Technical specifications and accuracy of the uChek urine analyzer

Technical specifications and accuracy of the uChek urine analyzer

Report by: Biosense Technologies Pvt Ltd

Date: 18th

April 2013

A) Name of test: uChekTM

urine analyser

B) Type of test : Automated urinalysis system – Qualitative and semi-quantitative

measurements based on reflectance photometry

C) Measurand : Urine pH, glucose, ketone, protein, specific gravity, bilirubin, urobilinogen,

blood, leukocytes and nitrite.

D) Developed by : Biosense Technologies Private Limited

E) Regulatory Information :

Name Regulation Product code Classification

Automated urinalysis

system

21 CFR §862. 2900 KQO I

F) Intended Use :

uChek is a semi-automated urine analyzer intended to be used with commercially available urine

dipsticks like the Siemens Multistix® SG10, Siemens Multistix SG ®, Siemens Uristix ®, Bayer

Diastix ® and Bayer Keto-Diastix ® ; as a test system to semi-quantitatively or qualitatively

measure the specified analytes in urine as follows: glucose, urobilinogen, pH, ketone, occult

blood, protein, bilirubin, nitrite, leukocyte, and specific gravity. Test results may provide

information regarding the status of carbohydrate metabolism, kidney and liver function, acid-

base balance and bacteruria.

uChek is for In Vitro Diagnostic use and only for use by or on the recommendation of a

qualified healthcare professional (Rx only).

G) Device description :

The uChek urinalysis systems is intended for use with Siemens Multistix SG10 ®, Siemens

Multistix SG ®, Siemens Urisitx ®, Bayer Diastix ® and Bayer Keto-Diastix ® reagent strips for the

qualitative and semi-quantita tive determination of urine analytes including glucose,

urobilinogen, pH, ketone, blood, protein, bilirubin, nitrite, leukocyte, and specific gravity. The

test system uses the camera and LED flash of the smartphone in conjuction with the uChek

cuboid to standardise illumination conditions and the uChek color mat which acts as a colour

and positional reference for the image taken. The usage of uChek in Auto mode is illustrated

below, in five simple steps.

H) Substantial equivalence information

Comparison with predicate

Item uChek urine analyser Predicate device

Similarities

Intended Use A semi-automated analyser which is

designed to read test strips for

urinalysis for the measurement of

bilirubin, blood, glucose, ketones,

leukocytes, nitrite, pH, protein,

specific gravity, and urobilinogen.

These measurements are useful in

the evaluation of renal, urinary and

metabolic disorders.

Same

Special Indications For prescription use only Same

Analyzer technology Reflectance photometry Same

Sample matrix Urine Same

Test parameters Glucose, urobilinogen, pH, ketone,

blood, protein, bilirubin, nitrite,

leukocyte, and specific gravity

Similar

Light source LED Same

Differences

Throughput/Tests per hour uChek : 12 tests per hour To the order of hundreds

of tests per hour

Measuring sensor CMOS image sensor Contact image sensor

I) Test Principle :

The uChek system works on the principle of reflectance photometry which analyses the

intensity and color of light reflected from the reagent areas of the urinalysis reagent strip.

Using the light emitting diode (LED) flash of the smartphone as the light source and a

complementary metal oxide semiconductor (CMOS) image sensor module, the optical

system reads the color change in the urine strips after the sample is applied.

J) Analytical performance :

1. Precision/Reproducibility :

The test system was evaluated for precision and reproducibility using two levels of

control materials (Dirui Positive and Negative urine control) . The precision evaluation

was conducted by two operators on the uChek system with iPhone 4, 4S and 5. Results

of both operators combined for iPhone 4, 4S and 5 are summarized below.

Level 1 control (Negative control) – uChek system with iPhone 5 (n= 30)

Analyte Expected result Exact agreement Within +/- 1 color

block

Glucose Negative 100% 100%

Bilirubin Negative 100% 100%

Ketone Negative 100% 100%

SG 1.010 83% 100%

Blood Negative 92% 100%

pH 6.5 95% 100%

Protein Negative 100% 100%

Urobilinogen 0.2 EU/dL 100% 100%

Nitrite Negative 100% 100%

Leukocytes Negative 100% 100%

Level 2 control (Positive control) – uChek system with iPhone 5 (n= 30)


block

Glucose 1000 mg/dl 70% 100%

Bilirubin +++/Large 100% 100%

Ketone 160 mg/dL 90% 100%

SG 1.010 100% 100%

Blood 200 ca cells/uL 80% 100%

pH 6.5 70% 100%

Protein 300 mg/dL 70% 100%

Urobilinogen 4 EU/dL 100% 100%

Nitrite Positive 100% 100%

Leukocytes ++/ 125 ca cells/uL 90% 100%

Level 1 control (Negative control)– uChek system with iPhone 4S (n= 30)


block




SG 1.010 50% 100%


pH 6.5 100% 100%





Level 2 control (Positive control) – uChek system with iPhone 4S (n= 30)


block



Ketone 160 mg/dL 100% 100%

SG 1.010 100% 100%


pH 6.5 50% 100%





Level 1 control (Negative control) – uChek system with iPhone 4 (n= 30)


block




SG 1.010 87% 100%


pH 6.5 100% 100%





Level 2 control (Positive control) – uChek system with iPhone 4 (n= 30)


block



Ketone 160 mg/dL 100% 100%

SG 1.010 100% 100%


pH 6.5 73% 100%





2. Comparison studies

Method comparison with an existing laboratory semi-automated urinalysis

Method comparison studies were performed on urine samples by two operators on

the iPhone 4, 4S and 5. The performance of uChek with Siemens Multistix SG10 ® was compared against Uri-Plus 200 with H10 urine dipsticks from Dirui and

marketed by Aspen Diagnostics Private Limited. It was ensured that the operators

have similar educational levels as the intended users of the device.

Samples were prepared for evaluation of glucose, protein (albumin), blood , pH ,

specific gravity and nitrites by adding specific concentrations of the above analytes

covering the entire reportable range to a negative stock of urine sample obtained

from Dirui. Samples were prepared by serial dilutions of the positive stock of urine

controls obtained from Dirui for evaluation for bilirubin, urobilinogen, ketone and

leukocytes. The summarized results are found in the tables below.

A) uChek with iPhone 5 :

Glucose Predicate device (mg/dL) (n = 75)

NEG 100 250 500 >1000

uChek

>2000 5

1000 10

500 15

250 14

100 13 1

NEG 15 2

Total 15 15 15 15 15

Exact agreement 100% 87% 93% 100% 66%

Within +/- 1 Color

block

100% 100% 100% 100% 100%

Bilirubin Predicate device (mg/dL) (n =60)

NEG 1 2 4

uChek

4 13

2 15 2

1 15

NEG 15

Total 15 15 15 15

Exact agreement 100% 100% 100% 87%

Within +/- 1 Color block 100% 100% 100% 100%

Ketone Predicate device (mg/dL) (n = 90)

NEG 5 15 40 80 160

uChek

160 1 13

80 12 2

40 15 2

15 4 15

NEG 15 11

Total 15 15 15 15 15 15

Exact agreement 100% 0% 100% 100% 80% 87%

Within +/- 1 Color

block

100% 100% 100% 100% 100% 100%

SG Predicate device (n =90)

<=1.005 1.010 1.015 1.020 1.025 >=1.030

uChek

>=1.030 15

1.025 13

1.020 14 2

1.015 1 11 1

1.010 13 4

<=1.005 15 1

Total 15 15 15 15 15 15

Exact agreement 100% 87% 73% 93% 87% 100%

Within +/- 1 Color

block

100% 100% 100% 100% 100% 100%

Blood Predicate device (ca Cells/ uL) (n = 75)

NEG 10 25 80 200

uChek

200 11

80 15 4

25 15

10 11

NEG 15 4

Total 15 15 15 15 15

Exact agreement 100% 73% 100% 100% 73%

Within +/- 1 Color

block

100% 100% 100% 100% 100%

pH Predicate device (n = 45)

<=5.0 6.0 6.5 7.0 7.5 8.0 >=8.5

uChek

>=8.5 15

8.0

7.5 1

7.0 13

6.5 1

6.0

<=5.0 15

Total 15 15 15

Exact agreement 100% 87% 100%

Within +/- 1 Color

block

100% 100% 100%

Protein Predicate device (mg/dL) (n = 75)

NEG TRACE 30 100 >=300

uChek

>=2000

300 15

100 11

30 13 4

TRACE 2 11 2

NEG 13 4

Total 15 15 15 15 15

Exact agreement 87% 73% 87% 73% 100%

Within +/- 1 Color

block

100% 100% 100% 100% 100%

Urobilinogen Predicate device (EU/dL) (n = 75)

0.2 1 2 4 8

uChek 8 6

4 15 9

2 3 15

1 2 12

0.2 13

Total 15 15 15 15 15

Exact agreement 87% 80% 100% 100% 40%

Within +/- 1 Color block 100% 100% 100% 100% 100%

Nitrite Predicate device (n = 30)

NEG POS

uChek POS 15

NEG 15

Total 15 15

Exact agreement 100% 100%

Within +/- 1 Color block 100% 100%

Leukocytes Predicate device (ca CELLs/uL) (n = 60)

NEG 15 70 125 500

uChek

500

125 1 11

70 4 13 4

NEG 15 11 1

Total 15 15 15 15



B) uChek with iPhone 4S :


NEG 100 250 500 >1000

uChek

>2000 1

1000 14

500 15

250 11

100 15 4

NEG 15

Total 15 15 15 15 15

Exact agreement 100% 100% 73% 100% 93%

Within +/- 1 Color

block

100% 100% 100% 100% 100%


NEG 1 2 4

uChek

4 2 13

2 13 2

1 15

NEG 15

Total 15 15 15 15




NEG 5 15 40 80 160

uChek

160 12

80 12 3

40 13 3

15 7 15 2

NEG 15 8

Total 15 15 15 15 15 15

Exact agreement 100% 0% 100% 87% 80% 80%

Within +/- 1 Color

block

100% 100% 100% 100% 100% 100%


<=1.005 1.010 1.015 1.020 1.025 >=1.030

uChek

>=1.030 15

1.025 14

1.020 13 1

1.015 2 12 2

1.010 12 3

<=1.005 15 1

Total 15 15 15 15 15 15

Exact agreement 100% 80% 80% 87% 93% 100%

Within +/- 1 Color

block

100% 100% 100% 100% 100% 100%


NEG 10 25 80 200

uChek

200 15

80 14

25 3 12 1

10 12 3

NEG 15

Total 15 15 15 15 15

Exact agreement 100% 80% 80% 93% 100%

Within +/- 1 Color

block

100% 100% 100% 100% 100%


<=5.0 6.0 6.5 7.0 7.5 8.0 >=8.5

uChek

>=8.5 15

8.0

7.5 2

7.0 12

6.5 1

6.0

<=5.0 15

Total 15 15 15


Within +/- 1

Color block

100% 100% 100%


NEG TRACE 30 100 >=300

uChek

>=2000

300 15

100 15

30 11

TRACE 13 4

NEG 15 2

Total 15 15 15 15 15

Exact agreement 100% 87% 73% 100% 100%

Within +/- 1 Color

block

100% 100% 100% 100% 100%


0.2 1 2 4 8

uChek 8 9

4 13 6

2 1 15 2

1 12

0.2 15 2

Total 15 15 15 15 15

Exact agreement 100% 80% 100% 87% 60%



NEG POS

uChek POS 15

NEG 15

Total 15 15




NEG 15 70 125 500

uChek

500

125 2 13

70 9 13 2

NEG 15 6

Total 15 15 15 15



C) uChek with iPhone 4 :


NEG 100 250 500 >1000

uChek

>2000

1000 2 15

500 1 13

250 8

100 15 6

NEG 15

Total 15 15 15 15 15

Exact agreement 100% 100% 53% 87% 100%

Within +/- 1 Color

block

100% 100% 100% 100% 100%


NEG 1 2 4

uChek

4 15

2 15

1 15

NEG 15

Total 15 15 15 15




NEG 5 15 40 80 160

uChek

160 5 15

80 3 10

40 12

15 10 15

NEG 15 5

Total 15 15 15 15 15 15

Exact agreement 100% 67% 100% 80% 67% 100%

Within +/- 1 Color

block

100% 100% 100% 100% 100% 100%


<=1.005 1.010 1.015 1.020 1.025 >=1.030

uChek

>=1.030 15

1.025 14

1.020 15 1

1.015 1 14

1.010 13 1

<=1.005 15 1

Total 15 15 15 15 15 15

Exact agreement 100% 87% 93% 100% 93% 100%

Within +/- 1 Color

block

100% 100% 100% 100% 100% 100%


NEG 10 25 80 200

uChek

200 5 15

80 7 10

25 2 8

10 8

NEG 15 5

Total 15 15 15 15 15

Exact agreement 100% 53% 53% 67% 100%

Within +/- 1 Color

block

100% 100% 100% 100% 100%


<=5.0 6.0 6.5 7.0 7.5 8.0 >=8.5

uChek

>=8.5 15

8.0

7.5 1

7.0 13

6.5 1

6.0

<=5.0 15

Total 15 15 15


Within +/- 1

Color block

100% 100% 100%


NEG TRACE 30 100 >=300

uChek

>=2000

300 15

100 15

30 15

TRACE 2 15

NEG 13

Total 15 15 15 15 15

Exact agreement 87% 100% 100% 100% 100%

Within +/- 1 Color

block

100% 100% 100% 100% 100%


0.2 1 2 4 8

uChek 8 15

4 2 15

2 2 13

1 10

0.2 15 3

Total 15 15 15 15 15

Exact agreement 100% 67% 87% 100% 100%



NEG POS

uChek POS 15

NEG 15

Total 15 15




NEG 15 70 125 500

uChek

500

125 2 12

70 6 13 3

NEG 15 9

Total 15 15 15 15



3. Limitations

a) uChek is limited by the performance and quality of the urinalysis reagent strip used.

This includes all false positive and negative reactions due to interfering chemicals in a

urine sample.

b) uChek cannot be used to measure non-haemolysed occult blood in urine.

c) Trace values of ketones and trace values of leukocytes are not included in the

reportable range.

d) uChek does not compensate for urine colour. A heavily pigmented urine sample may

lead to a false reading.

4. Reportable range

Test Reportable Range

Urobilinogen 0.2,1, 2,4, and 8 EU/dL

Glucose Neg, 100, 250, 500 , 1000 and 2000mg/dL

Bilirubin Neg, 1 (+), 2 (++) and 4 (+++) mg/dL

Ketones Neg, 15, 40, 80 and 160 mg/dL

Specific Gravity 1.000, 1.005, 1.010, 1.015, 1.020, 1.025, 1.030

Blood Neg, 10, 50,80 and 200 RBC/ ul

pH 5, 6, 6.5, 7, 7.5, 8, 8.5

Protein Neg, 15, 30, 100, 300 and >=2000mg/dL

Nitrite Neg, 10mg/dL

Leukocytes Neg, 70, 125, and 500 Leu/μl

5. Quality control and calibration

The uChek color mat contains eight reference colours which are used to assess the

quality of the image taken by the smartphone camera. In the event, an image of poor

quality is taken and/or the strip is moved out of the camera overlay, the test is rendered

invalid and a suitable error message is displayed.

Conclusion and note from authors

The uChek urine analyzer was found to be accurate with 100% readings within +/- 1 color block of

the urine test strip used. It may be concluded that the accuracy of the uChek urine analyzer is

comparable to the Uri-Plus 200 and other similar commercially available semi-automated urinalysis

machines in the predicate product classification.

Documents

Technical specifications and accuracy of the uChek urine analyzer