New sensor for fitness tracking
Osram Opto Semiconductors is optimizing its portfolio for the optical measurement of pulse rates and blood oxygen levels
11.08.2015 | Fachpresse
The new SFH 7060 sensor from Osram Opto Semiconductors is designed to measure pulse rates and the oxygen saturation level of blood. It offers excellent signal quality and low energy consumption. The main applications for this component include mobile devices such as smartwatches and fitness armbands – also known as wearables – for continuously monitoring fitness levels. The integrated optical sensor contains five light emitting diodes with three different wavelengths and one high-sensitivity photodiode.
SFH 7060 is a further development of optical sensor SFH 7050, which Osram presented in the fall of 2014. It performs the same functions as its predecessor but has improved power consumption and signal quality. SFH 7060 consists of three green LEDs, one red LED, one infrared LED and one large-format photodiode, which is optically separated from the emitters by an opaque barrier. It works by shining light into the skin. Different amounts of this light are absorbed by blood and the surrounding tissue. The light not absorbed is reflected to the detector. Absorption measurements with different wavelengths are used to determine the pulse rate and the saturation level of oxygen in the blood.
Efficient and reliable pulse measurements
Green light is best for measuring the pulse at the wrist. SFH 7060 is equipped with three green LEDs with a wavelength of 530 nanometers (nm) based on the latest high-efficiency UX:3 chip technology from Osram Opto Semiconductors. At their optimum operating point at a current of 20 milliamperes, they are particularly efficient and typically deliver an optical output of 3.4 milliwatts at a voltage of 3.2 V per chip. The higher light output compared with SFH 7050 results in better signal quality and more stable pulse measurements. The low power consumption also means long battery life in the device.
More accurate blood oxygen measurements
Oxygen saturation in your blood is calculated from the different absorption rates of red (660 nm) and infrared (940 nm) light. The quality of the measurements depends to a large extent on the achievable signal-to-noise ratio and on the linearity of the photodetector. The integrated photodiode with its active surface of 1.3 mm x 1.3 mm meets these requirements perfectly. In addition, the distance between the two transmitters and the photodiode in the SFH 7060 is greater than in the SFH 7050. This means the light penetrates deeper into the skin before it is reflected to the detector, which leads to more stable signals and a better signal-to-noise ratio. As in the case of its predecessor, the wavelength of the red transmitter is specified with a very narrow tolerance of ± 3 nm to ensure accurate measurements. The spectral bandwidth of the infrared and green LEDs is 30 nm in each case.
The new sensor is Osram Opto Semiconductors’ latest addition to its portfolio for fitness tracking applications, designed to meet all the latest needs. “The market for fitness tracking with the aid of wearables is growing at a rapid pace, and some of the requirements that the components have to meet are also changing fast”, explained Dr. Jörg Heerlein, Senior Marketing Manager at Osram Opto Semiconductors. “We are working very closely with our customers so that we are always in a position to offer suitable products continuously and speedy.” Users can now choose between a highly efficient solution designed for pule rate measurements, an extremely compact sensor for combined pulse rate and blood oxygen measurements and a slightly larger version with the same but significantly improved functionality.
|Dimensions||7.2 mm x 2.5 mm x 0.9 mm|
|Wavelength||530 nm / 660 nm / 940 nm|
|Optical output (per green LED) at 20 mA||3.4 mW|
|Photo-sensitive area||1.7 mm²|
OSRAM of Munich, Germany is one of the two leading light manufacturers in the world. The company's portfolio covers the entire value chain from components – including lamps, electronic control gear and opto semiconductors such as light-emitting diodes (LED) – as well as luminaires, light management systems and lighting solutions. OSRAM has around 34,000 employees worldwide and generated revenue of more than €5.1 billion in fiscal 2014 (ended September 30). The company's business activities have been focusing on light – and hence on quality of life – for over 100 years. The company was listed on the stock exchanges in Frankfurt and Munich on July 8, 2013 (ISIN: DE000LED4000; WKN: LED 400; Trading symbol: OSR).
Additional information can be found at www.osram.com.
This document contains statements and information pertaining to our future business and financial performance and future developments that may constitute forward-looking statements – i.e. statements about processes that take place in the future, not in the past. These statements pertaining to the future can be identified by expressions such as "anticipate", "expect", "want", "intend", "plan", "believe", "aspire", "estimate", "will”, "predict" or words of similar meaning. Such statements are based on current expectations and certain assumptions of OSRAM‟s management. They are, therefore, subject to certain risks and uncertainties. A variety of factors, many of which are beyond OSRAM‟s control, affect OSRAM‟s operations, performance, business strategy and results and could cause the actual results, performance or achievements of OSRAM to be material different from any future results, performance or achievements that may be expressed or implied by such forward-looking statements or anticipated on the basis of historic trends. These factors include in particular, but are not limited to the matters described in the chapter “Report on Risks and Opportunities” in the Annual Report of OSRAM Licht Group. Should one or more of these risks or uncertainties materialize, or should underlying assumptions prove incorrect, actual results, performance or achievements of OSRAM may vary materially from those described in the relevant forward-looking statement as being expected, anticipated, intended, planned, believed, sought, estimated or projected. OSRAM neither intends, nor assumes any obligation, to update or revise these forward-looking statements in light of developments which differ from those anticipated. Due to rounding, numbers presented throughout this and other documents may not add up precisely to the totals provided and percentages may not precisely reflect the absolute figures they reference.