Model-Based Design is a path from algorithm to hardware implementation, and in this case, a full custom mixed-signal integrated circuit for Class III implantable medical products. For applications like these, custom integrated circuit die area and power consumption are critical for circuit performance as these parameters translate directly to device size and device longevity. The model is used for design exploration and algorithm validation. The model is transformed to an RTL description using HDL Coder™. The model is refined to meet power and area constraints while iterating between HDL simulation results and model parameters to create the lowest possible power design. This presentation shows a typical design flow of modeling, validating, and implementing an algorithm into a custom ASIC. The steps in taking the design into an ASIC simulation environment to validate power and area are also presented.