It is
a common experience these days, that whenever we go and consult a
medical practitioner, he usually suggests number of investigative
pathological tests involving blood or urine analysis, scans like X
ray or MR besides ECG using an electrocardiograph. There is always a
debate, whether these are are really required or not in case of each
and every patient, but let us keep that controversy to a side.
Most
of these test are done by specialized pathological laboratories, who
collect your blood or urine samples and give you a report, indicating
the values of blood or urine constituents in some form of units,
unknown to a layman. Fortunately they also give the high and low
limits, within which these values must exist for a normal person,
indicating if there is any abnormality.
Use of
other types of medical instruments also has become very common. These
range includes simple instruments for blood pressure checking, blood
sugar checking, which are used by individuals, to complex scanners
and monitors used in hospitals. .
I have
been often wondering about accuracy of the results obtained from
these instruments as there have been many instances, where results
for the same test from two different laboratories are found to be
differing widely. This should not really come as a surprise or
something that is totally unexpected, as almost all analytical
instruments are always of comparison type, meaning that they would
compare a specimen against a standard specimen and indicate the
variation in percentage terms and their accuracy depends upon the
standard, used in the measurement.
The
process of setting up such an analytical instrument, usually involves
a step called standardization or calibration. In this process, the
instrument is set to zero or some other value using a standard
specimen for measurement. It should be obvious that the accuracy of
reading of an analytical instrument actually depends upon how
accurately the calibration has been done and the genuineness of the
standard.
The
calibration process is not something that is needed only for medical
or pathological instruments. Every measuring instrument needs this
process to set it up. Let us consider the simplest of all measuring
instruments like a measuring tape or a scale or a simple weighing
instrument like a balance. The markings on a measuring tape or a
scale tell us the length of an object, but how do we guarantee that
the reading obtained from a measuring tape or a scale is correct?
Similarly, we note weights of objects by comparing them with standard
weights that are put in other pan of the balance. But how do we
guarantee that these weights, we use for comparison, are of correct
weight?
To
ensure this, each country maintains standards of length, weight etc,
which are again compared with International standards. In India, such
standards of length and weight and maintained by national Physical
laboratory (NPL) in Delhi and each every manufacturer of measuring
instruments is expected to have his own standards, which have been
verified and compared to NPL standards.
Coming
back to the medical and pathological instruments, which tell us about
blood or urine constituents; it is easy to see the need for
calibrating these instruments against standards by a statutory body,
which can certify that the instrument is calibrated and accurate.
Unfortunately, India does not have a single nationally recognized
medical device testing laboratory. The Drugs and cosmetics act has
no regulatory provisions regarding standards. India has regulatory
mechanisms for the pharmaceuticals industry but none for the medical
instruments industry.
India
imports about 70 to 75% of its medical instruments requirements with
balance being locally manufactured in states of Haryana, Noida (UP)
and Gujarat. The Government has now decided to set up three medical
device testing laboratories in these places.
In a
first step towards recognizing medical devices as an industry
separate from the pharmaceuticals industry and requiring different
regulatory standards, the commerce ministry has decided to fund the
setting up of three medical device testing laboratories in Noida
(UP), Haryana and Gujarat, which already have device manufacturing
clusters.
I
think that it is an extremely positive step, which when functional,
would be able to enthuse little more confidence in the hearts of the
patients that the reports received by them are accurate and they have
not been taken for a ride.
17th
February 2015
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