For something over a year, I've been working through the archives of Jimmy Moore's Livin' La Vida Low-Carb Show podcast. (I started eating low-carb in June, 2012. Sometime after that I started listening to Jimmy's podcasts during my commutes.)
On the evening of November 6th, 2013, I listened to episode 724, Binx Selby Helps You Grow Younger By Battling Inflammation With A Low-Carb Diet, which was first broadcast September 11th, 2013.
Binx Selby was on to talk about his book, How I Grew Younger. . .And Why You Should Too: In just 2 weeks, you can reduce belly fat, cholesterol, inflammation, and the age of your arteries with the BalancePoint diet, and about the diet he recommended in that book.
His diet was a very specific protocol aimed at significantly reducing inflammation, and according to him, that would significantly lower cholesterol, very quickly.
I listened intently, because while 18 months of low-carb had helped me to lose a significant amount of weight, and to improve my health a great deal, I had plateaued some 20 pounds above where I would like to be, and my cholesterol numbers were higher than I had been told was normal on a low-carb diet. I'd just recently received the results of my first particle count and hsCrp tests, and they were too high for comfort.
He wasn't the first I'd heard suggest that inflammation can actually be a cause of raised LDL. But he was the first I'd heard talk about trying to measure levels of systemic inflammation in a fast, non-invasive way.
Starting about 15:30 into the podcost, Binx talks about measuring inflammation by examining the pressure wave of the pulse. According to him, measuring at the wrist, the wave shows a initial pulse from the left ventricle contraction, and an reflective pulse from the arterial branching in the groin. By knowing the delay between the two, and the distance between the heart and the groin, you can calculate the velocity of the pulse wave, and velocity is directly related to stiffness. The stiffer the arterial wall, the faster the pulse will travel.
And that struck me as opening up the possibility for a very interesting, and possibly significantly very beneficial DIY project.
Since I started low-carb, I've found my glucose meter to be a very helpful tool both in measuring my health status (I do fasting glucose most mornings, and oral glucose tolerance tests every six months to track my insulin sensitivity - both of which have improved significantly since I started low-carb), and to determine how I respond to different foods, and to see what I can and cannot tolerate. The glucose meter has been a fundamental tool in the management of health, for those with insulin sensitivity problems and diabetes, ever since Dr. Richard K. Bernstein first started self-testing, fifty years ago.
There's never been a tool for self-measurement of systemic inflammation, in the way there is for blood sugar, but there really should be. Inflammation seems to be the root cause of even more chronic disease than blood sugar. It might even be that inflammation is a cause of the metabolic disorders that result in insulin resistance. What I heard in this podcast suggested to me that such a device was possible,
If you look up Sphygmograph in Wikipedia, you'll find an article about a mechanical device that was developed in 1854 and drew the pulse wave on paper with a pen. There are books from the 19th century available on Google Books: The use of the sphygmograph in clinical medicine (1899).
And, apparently, there are new, high-tech medical devices being developed: SphygmoCor Technology. I'm sure that the "very expensive' device that Binx mentioned using in testing was of this sort.
What I wondered, though, was why this was expensive? All that is needed is a sensor that can detect the pressure wave in an electronic form. All the rest is signal processing. Could I find an inexpensive detector that I could use in a DIY electronics project? It didn't take much googling to find: Easy Pulse - a-diy pulse sensor based on photoplethysmography and Easy Pulse v1.1.
This little board outputs the wave form as an analog signal. It's currently being used in a crowd-sourced PC-Based Heart Rate Monitor. But if it's signal is as clear as it seems to be from the images at the above links, it should be possible to extract the echo pulse, and from that, the pulse wave velocity. And if we can't extract the echo, by we could still determine pulse wave velocity by using two sensors at different locations on the body.
All the rest is just signal processing. In other words, software.
To build something that you could certify for clinical use, to develop the data necessary to calibrate the system so that numbers from one person could be meaningfully compared to another would take tens of thousands of measurements on thousands of patients. That is to say, it'd be very expensive. But you wouldn't need any of that, to provide relative measurements. Without that calibration, you might not be able to tell whether your level of inflammation was higher or lower than another's, or whether your level of inflammation was or was not high enough to increase your risk of atherosclerosis. You can learn a lot, though, from relative changes. If this works, you could tell whether a given food increased or did not increase your level of inflammation. Are you sensitive to gluten? To lectins? To lactose? To Casein? To nightshades? Wouldn't it be nice if you had a way of finding out that took a couple of hours, instead of a couple of weeks?
The Easy Pulse Sensor costs less than $20. You should be able to plug it into any oscilloscope, and see whether this works.
At this point, I've ordered one. And I've been digging through the boxes in the basement trying to find my old PC-based oscilloscope. After it arrives, and if I can manage to get the oscilloscope to work on a modern computer (I used to use it on a Windows-95 laptop), I should be able to see whether this idea has an promise.
