While our glucose testing technology is a forerunner in the field of biochemistry, the biochemical sensor has experienced a long course of development. The earliest chemical sensor can be dated back more than one hundred years, with the invention of the H ⁺ ion selective electrode. The biosensor developed from Leland C. Clark’s (1918–2005) invention of the enzyme electrode in the mid-1960s. Then, during the 1980’s, Japanese research scientist Motoaki.Shichiri MD, PHD started his sensor experiments on the human body in the late 1980’s, The University of California, San Diego started to experiment with glucose sensors on diabetic dogs. And in the early 1990’s, Eli Lilly Corporation's patent technology of hypodermic glucose sensor was purchased by the U.S Minimed Corporation, approved by the FDA at the end of 1999, and came into the market with the name of CGMS (Continuous Glucose Monitoring System) system that same year. In May, 2005, the “short-term” continuous glucose examination system of DEXCOM was approved by the FDA, and in November, 2005, the Chinese SFDA authorized San Meditech’s Dynamic glucose monitoring system (DGMS®).