Nerva is a wristband your capture team wears while recording. Its 16 EMG channels read the muscles that move the fingers and turn them into per-finger force and 20-DoF hand pose, synced to your head camera. In published wrist-EMG research, robots trained on demos with per-finger force succeeded 12× more often on squeeze tasks: 90% versus 7.5% without it.
He et al., ForceBand (2026): 72 of 80 squeeze trials with force, 6 of 80 for the best policy without.
Every value is labelled by its basis. Target: a design goal for Nerva’s first units, which have not been measured yet. Published: results from other teams’ wrist-EMG hardware or the physiology literature. Measured: our own run of an open model on public data.
| Parameter | Conditions | Value | Unit | Basis |
|---|---|---|---|---|
| Signal | ||||
| EMG channels | Dry electrodes at the wrist | 16 | ch | Target |
| EMG sample rate | 2000 | Hz | Target | |
| Hand pose | ||||
| Joint angles | Per hand | 20 | DoF | Target |
| Joint angle error | Wrist EMG only, wearers not in training set | 12.2 | ° | Published1 |
| Joint angle error | Starting pose given, 328 windows, 36 held-out wearers; holding the starting pose scores 13.3° | 10.2 | ° | Measured2 |
| Force | ||||
| Fingertip force channels | 5 | ch | Target | |
| Fingertip force error | Calibrated wearer, per finger | 0.92 | N | Published3 |
| Force error relative to video | Against video-based estimators | < 0.5 | × | Published3 |
| Robot squeeze success, with force | 80 trials, same human demos | 90 | % | Published3 |
| Robot squeeze success, without force | Best force-free policy, 80 trials | 7.5 | % | Published3 |
| Signal quality | ||||
| Skin temperature accuracy | Beside the electrodes | ±0.2 | °C | Target |
| Skin humidity accuracy | Skin side of the band | ±2 | %RH | Target |
| Temperature and humidity rate | Logged with every episode | 10 | Hz | Target |
| Timing and setup | ||||
| EMG onset before force | Electromechanical delay | 30–100 | ms | Published4 |
| Calibration | Per wearer, against fingertip force sensors | 15 | min | Published3 |
Muscle activity starts 30 to 100 ms before fingertip force builds. Grasp onset and release come out of the EMG stream as timestamped events, before contact is visible on video.
Figure 2. Idealized timing, not measured data.
One folder per episode, every stream aligned to the first frame of your video. Delivered as LeRobot, RLDS or plain HDF5.
episode_000123/ head_rgb.mp4 # your camera, unchanged emg float32 [T, 16] 2000 Hz imu float32 [T, 9] 200 Hz hand_pose float32 [T, 20] rad, joint angles fingertip_force float32 [T, 5] N skin_temp float32 [T_aux] 10 Hz, °C skin_humidity float32 [T_aux] 10 Hz, %RH events.json # grasp_onset, release timestamps calibration.json # per-wearer force model
Pilots start November 2026.
We train a policy on your sessions with and without force, so your buyers see the difference.