At Rethinking Healthcare, we've covered topics ranging from ultrasound technology to the latest healthcare iPhone apps. Now, researchers at Worcester Polytechnic Institute have taken healthcare one step further. Ki Chon and his team of researchers have turned a smart phone into a vital sign monitoring app.
In an interview today with SmartPlanet, we caught up with researcher Ki Chon to ask about the vital sign monitoring app. Below is an excerpt of our conversation.
SP: How does the vital sign monitoring app work?
It works by using special signal processing algorithms we have developed that can measure vital signs based on shifts in the light reflected off pulsing blood vessels. So the video camera shines light onto and through the skin of a finger, and the light is reflected back and captured on the video clip. Our application then analyzes the data in that video clip to report the vital signs. In the first phase of the project, we took the video clip from the phone and downloaded it onto a computer and processed it with the algorithms. That was just for proof of principle. Now we have an application that lives right on the phone, processes the data from the video clip, and displays the vital signs right on the phone’s screen.
SP: How does it measure heart rate, heart rhythm, respiration ratem and blood oxygen saturation?
We have previously developed several signal processing algorithms that can extract heart rate, heart rhythms, respiratory rate, and blood oxygen saturation directly from heart rate fluctuations. Given that we can detect pulse signals from a fingertip placed on a video camera, we can derive all of the above mentioned physiological parameters.
SP: How does the video camera work? How is it used?
It’s used just as it’s designed. Nothing special is needed. The user simply starts to record with the light on, and presses his or her finger on the lens.
SP: How many patients was this tested with? How big of a sample group was used?
The first tests were on three graduate students in our lab. Now, a pilot clinical study is underway with colleagues at UMass Medical School in Worcester that will involve 45 patients with atrial fibrillation who will be treated with post cardioversion. We will monitor them before and after treatment, which if successful, returns the patients to normal sinus rhythm.
SP: What were the results of the study? How do you expect this technology to be used in the future?
The results published in the journal IEEE Transactions on Biomedical Engineering show the vital sign app gives results as accurate as the devices now used in hospitals, nursing homes, and clinics. In the future, the vital signs app may be useful for detection of atrial fibrillation. We're also working on developing our technology for use with iPads, or tablets with video cameras.
Image: Ki Chon with student via Worcester Polytechnic Institute