This paper presents the implementation results of a colorimetric algorithm for portable blood gas analysis. The need for diagnostic data to be available from the patient's living environment has given rise to the need for portable diagnostic equipment. Blood gas analysis is an important diagnostic tool which provides the medical practitioner with insights in to the health of the respiratory system and kidneys. Present day analysers are big, bulky, and expensive and run on mains supply. The paper discusses the implementation of an algorithm based on the change of colour of an indicator with respect to the change in pH. The algorithm maps the change in colour to a mathematical equation. The equation is implemented using floating point arithmetic architectures. The paper presents the implementation of the algorithm using the Altera Stratix FPGA and 0.35μm CMOS process. The design is aimed low power consumption and size. The design met the timing constraints for an operating speed of 50 MHz and consumes 2.78W of power.