US Patent No. 9,103,748


Patent No. 9,103,748
Issue Date August 11, 2015
Title Method For Detecting Microorganisms And Microorganism Detecting Apparatus
Inventorship Mitsuaki Koyama, Sayama (JP)
Shunichi Wakamatsu, Sayama (JP)
Wakako Shinobu, Sayama (JP)
Assignee NIHON DEMPA KOGYO CO., LTD., Tokyo (JP)

Claim of US Patent No. 9,103,748

1. A method for detecting microorganisms, comprising:
providing a piezoelectric vibrator having electrodes formed on both faces;
supplying a culture medium layer, which is an absorption layer, on the electrode on one face side of the piezoelectric vibrator,
wherein the culture medium layer comprises a sterilized agar medium having a layer thickness of 0.1 ?m to 1 ?m, and a sample
solution in which microorganisms which are detection targets are mixed; and

oscillating the piezoelectric vibrator by an oscillation circuit and measuring an oscillation frequency of the piezoelectric
vibrator causing a proliferation of said microorganisms,

detecting a rate of proliferation of microorganisms is obtained based on a change over time in the oscillation frequency caused
by a mass increase of the microorganisms proliferating in the absorption layer during said oscillating.