Modeling and realizing biological mechanisms on FPGA chip

We explore the feasibility of the study by considering a simplified blood-pressure regulation mechanism done by the kidney. The concept of this mechanism is illustrated as follows. If the blood pressure (bp) decreases, the activity of the sympathetic neural (sn)system increases, the renal blood flow (rf) decreases, the sodium excretion (Na⁺) decreases which leads to an increase (stabilization) in the blood pressure. A VHDL-behavioral modeling of the mechanism is shown below. In the modeling, the normal value of the blood pressure is assumed to be 17 units (any other value could have been assumed). To show that sn increases if bp decreases, we use a simple formula sn=(constant¹-bp)+constant². The simulation shows that the mechanism is working successfully. The simulation has been downloaded into a Xilinx FPGA XC4005. The chip behaves identically to the simulation