| Inertial sensing |
3-axis accelerometer, sensitive to 4 mg activity variations; dynamic range programmable ±2 g to ±16 g; typical sampling rate is 50 Hz |
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Stimulation Characteristics
|
| Channel Access |
8 independent electrodes, typ. arrangement is 2 leads × 4 electrodes |
| Stimulation overview |
2 independent channels, current-controlled, charge-balanced mono-phasic / symmetric biphasic with programmable interphasic delay |
| Multiplexing |
Full matrix configuration across electrodes (inc. the case reference) |
| Stimulation magnitude |
0–15 mA (0.05 mA increments) and 0–450 µs pulse width, fractionalized distribution available for guarded cathodes, etc; programmable and independent ramp rates |
| Recharge characteristics |
Programmable passive and active recharge, with variable recharge ratio |
| Stimulation frequency |
1–500 Hz frequency stimulation; can go sub-Hz with cycling enabled; independent frequencies available across stimulation channels |
| Stimulation cycling |
Adjustable cycle timing for enabling burst stimulation |
| Stimulation programs |
Up to 8 independent programs can be configured in the IPG and accessed by algorithms or patient controller |
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Algorithm Characteristics
|
| Motion Classification |
Absolute orientation, activity vs non-activity (parameterized), shocks and free-fall detection |
| Stimulation Control policy |
Detected classification states mapped to pre-configured stimulation programs with pre-specified transition ramp rate. Two independent stimulation programmes tied to motion states, and a default fall-back. |
| Risk mitigations |
Algorithm implementation aligns to 60601-1-10 specifications for physiologic control loops (e.g. limits, alerts, data logs, fallback modes) |
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Other System Characteristics
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| Battery capacity, recharge cycle |
< 2 h recharge with a target recharge interval of 4 days for typical Parkinson’s-like settings |
| Mechanical Characteristics |
Cranial-mount, 7.4 cc titanium package, with 2 leads for 4 contacts/lead |
| Telemetry/External Sensor and Stimulation Synchronisation |
MICS-band radio, > 1 m distance, with hand-held module |
| MRI compatibility (in process) |
MRI conditional imaging for 1.5 T and 3 T imagers |
| Electrodes |
Modular design with ability to customize lead length and electrode spacing; currently supports brain stimulation and peripheral extradural electrodes and cuffs |
| Clinician programmer |
Standard consumer tablet running Windows 10 |
