How to test a meditation wearable?

I suppose the answer to that question is obvious but not so easy to realise: during a retreat. But still, that is what I did. Last week I spend 6 days meditating while at the same time putting my brand new wearable and software platform to the test.

It was snowing outside while I was doing my 6-day retreat

It was snowing outside while I was doing my 6-day retreat

What is it all about?

For those of you who missed it: the past 3 months I’ve been working on the Meditation Lab Experimenter Kit. The focus on those first months has been to design and develop a new Silence Suit wearable, improve the electronics and create a software platform (the Data Server) to log and explore the data.
The whole team has been working really hard to get the prototype ready for single user testing. It was quite exciting to put all the different parts together which have been developed by different team members on separate locations. I managed only just in time to get everything to work for the start of my self conducted retreat.

Data science

The main goal was to gather as much baseline data as possible. At a later stage I will try to influence my meditation through manipulating the light. But to really see the effects I need insight into how my ordinary meditation data looks. So German, our AI and data science expert, advised me to get as many 20 minute sessions as possible. I managed to do 54!
Things I wanted to know:
Do all the sensors produce reliable data?
How stable is the software platform?
How easy is it to use the wearable and the platform?
Will I enjoy using both?

Do all the sensors produce reliable data?


Getting good heart-rate data was the biggest challenge

Because I had been working with most of the sensors in my first prototype I had a pretty good idea of what the data should look like. Programmer Simon had swiftly put together a script that could plot data from all the sensors in graphs. That way I could easily grasp the main trends. It immediately became clear that the heart-rate sensor wasn’t doing what I’d hoped. A lot of beats were missed, once even only 2 data points were collected in 20 minutes (and no, I was not dead).
Oddly enough the rest of the data was fine. I tried recharging the batteries and changing the ear clip but nothing worked and whether or not I’d get good data seemed unpredictable. Until the final day.
While looking at the graphs after I’d finished a session I casually rubbed my earlobe and it felt cold. I looked at the data and saw that the signal deteriorated towards the end of the session. Eureka! The blood flow to my earlobe was the problem, not the electronics.
Cold is a major influence but I also want to experiment with the tightness of the clip. It might prevent the blood from circulating properly.
So most sensors performed well, better even than I’d hoped. Unfortunately no data comes from the cute little PCB one of the students at Design Lab has designed and soldered. Also the soft sensor for detecting sitting down (also the start button) is still unstable.

Force sensor to measure pressure between fingers

How stable is the software platform?

The software runs on my old Dell laptop and Simon has installed the Lightweight X11 Desktop Environment (LXDE) on it. So it runs on Linux which was a new experience for me. But I like it, it is basic and simple and does what it should. To start the system I have to run the server for data storing and the adapter for communication with the hardware. I must say I am very impressed with the whole performance. There has been no data loss and the plots are great to get an impression of the session.


Data output from one meditation session

How easy is it to use the wearable and the platform?

I was pleasantly surprised by the comfortableness of the suit even after 10 sessions in one day. Putting it on with attention takes about 2 minutes and then you’re all set. You hardly notice that you are packed with 10 different sensors.
The pre and post qualitative forms are easy to use. At the moment I still have to use URLs to access certain functionality but everything works and that was such a relief. Plotting the data with around 5000 data points per sensor per 20 min session is hard work for my old Dell. But it gives me time to do a little walking meditation…

Maybe it is just me but I don’t mind filling in two forms for every session. I seriously consider every question and try to answer as honestly as I can.
Doing two or three session in a row is even easier. All I have to do is refresh the home page of the server and I can start another session.

Will I enjoy using both?

Well yes, using the system was a pleasant experience for me. I did learn that I should not look at the data before filling in the post meditation questionnaire because the data caused my mood to plummet. So it will be best to have the data summery after that has been done.

last Session

Session summary. The number of data points will be replaced by mean values.

I have a lot of confidence that the system will be useful and give a lot of insights. There is still a way to go until I can actually automate the light actuation intelligently. But the plots did show variations and now German can work his magic. I can’t wait to see what he will come up with.

calendar perforation

Being able to tear of pages is an important part of the calendar. So I’ve been investigating the possibilities. At first I hoped the printer, Tiggelman, would just do it for me. Alas their perforation turned out to be too vulnerable. The nice people at St Joost art academy and office supplies Benoist gave me the opportunity to test two different systems for perforation: one with a blade and the other with punch holes:

The top page has a stamp perforation. The stack is one year. This gives me insight into the size and weight of the calendar. The total weight will be around 5 kilogram. The thickness will be around 32 cm.

I still haven’t decided which perforation to use. I will have to do it by hand whichever one I choose. But the ease in which the papers can be torn off will be decisive.

test prints

Today I went to make test prints and the results look very promising.

The people at Tiggelman repro were very helpful. They suggested I use a paper called Reviva which has a nice newspaper look. The lines I use in my design are only 0.4 pixels thick and the lighter ones were barely visible when I printed them on my printer. But at Tiggelman they’ve got a very good printer which can print those lines and gives very sharp prints in general. This is necessary as lots of lines are very subtle. They will print a test stack of 500 pages and do all the manipulations like drilling and perforating. I’m really looking forward to holding that first stack in my hands.

xbee hello world!

Today I’ve had my first success with communicating between two Xbees. Mostly thanks to this simple but clear tutorial. After installing the XCTU software with Thijs a few months back I had forgotten quite a lot of his private class “introduction to Xbee”. From his instructions I ordered 7 Xbee antenna’s and one Xbee explorer USB. My goal is to make an Xbee network without using Arduinos with the Xbees. This apparently is possible. But before getting to that point I had to make an Xbee “hello world” to grasp the concept and get the basics right.

In this picture you see the a light sensor attached to an Arduino and Xbee antenna. The Arduino prints the measurements to the serial port. Through the TX and RX pin the Arduino is connected to the Xbee antenna. This sends data to the other Xbee antenna that acts as a receiver. The data is printed in red in the XCTU terminal on the right.

On to the next step: running the Xbee on a battery and programming the Xbee pins to read and send the wind sensor data. To be continued…

non-woven wearable

Because I’m extending the breathing_time project into a workshop I’m doing some research on non-woven materials to make the cones from. The first version was made of paper and felt. It looked very nice but wasn’t very practical. Paper folds and crumbles easily. The felt on the face gets dirty and as it was glued to the paper I couldn’t replace it. The department of wearable senses from the TU/e kindly gave me some samples to experiment with. These are the results:

Lantor producer of all sorts of non-woven materials:

To start of with the best one. This is a thin, black non-woven. It’s very easy to work with. Can be glued with just ordinary collall glue. It sticks very well. The ease of working reminds one of paper. It has some nice extras. You can use sticky tape on it and you can remove that tape without leaving a trace, even after a few days:

This is very useful, it allows me to make a replaceable, protective edge. The bare edge is too sharp on the face. You can also glue two layers on top of each other to make the cone more firm. This has a very stylish appearance:

You can just use scissors to cut out the shape. And it doesn’t tear like paper. So attaching the strap is no problem.

I also tried another non-woven by Lantor. It has a felt like appearance. Very nice but it is too floppy for my purpose and quite hard to glue:

Colbond producer of all sorts of non-woven materials:

This semi transparent, thermally bounded non-woven has a very appealing look. It is stiff, even a bit sharp on the edges. I was really looking forward to trying this out but the result was a bit disappointing. It was hard to glue due to its’ open structure. It also turned out to be very brittle. A fold doesn’t go away (view right end). In that sense it is worse then paper. As I will be reusing these cones with different people they have to stay clean and in shape. This one didn’t stand that test.

analogue input

Today I did a little test using analogue input for my LED. I build my third RBBB today and wanted to take the LED output a little further. For my breathing device it will have to respond to the analogue input of breathing. So I emulated that with a light sensor. Covering the sensor less or more changed the brightness of the LED. For a start it was fine, but with breathing the LED will have to go from no light to very much light to give proper feedback on the respiration pattern.

Testing 1, 2, 3…

Thursday I did it test with all my sensors for 24 hours. It went rather well but there art two main points of attention.

Mathe, Richard an me working (no were not terrorists)

Mathe, Richard an me working (no we're not terrorists)

1. The stealth cam. It has limited capabilities in storage capacity and battery capacity. When I set the resolution to low it should be able to hold 350 pictures. This is not the case, it holds 300 max. Another drawback is that it’s very hard to make out to which resolution the cam is set. So I accidentally set it to high. As a result I couldn’t complete the whole day because I was with friends and I forgot my cable so I was stuck for the evening with a full camera. But I did get some nice shots (view right.)

It takes just one AAA size battery. I used up only 2.5 in 13.5 hours so that was fine. I do have to carry a spare one with me where ever I go. I bought a quick, one hour charger for four AAA batteries so I will never go without.

Tiny cam can be attached with velcro to a card

Tiny cam can be attached with Velcro to a card

I’ve found a very nifty ┬ásolution for wearing the camera. I can pin or clip it to every sort of clothing. The images are still shaky but he, life is bumpy ;) To my relieve people didn’t look too suspicious when I passed them, I’m still a bit embarrassed though.

It was quite a puzzle to see where I missed pictures. (In the future I will note exactly when the camera stopped and restarted.) When I empty the storage it takes at least a couple of minutes to store them on hard disk. So there are gaps. I filled the gaps with duplicate pictures but I’m still files short…? I think the 60 second laps probably isn’t exactly 60 seconds so after a couple of hundred pictures you start noticing that. I’ll have to wait and see how that works out in the app.

The main challenge is dealing with the gaps in the data from all the devices.

2. My Suunto watch does a great job during the day but when I sleep it loses connection with the skin and it stopped at 4 a.m. Which was still almost all night. But it will have to do better when the project actually runs. I think I’ll buy some medical tape to fasten it for the night.

I don’t think it can log 24 hours of data, but it’s close. To be on the safe side I’ll store the data somewhere in the middle of the day.

Logging my activities was a very mindful thing to do. I thought it would irritate me but it made me quiet and alert at the same time. May be using pencil and paper helped there too.