👉 The term "calculagraph" is a device used in medicine to measure blood flow and pressure. It consists of a series of small tubes, each 1 centimeter long, that are connected end-to-end and are arranged in a grid pattern. The pressure readings from these tubes can be measured using a device called an oscilloscope, which can display the voltage or current across the cathode (the part of the tube where the blood is flowing) and the anode (the part of the
