Microstimulator Base Station

RX7

RX7 Microstimulator Base Station

The RX7G Multichannel Microstimulator System is a programmable current stimulator capable of delivering complex microstimulation patterns simultaneously across multiple microelectrode channels. The system also incorporates a user-programmable DSP and multi-channel A/D input (via one of our preamplifiers) for dynamic, real-time stimulus control based on analog control signals from virtually any signal source. You can generate complex arbitrary waveforms with a bandwidth of up to 10 kHz or design and deliver complex patterns of biphasic pulses with phase durations of less than 50 microseconds. A proven digital communication system optically isolates the electrical stimulator from the waveform generators to eliminate AC power surges and noise, ensuring superior safety and performance. This system can be used with our switching headstage and a medusa preamplifier, creating a complete stimulate and record solution. To add multi-channel data acquisition, consider the RX5 Pentusa Base Station.

Base Station technical specifications:

DSPs	two or five 100 MHz Sharc ADSP 21161
Memory:	128 MB SDRAM
Max sampling rate:	~25 kHz
D/A	4 channels, 16-bit PCM
S/N (typical):	82 dB (20 Hz to 20 kHz at 9.9 V)
THD (typical):	- 74 dB for 1 kHz output at 5 Vrms
Frequency response:	DC-Nyquist (~1/2 sample rate)
Sample delay:	4 samples
Digital I/O:	40 bits programmable
Fiber optic ports:	one or two 16-channel inputs
Power and communication:	zBus required

Stimulus isolator technical specifications:

Stimulus output channels:	4 or 16 PCM D/A
Stimulus output voltage (max): with the NC48 with HV250	+/- 24 V +/- 135 V
Stimulus output current (max): with the NC48 with HV250	up to 200 Kohm load +/- 100 µA up to 1Mohm load
Zero-Signal Leakage Current:	Less than 0.2% of full range setting
Digital output:	16 bits
Selectable reference:	channel or global
Stimulus Power:	NN48 rechargeable NiCad battery pack HV250 battery pack with carbon zinc batteries
Device power:	Rechargeable Li-Ion battery

System part numbers:

To order as a system:
RX7G-4 Two DSP Base Station, four channel Stimulus Isolator and battery pack
RX7G-16 Five DSP Base Station, 16 channel Stimulus Isolator and battery pack

To order components:
RX7-2 Two DSPs and one fiber optic input port
RX7-5 Five DSPs and two fiber optic input ports
MS4 Four-Channel Stimulus Isolator
MS16 16-Channel Stimulus Isolator
NC48 Battery Pack
HV250 Battery Pack
HV250-R Replacement Battery Pack

Choosing a battery pack:

TDT often recommends the NC48 due to its longer battery life. Investigators who use silicon probes, such as the NeuroNexus probes, find that the impedances of the probes drop in the range of 100 kOhms when the probes are activated for stimulation. As a result, a compliance voltage of +/-24 Volts work fine in most cases.

Issue	HV250	NC48
Battery life	130 mAmp (27 hours continuous stimulation)	1000 mAmp (240 hours of continuous stimulation)
Rechargeable	No	Yes
Compliance Voltage	+/- 135 Volts	+/- 24 Volts
Maximum impedance for delivering a 100 microAmp current	1 Mega Ohm	200 Kilo Ohm
Usable in 1 milliAmp mode	No	Yes