Rap music not only encourages rhythmic body movements but it now powers the rhythmic action of a rechargeable medical sensor that may potentially help treat people with aneurisms or incontinence due to paralysis.

The driving bass rhythm of rap music can be harnessed to power a new type of miniature medical sensor designed to be implanted in the body, according to a study by researchers at Purdue University.

The authors say the “acoustic waves from music, particularly rap, were found to effectively recharge the pressure sensor.”

Music within a certain range of frequencies, from 200-500 hertz, causes the cantilever in the sensor to vibrate, generating electricity and storing a charge in a capacitor, said Babak Ziaie, a Purdue University professor of electrical and computer engineering and biomedical engineering.

"The music reaches the correct frequency only at certain times, for example, when there is a strong bass component the acoustic energy from the music can pass through body tissue, causing the cantilever to vibrate," said Ziaie.

The cantilever of the sensor stops vibrating when the frequency falls outside the proper range and then then sends the electrical charge to the sensor, which takes a pressure reading and transmits data as radio signals.

As found in the study, the sensor is “capable of monitoring pressure in the urinary bladder and in the sack of a blood vessel damaged by an aneurism.”

"You would only need to do this for a couple of minutes every hour or so to monitor either blood pressure or pressure of urine in the bladder," Ziaie said. "It doesn't take long to do the measurement."

While playing tones within a certain frequency range can be used instead of music, Ziaie said that a plain tone is a “very annoying sound.”

"We thought it would be novel and also more aesthetically pleasing to use music."

After experiencing with four different types of music including rap, blues, jazz and rock, they found that rap worked the best.

"Rap is the best because it contains a lot of low frequency sound, notably the bass," Ziaie said.

The method involves inserting a probe with a catheter, which must be in place for several hours while the patient remains at the hospital, Ziaie explained.

"A wireless implantable device could be inserted and left in place, allowing the patient to go home while the pressure is monitored," Ziaie said.

 

(Findings are detailed in a paper to be presented during the IEEE MEMS conference, which will be Jan. 29 to Feb. 2 in Paris. The paper was written by doctoral student Albert Kim, research scientist Teimour Maleki and Ziaie.)