Fluid dose, flow and coagulation sensor for medical instrument

摘要

A method of immunizing the operation of an instrument which determines a characteristic of a biological fluid or a control against noise. The instrument includes a surface upon which a user deposits a sample of biological fluid or control the characteristic of which is to be determined. The instrument irradiates the sample and detects radiation from the sample to determine the characteristic. The method comprises monitoring the detected radiation a first time to determine if the detected radiation is increasing or decreasing, forming a first change in detected radiation from said first monitoring, subsequently monitoring the detected radiation a second time to determine if the detected radiation is increasing or decreasing, forming a second change in detected radiation from said second monitoring, forming an overall change in detected radiation from the first and second monitorings, establishing a first threshold, establishing a second threshold, comparing the first change to the first threshold, comparing the second change to the first threshold, if the magnitudes of both the first and second changes are greater than the first threshold, comparing the overall change in radiation to the second threshold, and determining the characteristic if the magnitudes of the first and second changes are greater than the first threshold and the overall change is greater than the second threshold.