Santorio Santorio

Santorio was the first to use a wind gauge, a water current meter, the pulsilogium (a device used to measure the pulse rate), and a thermoscope.[7] Whereas he invented the former two devices, it is possible that the puslilogium was inspired by his friend Galileo Galilei or Paolo Sarpi, both members of Santorio's learned circle of friends in Venice.[8]

Sanctorio sitting in the balance that he made to calculate his net weight change over time after the intake and excretion of food stuffs and fluids.

He also invented a device which he called the "trocar" (not identical to the modern trocar) for removing bladder stones.[9]

Santorio introduced the thermoscope in the work titled Sanctorii Sanctorii Commentaria in Artem medicinalem Galeni in 1612.[10]

The pulsilogium was probably the first machine of precision in medical history. Extensive experimentation with his new tool allowed Santorio to standardise the Galenic rationale of the pulse and to describe quantitatively various regular and irregular frequences.[11] A century later another physician, de Lacroix, used the pulsilogium to test cardiac function.[12]

Sanctorius studied the so-called perspiratio insensibilis or insensible perspiration of the body, already known to Galen and other ancient physicians, and originated the study of metabolism.[13] For a period of thirty years Santorio used a chair-device to weigh himself and everything he ate and drank, as well as his urine and feces. He compared the weight of what he had eaten to that of his waste products, the latter being considerably smaller because for every eight pounds of food he ate, he excreted only 3 pounds of waste.[14] Santorio also applied his weighing device to study his patients, but records of these experiments have been lost.[13]

His notable conclusion on finding this was that:

Insensible Perspiration is either made by the Pores of the Body, which is all over perspirable, and cover’d with a Skin like a Net; or it is performed by Respiration through the Mouth, which usually, in the Space of one Day, amounts to about the Quantity of half a Pound, as may plainly be made appear by breathing upon a Glass.[7]

This important experiment is the origin of the significance of weight measurement in medicine.[15] While his experiments were replicated and augmented by his followers and were finally surpassed by those of Lavoisier in 1790, he is still celebrated as the father of experimental physiology. The "weighing chair", which he constructed and employed during this experiment, is also famous.[12][14]