Contributions:MicroLeadsADC: Difference between revisions

Revision as of 22:11, 10 February 2023

Introduction

CortecADC is a source module that allows for inter-cranial recording and stimulating over 32 channels via a fully implantable device. It is intended for long-term measurement of neural activity and electrical stimulation of brain tissue. See the CorTec site for more information.

Versioning

Authors

Dhruva Mehta (mehta@neurotechcenter.org)

Version History

2/10/2023 Initial Creation and Setup

Source Code Revisions

Initial development:
Tested under:
Known to compile under:
Broken since: --

Known Issues

Parameters

SourceCh

The total number of digitized and stored channels. Because of device limitations, this is set to 4 channels explicitly.

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. For example, at 1000 Hz sampling and a SampleBlockSize of 20, the system (e.g., source signal display, signal processing, and stimulus presentation) will be updated 50 times per second.

SamplingRate

The sample rate of the system. This parameter cannot be edited, and will default to the sampling rate available from the implant which is 21500 Hz. In case you are experiencing problems by higher sampling rates (e.g., data loss, jerky display, etc.), increase the SampleBlockSize so that you are updating the system less frequently (usually, updating the system 20-30 times per second is sufficient for most applications), and increase Visualize->VisualizeSourceDecimation. This parameter will decrease the number of samples per second that are actually drawn in the Source display.

SourceChOffset

Offset for each channel.

SourceChGain

Gain for each channel.

ChannelNames

Names of each channel.

ReferenceCh

This list defines what channels will be used as reference. This list is uploaded to the device and set in hardware, effecting the raw bio-signal data that is recorded by BCI2000. If you do not want to effect the raw bio-signal data that is recorded, you can use the spatial filter. If this parameter is set to auto, no reference channels are used.

Stimulation Parameters

These parameters can be found in the "Stimulation" tab of the BCI2000 config window.

Enable STIM0

This parameter enables/disables stimulation for the STIM0 channel.

Enable STIM1

This parameter enables/disables stimulation for the STIM1 channel.

Enable Recording

This parameter enables/disables streaming of neural data.

Supply Voltage

This parameter sets the supply voltage from a range of 4V to 9V. When the user is recording only, the voltage must be 4V. When the user is stimulating at all, the voltage must be 9V.

Stimulation Pulse Settings

@@ Line 66: / Line 66: @@
 ====Phase1 Duration====
-==States==
-The states encode auxiliary information returned from the Cortec implant. The device provides this data in floating point numbers, however BCI2000 can only record integers to it's states. To maintain some precision, these floats are multiplied by constants, then recorded to the states as integers. To approximately recover the original data, divide the state by its corresponding constant. Constants are shown in the following table.
-{| class="wikitable" style="text-align:right;"
-|- style="font-weight:bold;"
-! State
-! style="text-align:center;" | Constant
-|-
-| ImplantVoltage
-| style="text-align:center;" | 1000
-|-
-| ImplantHumidity
-| style="text-align:center;" | 100
-|-
-| ImplantControlValue
-| style="text-align:center;" | 100
-|-
-| ImplantPrimaryCoilCurrent
-| style="text-align:center;" | 1000
-|-
-| ImplantTemperature
-| style="text-align:center;" | 100
-|}
-===ImplantLostSample===
-The communication protocol the device uses does not re-send lost data. This state annotates what samples were lost in the bio-signal data. Currently, lost samples are made up by duplicating the previous sample.
-===ImplantVoltage===
-bit state that changes when new supply voltage value is received from the implant. After dividing the integer state value by the the voltage multiplier defined in the StateInfo parameter, the units are in volts.
-===ImplantHumidity===
-bit state that changes when new humidity value is received from the implant. Units in %rh.
-===ImplantControlValue===
-bit state that changes when new current control value is received from the external unit. The power of the implant is controlled by the external unit. The control value provides a measure of how good the coupling between the two coils is and how much more power can be provided if necessary.
-The value is between 0.0 and 100.0 percent, where 0.0 translates to no power and 100.0 translates to maximum power applied.
-===ImplantPrimaryCoilCurrent===
-bit state that change when new primary coil current value is received from the external unit. The primary coil refers to the coil inside the head piece of the external unit. Units are mA.
-===ImplantTemperature===
-bit state that changes when new temperature value is received from the implant. Units are degrees Celsius.
-===ImplantStimulation===
-Binary state that changes when the device reports that it is stimulating.
-===RequestedStimulation===
-Binary state that records when a stimulation trigger expression evaluates true. State remains true for the duration triggered stimulation. This is useful for determining the latency between when stimulation is requested and when it is actually applied. This is done by computing the difference in time between the rising edges of ''ImplantStimulation'' and ''RequestedStimulation'' states.
 ==See also==