- BACKGROUND
Waste generation is one of the fundamental activity particularly with mankind
as we go about our daily activities, thus, work, exercising, sleeping etc. The
body undergoes metabolism as we take in air, water and food to produce
energy and waste (MFMER,2019). Urine is a waste product of metabolism and
it is it formed in the kidney after the body has undergone its metabolic
activities. The urine contains substances like protein, dead cells, glucose and
others. The increasing and decreasing of the concentration of these
substances will tell of the functionality of the body.
Urinalysis is used as a screening tool to detect substances in the urine
associated with metabolic disorders, urinary tract infections, kidney
dysfunction just to mention few.
Hippocrates around 400 BC recognized urine characteristics (odor /color)
were altered with different diseases. Urinalysis is one of the old laboratory
technique used in medicine. It is performed when one has frequent or painful
urination,abdominal pains as part of the health examination, before one is
admitted at a hospital and also during pregnancy check-up. Urinalysis involves
three main procedures thus;
Physical examination: this check the appearance of the urine like color
and clarity.
Chemical analysis: test chemically for about nine substances that provide
information about health and diseases and determines the concentration
of these substances in a urine.
Microscopic examination: this identifies and counts the cells, crystals,
casts and other components like bacteria and mucus in urine.
The nine substances are leucocytes,nitrite, urobilIinogen,protein, pH, blood,
specific gravity, ketone, bilirubin, glucose. The higher or lower concentration
of any of these substances can helps doctors to determine if indeed one is
suffering from a urinary tract infection or not. It also helps individuals to know
their health conditions.
There are various ways of doing urinalysis and they are;
Manual:involves the use of dipsticks which has chemicals embedded in
pads that reacts with the nine substances when dipped in the urine. After
the dipping, the dipsticks changes and one matches with the range of
colors on the dipstick container and the results recorded.
Semi-automated:Dipstick dipped in urine and inserted in a machine and
the machine analyses and gives out results in a printed form.
Fully automated: this makes no use of a dipstick. The machine picks the
urine and analyses it with results given in a printed form.
The manual type is the one widely used the dipsticks is cheap and is the type
that can easily be purchased unlike the semi-automated, fully automated
which is expensive. The manual types have numerous disadvantages and
some of these problems will be highlighted and expected solution will be
done to make the work of medical personnel easier at the same time
accurate.
PROBLEM
1. Precision of results: when urine is examined visually, determination of the
color or cloudiness sometimes seem challenging due to individual visual
differences which mostly results in different readings.
2. Color interpretation: challenges in the color interpretation sometimes give
inaccurate results. After the dipstick is ready for reading, thus after reacting
with the reagent and now having a color; it becomes difficult to read due to
the different range colors in variation to standard.
3. Conflict result reading: time is an important factor in the urinalysis process.
The nine substances on the dipstick has different time duration for chemical
reactions to occur for the appropriate resulting colors. Leucocyte takes two
minutes before a color will be displayed on the dipstick whiles glucose takes
30 seconds. The difference sometimes makes the reading inaccurate so from
glucose to leucocyte it might be that the two minutes will have overlap and in
a way will give a color which is false or inaccurate.
4. Contamination:contamination of dipsticks either by improper closing of the
dipsticks container or expired dipstick also gives inaccurate results when
used.
EXPECTED SOLUTION
To be able to build a colorimeter that makes use of no dipsticks but will give a
more precise, accurate and faster readings. It is a technique that is
inexpensive,easy to use, portable, and very sensitive. A device for
determining the concentration of a solution by measuring its absorbance of a
specific wavelength of light is called a colorimeter.
Colorimeters are analytical devices commonly used in science labs to
measure the amount of light of a specific wavelength that is absorbed by a
sample. Absorbance is related to concentration (Beer-Lambert Law) so the
greater the concentration (color intensity) of a sample, the greater the
absorbance (A) value. Standard colorimeter consists of an LED and a light
sensor mounted into an enclosure with a cuvette holder. The cuvette holder
positions the sample between the LED and the sensor. The sensor board
connects to an Arduino programmed with the colorimeter firmware via a
simple shield. When the colorimeter is operating, the LED illuminates the
sample in the cuvette with a specific wavelength of light.
There about nine substances for testing as already discussed yet we tend to
first determine protein concentration because it is mostly the indication for
kidney disease. Proteinuriain urine test is the first sign of kidney disease. Both
diabetes and high blood pressure can cause damage to the kidneys which
leads to proteinuria with many risk factors (WebMD, 2019). World Health
Organization has stated that, overall,it is estimated that 5-10 million people die
annually from kidney diseases.
Colorimeter can be used to determine the concentration, pH and turbidity of
urine. A concentrated urine means less water but more solutes. These solutes
are dissolved particles like proteins, sugars, salts. In urinalysis, concentration
of urine is determined based on the amount of water present. Urine
concentration is measured in specific gravity (ratio of the density of urine to
the density of water). With specific gravity the concentration of urine can be
determined. Since we are working with colorimeter, we want to look at the
reagents that they used to react with specific gravity pad on the strip that
gives out color and apply the concept in our work.
Normal urine is clear with a light straw yellow color. A urine becomes turbid
when it looks milky or cloudy. When a cloudy urine is placed in a cuvette for
testing, light passing through the urine, the dead cells and other components
would tend to absorb the incident light and the transmitted light will tell how
turbid the urine is.
MATERIALS
1. White LED
2. Photoresistor
3. White LED
4. Screws
5. Nuts
6. Washers
7. Tongues
8. Glue
9. Mini cuvette
10. Wires
11. Arduino
12. Silicon rubber feet
13. Bread board
14. Acrylic plate
15. SD card to record the data.
LINKS
urinalysis colorimeter.pdf
..\Downloads\Urine - Biology-Online Dictionary _ Biology-Online
Dictionary.html
..\Downloads\Urinalysis - Mayo Clinic files
https://www.healthline.com/health/urine-concentration-test
http://https://www.instructables.com/id/An-Inexpensive-Photometer-andColorimeter
Team Richmond Emmanuella Abigail
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