It seems this year (2016) is the year that biomedical engineers will show off the most. It's almost June and we've seen dozens of amazing new technologies being developed in the biomedical industry that pertain to wearable technology. The latest piece of gear that could be improving our lives is a device that would listen to the cracks in our knees. A Professor Omer Inan, who graduated from Stanford University and is now at the Georgia Institue of Technology has invented a device that uses sound sensors to listen to the sound of joints rubbing together. This would have benefits for doctors in terms of diagnosing the problems with a knee without having to x-ray as the first resort. 

The following video will play an amplified sound of a patient's knee which might make you wince. You've been warned. 

Omer Inan - from the School of Electrical and Computer Engineering at Georgia Tech- says: "We use piezoelectric film microphones and these are contact microphones, they don't measure sound and air, but they measure the vibrations of the surface of the skin." The data that is measured into a computer displays similar traits to an EKG scan, and thereby the engineers and scientists would be able to determine the health of a knee. 

The benefit of this sensory device will also lead to a future of tracking the progress of how an injured knee repairs itself. The device was funded through the Defense Advanced Research Projects Agency (DARPA) who were asking engineers to submit proposals for wearable technologies. DARPA is hoping that the devices will also assist soldiers in the military who have "repeat battlefield knee injuries." "What most people don't know is that musculoskeletal injuries of the knees and ankles are among the top reasons for discharge for active duty service members," said Inan. He also sees a future where it would help with athletes and elderly patients.

The researchers have published their findings in the IEEE Xplore Library under the title, Novel Methods for Sensing Acoustical Emissions from the Knee for Wearable Joint Health Assessment

The good thing about the human body is that the right and the left knees have similar acoustic measurements. Thank goodness. Otherwise, the engineers might have had their work cut out for them. They say in the abstract of their journal:

Conclusion: We reccommend using air microphones for wearable joint sound sensing; for practical implementation of contact microphones in a wearable device, interface noise must be reduced. Importantly, we show, that airborne signals can be measured consistently and that healthy left and right knees often produce a similar pattern in acoustic emissions. 


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