Channels and units in Paradigma schemas

Within the paradigma project, some of the field types are further specialised to provide a better description of the data. These are described in the following sections.

Field: `channels`

Type: channel_type[]
Description: Describes the content of the data written. channel_type is specific to the Digital biomarkers for PD extension.

General types

`channel_type` name	Recommended `unit`	Description
`time`	`absolute_ms`	Time corresponding to the start of each window/segment (also see units below).
`accelerometer_x`	`g`	Acceleration along the x-axis.
`accelerometer_y`	`g`	Acceleration along the y-axis.
`accelerometer_z`	`g`	Acceleration along the z-axis.
`rotation_x`	`deg/s`	Angular rotation rate around the x-axis.
`rotation_y`	`deg/s`	Angular rotation rate around the y-axis.
`rotation_z`	`deg/s`	Angular rotation rate around the z-axis.
`green`	`deg/s`	Green signal values indicate blood volume changes for physiological analysis.

PPG-related types

`channel_type` name	Recommended `unit`	Description
`ppg_quality_post_prob`	`probability`	`[TODO]` Posterior probability that the corresponding PPG signal is of high quality (0 to 1).

Tremor-related types

`channel_type` name	Recommended `unit`	Description
`gyro_tremor_prob`	`probability`	Probability values (0 to 1) indicating the likelihood of tremor activity for each sample.
`gyro_tremor_hat`	`boolean_num`	Estimated values representing the presence or absence of tremor activity for each sample.
`gyro_arm_actv_prob`	`probability`	Probability values (0 to 1) indicating the likelihood of arm activity for each sample.
`gyro_arm_actv_hat`	`boolean_num`	Estimated values representing the presence or absence of arm activity for each sample.
`GyMeanDx`	`unitless`	Mean gyro derivative in the x axis.
`GyMeanDy`	`unitless`	Mean gyro derivative in the y axis.
`GyMeanDz`	`unitless`	Mean gyro derivative in the z axis.
`GyLTreDomPowerX`	`unitless`	Gyro Low tremor (range [3.5-8 Hz]) dominant power in the x axis.
`GyLTreDomPowerY`	`unitless`	Gyro Low tremor (range [3.5-8 Hz]) dominant power in the y axis.
`GyLTreDomPowerZ`	`unitless`	Gyro Low tremor (range [3.5-8 Hz]) dominant power in the z axis.
`GyGaitBandPower`	`unitless`	Gyro gait bandpower (range [0.4 – 2] Hz) – PSD: sum of the axes.
`GyGaitBandpowerRatio`	`unitless`	Gyro gait bandpower sum / total bandpower sum up to 15 Hz – PSD: sum of the axes.
`GyGaitFreqPeak`	`unitless`	Frequency peak of the in the gyro gait range – PSD: sum of the axes.
`GyGaitFixedDomPower`	`unitless`	`[TODO]` Gyro dominant power in a fixed range (specific frequency range not provided).
`GyGaitFixedDomPowerRatio`	`unitless`	`[TODO]` Ratio of dominant power in the gyro gait range to total power.
`GyGaitDomPower`	`unitless`	`[TODO]` Dominant power in the gyro gait range.
`GyGaitDomPowerRatio`	`unitless`	`[TODO]` Ratio of dominant power in the gyro gait range to total power.
`GyGaitPeakFreqWidth`	`unitless`	`[TODO]` Width of the frequency peak in the gyro gait range.
`GyLTreBandPower`	`unitless`	`[TODO]` Low tremor bandpower (specific frequency range not provided).
`GyLTreBandpower`	`unitless`	`[TODO]` Low tremor bandpower (specific frequency range not provided).
`GyLTreFreqPeak`	`unitless`	`[TODO]` Frequency peak in the low tremor range.
`GyLTreFixedDomP`	`unitless`	`[TODO]` Low tremor dominant power in a fixed range (specific frequency range not provided).
`GyLTreFixedDomP`	`unitless`	`[TODO]` Low tremor dominant power in a fixed range (specific frequency range not provided).
`GyLTreDomPower`	`unitless`	`[TODO]` Low tremor dominant power (specific frequency range not provided).
`GyLTreDomPowerR`	`unitless`	`[TODO]` Ratio of low tremor dominant power to total power.
`GyLTrePeakFreqW`	`unitless`	`[TODO]` Width of the frequency peak in the low tremor range.
`GyHTreBandPower`	`unitless`	`[TODO]` High tremor bandpower (specific frequency range not provided).
`GyHTreBandpower`	`unitless`	`[TODO]` High tremor bandpower (specific frequency range not provided).
`GyHTreFreqPeak`	`unitless`	`[TODO]` Frequency peak in the high tremor range.
`GyHTreFixedDomP`	`unitless`	`[TODO]` High tremor dominant power in a fixed range (specific frequency range not provided).
`GyHTreFixedDomP`	`unitless`	`[TODO]` High tremor dominant power in a fixed range (specific frequency range not provided).
`GyHTreDomPower`	`unitless`	`[TODO]` High tremor dominant power (specific frequency range not provided).
`GyHTreDomPowerR`	`unitless`	`[TODO]` Ratio of high tremor dominant power to total power.
`GyHTrePeakFreqW`	`unitless`	`[TODO]` Width of the frequency peak in the high tremor range.
`GyMFCC1`	`unitless`	`[TODO]` Mel-frequency cepstral coefficient 1.
`GyMFCC2`	`unitless`	`[TODO]` Mel-frequency cepstral coefficient 2.
`GyMFCC3`	`unitless`	`[TODO]` Mel-frequency cepstral coefficient 3.
`GyMFCC4`	`unitless`	`[TODO]` Mel-frequency cepstral coefficient 4.
`GyMFCC5`	`unitless`	`[TODO]` Mel-frequency cepstral coefficient 5.
`GyMFCC6`	`unitless`	`[TODO]` Mel-frequency cepstral coefficient 6.
`GyMFCC7`	`unitless`	`[TODO]` Mel-frequency cepstral coefficient 7.
`GyMFCC8`	`unitless`	`[TODO]` Mel-frequency cepstral coefficient 8.
`GyMFCC9`	`unitless`	`[TODO]` Mel-frequency cepstral coefficient 9.

Gait-related types

`channel_type` name	Recommended `unit`	Description
`std_accel_norm`	`g`	Standard deviation of the norm of the accelerometer axes in the temporal domain.
`x_accel_grav_mean`	`g`	Mean of the x-axis acceleration gravity component.
`y_accel_grav_mean`	`g`	Mean of the y-axis acceleration gravity component.
`z_accel_grav_mean`	`g`	Mean of the z-axis acceleration gravity component.
`x_accel_grav_std`	`g`	Standard deviation of the x-axis acceleration gravity component.
`y_accel_grav_std`	`g`	Standard deviation of the y-axis acceleration gravity component.
`z_accel_grav_std`	`g`	Standard deviation of the z-axis acceleration gravity component..
`x_accel_power_below_gait`	`g^2/Hz`	Total power in the [0, 0.7] Hz range of the x-axis accelerometer.
`y_accel_power_below_gait`	`g^2/Hz`	Total power in the [0, 0.7] Hz range of the y-axis accelerometer.
`z_accel_power_below_gait`	`g^2/Hz`	Total power in the [0, 0.7] Hz range of the z-axis accelerometer.
`x_accel_power_gait`	`g^2/Hz`	Total power in the [0.7, 3.5] Hz range of the x-axis accelerometer.
`y_accel_power_gait`	`g^2/Hz`	Total power in the [0.7, 3.5] Hz range of the y-axis accelerometer.
`z_accel_power_gait`	`g^2/Hz`	Total power in the [0.7, 3.5] Hz range of the z-axis accelerometer.
`x_accel_power_tremor`	`g^2/Hz`	Total power in the [3.5, 8] Hz range of the x-axis accelerometer.
`y_accel_power_tremor`	`g^2/Hz`	Total power in the [3.5, 8] Hz range of the y-axis accelerometer.
`z_accel_power_tremor`	`g^2/Hz`	Total power in the [3.5, 8] Hz range of the z-axis accelerometer.
`x_accel_power_above_tremor`	`g^2/Hz`	Total power in the [8, 50] Hz range of the x-axis accelerometer.
`y_accel_power_above_tremor`	`g^2/Hz`	Total power in the [8, 50] Hz range of the y-axis accelerometer.
`z_accel_power_above_tremor`	`g^2/Hz`	Total power in the [8, 50] Hz range of the z-axis accelerometer.
`x_accel_dominant_frequency`	`Hz`	Dominant frequency of the x-axis accelerometer.
`y_accel_dominant_frequency`	`Hz`	Dominant frequency of the x-axis accelerometer.
`z_accel_dominant_frequency`	`Hz`	Dominant frequency of the x-axis accelerometer.
`accel_norm_cc_{n}`	`g`	Cepstral coefficient n with n $\in$ [1,2,…,16] of the accelerometer.
`gd_pred_gait_proba`	`probability`	Predicted probability of gait being the predominant activity within the window span.
`gyro_norm_cc_{n}`	`?`	Cepstral coefficient n with n $\in$ [1,2,…,16] of the gyroscope.
`x_gyro_dominant_frequency`	`Hz`	Dominant frequency of the x-axis gyroscope
`y_gyro_dominant_frequency`	`Hz`	Dominant frequency of the x-axis gyroscope
`z_gyro_dominant_frequency`	`Hz`	Dominant frequency of the x-axis gyroscope
`angle_mean_amplitude`	`deg`	Mean of the sum of consecutive minima and maxima angles (angle amplitude is often referred to as range of motion)
`angle_std_amplitude`	`deg`	Std of the sum of consecutive minima and maxima angles
`angle_sum_amplitude`	`deg`	Sum of the sum of consecutive minima and maxima angles
`ange_perc_95_amplitude`	`deg`	95th percentile of the sum of consecutive minima and maxima angles
`forward_peak_ang_vel_mean`	`deg/s`	Angular velocity mean in forward direction of the first principal component
`forward_peak_ang_vel_std`	`deg/s`	Angular velocity standard deviation in forward direction of the first principal component
`backward_peak_ang_vel_mean`	`deg/s`	Angular velocity mean in backward direction of the first principal component
`backward_peak_ang_vel_std`	`deg/s`	Angular velocity standard deviation in backward direction of the first principal component
`angle_perc_power`	`percentage`	Percentage of total power in the arm swing frequency band [0.3 - 3 Hz]

Field: `units`

Type: unit_type[]

Description: Describes the format of the data written. unit_type is specific to the Digital biomarkers for PD extension.

`unit_type`	Description
`relative_ms`	Time (in milliseconds), relative to the `start_iso8601`, i.e., time elapsed since the start time of the recording.
`difference_ms`	Time (in milliseconds) elapsed since the previous sample.
`absolute_ms`	Absolute time in milliseconds, relative to Unix epoch.
`probability`	Probability values (0 to 1) indicating the likelihood of tremor activity for each sample.
`boolean_num`	Integer values (0 or 1) representing the true (1) or false (0) presence of an activity.
`unitless`	Numerical values without units.
`g`	Acceleration in g (meters per second squared / 9.81).
`deg/s`	Angular velocity in degrees per second.

Channels and units in Paradigma schemas

Field: channels

Field: units

Field: `channels`

Field: `units`