Wednesday 30 January 2008

Color blindness: Deuteranopia (Rot-Grün-Blindheit)

Users exhibiting Deuteranopia have a rare case of color blindness. Their perception of red/green is reduced. Which makes the distinction between these two colors difficult. We checked our diagrams with VisCheck and got good results which makes us believe that people with Deuteranopia can read our diagrams without problems:

Glucose and Insulin curve:





Comparison of days:





Trend:


Color blindness: Protanopia (Rotblindheit)

Users exhibiting Protanopia have a rare case of color blindness. Their perception of red/green is reduced. Which makes the distinction between these two colors difficult. We checked our diagrams with VisCheck and got good results which makes us believe that people with Protanopia can read our diagrams without problems:

Glucose and Insulin curve:





Comparison of days:





Trend:


Color blindness: Tritanopia (Blaublindheit)

Users exhibiting Tritanopia have a very rare case of color blindness. Their perception of blue/yellow is reduced. Which makes the distinction between these two colors difficult. We checked our diagrams with VisCheck and got good results which makes us believe that people with Tritanopia can read our diagrams without problems:

Glucose and Insulin curve:





Comparison of days:





Trend:


Tabulator bar is now scalable

Visually impaired users often use the key combinations "Ctrl" plus "+" or "Ctrl" plus "-" to increase or decrease the font size of the page. The key combination "Ctrl" plus "0" will set the default size.

Our tabulator bar was composed of graphical elements. The problem was that these elements are not scalable. This makes them very hard to read for visually impaired users. Therefore we switched the tabulator bar to pure HTML which is fully scalable.

Monday 28 January 2008

Internet Explorer: max-width of page

One user requested that we should limit the width of the page to make it more readable on wide screen displays. The CSS attribute max-width looked like the prefered way to realize this limitation - it will behave nicely on small screens. But it turned out that this attribute is not supported by the Internet Explorer. After some fruitless approaches we found this solution for our css file:

#mainContent
{
max-width:62em;
width:expression(document.body.clientWidth > 1024?"62em":"auto");
}

The max-width will work on all conforming browsers. The expression for width will only work on the Internet Explorer. The other browsers will ignore this command.

Oh dear, why is it such a problem to adopt and respect newer CSS standards?

Friday 25 January 2008

Insulin curves

I am very proud to announce that we have managed to display the schematical progression of the insulin curve. The diagram "Glucose - Curve" contains the insulin curve when Details:on is set. Of course these curves will not describe the reality in the blood stream of diabetics. But they are meant to provide very basic insights in the mechanisms of rapid and basal insulin. We are very sure that this visualization is helpfull for educational purposes. Furthermore very basic problems like the overlapping of insulin doses or the fade-out of basal insulin are much easier to understand.

Tuesday 15 January 2008

Internet Explorer and YouTube videos

The security concept of the internet explorer is a mystery. The browser will give you an ActiveX warning when you embed YouTube videos into the page. The only way to solve the problem is to allow ActiveX controls on the page OR to trust the page. But this allows much more than playing the YouTube video. It will enable the page to inject every ActiveX control that it would like to inject. These controls are running directly on your computer and they have the same rights as the user that is running the internet explorer. We got around the problem by making an image of the YouTube video that is acting as a link to YouTube now. This example shows that the security concept does not enhance security. Therefore we can not recommend to use the Internet Explorer for browsing. Please use open source software like Mozilla FireFox for browsing.

Apple Safari is working

Finally we found the JavaScript problem that prevented Apple Safari users to switch between the diagrams. The diagram select box was always disabled. The problem was caused by the event handlers onmousedown and onmouseup that where set for the whole document. The problem disappeared after we have registered our handlers on the appropriate div alone. It seems unlikely that this behaviour is intended by Apple so we think that it is some sort of bug in Apple Safari.

Addon: we reported the problem and found out that our mouse handlers did not return valid return codes in all cases. Our mistake of course, but we recommend that this situation should be handled more fault tolerant by Safari.

CSII basal profile

Some users requested a basal profile for CSII treatment. Visitors of a CSII diary should be able to see this profile to look for potential problems. We have implemented the basic data structures and input fields. This means that you can already maintain your profile. In the second step these values will be visible in the diagram "Glucose - Curve Glucose/time". This will take some days to implement.

mmol/L values on mobile phones

Users with blood glucose values in mmol/L can enter these values more convenient. We split the fields in two input fields: one for the integer and one for the decimal places like we did for the BU (bread unit) values. This handling is much more convenient on mobile phones.