Inexpensive physiological recording system of didactic and formative value

A physiological recording system using inexpensive elements was designed and built by a group of bioengineering students. Three consecutive upgrading stages were developed over a 26-week physiology course period: (1) a single-channel mechanical recorder (for myograms) with a long and very light wooden dowel and an arrangement of pulleys and levers; (2) a two-channel recorder (mechanical and electrical) by means of an inductive proximity transducer; and (3) digital data acquisition and display using adequate A/D conversion, a Commodore 128, and the GRAPHICS 1 software with a joystick. The instrument showed good performance plus excellent value in generating enthusiasm and motivation in the students.< >