Esteman's Timer


About Esteman's Timer

Esteman’s Timer is an asymmetric interval countdown timer developed on Visual Basic 2010 Express and specifically designed for research on repetitive anoxia in Drosophila melanogaster (for more details, see Rodríguez and Robertson 2012) . Given that the anoxia/normoxia cycles the fly was subjected to were asymmetric (3.0 min / 0.5 min, respectively), a regular countdown timer was not suitable for the task of indicating the time for N2/compressed air application. The use of a regular countdown timer can increase the probability of error by distraction of the experimenter and does not allow proper use of periods of inactivity.

Esteman’s Timer can deal with asymmetric time intervals and it counts the number of cycles from the beginning of the experiment. It is possible to visualize the stage of the experiment through a progress bar and an alarm tells the researcher when it is time to apply N2/compressed air. A remarkable feature is the option of getting the alarm warning before the end of the time interval, helping the experimenter to be ready beforehand.

Additionally, the increment mode allows gradual increase of the second time interval at a constant value once a cycle is finished. The first time interval remains constant and cannot be changed. This mode was developed for experiments intended to establish threshold to anoxic coma in D. melanogaster. A N2 pulse (5 s) was applied followed by 3 min of normoxia (compressed air). The same protocol was applied repetitively, each time increasing the N2 pulse by 5 s until 12 cycles were completed (figure 1).


Threshold trace


Figure 1. Brain extracellular K+ concentration ([K+]o) in a W1118 D. melanogaster mutant during a threshold-to-anoxic-coma experiment. The arrows and the numbers indicate the N2 pulses (in seconds) that did not successfully induced an anoxic coma (evidenced as a surge in [K+]o) (Rodríguez and Robertson, unpublished).

Finally, a regular single interval countdown timer has also been included. Esteman’s timer is a piece of software that can be helpful during any type of experiments involving application of a treatment according to a moderately complex time pattern.

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Understanding Esteman's Timer

Since at first glance Esteman’s Timer may not seem user friendly, a brief description of the window parts and their functions will be provided (figure 2):


Window parts


Figure 2. Main components of Esteman's timer window.


Warning sound effect

Choose among 5 different options the warning sound to be heard when the time interval is about to reach 0 s.

End sound effect

Choose among 3 different options what to hear once the experiment is finished.

Single interval mode

The checkbox enables a regular single interval countdown timer.

Increment mode

The checkbox enables increment mode, used to increase the duration of the second time interval by a constant number every time a cycle is completed. The first time interval remains constant and cannot be changed.

1st interval duration

Insert the value of the first time interval (in seconds).

Warning time

Insert the time (in seconds) for the warning sound effect chosen to be played. The time selected will activate the warning sound when any of the time interval displays reaches the chosen time value. For instance, if a warning time of 15 s is set, the warning sound will start when any of the previously set time intervals goes down to 15 s.

Increment value


When increment mode is enabled, insert the constant value by which the second time interval is going to be increased after a cycle is finished. For instance, an increment value of 5 s will increase a second interval value set to 60 seconds by 5 (65 s)after a cycle has been completed. A similar increment will be performed after each cycle, until the end of the experiment.

2nd interval duration

Insert the value of the second time interval (in seconds).

Total number of cycles

Input the number of times you intend to alternate both time intervals. Once both time intervals have reached (one after the other) a value of zero, a cycle is completed.

Current cycle

It quantitatively shows the progress of the experiment.

Progress bar

It visually shows the current progression of the experiment.

Time interval displays

The current time course of the experiment can be visualized here.

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The timer requires Microsoft.NET Framework 4, which is automatically downloaded from Microsoft’s website when the setup file is run, and works in Windows 7 and Vista. To install the timer double click on the Setup file. Esteman’s Timer can be uninstalled through the “Uninstall a program” option in the control panel.

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Problems and bugs

As stated previously, this piece of software was specifically created for research on repetitive anoxia and was never intended to be used by other people different from the members of the lab. However, we believe that the asymmetrical time interval and the increment features maybe of help to people undertaking research or other related activities. The program still has a number of bugs to be fixed, but they do not compromise the performance of the main features of the timer.

A problem detected on Widows 7 is that the time interval displays appear black instead of white. Consequently, the numbers cannot be visualized. To fix it go to:

Control Panel > Appearance and Personalization > Personalization > Change the Theme > Windows Classic

Although the Windows Classic theme looks dull compared to the Windows 7 theme, the displays will look normal and the timer will be fully functional.

Any feedback to improve Esteman’s Timer can be sent to the following email address:

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