# US 5,710,622 A · Fluid dose, flow and coagulation sensor for medical instrument

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- Number: US 5,710,622 A
- Document ID: US5710622A
- Status: Granted
- Kind: A
- Application number: 08/478,409
- Filed: 1995-06-07
- Granted: 1998-01-20
- Earliest claimed: 1993-08-31
- Assignees: Boehringer Mannheim GmbH
- Inventors: Gary T. Neel; James R. Parker; Rick L. Collins; David E. Storvick; Charles L. Thomeczek, Jr.; William J. Murphy; George R. Lennert; Morris J. Young; Daniel L. Kennedy
- Web page: https://patentgrep.com/patent/US5710622A

## CPC

- G01N 35/00594: {Quality control, including calibration or testing of components of the analyser}
- G01N 11/06: by timing the outflow of a known quantity
- G01N 21/0303: {Optical path conditioning in cuvettes, e.g. windows; adapted optical elements or systems; path modifying or adjustment (G01N21/031 - G01N21/15 take precedence)}
- G01N 21/0332: {with temperature control (control of temperature G05D23/00; cryostats F17C3/08)}
- G01N 21/8483: {Investigating reagent band (test-element handling not specific to a test method G01N33/4875; analytical elements specific to chemical analysis of biological material G01N33/52; autometer with reagent band G01N35/04)}
- G01N 33/4905: {Determining clotting time of blood (by chemical methods G01N33/86, C12Q1/56)}
- G01N 35/00693: {Calibration}
- G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q)

## Abstract

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.

## Claims

### Claim 1

A method of determining a characteristic of a biological fluid or a control using an instrument, the instrument including a surface upon which a user deposits a sample of biological fluid or control the characteristic of which is to be determined, the instrument irradiating the sample and detecting radiation from the sample to determine the characteristic, the method comprising the steps of 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.

### Claim 2 (depends on 1)

The method of claim 1 further comprising the step of determining if the detected radiation is negative relative to a reference at the beginning of the first time, at the end of the first time, at the beginning of the second time, and at the end of the second time.

### Claim 3 (depends on 2)

The method of claim 2 wherein the end of the first time is the beginning of the second time.

### Claim 4

A method of immunizing the operation of an instrument which determines a characteristic of a biological fluid or a control using an instrument, the instrument including a surface upon which a user deposits a sample of biological fluid or control the characteristic of which is to be determined, the instrument irradiating the sample and detecting radiation from the sample to determine the characteristic, the method comprising the steps of establishing first, second and third thresholds, 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 if the magnitude of the detected radiation during the first time is greater than the first threshold, 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 if the magnitude of the detected radiation during the second time is greater than the first threshold, comparing the first and second changes to the second threshold if the magnitudes of the detected radiation during both the first and second times are greater than the first threshold, forming an overall change in detected radiation from the first and second monitorings, comparing the overall change to the third threshold if the magnitudes of the detected radiation during both the first and second times are greater than the first threshold and the magnitudes of both the first and second changes are greater than the second threshold, and determining the characteristic if the magnitudes of the detected radiation during the first and second times are greater than the first threshold, the magnitudes of the first and second changes are greater than the second threshold, and the overall change is greater than the third threshold.