Technical Description

• MS-Windows based interface and control software.
• Script-language parser for use in experiments (This allows a researcher to easily structure complex, repeatable experiments, and allows for data collection/organization.)
• Image translation (capable of translating BMP or DIB format bitmaps as well as NTSC or PAL/SECAM video into an electro-tactile equivalent)
• Digital Signal Processor based sub-system
• 16 simultaneous waveform generation channels each of which can be independently addressed.
• The waveform of the energy delivered by each tactor is programmable over a wide practical range.

Each channel drives up to 48 multiplexed tactors
• 0.1us timing resolution.
• 16-bit data (65,535 combinations) for frame rate, images per frame, pulse phase width, inter-pulse null, and number of pulses.
• 2 8-bit D/A ports associated with each channel (32 total).
• Frame rate and images per frame independently controlled global variables.
• Pulse width, pulse amplitude (for each phase), inter-pulse null, and the number of pulses per burst are each independently controlled variables for each tactor (see figure below).
• Better than 100 Hz frame rate with 768 tactors (depending on pulse parameters selected).

Tactor Waveform
Composite voltage waveform with various programmable features:
• Pulse Amplitude (only one phase is programmable, the other phase is determined by the pH neutrality criterion)
• Pulse Width
• Inter-Pulse Null (the delay between consecutive pulse in a multiple pulse burst)
• Pulse Number (in a multiple pulse burst)
• Image Frame Rate

 

 
 
 
 
 
 
 

The very fast timing required for the control of these pulse parameters is managed by a set of 4 Field Programmable Gate Array (FPGA) counter arrays that are seen on the Remote Processor Card shown below.
Remote Processor Card

• Watchdog timer system for monitoring software or hardware faults.
• Capable of interfacing to a PC-based image-grabber board for video camera image processing.
• 35 dedicated A/D ports, 2 general purpose (currently connected to potentiometers for user-control input).
• Overall operation entirely software configured - no PROMs need be reprogrammed for system software updates.
• Isolated power is derived from the host PC, or from a battery in the stand-alone portable mode (not connected to a host computer).
• Multichannel electrotactile array technology consisting of thin, flexible, and relatively inexpensive laminated Kapton/conductive Kapton substrate, with titanium electrodes configured according to your specifications.

768 Point Array
32 Point Linear Array
Close-up look at tactors
• System may be interfaced to other array technologies such as electromechanical 

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