Category: Neuroscience

Idea shared #1 – measure your sleep

I don’t consider having more or better ideas than others. But I gradually realized I have less and less time for some activities like programming, electronics etc. Maybe that’s how we realize we are getting older now adults. So I decided to share these ideas rather than fueling the illusory idea that I will implement them one day.

So idea 1 is about measuring sleep. I recorded animals’sleep during my Ph.D. – but it was thanks to an EEG device. I think that if you want to understand or improve something you have to first measure it in a way or another. So I started to try to measure my own sleep with an app (Sleep Cycle). But despite its good reviews it doesn’t work, at least for me.

For instance the chart below is supposed to represent my sleep cycle for the night of the September 14th, 2012. I was certainly not in deep sleep at 1.30AM (baby did not want me to sleep immediately). I also woke up around 4AM (baby was again the reason). And I woke up at 6.45 (with a backup clock – had to wake up for work)?

My Sleep Graph with Sleep Cycle app for September 14th, 2012 night

The last version of the Sleep Cycle app improves things a bit by providing more statistics (so at last you can rely on the approximate time slept and compare your “sleep” across days etc.), more beautiful gaphs and the ability to download raw data. Don’t be fooled however, “raw data” means only start time, end time, sleep quality (how is it measured?), time in bed, number of wake ups and sleep notes. You unfortunately won’t be able to reproduce anything like the graph above.

Hardware devices like the Wakemate or the Zeo might give better results because part of the solution is using a real accelerometer. But the Up story shows that not everything is obvious in this world.

For me the fundamental flaw is to rely only on body movements to detect, quantify and even score sleep. Of course there is an abundant scientific literature about how muscle tone (of different muscles) is related to sleep stages (see here and here for introductory texts). But this is often measured by electrodes glued on your body.

So I think it could be very easy to develop a simple, cheap “sleep T-shirt” with light electrodes that will just stick to your body when you sleep (and you put enough of them so at any time at least some of them are connected). In fact it might happen that the Rest SleepShirt would already do the job – it’s a pity they don’t elaborate more on how they measure and collect data (but I understand they will want to sell the product later on ;-)). In my idea light wires would then go to a small pouch where they would be connected to something like a LilyPad Arduino (because it is flexible and can be sewed to a T-shirt – there may be other devices available). The LilyPad would serve as data collector or as data transmitter to a computer / a smartphone / a specific receiver (coupled to a real clock, like the Zeo). The advantage would be to remain sole owner of your sleep data – but of course the business plan should include some “social” features 😉

In the end it should look a bit like this:

Idea shared #1 - measure your sleep with sleep T-shirtThe other advantage would be that in such way you may also measure electrical activity through the body.

Will it work? I’m sure of it. Will it be enough to sleep correctly? I don’t think so: it’s not because you measure something that it improves. But at least you will have some clue on what is going on. Some other advices may be interesting. And for the moment nothing replaces a visit to a real doctor / sleep specialist!

Creative Commons Licence
This work is licensed under a Creative Commons Attribution-ShareAlike 3.0 Unported License.

Ph.D. thesis

As I promised before, you’ll find here the text and slides of my Ph.D. thesis (btw text and slides are in French). The oral presentation was on March 24th, 2010 and everything was fine 🙂 Slides can be watched below.

Baby movements during sleep

After a while, here is why I got a TV tuner for my Linux laptop, took screen captures and wrote a script to add a timestamp on pictures … I wanted to know how my (then 5-month-old) son was sleeping (his mom can be reassured: I was not planning to put electrodes on his scalp 😉 ).

Get the Flash Player to see this player.

var s1 = new SWFObject(“../videos/player.swf”,”ply”,”360″,”240″,”9″,”#FFFFFF”);
s1.addParam(“allowfullscreen”,”false”);
s1.addParam(“allowscriptaccess”,”sameDomain”);
s1.addParam(“flashvars”,”file=../videos/081129-night.flv&image=../videos/081129-night.jpg”);
s1.write(“container”);

Following this, I had interesting discussions with my dad about sleep patterns in babies. It could also be interesting to hybridize what we did for Gemvid and this simple solution in order to be able to quantify human/baby movements during sleep. My little knowledge of OpenCV can then come in handy for the motion and pattern detection …

Some additional technical details : Video was made from 321 TV screen captures (1 every 2 minutes) and played back at 1 frame per second. It was converted with FFmpeg (LGPL) and the Flash player is JW FLV Media Player (CC by-nc-sa). Ok: Flash is not free.

A seventh scientific paper from the Poirrier-Falisse!

Finally, a seventh scientific paper is published by the Poirrier-Falisse. After a huge batch of articles from Nandini, here is my second paper:

Poirrier J.E., Guillonneau F., Renaut J., Sergeant K., Luxen A., Maquet P. and Leprince P.: “Proteomic changes in rat hippocampus and adrenals following short-term sleep deprivation” Proteome Science, 2008, 6(1):14
doi: 10.1186/1477-5956-6-14

Very briefly, in this study we show the influence of 4 hours of prolonged wakefulness in rats hippocampus and adrenals proteome. As usual, this paper is published in an Open Access journal. Here is my updated BibTeX file (and I also updated Nandini’s BibTeX file).

Since the publication of two papers in peer-reviewed journals is a requirement, I will now be able to finish and defend my Ph.D. thesis …

Published in Nature!

I was very pleased to see my first publication in Nature (1), the scientific journal with an impact factor of 26! Well, it’s not really what you can expect (especially if you are one of my two mentors): one of my photos on Flickr, representing a rat eating (or praying?), was chosen to illustrate a summary of UK Academy of Medical Sciences report on animal-human chimeras 🙂

Screenshot of the article containing a photo I took
Click on the thumbnail above to see the full screenshot

Here is the article full reference: DeWitt, N. “Animal-human chimeras: Summary of UK Academy of Medical Sciences Report” Nature Reports Stem Cells, published online on August, 2nd, 2007.

Note that I don’t know if they completely comply with the photo license since the Creative Commons Attribution-ShareAlike 2.0 allows them to re-use the photo and do the modifications, provided they give credit (ok) and distribute the resulting work only under a licence identical to the CC-by-sa. They are not clearly stating to others the licence terms of their new work …

(1) As Jan Schoones wrote in his comment, it’s not published in Nature itself but in Nature Reports Stem Cells, a journal published by the same company as Nature but which does not have an impact factor! (Edited on August, 20th)