Contributions:RippleADC
RippleADC is a source module that allows for neural recording and stimulation using Ripple's Grapevine Neural Interface Processor. It supports high-channel-count recording and precise electrical stimulation capabilities. See the Ripple site for more information.
Detailed installation instructions
Versioning
Authors
- Nicholas Luczak (luczak@neurotechcenter org)
Version History
- 04/29/2025 - Initial version
- 06/10/2025 - Added stimulation support
Source Code Revisions
- Initial development: XXXX
- Tested under: XXXX
- Known to compile under: XXXX
- Broken since: --
Source Parameters
These parameters can be found in the "Source" tab of the BCI2000 config window.
SourceCh
The total number of digitized and stored channels. This can be set manually or left as "auto" to detect all available channels.
SampleBlockSize
Samples per channel per digitized block. Together with the sampling rate, this parameter determines how often per second data are collected, processed, and feedback is updated.
SamplingRate
The sample rate of the system. Supported rates are:
- 30,000 Hz (RAW)
- 15,000 Hz (HiFreq)
- 2,000 Hz (HiRes/EMG)
- 1,000 Hz (LFP)
SourceChOffset
Offset for each channel in raw A/D units.
SourceChGain
Gain for each channel in physical units per raw A/D unit (typically µV).
ChannelNames
Names of each channel in the format "FrontendName_ChannelNumber".
SourceChList
List of channels to actually transmit (subset of available channels).
Stimulation Parameters
These parameters can be found in the "Stimulation" tab and in both the BCI2000 config window and the Ripple Stimulation Tool. Parameters are checked and will throw a warning if they exceed device's safety limits or capabilities in both BCI2000 and the Ripple Stimulation Tool.
StimEnable
Enable/disable stimulation functionality (0 or 1).
Step Size
This parameter defines the amplitude resolution of the stimulator in µA. It indicates the granularity with which the stimulation amplitude may be adjusted. The allowed values depend on the hardware and are typically fixed by the front-end.
Frequency
This parameter defines the frequency of stimulation pulses in Hz. It specifies how many biphasic pulses occur per second during stimulation. Controls the pulse rate within a stimulation train. Higher frequencies produce temporally denser stimulation. Unit: Hz
Amplitude
This parameter defines the stimulation amplitude in mA. It sets the magnitude of the delivered current for each pulse in the stimulation train. Primary determinant of stimulation intensity. Unit: mA
Duration
This parameter defines the total duration of the stimulation train in seconds. It specifies how long stimulation continues once triggered. Unit: s
Burst Length
This parameter defines the length of each stimulation burst in seconds. If burst-mode stimulation is used, pulses are grouped into bursts separated by silent periods.
Unit: s Significance: Controls how long each burst remains active before an interburst pause occurs.
Interburst Length
This parameter defines the silent interval between bursts in milliseconds. Sets the recovery or idle period between active bursts; used to generate patterned or duty-cycled stimulation.
Unit: ms
Pulse Width
This parameter defines the width of each stimulation phase in microseconds (µs). It corresponds to the duration of the main pulse phase. Affects charge delivery per pulse. Unit: µs
Interpulse Width
This parameter defines the interval of time between pulses in microseconds. Controls how tightly pulses are packed in time; together with Pulse Width and Frequency, shapes the temporal profile of stimulation. Unit: µs
Gap Until Next
This parameter defines the delay between this stimulation block and the next block in seconds. Unit: s Significance: Used in multi-step or sequential stimulation programs to introduce timing gaps before the next configured stimulation event.
StimulationTriggers
This parameter defines when stimulation is applied, what pulse is used, how many pulses are applied, and the source and destination locations of the stimulation. These parameters are defined in the rows of this matrix with labels
Device Parameters
DeviceInfo
This parameter cannot be edited and is automatically populated with information returned from the device, including:
- Processor type
- Firmware version
- Network address
- Available front ends
ConnectionSettings
Advanced TCP/IP connection settings for the Grapevine processor.
States
The states encode auxiliary information about the system status and stimulation events.
Timestamp
16-bit state containing the processor timestamp for each sample block.
StimulusCode
16-bit state that records the amplitude of active stimulation.
StimulusType
16-bit state that indicates stimulation status.
ConnectionStatus
8-bit state reporting the network connection quality.
Technical Details
Supported Front Ends
| Front End Type | Channels | Supported Sampling Rates |
|---|---|---|
| Stimulation | 32 | HiRes (2kHz), HiFreq (15kHz) |
| Raw | 32 | LFP (1kHz), HiRes (2kHz), Raw (30kHz) |
Stimulation Waveforms
Pulse parameters are converted to Ripple's stimulation command format as described in XippStimCmd.h.
Network Protocol
The module uses Ripple's xipplib library to communicate with the Grapevine processor over TCP/IP. All data is transmitted in real-time with timestamps for synchronization.