Bad medicine sings false
September 19, 2018 10:27 AM   Subscribe

Musical instrument goes flat in presence of adulterated medicine (Ars Technica). Heran C. Bhakta, Vamsi K. Choday, and William H. Grover at the Grover Lab in the Department of Bioengineering, University of California, Riverside have figured out a way to modify an mbira to turn the instrument into or allow people to make an inexpensive sensor, when paired with a digital audio recorder, such as an iOS or Android phone, and the lab's online sound analysis tool. Full description in their paper Musical Instruments As Sensors (ACS Omega, 2018, DOI: 10.1021/acsomega.8b01673).

The abstract:
The frequencies of notes made by a musical instrument are determined by the physical properties of the instrument. Consequently, by measuring the frequency of a note, one can infer information about the instrument’s physical properties. In this work, we show that by modifying a musical instrument to contain a sample and analyzing the instrument’s pitch, we can make precision measurements of the physical properties of the sample. We used the mbira, a 3000-year-old African musical instrument that consists of metal tines attached to a wooden board; these tines are plucked to play musical notes. By replacing the mbira’s tines with bent steel tubing, filling the tubing with a sample, using a smartphone to record the sound while plucking the tubing, and measuring the frequency of the sound using a free software tool on our website, we can measure the density of the sample with a resolution of about 0.012 g/mL. Unlike existing tools for measuring density, the mbira sensor can be made and used by virtually anyone in the world. To demonstrate the mbira sensor’s capabilities, we used it to successfully distinguish diethylene glycol and glycerol, two similar chemicals that are sometimes mistaken for each other in pharmaceutical manufacturing (leading to hundreds of deaths). We also show that consumers could use mbira sensors to detect counterfeit and adulterated medications (which represent around 10% of all medications in low- and middle-income countries). We expect that many other musical instruments can function as sensors and find important and lifesaving applications.
posted by filthy light thief (9 comments total) 33 users marked this as a favorite
 
I can't tell where the fluid is located in some of those examples in the video. For example, in the clip where they are testing the river water, it just looks like a flat board. Where is the sample? Isn't it inside the mbira?
posted by This_Will_Be_Good at 11:21 AM on September 19, 2018


It's inside the bent U-shaped tube:

By replacing the mbira’s tines with bent steel tubing, filling the tubing with a sample, using a smartphone to record the sound while plucking the tubing
posted by Lexica at 11:48 AM on September 19, 2018 [1 favorite]


It's so beautifully simple, I love it, doubly so as an alternative to expensive, finicky hardware. I also love the hopeful note the end of the abstract:

"We expect that many other musical instruments can function as sensors and find important and lifesaving applications."
posted by filthy light thief at 12:14 PM on September 19, 2018


In an episode of Star Trek: Voyager (S1:E9 "Prime Factors"), the function of an "Atmospheric Sensor" that looks like a futuristic harp is explained: "The frequency of the chimes indicates changes in weather conditions."

When I watched last night, I thought: Why would a scientific device ever be constructed in such a way? And here, today, is the answer.
posted by tummy_rub at 1:07 PM on September 19, 2018 [5 favorites]


This is just excellent. Thanks for sharing!
posted by freethefeet at 3:15 PM on September 19, 2018


I am seldom this delighted by ingenuity. Thanks for the post.
posted by Johnny Wallflower at 9:45 PM on September 19, 2018


In this case sufficiently advanced technology really does look like magic!

I can imagine an alchemist in a medieval court using this to protect the Prince from poisoners.
posted by monotreme at 9:55 PM on September 19, 2018 [3 favorites]


This is really neat.

That a hand-held computer with hifi audio inputs and an astonishingly accurate clock is cheaper (when including other uses) than a well-made balance and a few volume-labeled sample containers suggests that making predictions about the future of technology is harder than I usually imagine.
posted by eotvos at 2:24 AM on September 20, 2018 [2 favorites]


Grover's group also made the news with a $12 piezoelectric sensor with nanogram sensitivity using the same concept.

Resonant frequency shift has been the basis for cutting edge techniques for weighing things like individual atoms or individual living cells. It's cool that they're finding new ways to apply it that are both genuinely useful and within reach of so many people.
posted by mubba at 7:16 AM on September 20, 2018 [2 favorites]


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