My New Wearable
In last week’s blog, I wrote about New Year’s resolutions. One of the resolutions I have for this year is to work hard at keeping fit. I try to get in about four workouts each week. “Workout” is a bit of a stretch, in that pretty much my only goal is to just keep doing it. During my workouts I try to measure my heart rate. In the past I’ve used a chest strap synchronized to a watch, which is very accurate at capturing my heart rate. These devices use a conductive smart fabric with built-in microprocessors that analyze the EKG signal to determine heart rate.1
However, unfortunately I lost my carry-on luggage on the Via Rail train a month ago. I had placed it at the front of the train when I boarded and unfortunately it wasn’t there when I went to get off. Unfortunately my chest strap and heart rate monitor watch were in the suitcase.
In seeking out a replacement it became clear to me that the chest strap and watch combination, while accurate and tried and true technology, is somewhat outdated. Always enthralled by new technology, I eagerly started watching many videos on YouTube in search for what modern “wearables” have to offer.
I soon learned that there are many devices out there, most of which use optical sensors for measuring heart rate. The sensors are usually embedded in a watch-like wristband and obviate the need for wearing a chest strap.
While the chest strap measures electrical signals, the modern wearables use optical sensors to measure the heart rate.
Optical heart rate sensors measure your heart rate by shining a microscopic light on your blood vessels and analyzing the amount of light reflected back.2
More specifically, the sensor technology I ended up buying, the Mio Fuse®, uses the following specific technology. “An optical heart rate sensor determines heart rate through a process known as photoplethysmography. The sensor consists of LEDs and an electro-optical cell. The LEDs shine light into the skin, enabling the electro-optical cell to detect the pulsing volume of blood flow. Since blood absorbs light, fluctuations in light level are correlated to heart rate. A traditional sensor measures heart rate differently with two areas that determine heart rate by measuring the bio-electric impulse that occurs when your heart beats. The number of impulses the sensor counts corresponds to the same number of heartbeats over the same amount of time”.4
Wearables are now all the rage. I bought my first wearable, my Fitbit®, about 18 months ago. I have been religiously wearing it ever since, and aspire each and every day to do my 10,000 steps. You may recall my blog from August 2014, http://meds.queensu.ca/blog/?p=2724
In addition to step-trackers like the Fitbit®, there are smartwatches like the Apple® watch, smart glasses like Google Glass®5, virtual retinal displays, fitness socks which measure your stride and cadence,6 and bionic t-shirts with embedded microsensors that measure temperature, heart rate, speed and intensity.7
So gone is my “old-fashioned” chest strap, and I’m armed with my first real “wearable” my new heart rate monitoring wrist band…which by the way, also measures my steps too. The only trouble is, my trusty Fitbit measures about twice as many steps as my new Mio Fuse does. Now which one should I believe?
If you wear a wearable, or have something to add to our understanding of the technology, respond to the blog, or better yet please stop by the Macklem House, my door is always open.