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COSMIIC Pulse Generator Eval Board

Public Unreviewed

by Kyle Bergstedt

COSMIIC PG4 Pulse Generator — AT90CAN128 AVR, 4-channel monopolar stimulation (0–20 mA, 1–255 μs), triple failsafe, CANopen networked. Altium project, Gerbers, STEP, BOM.

moleculecosmiicpcbimplantableneurostimstimulator
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render Override with Fusion 360 Electronics source (PG4 FRAME MOL): EAGLE .brd/.sch + OCCT GLB (Z-up) + render assets so Nucle… · barrett-land 2mo ago
screenshots Override with Fusion 360 Electronics source (PG4 FRAME MOL): EAGLE .brd/.sch + OCCT GLB (Z-up) + render assets so Nucle… · barrett-land 2mo ago
cosmiic-pulse-generator-eval-board-545000-fab.zip Add fabrication sources and export provenance for molecule builds · AdityaAngajala 1d ago
cosmiic-pulse-generator-eval-board-545000.glb Override with Fusion 360 Electronics source (PG4 FRAME MOL): EAGLE .brd/.sch + OCCT GLB (Z-up) + render assets so Nucle… · barrett-land 2mo ago
export.json Add fabrication sources and export provenance for molecule builds · AdityaAngajala 1d ago
package.json Publish 1.1.1 · barrett-land 2mo ago
page.json Publish 1.1.1 · barrett-land 2mo ago
pg4.brd Override with Fusion 360 Electronics source (PG4 FRAME MOL): EAGLE .brd/.sch + OCCT GLB (Z-up) + render assets so Nucle… · barrett-land 2mo ago
pg4.f3d Override with Fusion 360 Electronics source (PG4 FRAME MOL): EAGLE .brd/.sch + OCCT GLB (Z-up) + render assets so Nucle… · barrett-land 2mo ago
pg4.sch Override with Fusion 360 Electronics source (PG4 FRAME MOL): EAGLE .brd/.sch + OCCT GLB (Z-up) + render assets so Nucle… · barrett-land 2mo ago
pg4.step Override with Fusion 360 Electronics source (PG4 FRAME MOL): EAGLE .brd/.sch + OCCT GLB (Z-up) + render assets so Nucle… · barrett-land 2mo ago
README.md test: fusion override permission probe · barrett-land 2mo ago

COSMIIC Pulse Generator (PG4)

The PG4 is a four-channel implantable pulse generator for electrical stimulation of nerve and muscle tissue. It delivers programmable monopolar stimulation through four independent electrodes, using the device case as the common return path.

How it works

The PG4 receives stimulation parameters over the CANopen network from the Power Module. Its Atmel AT90CAN128 processor converts control signals into precise charge-balanced stimulus pulses according to pre-programmed patterns or real-time commands. The SYNC message from the PM controls pulse frequency.

Three independent failsafe mechanisms protect against overstimulation:

  1. Hardware limits on total charge per pulse
  2. Software limits on stimulation parameters
  3. Magnetic shutdown switches in both PG4 and PM

Hardware

Parameter Value
Processor Atmel AT90CAN128 (8-bit AVR)
Channels 4 independent monopolar
Pulse Width 1–255 microseconds
Pulse Amplitude 0–20 mA
Inter-Phase Interval 5–100 μs (default 50)
Frequency 1–50 Hz (via SYNC period)
Network CANopen, 4 ports (1 in + 3 out)
Power Network-powered from PM
Case Titanium with epoxy header
Placement Extremities (upper arm, forearm)

Stimulation Modes

  • Direct PM parameter setting — ~50 Hz update, up to 24 channels
  • SDO direct setting — ~4 Hz for 12 channels, ~50 Hz single channel (recommended for testing)
  • Pattern-based lookup tables — preloaded, up to 48 patterns per PG4 (recommended for permanent systems)

MATLAB Control

nnp.networkOn;
nnp.setSync(50);            % 50ms = 20 Hz
nnp.enterTestStim;
nnp.write(node, '3212', ch, [PW, PA*10]);  % pulse width, amplitude
nnp.write(node, '3212', ch, [0, 0]);       % stop
nnp.enterWaiting;

Design source

This page publishes the Fusion 360 Electronics molecule for the PG4 (PG4 FRAME MOL). Fusion Electronics is EAGLE underneath, so the board and schematic ship as EAGLE-format .brd/.sch, which the Adom viewers render natively — the interactive schematic, PCB and 3D shown on this page (and in Adom Nucleus) all come from this Fusion export.

Files

File Description
cosmiic-pulse-generator-eval-board-545000.glb 3D assembly (OCCT step2glb, Z-up)
pg4.step Complete mechanical assembly STEP (titanium case, headers, board)
pg4.brd PCB layout — Fusion 360 Electronics / EAGLE board
pg4.sch Schematic — Fusion 360 Electronics / EAGLE
pg4.f3d Fusion 360 archive (parametric source)

Created by: COSMIIC · Fusion 360 Electronics export