VHDL implementation of the Biostator II glucose control algorithm for critical care

This paper presents the hardware implementation and optimisation of the Biostator II algorithm for control of blood glucose in the hospital. Elevated blood glucose levels occur frequently in hospitalised patients suffering from acute illness and needs to be controlled to minimise secondary complications. Unlike previous efforts, we use subcutaneous glucose sensing, minimising risks and discomfort associated with the intravenous route. Implemented in VHDL, the algorithm is geared towards integration in a CMOS ASIC, combining sensor instrumentation as well as serving as the core for a portable, reliable and affordable system for safe and effective control of blood glucose in hospitalised patient using commercially available subcutaneous continuous glucose sensors and intravenous insulin pumps. The algorithm has been successfully tested in hardware using a commercially available simulator of type 1 diabetes mellitus subjects. It achieves good control with the adults subjects being 98.7% in target with a mean blood glucose of 134.67 mg/dl and the adolescent subjects being 93.56% in target with a mean blood glucose of 126.01 mg/dl.