@Kristopher;

Thank you for your precious topic presentation. 

"Paroxysmal" respiratory sinus arrhythmia is difficult to be detected in case of 24hr ECG failure to find it. OMRON event ECG might be help to detect those paroxysmal ECG changes. Device 200 dollars, more or less.

Best Regards;

Kazuo Oie M.D. 

Hi-- we have recently started using BIOPAC to measure RSA and it seems to be working well.

https://www.researchgate.net/publication/295548322_A_Practical_Guide_to_Heart_Rate_Variability_Estimation

Method A Practical Guide to Heart Rate Variability Estimation

There are a number of relatively easy methods to measure RSA  that produce equvalent results (e.g. see my comparison of 3 available methods from 1991; Grossman, van Beek and Wientjes, which can be downloaded at this site).  However, it is really important that one measures respiration rate and depth, as well as Heart period (60000/heart rate), since changes  particularly in respiration rate can profoundly distort within-person relations between RSA magnitude and cardiac vagal tone. Also regarding individual differences in cardiac vagal tone, we showed in another available paper that  resting heart period was a far better marker of cardiac vagal tone than RSA is (Grossman & Kollai, 1993), a finding that has gone ignored in the literature but which was replicated in another study by Kollai. Somewhat better than heart period, alone, were multiple regression prediction, using both heart period and RSA (including respiratory measures did not make a difference in these between-individual assessments. Please study the early RSA physiological literature to learn the caveats of RSA indexing of cardiac vagal tone. Respiration, and with- vs. between-individual difference, are but two relevant factors. 

Hi Kris,

Can you please clarify? Are you primarily looking for methodological knowledge on how to measure RSA (which can be answered by James Miller and Paul Grossman's posts), or are you looking for affordable technology that enables you to collect/record RSA? If it's the latter, then can you provide us with more information (e.g., price range)?

If I understand the concept properly, you might be best served by collaborating with your sleep colleagues! A basic sleep cart will be able to generate an ECG, and will have a chest band that can give you respiratory rate and 'depth' measurements. An added benefit here is that this equipment will go largely unused during the day, so will likely be at your disposal.

Jared,  Thanks for the prompt to clarify.  My vague posting reflects my ignorance on both accounts.  I am both trying to learn more about what RSA is (and isn't), and what might be a way to measure it. 

At the end of the day, my hope is to find affordable technology that enables us to collect and record RSA.   My budget is all out of pocket at this stage.  I was hoping for less than $1000.  At some future date I hope it will be funded and this will increase.

Kris, for that type of price tag I think what you'll be looking for is one of the ambulatory/mobile monitors that can also provide you with a heart rate variability (HRV) metric. RSA and HRV (especially the high-frequency component of HRV) are often used synonymously, even though they can be separated. I am gathering that your question is really looking at the vagally-mediated (i.e., parasympathetic) influence on cardiac activity. Therefore, any ambulatory measure that provides you with HRV over-and-above simple heart rate will probably do the trick.

You should look at the following ambulatory devices:

First recommendation:

https://www.movisens.com/en/products/ecg-and-activity-sensor-ecgmove-3/

Others to look into:

One of Polar's devices that include HRV: http://support.polar.com/us-en/support/Heart_Rate_Variability__HRV_

https://elitehrv.com/ ... although I'm not yet sure about their use in empirical work.

This is probably a bit pricier--but is the best in terms of being research grade--if they still make it: http://www.vu-ams.nl/vu-ams/hardware/

Dear All

Spontaneious RSA(Respiratory Sinus Arrythmya) could be recorded HCG-801.

healthcare.omron.co.jp

Hello there!

I'm using Battium Faros ECG Device (https://www.bittium.com/products_services/medical/bittium_faros).

Does someone make RSA analysis?

Here's a simplistic approach (attached).

Hi,

we've created an iOS app called HeartBreath.

It is a biofeedback tool that addresses the relationship between respiration and heart rate.

RSA - respiratory sinus arrhythmia.

Paced breathing and HRV measurements from the iPhone camera or a bluetooth HRM.

Also inspired by the work of Dr. Richard Gevirtz.

The app is published on the App Store.

Homepage: https://www.heartbreath.app33

If anyone is interrested in free testing, I can post a TestFlight link here or offer some promo-codes.

In addition whe have an experimental version that integrates with a Faros (180) device (live display of ECG and more).

Thanks

Daniela Gabler

use, The peak to trough (P2T) . https://neurokit.readthedocs.io/en/latest/documentation.html#neurokit.ecg_rsa