Duty cycle (inhalation & exhalation)

Owned by Beatrix Krause (Unlicensed)
Dec 16, 2021
2 min read

We can compute the time of inhale, exhale and the inspiratory duty cycle (inhale/(inhale + exhale).

1. Inhalation

We export the time in seconds from the inspire start to the expire start marker. This time reflects the duration of the inhalation.

In the channel calculation pane, select CH2, Respiration for the first window. We only need time.

  1. Time

→ this variable will be exported into the spreadsheet.

Select the channel 2

 

Analysis → Find cycle →

Events/Peaks

  1. Events

  2. Start event:

    1. Inspire start

    2. CH2, Respiration

  3. End event:

    1. Expire start

    2. CH2, Respiration

Selection

  1. Zero to zero

  2. Check box for “Match pairs of events”

Output

  1. Export excel spreadsheet

2. Exhalation

NOTE: this is the opposite of the previous step.

We export the time in seconds from the expire start to the inspire start marker. This time reflects the duration of the exhalation.

In the channel calculation pane, select CH2, Respiration for the first window. We only need time.

  1. Time

→ this variable will be exported into the spreadsheet.

Select the channel 2

 

Analysis → Find cycle →

Events/Peaks

  1. Events

  2. Start event:

    1. Expire start

    2. CH2, Respiration

  3. End event:

    1. Inspire start

    2. CH2, Respiration

Selection

  1. Zero to zero

  2. Check box for “Match pairs of events”

Output

  1. Export excel spreadsheet

3. Duty cycle

Use the time column from the inspiration and the time column from the expiration to calculate the duration of inhale and exhale.

  1. Check whether your focus area started with an inhale or an exhale. If it started with an exhale, the column of the inspiration needs to be moved down by one cell so it starts with an empty cell.

  2. Inhale duration: Create a new column, in which you subtract the exhale from the inhale (“=SUB(exhale:inhale)”). Draw the function all the way down. Delete cells that show zeroes, i.e. where there was no matching inhale to an exhale or vice versa.

  3. Exhale duration: Repeat step 2 but reverse; subtract each inhale from the PREVIOUS exhale.

  4. Duty cycle: Create a third column and use this formula “=Inhale/(Inhale+Exhale)” (these refer to the cells, not to the words).

ADD SCRENSHOT

1. Import columns into Matlab

This is to plot the shape of the responses to challenges.

2. Compute variables across the whole task period

This is mostly relevant for Rest and Meditation, where there are no challenge responses.

Compute the means and standard deviation for each column:

  1. Click in an empty cell, type “=AVERAGE()” → inside the parentheses, select your column values from top to bottom

  2. Do the same for “=STDEV”

  3. “=MEDIAN”

  4. “=MIN”

  5. “=MAX”