technical specifications and accuracy of the uchek urine analyzer
TRANSCRIPT
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)
Analyte Expected result Exact agreement Within +/- 1 color
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)
Analyte Expected result Exact agreement Within +/- 1 color
block
Glucose Negative 100% 100%
Bilirubin Negative 100% 100%
Ketone Negative 100% 100%
SG 1.010 50% 100%
Blood Negative 100% 100%
pH 6.5 100% 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 4S (n= 30)
Analyte Expected result Exact agreement Within +/- 1 color
block
Glucose 1000 mg/dl 60% 100%
Bilirubin +++/Large 100% 100%
Ketone 160 mg/dL 100% 100%
SG 1.010 100% 100%
Blood 200 ca cells/uL 100% 100%
pH 6.5 50% 100%
Protein 300 mg/dL 63% 100%
Urobilinogen 4 EU/dL 100% 100%
Nitrite Positive 100% 100%
Leukocytes ++/ 125 ca cells/uL 100% 100%
Level 1 control (Negative control) – uChek system with iPhone 4 (n= 30)
Analyte Expected result Exact agreement Within +/- 1 color
block
Glucose Negative 100% 100%
Bilirubin Negative 100% 100%
Ketone Negative 97% 100%
SG 1.010 87% 100%
Blood Negative 97% 100%
pH 6.5 100% 100%
Protein Negative 100% 100%
Urobilinogen 0.2 EU/dL 73% 100%
Nitrite Negative 100% 100%
Leukocytes Negative 100% 100%
Level 2 control (Positive control) – uChek system with iPhone 4 (n= 30)
Analyte Expected result Exact agreement Within +/- 1 color
block
Glucose 1000 mg/dl 60% 100%
Bilirubin +++/Large 100% 100%
Ketone 160 mg/dL 100% 100%
SG 1.010 100% 100%
Blood 200 ca cells/uL 100% 100%
pH 6.5 73% 100%
Protein 300 mg/dL 73% 100%
Urobilinogen 4 EU/dL 90% 100%
Nitrite Positive 100% 100%
Leukocytes ++/ 125 ca cells/uL 87% 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
Exact agreement 100% 73% 87% 73%
Within +/- 1 Color block 100% 100% 100% 100%
B) uChek with iPhone 4S :
Glucose Predicate device (mg/dL) (n = 75)
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%
Bilirubin Predicate device (mg/dL) (n =60)
NEG 1 2 4
uChek
4 2 13
2 13 2
1 15
NEG 15
Total 15 15 15 15
Exact agreement 100% 100% 87% 87%
Within +/- 1 Color block 100% 100% 100% 100%
Ketone Predicate device (mg/dL) (n = 90)
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%
SG Predicate device (n =90)
<=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%
Blood Predicate device (ca Cells/ uL) (n = 75)
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%
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 2
7.0 12
6.5 1
6.0
<=5.0 15
Total 15 15 15
Exact agreement 100% 80% 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 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%
Urobilinogen Predicate device (EU/dL) (n = 75)
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%
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 2 13
70 9 13 2
NEG 15 6
Total 15 15 15 15
Exact agreement 100% 60% 87% 87%
Within +/- 1 Color block 100% 100% 100% 100%
C) uChek with iPhone 4 :
Glucose Predicate device (mg/dL) (n = 75)
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%
Bilirubin Predicate device (mg/dL) (n =60)
NEG 1 2 4
uChek
4 15
2 15
1 15
NEG 15
Total 15 15 15 15
Exact agreement 100% 100% 100% 100%
Within +/- 1 Color block 100% 100% 100% 100%
Ketone Predicate device (mg/dL) (n = 90)
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%
SG Predicate device (n =90)
<=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%
Blood Predicate device (ca Cells/ uL) (n = 75)
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%
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 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%
Urobilinogen Predicate device (EU/dL) (n = 75)
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%
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 2 12
70 6 13 3
NEG 15 9
Total 15 15 15 15
Exact agreement 100% 0% 87% 100%
Within +/- 1 Color block 100% 100% 100% 100%
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.