensor array has been previously developed for implantation in a hamster skinfold window chamber preparation to study these effects. The preparation allows recording of concentration-dependent signals from multiple sensors while non-destructively visualizing the adjacent tissue and microvascular function. Variants of the tissue-sensor array window chamber described here have respective advantages over the original chamber design, including improved tissue visualization and reduced surgical intervention, and allow exposure of the sensor to different tissues. Results indicate that mass transfer within tissues is heterogeneous and sensor signals are affected by variable perfusion of local microvasculature, in addition to vascular metabolite concentration. These observations suggest new strategies for sensor design and operation. Window chamber variants are important tools for validation of implanted sensors.
