Photo courtesy of Vincent Van Duysen website.
On our blog we often talk about things around light, or things light can be and can do. Here is another example of what a light can do: measure your blood pressure. Two LED flicker while you wear it on your wrist and an optic sensor “reads” how the blood pulsates.
This technology is known as photoplethysmography. Blood absorbs light and fluctuations of light correlate to heart rate. LED emits light in AC and DC current (alternating current flickers, and direct gives steady light). The waveform of the latter corresponds to the detected transmitted or reflected optical signal from the tissue. DC component also changes slowly with respiration. The AC component shows changes in the blood volume during the phases phases of the cardiac cycle; the fundamental frequency of the AC component depends on the heart rate and is superimposed onto the DC component.
If you ever used such device you might have mused about the choice of green color LEDs. The answer lies in the spectrum or wavelengths (to be even more scientific, between 500 and 600 nm). Green or green-yellow light is much better reflected and detected by a sensor when blood pulsates through skin, and gives a more accurate result compared to infra-red.
From purely medical use, these sensors found their way to popular wearables, and many a runner already tear off their chest-strapped monitors. Devices like my Fitbit combine BPM with distance and speed, sleep monitor and all at a convenience of a wrist-band.
Reference: Paper on Wearable Photoplethysmographic Sensors by Toshiyo Tamura, Yuka Maeda, Masaki Sekine and Masaki Yoshida
This post somehow got incepted and talked about and even written on the plane. Call this serendipity, but light fixtures created by Dan Vakhrameyev and Kateryna Fedorenko have a great load of air in them. No surprise that some of our readers see this post in an airport or perhaps even aboard above the Arabian Gulf.
We got in touch with the duo from Kiev — The Fild — and asked them to tell Light Intelligence about their light fittings.
Dan, Salvador Dali International University Alumni, has started The Fild in 2012. Path to lighting trailed through successful collaborations in the world of fashion and graphic design, when Kateryna Fedorenko and Dan have joined forces. Kateryna has before successfully founded a fashion brand L’UVE and brought with her unique fashion vision.
Their collection Sustainable Origins (SO) consists of eight objects. As Kateryna describes it “Light is simply one of the necessary decorative elements of interior design. We have just expressed the ideas that visited us!” Designers describe their style as clean minimalism and seek inspiration in graphic design. Texture is a key, and to metaphysical light, they add wood and metal.
Dan and Kateryna meticulously select their suppliers and demand only the best quality of LED light sources and gears. Impossible to miss, textile cords that match the color of wooden base, are a sign of good taste.
We loved the suspended linear fixture SO8. A sheet of metal lovingly wraps around the wooden base and leaves an opening just enough for the right amount of light to pour. We won’t be too much far off if we predict this fixture would even meet EN standards for glare control!
Pardon the pun, but there may be a new filed of science happening here. Aetherophosology, we shall call it, with a great load of light in the air.
Visit local Apple reseller. Check.
Visit local Ikea. Check.
Assemble a floor lamp. No check.
Read the manual and assemble the floor lamp properly. Check.
Pair an LED bulb with a phone. Check.
Control and play.
Apparently there are scenarios on IFTTT so that your floor lamp flashes blue if someone tags you on Facebook, and other options.