Biomedical Engineering Reference
In-Depth Information
Power Telemetry
Reverse Data Telemetry
External Unit (Primary side)
Implant Unit (Secondary side)
Power
Controller
Power
Transmitter
Power
Receiver
Voltage
Regulators
Reverse Data
Receiver
Reverse Data
Transmitter
Sensors
Sensors
Skin
Forward Data
Transmitter
Microstimulator
and/or Recorder
Data
Acquisition
Forward Data
Receiver
External Controller
Implant Controller
Electrode Array
Interfaced with Tissue
Battery
Forward Data Telemetry
FIGURE 16.2
A. generic. neural. implant. architecture.. (From. Keefer. E,. Booterman. B,. Romero. M,. Rossi. A,. Gross. G.. Carbon.
nanotube.coating.improves.neurenal.recording,.
Nat Nanotech
;.3:.434-439.)
Neural. prosthesis. deals. with. the. degeneration. of. nerve. or. muscle. tissues. that. have.
undergone.pathological.changes.due.to.diseases..Major.technology.to.ensure.high.eficacy.
of.the.neural.prosthetic.systems.involves.electrodes,.sensors,.wireless.technology,.micro/
nanoelectronics,.energy.sources,.signal.processing,.and.packaging..A.generic.neural.pros-
thetic. system. is. shown. in. Figure 16.2.. It. consists. of. a. telemetry. system. and. peripheral.
accessories. to. provide. power. transmission,. bidirectional. data. transmission,. stimulation,.
and.recording.via.electrodes.
Functionally,.a.telemetry.system.consists.of.two.links:.a.power.telemetry.link.to.deliver.
energy. for. powering. electronics. and. a. data. telemetry. link. to. communicate. information.
between.the.external.units.and.the.neural.implant..To.deliver.power.and.data.wirelessly.
for.implants,.both.links.have.two.components.of.electronics..Those.located.externally.or.
physically.detached.from.the.objects.are.referred.to.as.primary.side.units,.e.g.,.external.bat-
tery,.power.transmitter,.signal.processing.station,.forward.data.transmitter,.reverse.data.
receiver,.etc..Those.located.under.the.skin.(implanted.electronics).are.typically.referred.to.
as.secondary.units,.including.the.power.receiver,.forward.data.demodulator,.stimulator,
26
.
signal.sensor.and.processor,
27
.reverse.data.transmitter,.etc..To.accomplish.the.functions.of.
powering. and. communicating. with. secondary. electronics,. the. telemetry. system. should.
achieve.a.high.power.eficiency.to.avoid.heating.tissue,.a.low.bit.error.rate.(BER).to.ensure.
reliable.data.communication,.and.a.small.size.and.light.weight.to.target.the.highest.level.
of.system.integration.and.miniaturization.
