Monday, February 8, 2010
Here lies one of our difficulty in popularizing the 'Heart Sound Analyzer', a VERY low cost non-invasive primary diagnostic solution from Dept. of Electronics & ECE, IIT Kharagpur, a winner of DST Lockheed Martin India Innovation Growth Program 2009. That it is non-invasive and zero risk in nature, that invasive technology should not be abundantly used specially as primary diagnostic tool, that for cases where something suspicious is found in primary analysis a more detailed observation can be made from invasive ultrasound based technology etc... are finding roadblocks for popular misconceptions such as these. BBC News healthcare medical notes put ultrasound based echocardiography in 'Non-invasive' category. Here is the link.
I had to fight a lot with a senior person holding important portfolio in a VERY big multinational medical device manufacturer company at IKMC 2009 ( http://www.ikmc2009.com ) who was pushing their echocardiogram as non-invasive device and are trying to market a reduced feature version for mass-market saying it is absolutely safe. After contradicting him I gave him and the audience at Taj GVK, the reference of the British Medical Ultrasound Society (BMUS) safety guidelines
I am surprised to see the ignorance around non-invasiveness of a medical device where general population are held under a misconception and given a false sense of security by calling a invasive device non-invasive. Simply speaking, from these devices high power ultrasound signal invades the body and gets reflected back which is analyzed. The high energy signal when absorbed by body cell can affect kinetics of chemical reaction, cause cavitaion etc. depending on amount of temperature rise and thus is potentially harmful. Higher power level and higher duration give better image/information (in the reflected wave) but that are more harmful to human body. It depends on the operator if he is following safety guidelines or more importantly educated about safety issues. Even then, under pressure (if he does not get a good reflected image and his efficiency questioned) he might overshoot the limits.
However, this post is to address a more fundamental issue, whether an invasive device can be marketed as non-invasive. My little experience shows that here is where engineering professionals are fooling medical professionals. A physician does not see any incision, neither the ultrasound is visible (so is X-Ray, but it is much more harmful so nobody tries to market X-ray as non-invasive), what he finds a reflected image where inside body parts are moving and he feels that movement itself generating the image/video itself and the device is non-invasive.
Let me end this post by quoting BMUS safety guidelines. Much harsher words about potential safety hazards are used by others but surprisingly are never highlighted.
"Despite its apparent excellent safety record, ultrasound imaging involves the deposition of energy in the body, and should only be used for medical diagnosis, with the equipment only being used by people who are fully trained in its safe and proper operation. It is the scan operator who is responsible for controlling the output of the ultrasound equipment. This requires a good knowledge of scanner settings, and an understanding of their effect on potential thermal and mechanical bio-effects.
A fundamental approach to the safe use of diagnostic ultrasound is to use the lowest output power and the shortest scan time consistent with acquiring the required diagnostic information."