Continuous Monitoring of Tissue Blood Lactate in the Field

Blood lactate concentration is a highly sensitive measure of tissue oxygen deprivation from trauma and blood loss, which produces shock in wounded personnel. It is the most reliable end pint of resuscitation and predictor of survivability. Development ofa rugged, compact device capable of continuously monitoring tissue blood lactate in the field is extremely desirable and is the goal of this Phase II program. The key novel component is a silicon microprobe, comparable in cross-section to a human hair,containing an integrated electrochemical lactate biosensor. This biosensor microprobe protrudes subcutaneously from a small button-like device firmly affixed to the skin, continuously measures lactate, and a co-packaged telemetry chip transmits the datato a suitable receiver. Silicon microprobes possessing high strength, flexibility, and fracture toughness are an advanced development from extensive MEMS (Micro-Electro-Mechanical Systems) R&D in the proposer's laboratory. Integrating miniaturizedbiosensors into out unique silicon microprobes will produce low cost disposable continuous lactate monitors which are painless and easy to use. The Phase I work to date has successfully miniaturized biosensors to an area of 1000 mm2, suitable forintegeration with silicon microprobes. These new miniature biosensors can be placed onto a structure the size of a human hair, whereas existing biosensors are a thousand times larger. The goal of Phase II is to improve performance of these lactatesensors, develop practical fabrication techniques, design and implement device packaging and attachment methods, and evaluate system performance by animal and human testing.