Friday, January 11, 2013

Acoustic systems design

The pain associated with a kidney stone can be very severe. As anyone who has ever had one will testify, the pain tends to come in waves and can be so great that it can cause individuals to double over in agony.

Medical professionals recognize the symptoms caused by such stones, after which they usually perform an x-ray scan to determine their location and size. When the x-rays pass through soft body tissues, they cause the x-ray film to turn black. But when a calcium stone is present the x-ray cannot pass through it and the image of the stone shows up as white on the x-ray image.

If kidney stones cannot be dissolved by drugs, the favored procedure is lithotripsy. Lithotripsy works by focusing shock waves onto the kidney stones in an effort to break them into pieces small enough to pass out of the body. After the procedure, another x-ray is taken to see if the procedure has been successful in clearing the kidney stone.

Now, researchers in the UK led by Professor Tim Leighton from Southampton University (Southampton, UK) in collaboration with Guy's and St Thomas' Foundation Trust (GSTT) and Precision Acoustics (Dorchester, UK) have developed an acoustic instrument called the "smart stethoscope" that also aims to assess whether the lithotripsy treatment is working, obviating the need for more x-rays.

In operation, a transducer is placed on a patient's skin as they undergo shock wave treatment for kidney stones, and the smart stethoscope system the transducer is attached to analyzes the characteristics of the acoustic signals from the stone after each shock wave has hit it. By doing so, it can determine whether the treatment has been effective or not at breaking it up.

According to Dr. Fiammetta Fedele of GSTT, the instrument has diagnosed successful treatments with 94.7 per cent accuracy in clinical trials. The UK National Health Service (NHS) is now trialing the smart stethoscope as part of major plans to reduce inaccurate diagnoses and ineffective treatments, and so far GSTT has used the sensor on over 200 patients.

What fascinates me most about this development is that is that it represents an acoustic alternative to a well established tried and tested imaging approach that has served the medical field well for years.

Of course, characterizing materials and products by analyzing their acoustic properties in industrial settings is nothing new. However, it's usually the case that such acoustic scanning systems are deployed because of their unique abilities to find hidden defects within assemblies and materials that can occur during manufacturing, characteristics that pure vision-based systems are unable to spot.

But the work by the UK researchers at Southampton University shows that there is scope to develop such acoustic systems in industry as a direct replacement for vision-based inspection systems. And I'd be pleased to hear from any of our readers who might have done just that.

No comments:

Post a Comment