Method and apparatus for determining ketosis

A method for determining ketosis, comprising:

• providing gas detection means with a gas generated from a body fluid collected from an animal other than humans;
• and
• determining ketosis of the animal based on a composition of the gas generated from the body fluid using a response of the gas detection means to the gas generated from the body fluid,
• wherein the gas detection means is a gas sensor, the gas sensor being a surface stress sensor, the response of the gas detection means is a signal output from the surface stress sensor, and the determining of ketosis is performed based on a pattern of a temporal change in the signal output from the surface stress sensor,
• wherein the gas generated from the body fluid and a purge gas are alternately supplied to the surface stress sensor, and the determining of ketosis is performed using the signal output from the surface stress sensor corresponding to the gas generated from the body fluid and the signal output from the surface stress sensor corresponding to the purge gas,
• wherein an offset treatment is performed to the signal output from the surface stress sensor, a reference point of the offset treatment is set at an end point of a time frame during which the purge gas is given to the surface stress sensor, and a determination point is set at an arbitrary time point when a certain time has elapsed from an end of a time frame during which the gas generated from the body fluid is supplied to the surface stress sensor, and
• wherein the body fluid is selected from the group consisting of milk, blood, urine, saliva, and sweat.