This message is from Alex Gersten, a colleague of Dr. Robert Fried’s. He is doing some fascinating work with the effects of various yogic exercises on human physiology. I told him I’d be happy to send this out to the list as a way of recruiting yoga practitioners for his current study, and I’ve volunteered the use of the Breathing Project studio to conduct the testing.
Click here to read about his experiment to test the effect of pranayama on brain oxygenation and on CO2 arterial level.
Aug. 10, 05
From: Alexander Gersten
Visiting Professor of Physics
To: Practitioners of pranayama
Experiment to test the effect of pranayama on brain oxygenation and on CO2 arterial level.
The aim of this experiment is to learn about the physiological effects of pranayama on CO2 and oxygen levels in the brain.
It is well known that breathing patterns affect the CO2 levels in the arteries, which in turn affect cerebral blood circulation and oxygenation. CO2 levels were measured extensively before, but the correlated oxygenation was not yet researched. I have done on myself many preliminary experiments from which it seems that the oxygenation is not directly proportional to increased blood flow but is an accumulative process.
This experiment will shed new light on the oxygenation in the brain and may be important in evaluating the effect of pranayama and other breathing techniques on mental performance and health.
It will be interesting for each participant to learn how breathing exercises influence her/his physiology.
The CO2 levels in this experiment will be estimated using a capnometer, manufactured by Better Physiology LTD. This device measures end tidal CO2 (EtCO2) during exhalation. EtCO2 is known to be highly correlated with the CO2 levels in the arteries. The collection of the EtCO2 will be done with the help of a nasal insert. The data will be transferred via a USB output cable connected to a computer and stored for subsequent review.
The oxygen levels will be estimated using an INVOS Cerebral Oximeter, a device based on advanced near infrared spectroscopy (NIRS) technology, produced by Somanetics Corp. (see www.somanetics.com).The oxygenation level of the brain will be measured via two sensors attached to the forehead. These sensors allow to measure levels of oxygenation up to a depth of one inch in the cortex. The data will be stored on a floppy disk.
The data of the capnometer and of the oximeter will be combined together and analyzed for each participant using Matlab subprograms that I have developed.
We shall start with preliminary experiments. We shall allocate one hour for each participant. The first and last 5 minutes will be devoted to baseline measurements during which the participants will be asked not to pay attention to their breathing. After the first 5 minutes the participants will do for 30 minutes their preferred breathing exercise, next, for 20 minutes they will meditate and for the last 5 minutes relax without paying attention to their breathing.
After the first round of experiments and their analysis we shall decide for the next round on one specific breathing exercise for all participants using the same pattern of 5 minutes for baseline, 30 minutes exercise , 20 minutes meditation, and 5 minutes for baseline.
There will be no competition, and no over-performance. As it takes time for brain oxygenation level to change, sufficient time is allocated to each participant.
The participants should be in good health. They have to be well acquainted with different pranayamas.
At least two experimenters will be present during each experiment.
The participants will not see the screens of the devices in order to avoid biofeedback.
The theory will be explained to the participants after the whole experiment will be concluded. The computer analysis of each participant will include figures depicting the time dependence of EtCO2 (end tidal CO2) and rSO2 (oxygen saturation) and the dependence of rSO2 on EtCO2 .
We shall also consider future experiments including headstand (I have interesting results on myself).
Leslie Kaminoff has agreed to allow us to use The Breathing Project facilities during the weekends. For those who will not be able to come during weekends other arrangements will be possible. Please let me know when you will be able to participate (dates and times) and we shall plan accordingly the time schedules.
With best wishes,