Slashdot Mirror
More Effective Ultrasound Using Naval Sonar Tech
Makarand writes "With obesity levels skyrocketing in the west it is becoming necessary to find
more reliable ways of effectively scanning obese patients using ultrasound
especially when the organ of interest in under layers of fat resulting in
poor ultrasound images. Latest advances in ultrasound are increasing the accuracy of
the imaging systems by using image enhancement methods borrowed
from the Navy's sonar equipment according to this BBC News article. The Navy's sonar techniques effectively double the resolution in
ultrasound systems. The technology could be in hospitals within a year."
It was mine detection, actually, but the joke was great anyway.
There are two parts to the new trick. One is to change the signal the device sends out to a broadband pulse, but the main part is the software to tease the extra information out of the echo.
I'm picturing some British slashdotter coding away frantically while scarfing down typical programmer food, wondering if his new invention will help him in time.
There is a bit more information on this horribly laid-out page. I haven't found the patent application yet, maybe someone with better access to British patents can help out here. Also nothing scholarly on the web that I can find. Who did the work?
Free book: Science Toys You Can Make
As a grad student studying the physics of ultrasound, I wish there were more details. It sounds like this company has announced some image processing technique that improves both navy sonar and medical ultrasound. Here's a little background about how ultrasound quality decreases with depth.
There are (at least) two issues when it comes to seeing through layers of fat: attenuation and beam spreading. Both of these are fundamental to the physics of ultrasound.
Attenuation refers to the decrease in amplitude in the ultrasound wave as it passes through a medium. The effect is exponential with depth, so that if at some point the amplitude is 10, at some later point it is 10 e^(-a d), where d is the distance between the two points and a is the attenuation coefficient (a property of the medium). This limits how far ultrasound can penetrate in tissue since the signal can quickly get to be about the same magnitude as electronic noise.
The other problem is beam spreading. You need a narrow "beam" of ultrasound to be able to know where an object is the field of view. The width of the beam is related to how well you know the size of the object. Just like with a flashlight, the further you are from the source, the wider the "beam". With a wider beam, you know the size of an object with less precision, hence you have less image resolution.
Both of these are problems that could be reduced with image processing. But the company's web site is down and there are few details in the article.