Wireless sensor breakthrough: Datacom via contact lens

Swiss startup puts MEMS sensor, ASIC, RF link in a tiny package that gathers and sends real-time data.

03/30/2010


Eye with Sensimed MEMS contact lens

The main component is the soft, disposable contact lens with an embedded MEMS sensor and microprocessor. Source: Sensimed

 

Taking wearable technology and real-time data acquisition to new extremes, a Swiss company working with STMicroelectronics has developed a micromachined sensor and radio frequency (RF) link packaged in a contact lens.

Sensimed AG, a startup whose principal focus is the design, development and commercialization of integrated microsystems for medical devices, says its first product is a non-invasive solution for continuous monitoring of intra-ocular pressure to aid the diagnosis and treatment of glaucoma. The device is a wireless MEMS sensor that acts as a transducer, antenna and mechanical support for additional read-out electronics.
Wireless instruments frequently deliver a wealth of new data. In this example of a wireless optical sensor, a smart contact lens with a tiny embedded strain gauge continuously monitors the curvature of the patient's eye over a period of 24 hours—providing data not currently obtainable any other way.

The lens also contains an antenna, a tiny dedicated processing circuit, and a passive RF transmitter to communicate the measurements to a receiver that is hung around the patient's neck. The embedded components are positioned in the lens in such a way that they do not interfere with the patient's vision. The microprocessor is a small full custom ASIC about 2mm square and 50 microns thick.

"We have a strong focus on developing and manufacturing wireless sensor networks for diagnostics and other applications in medicine," said Benedetto Vigna, general manager of STMicroelectronics' MEMS, sensors and high performance analogue division. "This wireless, self-powered, on-body sensor will be used in a product that promises to greatly help the millions of people at risk and suffering from glaucoma."

Sensimed MEMS contact lens

The MEMS sensor includes circular active and passive strain gages to measure corneal curvature changes, and a loop antenna to receive power and to send back information to the external system.

Source: Sensimed

 


The product combines leading edge technologies in three different fields: microtechnology(the MEMS sensor), microelectronics (the telemetric microprocessor) and micropackaging (embedding it all in a soft contact lens). The first challenge was to design a sensor sensitive enough to measure the tiny changecorneal curvature. A MEMS sensor based on a tiny circular strain gage was developed at the microtechnology department of the Swiss Fedral Institute of Technology of Lausanne. The sensor will pick up intraocular pulsation, a tiny modulation of eye pressure due to blood pressure.

"Designing a telemetric system respecting norms and regulatory constraints such as electromagnetic spectrum or heat generation was not trivial," says Jean-Marc Wismer, CEO of Sensimed. "Norms strictly limit the maximum heat to which the eye can be exposed, as well as the maximum amount of harmonic frequencies emitted by the system."

Bringing the prototype to an industrial, comfortable product was one of the main challenges.

"Production of our MEMS sensor is on the edge of technology for most MEMS manufacturers," says Wismer. "Furthermore, the design of a comfortable shape of the lens, while encapsulating the MEMS, the microantenna and the microprocessor required combined efforts of a number of experts in the field of molding and contactology."

Large growth

Wismer expects manufacturing to start in Q3 2010, with various parts of the solution manufactured by different subcontractors around the world. The company expects to ship about 20,000 sensors by 2010, and about 100,000 by 2011, says Wismer.

Also read:

 

Sensimed MEMS contact lens body system illustration

Other components of the system include the adhesive external loop antenna worn around the eye, the data cable driving the antenna and connected to a portable rechargeable battery-powered recorder. Finally, software on the ophthalmologist's computer initiates the monitoring session to present eye pressure data collected over as much as a 24-hour period. Source: Sensime

 

 

- Sensors: Process and Discrete Sensors news from Control Engineering

- H ow to Improve ROI with RFID ; and
- RFID for Industry .
www.st.com
www.sensimed.ch

- Edited by Renee Robbins, senior editor Control Engineering News Deskwww.controleng.com



No comments
The Engineers' Choice Awards highlight some of the best new control, instrumentation and automation products as chosen by...
Each year, a panel of Control Engineering editors and industry expert judges select the System Integrator of the Year Award winners.
The Engineering Leaders Under 40 program identifies and gives recognition to young engineers who...
Learn how to increase device reliability in harsh environments and decrease unplanned system downtime.
This eGuide contains a series of articles and videos that considers theoretical and practical; immediate needs and a look into the future.
Learn how to create value with re-use; gain productivity with lean automation and connectivity, and optimize panel design and construction.
Go deep: Automation tackles offshore oil challenges; Ethernet advice; Wireless robotics; Product exclusives; Digital edition exclusives
Lost in the gray scale? How to get effective HMIs; Best practices: Integrate old and new wireless systems; Smart software, networks; Service provider certifications
Fixing PID: Part 2: Tweaking controller strategy; Machine safety networks; Salary survey and career advice; Smart I/O architecture; Product exclusives
The Ask Control Engineering blog covers all aspects of automation, including motors, drives, sensors, motion control, machine control, and embedded systems.
Look at the basics of industrial wireless technologies, wireless concepts, wireless standards, and wireless best practices with Daniel E. Capano of Diversified Technical Services Inc.
Join this ongoing discussion of machine guarding topics, including solutions assessments, regulatory compliance, gap analysis...
This is a blog from the trenches – written by engineers who are implementing and upgrading control systems every day across every industry.
IMS Research, recently acquired by IHS Inc., is a leading independent supplier of market research and consultancy to the global electronics industry.

Find and connect with the most suitable service provider for your unique application. Start searching the Global System Integrator Database Now!

Case Study Database

Case Study Database

Get more exposure for your case study by uploading it to the Control Engineering case study database, where end-users can identify relevant solutions and explore what the experts are doing to effectively implement a variety of technology and productivity related projects.

These case studies provide examples of how knowledgeable solution providers have used technology, processes and people to create effective and successful implementations in real-world situations. Case studies can be completed by filling out a simple online form where you can outline the project title, abstract, and full story in 1500 words or less; upload photos, videos and a logo.

Click here to visit the Case Study Database and upload your case study.