# US 10,309,905 B2 · Method and device for detecting an analyte in a body fluid

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- Number: US 10,309,905 B2
- Document ID: US10309905B2
- Status: Granted
- Kind: B2
- Application number: 15/988,200
- Filed: 2018-05-24
- Published: 2018-09-20
- Granted: 2019-06-04
- Earliest claimed: 2012-06-22
- Assignees: Roche Diabetes Care, Inc.
- Applicants: Roche Diabetes Care, Inc.
- Inventors: Kai Dickopf
- Web page: https://patentgrep.com/patent/US10309905B2

## CPC

- 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)}
- C12Q 1/54: involving glucose or galactose
- G01N 21/78: producing a change of colour
- G06T 7/32: using correlation-based methods
- G06V 10/242: {by image rotation, e.g. by 90 degrees}
- G06V 20/693: {Acquisition}
- G01N 2021/7769: {Measurement method of reaction-produced change in sensor}
- G06T 2207/30024: Cell structures in vitro; Tissue sections in vitro
- G06V 10/245: {by locating a pattern; Special marks for positioning}
- Y10T 436/144444: Glucose
- 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)
- C12Q: MEASURING OR TESTING PROCESSES INVOLVING ENZYMES, NUCLEIC ACIDS OR MICROORGANISMS (immunoassay G01N33/53); COMPOSITIONS OR TEST PAPERS THEREFOR; PROCESSES OF PREPARING SUCH COMPOSITIONS; CONDITION-RESPONSIVE CONTROL IN MICROBIOLOGICAL OR ENZYMOLOGICAL PROCESSES
- G06T: IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
- G06V: IMAGE OR VIDEO RECOGNITION OR UNDERSTANDING
- Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

## Abstract

A method for detecting at least one analyte in at least one sample of a body fluid is disclosed. Therein, at least one test element (124) is used, the at least one test element (124) having at least one test field (162) with at least one test chemistry (154) is used, wherein the test chemistry (154) is adapted to perform at least one optically detectable detection reaction in the presence of the analyte. The method comprises acquiring an image sequence of images of the test field (162) by using at least one image detector (178). Each image comprises a plurality of pixels. The method further comprises detecting at least one characteristic feature of the test field (162) in the images of the image sequence. The method further comprises correcting a relative position change between the image detector (178) and the test field (162) in the image sequence by using the characteristic feature, thereby obtaining a sequence of corrected images.

## Claims

### Claim 1

A method for detecting at least one analyte in at least one sample of a body fluid, wherein at least one test element with at least one test field is used, the at least one test field having at least one test chemistry, wherein the test chemistry is adapted to perform at least one optically detectable detection reaction in the presence of the analyte, wherein the method comprises acquiring an image sequence of images of the test field by using at least one image detector, wherein each image comprises a plurality of pixels, wherein the method further comprises detecting using a control unit at least one characteristic feature of the test field in the images of the image sequence, wherein the method further comprises correcting using the control unit a relative position change between the image detector and the test field in the image sequence by using the characteristic feature, thereby obtaining at least one corrected image.

### Claim 2 (depends on 1)

The method according to claim 1, wherein the detecting of the characteristic feature comprises selecting at least one specific part of one or more images of the image sequence, denoting the information contained in this part as the characteristic feature, wherein other images of the image sequence are scanned or searched for this information or similar types of information.

### Claim 3 (depends on 1)

The method according to claim 1, wherein the correction is individually adapted for each image of the image sequence, according to the characteristic feature detected in the specific image.

### Claim 4 (depends on 1)

The method according to claim 1, wherein the correction of the relative position change comprises using at least one image of the image sequence as a reference image, wherein the reference image is kept unchanged, wherein the remaining images of the image sequence are corrected by using at least one calculational correction of the position of the pixels, wherein the calculational correction is chosen such that a correlation between the reference image and the corrected remaining images of the image sequence is maximized.

### Claim 5 (depends on 4)

The method according to claim 4, wherein the calculational correction comprises at least one of the following:
a shifting of the pixels of the remaining images of the image sequence in at least one spatial direction, wherein the shifting is chosen such that the correlation between the reference image and the corrected remaining images is maximized; or
at least one rotation of the remaining images of the image sequence about at least one rotational axis by at least one rotation angle, wherein one or both of the rotational axis and the rotation angle are chosen such that the correlation between the reference image and the corrected remaining images is maximized.

### Claim 6 (depends on 1)

The method according to claim 1, wherein the characteristic feature comprises at least one feature selected from the group consisting of: a roughness of the test field detectable in the images of the image sequence; a granularity of the test chemistry of the test field detectable in the images of the image sequence; faults of the test field detectable in the images of the image sequence; at least one fiducial mark comprised in the test field and detectable in the images of the image sequence.

### Claim 7 (depends on 6)

The method according to claim 6, wherein the characteristic feature comprises at least two fiducial marks comprised in the test field and detectable in the images of the image sequence.

### Claim 8 (depends on 1)

The method according to claim 1, wherein the sample of the body fluid is applied to the test field during acquisition of the image sequence, wherein at least one touchdown image is detected in the image sequence, wherein the touchdown image is an image of the image sequence acquired at a point in time closest to the moment of application of the sample of the body fluid onto the test field.

### Claim 9 (depends on 1)

The method according to claim 1, wherein the sample of the body fluid is applied to the test field during acquisition of the image sequence, wherein the image sequence comprises a blank image sequence, wherein the blank image sequence comprises a plurality of blank images acquired before applying the sample of the body fluid to the test field, wherein at least one averaged blank image is derived from the blank images of the blank image sequence after performing the correction of the relative position change of the blank images of the blank image sequence.

### Claim 10 (depends on 9)

The method according to claim 9, wherein the averaged blank image is derived in a continuous process during acquiring the images of the image sequence, wherein a preliminary averaged blank image is derived from the corrected blank images acquired so far, wherein new acquired blank images are used for revising the preliminary averaged blank image.

### Claim 11 (depends on 1)

The method according to claim 1, wherein a moment of application of the sample of the body fluid onto the test field is detected in the image sequence.

### Claim 12 (depends on 1)

The method according to claim 1, wherein after application of the sample of the body fluid onto the test field at least one region of interest is determined in the image sequence.

### Claim 13 (depends on 12)

The method according to claim 12, wherein at least one corrected image acquired before or during application of the sample of the body fluid onto the test field is compared to at least one corrected image acquired after application of the sample of the body fluid onto the test field on a pixel-by-pixel basis, thereby generating a difference value for each pixel, wherein the difference value denotes a difference of the information contained in corresponding pixels of the corrected images acquired before or during and after application of the sample of the body fluid onto the test field, wherein the pixels are classified as pixels belonging to the region of interest or as pixels not belonging to the region of interest based on the difference values.

### Claim 14 (depends on 12)

The method according to claim 12, wherein an image mask is generated denoting the pixels belonging to the region of interest.

### Claim 15

A device for detecting at least one analyte in at least one sample of a body fluid, wherein the device comprises at least one test element receptacle for receiving at least one test element having at least one test field with at least one test chemistry, wherein the device further comprises at least one image detector for acquiring an image sequence of images of the test field, wherein the device further comprises at least one control unit, wherein the control unit is adapted to:
acquire an image sequence of images of the test field by using at least one image detector, wherein each image comprises a plurality of pixels,
detecting at least one characteristic feature of the test field in the images of the image sequence, and
correct a relative position change between the image detector and the test field in the image sequence by using the characteristic feature, thereby obtaining at least one corrected image.

### Claim 16

A test system for detecting at least one analyte in at least one sample of a body fluid, the test system comprising: at least one device for detecting at least one analyte in at least one sample of a body fluid and at least one test element having at least one test field with at least one test chemistry, wherein the test chemistry is adapted to perform at least one optically detectable detection reaction in the presence of the analyte, wherein the device comprises at least one test element receptacle for receiving at least one test element having at least one test field with at least one test chemistry, wherein the device further comprises at least one image detector for acquiring an image sequence of images of the test field, where-in the device further comprises at least one control unit, wherein the control unit is adapted to:
acquire an image sequence of images of the test field by using at least one image detector, wherein each image comprises a plurality of pixels,
detecting at least one characteristic feature of the test field in the images of the image sequence, and
correct a relative position change between the image detector and the test field in the image sequence by using the characteristic feature, thereby obtaining at least one corrected image.

### Claim 17 (depends on 16)

The test system according to claim 16, wherein the test system further comprises at least one puncture element, wherein the test system is adapted to puncture at least one skin portion of a user by using the puncture element, thereby creating the sample of the body fluid, wherein the test system is further adapted to transfer the sample of the body fluid onto the test field of the test element.
