for just understanding various POCT devices and their basic principles.

1. Point of care testing
Dr. Kamal Modi

2. Definition
When a test is performed at a time
At which test results enables a decision to be made
And an action taken
That leads to an improved health outcome.

3. patient
doctor
request
phlebotomy
transport
register
prepare
analysis
Quality control
validate
report
transmit
interpret

4. Advantages
Reduced turn around time
Improved patient morbidity & mortality
Reduction in hospital admission
Improved interaction between patient
and carer
Reduction in clinical visits
Improved cost of care
Reduction in administrative work associated
With test requesting & reporting

5. Disadvantages
Increase in administrative work associated with training and
Certification of operators
Caregivers required to perform test
Increased risk of errors

6. Classification of types
Single use Multiple use quantitative
Cartridge/ bench-top devices
Qualitative
cartridge/strip
Quantitative
cartridge/strip
With reader device

7. Analytical Principle
 Reflectance
 Lateral flow or flow through immunoassays
 Electrochemistry
 Electrical impedance

8. Reflectance
e.g.
Urine and blood
dipsticks for glucose and
various other analytes.

9. Electrochemistry
Strip device
Cassette and bench-top
device

10. Glucose strip
A. Electrode sensors
B. Separating layer

11. Principle of Electrochemical Glucose strip

12. Glucose meter
A negative voltage of –0.4 V is applied at the reference electrode.
When blood or a glucose solution is placed in the strip, a chemical reaction
occurs inside it, generating a small electrical current proportional to the
glucose concentration

13. Bench-top Devise

14. Principle
Measurement of
PH, PCO2, PO2,
Electrolyte, Glucose,
Lactate.

15. Cassette device

17. Lateral flow immunoassays
It is a biological sensors in
which the recognition
agent is an antibody that
binds to the analyte.
e.g. measurement of
troponin T , myoglobin,
and D-dimer.

19. Electric Impedance
• Based on Coulter principle
• As fluid containing particles
or cells is drawn through
each micro-channel, each
particle causes a brief
change to the electrical
resistance of the liquid.
• The counter detects these
changes in electrical
resistance.
• E.g. complete blood count

20. Unresolved Queries ???

Use of following principle in
POCT

Light scattering / optical motion

Immunoturbidometry

Fluorescence

Multiwavelength
spectrophotometry