Proceedings Article | 4 March 2019
KEYWORDS: Ocean optics, Oxygen, Optical sensing, In vivo imaging, Sensors, Physiology, Medicine, Sensor calibration, Calibration, Ecosystems
Optical oxygen detection in humans is a well-established technology commonly used in different fields, such as research, diving, and healthcare, among others. For measurements in humans, oxygen sensors can be calibrated easily and put on the patient for extended periods of time. For measurements in other species, like marine mammals, existing technologies are inadequate. Management of oxygen stores is a key physiological process that dictates the breath-hold ability of marine mammals. Understanding this physiological specialization is an area of active research that could frame how protected species function within their marine ecosystems, and unlock new therapies to mitigate low oxygen injury in humans. In the present work, we addressed the technology gap by developing an implantable, minimally-disruptive optical oxygen sensor that is encased in a biocompatible soft elastomer. The mechanical properties of the elastomer were tailored to make it elastic, and resistant to rupture. This material is expected to pose less interference in normal muscle movements than a stiff sensor, and is, therefore, more suitable for extended at-sea deployments in marine mammals. The optical components encased in the elastomer are two multiwavelength LEDs and a silicon photomultiplier detector. Different elastomers were tested as biocompatible encasings for the sensor. Among the evaluated parameters were: cell viability, inflammatory response, biodegradability, temperature stability, electroconduction, mechanical properties, and oxygen levels in ex- and in vivo models. In summary, we have developed a biocompatible, implantable, minimally-disruptive, stable optical oxygen sensing probe for studying management of oxygen in the muscle of free diving marine mammals.
