About my blog

The aim of the ITD course (ID4220) at the Delft University of Technology is to provide Design For Interaction Master students with in-depth theoretical and practical interaction design knowledge to help develop future products based on user-product social interaction. ITD proceeds through a sequence of iterations focusing on various aspects of the brief and the design, and culminates in an experiential prototype.

This blog is managed by Walter A. Aprile: please write if you have questions.



De meningen ge-uit door medewerkers en studenten van de TU Delft en de commentaren die zijn gegeven reflecteren niet perse de mening(en) van de TU Delft. De TU Delft is dan ook niet verantwoordelijk voor de inhoud van hetgeen op de TU Delft weblogs zichtbaar is. Wel vindt de TU Delft het belangrijk - en ook waarde toevoegend - dat medewerkers en studenten op deze, door de TU Delft gefaciliteerde, omgeving hun mening kunnen geven.

Posts in category exercise1

Exercise1, our final concept: FLEXCURE

At the end of the project we presented our concept on the exhibition day. Also specialists that were involved earlier in the project, were enthousiastic about our concept ‘fitting the trend of using more interactive and therapy supporting healthcare products. See our latest video showing our final concept and prototype "flexcure":

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Finalizing prototype; sewing and laser cutting

The exciting time where things come together, we are finalizing our prototype! The electronics part with arduino, bending sensor and display with status bar is fully functional. This week we have therefore been working on the hardware of the prototype. This included sewing for embedding the batttery in the self made wristband and lasercutting for a small and precise case for arduino and display. Look at the details of this case; it mentiones "ITD 2011" on top and "power" on a side for the connection of the battery. There is also space to connect to laptop and to reset when necessary. See our pictures:

 Sewing the cover of our wristband:



 Stitching velco on to make the prototype fit on every wrist:



 Embedding the battery in a little pocket of the wristband:

The battery sticking out a bit for the picture, but will be fully hidden in the band: 
Laer cutting in progress:
The seperate parts of the case for arduino and display. Notice the lasered texts on the surface: 









Preparations for the exhibition!

We are already preparing the exhibition day. Exercise 1 and 2 will be together in one studio. We will decorate one half of the studio as a doctor’s office and the other half as a living room. Why? Well, because both our concepts are related to hand therapy but are also designed for home use!
We made a list of all needed things, so we can divide everythings.
The couch is already there!

Finalizing prototype

The product idea is getting serious developed shapes now. We bought a sweat band, used in sports, to embed our small Arduino and battery. The display is the only that a patient will see, on the surface of the band. This is an arm with the sweatband:

Arm with sweatband


Furthermore we use a bending sensor taped at the top (healthy) part of the vinger. Not directly taped, since the finger has to bend, but the idea is to stick little tubes at the phalanges of the finget. The bending sensor runs through these tubes, free to bend. Also, an additional idea is to place touch sensors on the vinger tips, to measure, in the final stage of the treatment, whether patients are able to bend the vingers totally till vingertips touch handpalm. Since patients are not able to do this ‘total flexion’, it has no use to make use of the bendingsensor to determine whether a patient bends totally. but above all, this would imply some form of callibration of the bending sensor, with a more compicated interface that does not match with our concept of easy and everywhere to use.

First, we will focuss on the bending sensor, but we’re almost there. Ex(er)citing isn’t? See the picture of the hardware, with the working display :). The second picture shows the sweat band partly cut open, to be able to squeeze the Arduino and battery in.  

Sweatband cut open for assembly

Developing our new product idea


After ourmeeting with a field expert, a therapist, where we showed and explained our prototype we had some though time, changing our product idea. The concept was ok, but the physical object we had in mind, a glove, turned out to be not suitable for use in therapy.

Thu; discussions and talks and ordering stuff! The idea has changed to taping a bendingsensor on the top part of the finger connected to an Arduino, instead of the original glove. This does not obstruct the movement of the exercise that patients have to do and it still fits our concept of easy and everywhere to use.

See our picture of our programming hardware. Yes, there is a display! What it should do? See the sketch. It gives feedback on the amount of exercises done and the amount of series done that day.


About our prototypes

Since the last few posts have been descriptions on a more conceptual level, we would like to enlighten you with a more technical story. Read about the ins and outs of our prototype!

First iteration

The first Iteration was done in a single afternoon. We were introduced to the Phi get I/O board and suitable software applications like MAX/MSP. After some struggling installing, we managed to get our first iteration working. However, it wasn’t stand-alone; we used the PC to control the lights ourselves. In the upcoming iterations, this would change.

Second iteration

The second iteration we used a touch-sensor and the Phidget I/O board connected to a laptop. On the laptop, we ran a Flash-application, which was capable to read the data from the touch-sensor. The Flash-application counted the amount of touches and this was translated in the size of the balloon on the computer-screen. In addition, we added a reset button when the balloon exploded, so the exercise could start over again. This iteration was semi-stand-alone. Since it was still connected with the PC, but no user intervention was required anymore.

The touch sensor of the second iteration  

Third iteration

For the third iteration we decided to go stand-alone, so no user intervention is required anymore. We used first an Arduino board that is programmable and can operate stand-alone, using a 9V battery. We connected eight LEDs to the Arduino so the progress of the exercise could be shown. However, we had some difficulties with sensing the bending-sensor, in order to sense the exercise. Therefore, we had to simulate the exercise using a linear potential meter. In addition, we also though ahead in order to make the system more mobile and compact we played around using the Seeedruino Film; A small flexible Arduino-compatible interface which is very small. However, we had some difficulties programming the Seedruino and we already noticed this solution was not solid enough to complete the end of the course. 

We sewed the bending sensor ourselves 

Fourth iteration

For the fourth iteration, we decided to change the LEDs into a small-display, capable of notifying the user more concrete and precise. In addition, this solution enables the user to get more insight in the exercise and can give the user direct feedback while performing the exercise. Since it was still a prototype, we used the Arduino Uno, a 2×16 LCD display and a bending sensor to show the status of the exercise: “too fast”, “OK” or “too slow”. In addition using a counter, we could notify the user when the required 10 excersies were performed. Moreover, we investigated the use of the ordered bending-sensor in textile. It was working though, but since there was too much bias while sensing we decided to go back to a more reliable method; a bending sensor. We made a list of stuff we had to order for the first iteration, in order to make it more compact and professional looking. This included a small OLED-display, a bending sensor and the Arduino min Pro.

Fifth iteration

For the fifth iteration we went to miniature scale; using a small 2 cm wide OLED-display, Arduino Mini Pro, a 3,7V battery and a bending sensor this design becomes small enough to be placed in a watch. Libraries for the display were created so the Arduino could communicate with the display. At time of writing this blog post we were porting the previous code to make it work for the new sensor and display. We’re looking forward to test the final design in practice when it’s finished.

The little OLED display

Different concepts + final idea!

After our visit to the hand therapist we had to think of a new concept. The hand therapist told us that the most important aspect of the exercise is the total flexion (the fingertips need to touch the palm of the hand) and total extension (straight fingers). How fast the patient does the exercise is of less importance.

So we decided to focus on those two things.

But before we reached that decision a lot of ideas were passed in review.

At first we thought: If the fingertips touching the palm is so important, then we should put sensors on the palm that can measure whether the total extension is reached. In that case we could even put multiple sensors in the palm, that give feedback about the different types of fists. On the picture below you can see different sensors. In the picture you don’t see sensors for the different types of fists; therefore for every ‘color’ a sensor should be placed in the middle of the palm en at the very bottom of the palm. However, it turned out to be impossible to put things directly on the palm, because of sutures and scar tissue.

Then we thought: We should use the bending sensor to measure the flexion. If the bending sensor is put on the back of the hand, it can measure whether the fingers is flexed enough. But, as we already noticed with our Exercited concept, the bending sensor gives too different values. It is hard to really draw conclusions from the sensor, so we had to think of something else.

Finally, we decided to put the sensors on the fingertips themselves. Pressure sensors on the fingertips can measure whether the fingers touch the palm, without bothering the scars on the palm. Unfortunately, in this way it is not possible anymore to give direct feedback about the different types of fists, but we don’t see a way to implement this. The hand therapist said that an important part of the recovery process is giving patients own responsibility, so we’ll just have to trust them on this.
We also considered light sensor instead of pressure sensors, but those will not be accurate enough, so we stick with the pressure sensors.
In addition to the sensors on the fingertips, we also decided to make something to measure the extension, because this is important, too. A bending sensor will be put on the back of the hand to measure -roughly- whether the fingers are totally stretched or not. The bending sensor will be ‘glued’ to the hand with kinesio tape. The pressure sensors on the fingertips will be placed on a flexible thimble, that the patient can put on his fingertip.

Sensors on the fingertips would correspond with sensors on the palm.


Now we’re only six weeks away from the final presentations, it’s time for a recapitulation. What have we done in the past few months? Why did we make certain decisions? What concepts have been developed and which ones have failed again?
Until now, the blog only gave little snippets of information. To give you a good overview of our process, here is a summary of everything we’ve done so far!

First iteration
During the first iteration, we made a game based on Simon Says. This concept aims on letting the user move his whole body; at that point we hadn’t decided on a specific part of the body yet. We used electrical click switches for the buttons. The link to our first presentation movie is: First Iteration movie

Second iteration
At the start of the second iteration we decided to focus on rehabilitation of the hand. To be more specific: the flexor tendons. We learned about the Kleinert protocol, which prescribes what exercises the patient should do and when he should do them. We wanted to focus on one exercise: the total flexion and extension of the hand. We made a device with a touch sensor, that notices when the fingers of the patient are totally extended. For every correct movement, feedback was given on a screen: a balloon gets bigger for every exercise. When the needed amount of exercises is done, the balloon pops. The link to our second iteration presentation movie is: Second Iteration movie

Third iteration
During the third iteration we changed our concept into something portable. We wanted to give patients the possibility to do their exercises everywhere (without the need for a computer screen), so we decided to put the feedback on a glove. The patient needs to put on the glove. A bending sensor is sewed to the ‘back’ of the glove, which measures the bending of the fingers. Compared to the concept of iteration 2, a big improvement is that the glove (which we called the ‘Exercited’) measures the flexion of the fingers, instead of emphasizing the extension. Around the wrist of the glove, 20 LEDs were put that gave feedback about the exercises; for every correct movement one LED would go on.
For the prototype we used a linear potentiometer to simulate the bending, since we didn’t receive the ordered bending sensor yet. We tried to implement a Seeeduino, but it didn’t work, so we had to use the Arduino One.
The link to our third presentation movie is:Third Iteration movie

Fourth iteration
The fourth iteration was rather short, only two weeks. During this iteration we decided to lose the LEDs, because they were a littlebit too bright and besides, they were only suitable for giving a very limited way of feedback giving. So we decided to put a display on the wrist of the glove. With a display it is possible to give more elaborated feedback, for example about the speed of the exercise. The first display we used was a 2×16 LCD bar. On this movie you can see the display giving feedback. During this iteration we didn’t make a presentation movie, but we made a ‘prototype plan’, which precisely describes what we are going to do in the last few weeks.

Fifth iteration
Now we are in the fifth iteration. This is the phase of making final decisions and detailing our concept. As you can read in the previous blog post, we went to a hand therapist to get some useful information. We tried to schedule a meeting with a professor of Erasmus MC, but due to circumstances and miscommunication we had to change our plans. Hence, it’s relatively late that we get to know about crucial information (about the fact that a glove is not possible). But luckily, there is still enough time to change our concept and make it something really useful.
Read our next blog post to learn about the concepts we thought of after our meeting with the hand therapist!

Interview with hand therapist

We just had our interview with a hand therapist in Delft. She is specialized in treating injuries and disorders of the hand and she answered a lot of questions we had regarding the topic of our project. The interview gave us insight in the exercises that patients have to do and why they need to do them. It appears that different exercises fit the different stages of rehabilitation. We focus on the last phase of rehabilitation, the phase wherein the patient has to do flexion and extension exercises, without any help of -for example- rubber bands.

On the picture below you can see the possible ‘types of fists’ a person can make.The patient has to make all these three fists, in order to train his tendons.

Currently, the only way to check the improvement of the patient is by measuring the angle that can be achieved in the different joints of the finger(s).

The most important finding of today reaches to the foundation of our project; using a glove is not possible. A glove is too much obstructing the flexion and extension movement, and it makes it harder to determine were -and if- the fingers touch the palm. So, our concept has to change drastically.

So, we have a lot to do today!


We have a display!

We decided that we want to give feedback in a different way. During the last presentations it appeared that the LEDs are quite bright. Too bright actually, they almost illuminate the whole room, which makes the prototype a bit too present.
So, we decided to think of another way of feedback that is a bit more unobtrusive.
Since we want to tell the user several things (whether they are doing the exercise well, how many exercises they did so far, etc.) an obvious solution would be to use a display. A display can show a lot of different things while using a relatively small amount of space.

We got an LCD bar (2×16) from the Studio Lab and started working. The current prototype can show whether the exercise is done quick/slow enough and tells when the needed amount of exercises is done (in the prototype 8, in ‘real life’ 20 per hour). The backlight of the display goes on when the fingers are maximally stretched.

Look at the video!

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