Jul 182015

We have seen examples where the respiration rates for experienced meditators are lower than those for novices. What about patterns of inhalations and exhalations? Plotting the average respiration waveform for a novice (<200 hrs) and an expert meditator (>5,000 hrs), we see that the exhalation time is 50% longer than the inhalation time for novice and 70% longer for the expert.


comparison of respiration waveforms

Ratio of exhalation to inhalation time for novice is 1.5 while for expert is 1.7.

Furthermore, the expert breathes much more deeply than the novice, as indicated by the difference in pressure from the bottom of the exhalation to the top of the inhalation.


Jul 162015

In the following plot of respiration during meditation, we see a regular repetition of inhalations and exhalations with a wave-like quality.

Recording of breath during Zazen meditation

My breath recorded on the 7th day of a meditation retreat.

Selecting a range of cycles, we can average the values centered around the peaks to extract a waveform that represents the entire range. Averaging over 12 cycles, we get the following:

Respiration waveform

Average waveform of the breath for subject S1 (myself) at the end of a 7-day meditation retreat

An interesting aspect of this waveform is that the exhalations are almost twice as long as the inhalations. Here, one complete cycle is 19 seconds long which corresponds to 3.2 breaths/minute. Compare this with the waveform for reading:

Reading waveform

Average waveform of the breath for subject S1 quietly reading

Jul 152015

To compare respiration rates for meditation and non-meditative activities, I recorded my breath using a Vernier LabQuest device connected to a gas pressure sensor and a respiration monitor belt. the first plot below shows my respiration sitting quietly and reading. The second plot is a recording of meditation during the 7th day of a meditation retreat.

Respiration while reading

Respiration while sitting quietly and reading. Breath rhythm was variable. Occasionally I took a deep breath. Average breathing rate was 14.6 breaths/min.


Recording of breath during Zazen meditation

Breath recorded on the 7th day of a meditation retreat. Breathing rate was 2.85 breaths per minute.

Below is a comparison of breathing rates for various other activities.

Respiration Rates

Comparison of respiration rates for various activities, including meditation.

Clearly my zazen practice is characterized by a slower breath rate compared to other activities during the day.


Jun 162015

In September 2014 I enrolled in an online course Exploring Neural Data offered by Brown University via coursera.org. The basic premise of the course was that students would be able to access data coming from various neuroscience labs around the country and learn techniques for analyzing that data, forming hypotheses and testing them. Participation in the course required learning the Python programming language. It sounded like an opportunity I couldn’t pass up. I had already completed two coursera online courses, Duke University’s Medical Neuroscience and Hebrew University of Jerusalem’s Synapses, Neurons and Brains, which gave me a bit of orientation to neuroscience (my background is physics and astronomy). I also discovered some good online tutorials on Python, so I could start familiarizing myself with a new language.

The final project for the Exploring Neural Data course was to apply some of our programming skills to a new data set. I chose to collect respiration and and electrocardiogram (ECG) data for subjects during meditation and reading. I chose to develop a new application I called the Cardiorespiratory Viewer. Written in Python, using the Anaconda Spyder programming environment, it imports program modules from the Tkinter, numpy, scipy and matplotlib libraries. The application reads data files generated by the LabQuest recorder, displays simultaneous plots of EKG voltage and breath pressure, and enables the user to specify time segments and signal threshold levels for analysis.

Cardiorespiratory Viewer

Program for displaying and analyzing ECG and respiration signals

PDF for final project, Exploratory Investigation of Cardiorespiratory System during Meditation


Jun 132015

A few years ago I realized that during Zen meditation, while paying attention to my breath, I was also aware of my heart beating. I started counting heartbeats during my inhalations and exhalations and found that during an inhalation, there were about four beats and during the exhalation roughly 8-10 beats. I thought it would be interesting to match a fixed number of beats, say ten with each exhalation, and maintain the synchronization during the meditation period. The synchronized rhythm felt pleasurable—having both the heart and lungs involved seemed to help me to maintain a clear mind. This experience was my motivation for recording an electrocardiogram (ECG) of heart rhythm simultaneously with respiration.