[blindza] Fw: Haptic lens converts light into touch
- From: "Jacob Kruger" <jacob@xxxxxxxxxxxxx>
- To: "NAPSA Blind" <blind@xxxxxxxxxxxx>
- Date: Tue, 11 Mar 2014 07:25:00 +0200
----- Original Message ----- Hi All,
For your information. Appended is an article from today's EE Times.
Best wishes,
Peter Meijer
Seeing with Sound - The vOICe
http://www.seeingwithsound.com/winvoice.htm
Haptic lens converts light into touch.
March 10, 2014 // Julien Happich.
A lot of research goes into bringing back some level of sight to visually
impaired people. Often, researchers look into ways to connect artificial
photoreceptors to retinal or optical nerves, bypassing the faulty retina
through
surgically implanted devices and microelectrodes.
But in the vast majority of people suffering from untreatable blindness, the
cornea remains unaffected by disease-related retinal dis-functions, observes
Prof. Zeev Zalevsky, a proponent of less intrusive solutions.
And according to anatomical studies, cornea is one of the most sensitive
tissues
of the body, densely innervated (distinctly from optic nerves which only
transmit vision signals), with a density 300 to 600 times that of skin.
The nerves in question are sensory, producing touch, thermal and chemical
sensations that drive the blink reflex necessary to preserve the integrity
of
the ocular surface, notes Zalevsky in a 2013 paper discussing the use of
tactile
corneal stimulation through Braille-like pressure points.
In recent research, Zalevsky has also demonstrated through human trials that
the
cornea’s sensing capacity to discriminate between two points is around 1mm,
which in theory could allow the cornea to identify simple spatial shapes and
images using adequate stimulation.
The Head of the Electro-Optics study program at Bar-Ilan Universitys’
Faculty of
Engineering (Israel) and director of the Nano Photonics Center at the
Institute
of Nanotechnology and Advanced Materials (BINA), Zalevsky together with
Prof.
Michael Belkin from Tel-Aviv University are now launching a startup called I
C
Touch with the goal to design a wearable haptic lens together with a
dedicated
image processing chip that would parse the input from a video camera into a
time-multiplexed matrix of surface electrodes or micro-actuators embedded
into
the lens.
Although the initial clinical trials were done using hardwired tubing and
air
pressure (using micro-channels to stimulate the cornea across discrete
points
for the patient to recognize basic shapes), the ultimate goal would be to
power
and control such a lens wirelessly, using an embedded antenna coil and RF
energy
harvesting to drive surface electrodes.
“We started with pressure stimulation in order to prove our basic claim:
that
cornea has two points discrimination capability and can sense spatial
shapes.
This is novel to the world of medicine and was never examined before”
clarified
Zalevsky in an email exchange with EE Times Europe.
“Another reason was that for pressure stimulation it is much simpler to get
clinical approval for experiments. The third reason is that as in any R&D
process there always many non-anticipated difficulties. So our aim is to do
electrical stimulation which is simpler from the system point of view but it
might not perform as well as expected so we have our fold back path of doing
the
pressure based stimulation which can also be realized in practice”.
Currently Zalevsky’s research team is experimenting with prototypes
assembled
manually from printed electronic circuits inserted between two soft lenses.
The
current design includes pixels with a pitch of around 1mm, and the distance
between the electrode and the cornea surface is around 50 microns.
Although the initial proof of concept was done using pressure stimulation,
the
team has to figure out what would be the right comfort zone for electrical
stimulations to properly define the voltage level at which the stimulation
would
be felt without being disturbing to the user.
So what sort of practical information does the wearer get from such a haptic
lens since we humans are not accustomed to make any sense of tactile
feedback on
the cornea?
Zalevsky describes a feeling similar to what someone would get when touching
Braille writing with his/her fingertips.
“It is a feeling one can train to recognize similarly to how a blind person
learns how to recognize the Braille alphabet through touch”, explains
Zalevsky.
And indeed, during preliminary trials, the researcher confirms that various
transmitted shapes (lines, crosses, squares etc…) were recognized by the
subjects about 9 times out of ten after only 2 minutes of training.
It only took a few minutes for the subjects to learn and distinguish between
10
to 20 different shapes, but that could vary with the pixel density.
The current prototypes include electrodes which are like small antennas. The
transmitted image induces voltages in them and the voltages do electrical
stimulation of the cornea. Alternatively, electro-active polymers could be
used
to implement micro-actuators.
But once the concept proven, what sort of resolution would you get and would
that be enough for basic obstacle avoidance?
“We aim to get a physical resolution of 100 pixels at the contact lens
level.
This after proper encoding in the camera will be equivalent to 1000 pixels
resolution at the object plane” explains Zalevsky.
“Therefore in order to improve the spatial resolution we intend to use time
multiplexing, aiming to improve the resolution by almost another order of
magnitude in each axis to produce a final image resolution of around 10,000
pixels, as close to one million”.
I C Touch thinks its findings could benefit visually impaired people but
could
also lead to new augmented reality applications, converting particular
situational information into tactile feedback. In the future, the company
aims
to license the concept to third party manufacturers.
Source URL:
http://www.electronics-eetimes.com/en/haptic-lens-converts-light-into-touch.html?cmp_id=7&news_id=222920347
----------
To send a message to the list, send any message to blindza@xxxxxxxxxxxxx
----------
To unsubscribe from this list, send a message to blindza-request@xxxxxxxxxxxxx
with 'unsubscribe' in the subject line
---
The 'homepage' for this list is at http://www.blindza.co.za
Other related posts:
- » [blindza] Fw: Haptic lens converts light into touch - Jacob Kruger
