Hi Geoff, et al,
Your switching unit is very similar to one we have in place with a
client: It's based on a 3D accelerometer IC, and in our case responds to
movement in any plane. We've dubbed the device an analogue tilt switch.
I agree, power consumption in the monitor/base unit is a problem which
affects the portability of the system. While most of our clients who
would use this type of system are not likely to be spending extended
periods in the great outdoors, we'd still like it to be an option. To
this we are looking at low power devices and design strategies. If they
can do it in mobile phones, we can also!
In relation to the more general request that started this discussion
thread, we used to make a series of "twitch" switches using Piezo
sensors. They either used Piezo film, which was attached to the skin at
two points, and generated a Voltage when flexed, or a Piezo disk, which
was typically held under a fabric headband or belt. Our colleagues
Enabling Devices in the USA may still offer a similar device. (I've
still got a crate of bits if you want a DIY kit!)
I've recently been evaluating a device from the USA called the
BrainFinger, with a view to supplying it in Australia. I'm very
impressed! It's a very easy to use system that analyses a variety of
electrical signals via a simple forehead worn sensor array. The simplest
and fastest signals are muscle 'triggers', which reliably detect jaw
clenching, eyebrow raising etc at a rate of several triggers/second. The
next step is to move into the real power of the system, using eye
glance, and actual brain wave signals.
Cheers,
James Dean
([log in to unmask])
Technical Solutions Australia P/L
109 Ferndale Rd
Silvan Vic 3795
Ph: 03 9737 9000
Fax: 03 9737 9111
www.tecsol.com.au
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