For car designers, secret agents in movies, jet fighter pilots, would-be virtual realitists  (and artists, surely?) data eyeglasses, currently called head mounted displays, or HMDs, are everyday objects but perhaps a thing of the  past.

They transport the wearer into virtual worlds or provide the user with data from the real environment. At present these devices can only display information. “We want to make the eyeglasses bidirectional and interactive so that new areas of application can be opened up,” says Dr. Michael Scholles, (right) business unit manager at the Fraunhofer Institute for Photonic Microsystems IPMS  in Dresden.

A group of scientists at IPMS are working on a device which incorporates eye tracking – users can influence the content presented by moving their eyes or fixing on certain points in the image.

Without having to use any other devices to enter instructions, the wearer can display new content, scroll through the menu or shift picture elements. Scholles believes that the bidirectional data eyeglasses will yield advantages wherever people need to consult additional information but do not have their hands free to operate a keyboard or mouse.

The Dresden-based researchers have integrated their system’s eye tracker and image reproduction on a CMOS chip making new HMDs small, light, easy to manufacture and inexpensive.

The 19.3 x 17mm chip is fitted on the prototype eyeglass behind the hinge on the temple. From the temple, the image on the microdisplay is projected onto the retina of the user so that it appears to be viewed from a distance of about a meter. The image has to outshine the ambient light to ensure that it can be seen clearly against changing and highly contrasting backgrounds. For this reason the researchers use organic light-emitting diodes (OLEDs), to produce microdisplays of very high luminance.

In industry and medicine, interactive data eyeglasses could enable numerous tasks to be performed more simply, efficiently and precisely. Many scenarios possibilities, include patients’ vital functions, MRT and x-ray images for surgeons, construction drawings for building engineers or installation details for service technicians.

Users have already tried out conventional HMDs, with unimpressive results. In most cases they found too expensive,  heavy, bulky and unergonomic.

“We have now overcome these hurdles,” says Scholles. With his team and colleagues from other Fraunhofer institutes he is already working on the next development stage of the bidirectional eyeglasses.

The artificial retina consist of a single lens placed on a circuit
Courtesy F Barranco/SINC

Granada University 'retina' detects movement, colours and textures

Mimicking the way in which a retina works is a hard as it sounds. Scientists from Stanford University, USA, have spent the past two years work on imitating the way in which information is processed in biological systems, through the transmission of events in specifically connected networks (where information is simultaneously captured and transmitted).

Now a research team from the UGR has evaluated the degree of precision of different models in estimating movement, and combined the responses of four movement detection cells, two  static (on and off), and two transitory (decrease and increase). "One of our developments is a multimodal attention operator, which can detect movement in objects of different colours and textures", says Fran Barranco, (right) a researcher involved in this project.

The objective of this study, published in IEEE Transactions on Systems. Man and Cybernetics, was to combine movement and attention based on information provided by the artificial retina, a visual system capable of selectively capturing moving objects in real time.

The use of an event-driven model, which makes it possible to focus only on areas of activity, has been fundamental, both in the movement processing model, as well as in the multimodal selective attention model created in Granada.

One of the most interesting results of the study is the ability to estimate movement reasonably precisely using the responses from each of these cells alone (4% of the information provided by a camera). "By selecting only 10-20% of the information, which we selected on the basis of reliability of the measurements, we obtained precise results at a lower computational cost and with greater stability", explains Barranco. This is very important to enable the model to be used in applications with broadband limitations.

The Spanish researchers also developed ‘advanced integrated intelligent sensors', which can pre-process a scene in a manner similar to that used by retinas.

"We are carrying out reverse engineering. In other words we are trying to study how Nature behaves in order to imitate it, because thousands of years of evolution have created a highly-advanced model adapted to the task for which it evolved", says Barranco.

The devices created have been designed for use in video surveillance and monitoring applications. However, their low energy consumption could make them of great interest in the future for implants in patients or in work to understand the functioning of the brain, and particularly the visual system.