A bit more than a year ago, in one of my first news writeups on this site, I gave my upbeat hands-on assessment of a pulse-monitoring application called Azumio. The program leverages the built-in image sensor and LED illumination resources of modern smartphones and tablets. After you press your finger against both of them, Azumio looks for minute skin color changes reflective of periodic blood flow and uses the variation to calculate your pulse rate with surprising (at least to me) accuracy.
Later that same year, I told you about Philips' Vital Signs Camera application, which has quickly become one of Alliance founder Jeff Bier's favorite embedded vision demonstrations. Vital Signs tackles a more substantial challenge than Azumio in at least three key respects:
- It doesn't leverage supplemental illumination, instead relying on normal ambient illumination (with the qualifier that its accuracy notably improves with adequate room light)
- It doesn't require skin tone close-ups, instead discerning minute blood flow-induced facial color oscillations from a foot or more away, and
- It calculates not only pulse rate but also respiration, in the latter case by measuring the rise and fall of the subject's chest caused by his or her expanding and contracting lungs
Earlier this summer, researchers at MIT made public the to-date outcome of their work to amplify video frame-to-frame variations that would normally be invisible to the naked eye. The primary example they showcased was…you guessed it…pulse rate monitoring, although as the video below makes clear, this is only one of many possible applications for the technology.
For more on MIT's breakthrough, see the following additional coverage sources:
And more recently, a $4.99 application called Cardiio was released in the Apple iTunes App Store. The company is founded by a group of MIT Media Lab Ph.Ds; their relationship (if any) to the above-mentioned researchers is unknown to me. Although Cardiio costs $4 more than Philips' Vital Signs Camera and doesn't also measure respiration, it's also not restricted to the iPad 2 (and "New iPad") and iPhone 4S (at least for pulse rate measurement purposes; Vital Signs Camera will still assess respiration on older Apple devices). I can (and plan to) install Cardiio on my two iPhone 4 handsets, my first-generation iPad and my iPod touch. Stay tuned for my evaluation results. And until then, check out the additional coverage at GigaOm and TechCrunch.