Pressure Algometer

Instrument for computerised cuff pressure algometry.

The PressureAlgometer instrument represent an abstraction of computerised cuff pressure algometry devices.

context.Instruments.PressureAlgometer

String Literals

Outlet

Value Definition
'outlet-1' Pressure outlet 1
'outlet-2' Pressure outlet 2

Channel

Value Definition
'none' Used for declaring no waveform channel is mapped to an outlet.
'channel-1' Waveform channel 1.
'channel-2' Waveform channel 2.

Criterion

Value Definition
'stop-on-maximal-rating' Stimulation will stop on a VAS of 10cm.
'stop-when-button-pressed' Stimulation will stop when the button is pressed.
'stop-when-button-released' Stimulation will stop when the button is released.

Properties

Name Type Description
CompressorMode AlgometerCompressorMode Compressor operation mode (auto or manual).
MaximalPressure double Maximum pressure the device can generate.
Pressure double[] Current pressure values per channel.
UpdateRate double Update rate for pressure generation.
SamplePeriod double Sampling period for pressure and ratings.
State AlgometerState Current device state.
DeviceError string Error message if the device cannot start stimulation.
SupplyPressure double Current supply pressure.
FinalRating double Final VAS rating after stimulation.
Rating double Current VAS rating.
VasConnected bool Indicates if a VAS device is connected.
VasReady bool Indicates if the VAS device is ready.
PressureAvailable bool Indicates if sufficient pressure is available.
StopCondition AlgometerStopCondition Stop condition that ended the stimulation.
NumberOfPressureChannels int Number of available pressure channels.
Channels IList<IPressureChannel> Available pressure channels.

Methods

Name Signature Description
GetCompressorMode GetCompressorMode() → str Returns compressor mode as string ("auto" or "manual").
GetState GetState() → str Returns current state as string.
GetStopCondition GetStopCondition() → str Returns stop condition as string.
ResetAlgometer ResetAlgometer() Resets device configuration to default.
ConfigurePressureOutput ConfigurePressureOutput(outlet, channel) Maps a pressure channel to an outlet.
StartStimulation StartStimulation(criterion, forcedStart, externalTrigger=False) Starts pressure stimulation with specified stop criterion.
StopStimulation StopStimulation() Stops pressure stimulation.
StartUpdates StartUpdates() Starts streaming updates from the device.
StopUpdates StopUpdates() Stops streaming updates.
GetUpdates GetUpdates() → list Returns collected update data.
GetTime GetTime(sample) → float Returns time corresponding to a sample index.

Typical usage

alg = context.Instruments.PressureAlgometer
alg.StartStimulation("stop-on-maximal-rating", forcedStart=False)

# Read current rating
rating = alg.Rating

alg.StopStimulation()

Pressure Channel (IPressureChannel)

Represents a single pressure output channel capable of executing stimulus programs.

Availability

channel = context.Instruments.PressureAlgometer.Channels[0]

Properties

Name Type Description
Name string Channel name.
ID ChannelID Channel identifier.
Channel int Channel index.

Methods

Name Signature Description
SetStimulus SetStimulus(repeat, instructions) Assigns a stimulus program using instruction list.
SetStimulus SetStimulus(repeat, waveform) Assigns a stimulus using a waveform object.
ClearStimulus ClearStimulus() Clears the assigned stimulus.
CreateWaveform CreateWaveform() → PressureWaveform Creates a new waveform builder.

Typical usage

channel = context.Instruments.PressureAlgometer.Channels[0]

wave = channel.CreateWaveform() \
    .Step(50, 1) \
    .Increment(10, 2)

channel.SetStimulus(1, wave)

Pressure Waveform (PressureWaveform)

Builder for constructing pressure stimulus waveforms using sequential instructions.

Availability

wave = channel.CreateWaveform()

Methods

Name Signature Description
Increment Increment(delta, time) → PressureWaveform Increases pressure by delta over time.
Decrement Decrement(delta, time) → PressureWaveform Decreases pressure by delta over time.
Step Step(pressure, time) → PressureWaveform Sets pressure to a fixed value.
Zero Zero() → PressureWaveform Sets pressure to zero immediately.
Trigger Trigger(time) → PressureWaveform Inserts a trigger event.

Typical usage

wave = channel.CreateWaveform() \
    .Step(30, 1) \
    .Increment(10, 2)

Notes:

  • Methods are chainable and mutate the same waveform instance.
  • Execution depends on assigning the waveform to a channel via SetStimulus.

AlgometerStatus

Algometer Status (IAlgometerStatus)

Description

Represents a snapshot of the pressure algometer state during updates, including pressures, ratings, and device status flags.

Availability

Returned from:

context.Instruments.PressureAlgometer.GetUpdates()

Each element in the returned list is an IAlgometerStatus.

Properties

Name Type Description
NumberOfChannels int Number of pressure channels in the device.
State AlgometerState Current device state.
VasConnected bool Indicates if the VAS device is connected.
VasIsLow bool Indicates low VAS signal or condition.
PowerOn bool Indicates if the device is powered on.
CompressorRunning bool Indicates if the compressor is currently running.
StartPossible bool Indicates if stimulation can be started.
UpdateCounter int Incrementing counter for updates.
StopCondition AlgometerStopCondition Stop condition associated with the current/last stimulation.
VasScore double Current VAS score.
FinalVasScore double Final VAS score after stimulation.
SupplyPressure double Current supply pressure.
ActualPressure IList<double> Measured pressure values per channel.
TargetPressure IList<double> Target pressure values per channel.
FinalPressure IList<double> Final pressure values reached per channel.
StopPressed bool Indicates if the stop button has been pressed.

Methods

Name Signature Description
GetState GetState() → str Returns device state as string.
GetStopCondition GetStopCondition() → str Returns stop condition as string.

Notes:

  • Requires StartUpdates() to be called before data is collected.
  • Each call to GetUpdates() returns accumulated updates since last retrieval.
  • Lists (ActualPressure, TargetPressure, etc.) are indexed per channel.
Last modified May 21, 2026: Device server implementation (#1375) (5dd5648d)