Microcomputer-based system for the on-line analysis and topographic display of human brain electrical activity

A method of defining a topographic map comprising:

• (a) establishing a map file memory containing therein for each of a plurality of pixels a weighting factor for four measured signals corresponding to the electrode locations nearest to the pixel, a pixel address, and an electrode address for each of said four nearest electrode locations;
• (b) transferring electrode addresses in sequence to a plurality of electrode address flip flops;
• (c) transferring pixel addresses in sequence to a plurality of electrode pixel address flip flops;
• (d) transferring weighting factors in sequence to a plurality of electrode weight flip flops;
• (e) storing in a data buffer memory ram digital data obtained from said preprocessor;
• (f) multiplying with a multiplier outputs from the data buffer memory and from the electrode weight flip flops;
• (g) controlling operation of said multiplier using a programmable read-only memory for providing to said multiplier, successive outputs of said buffer memory and electrode weight flip flops representing the flow nearest electrodes;
• (h) summing the products of four weights and their respective data point values.

Apparatus for computing and supplying an image into a frame buffer, while simultaneously allowing display of a previously generated image in said frame buffer, comprising:

• a. a clock having two phases;
• b. A CRT display controller having as control input one phase of said clock and providing sequential frame buffer addresses to said frame buffer in response to said one phase;
• c. means for computing an image;
• and
• d. means for providing the outputs of said computing means to the frame buffer during the other phase of said clock, whereby access to the frame buffer by said means for computing and display controller will be arbitrated.

Apparatus for computing an image comprising:

• a. a digital data memory;
• b. means for supplying a set of digital data to said memory;
• c. means for generating an image frame of a topographic map from said set of digital data;
• d. means for arbitrating access to said digital data memory between said means for supplying and means for generating;
• and
• e. means for automatically starting said means for generating after a full set of data is supplied thereto and for stopping said means for generating after an image frame has been generated.