Two intraoperative human DOT tests

The 2024 paper reports two studies at Baylor St Luke’s Medical Center during tumor-resection surgeries, with institutional review approval and informed consent. Both patients were under anesthesia with motor cortex exposed by craniotomy. This is a temporary intraoperative test of the published DOT hardware, not a completed chronic implant trial.

Separate placements

• First patient: the device was placed directly on the right motor cortex after standard motor mapping, producing left-hand contractions. The protocol used 14.5-V biphasic, 250-µs pulses in 10-pulse, 500-Hz trains repeated at 1 Hz. This was not intact-dura epidural placement.
• Second patient: the mapped target was on the left motor cortex, with the dura laid back over the brain and the DOT placed above it. The response was in the right hand. Visible thumb movements occurred above 10 V; EMG responses in APB/ADM muscle groups were recorded as low as 8 V.

Saline-wetted gauze connected the top return electrode to tissue. An external coil wirelessly powered and commanded the implant. Placement during an already-open surgical procedure does not demonstrate the proposed small-burr-hole implantation workflow in humans.

What was measured

The study analyzed video-derived movement using DeepLabCut, with audio cues providing approximate stimulation timing. EMG was recorded in the second study. These are stimulation-evoked motor responses, not decoded intent, restored independent function, depression relief or recorded neural data transmitted from the implant.

The abstract’s broad description of stimulation through the dura should not collapse these two configurations. Only the second test placed dura between the DOT and cortex.

Boundary

No chronic human follow-up, at-home use, therapeutic psychiatric outcome or multi-year device qualification is established by these intraoperative experiments. The separate pig application supplies the reported chronic animal evidence, not a human safety result.

Primary source

• Published full manuscript, 2024, human Results, Figure 4 and Intraoperative human testing Methods.