Low-cost, small animal thermal ablation system

 The goal of this project was to develop a cheap, simple and robust ablation system for creating small thermal lesions in animals. As soon as biological tissues are exposed to temperatures > 40 degree Celsius for several minutes (~>30) tissue necrosis occurs and introduces cell death. This technique is used in cancer therapy to kill cells and to destroy tumors. 

Schematic of small animal ablation example in a mouse brain to study brain cancer treatments.

The understanding of ablation techniques and the development of heating algorithms/strategies rely on animal research studies. To provide a low cost system for ablation studies in small animals (mice,rats) I developed a simple system including a graphic user interface.

Schematic connection sketch for the micro-controller and electronic board.

The system uses an Arduino-Uno Micro-Controller (MC) board and an ordinary, resistive thermistor. The graphic user interface (GUI) communicates with the MC about 4 times per second. In a first request voltage is read from the thermistor to determine the actual temperature. Then in a second step the GUI/program calculates the necessary voltage to reach the required set-temperature (defined by user) and  sends the info to the MC. On the MC the voltage reaching the thermistor will be set accordingly. An integrated PI (proportional/integral) controller regulates the voltage to keep the temperature at the thermistor constant.

Graphic user interface for the Thermistor control

Total costs of the utilities < $50 (Micro controller board $25, Thermistor $8, Wires, etc $17)

Links:
Thermistor:
http://www.mouser.com/ProductDetail/Honeywell/112-102EAJ-B01/?qs=F1jq4PciTHu%252b30xNPtI64w%3D%3D&gclid=CJzDjPjl1bkCFdSd4Aod5VYA8A

Automatic greenhouse control system (Code Files)

A few people asked me if they can have the source code files to following project:

http://scientificcomputingco.blogspot.com/2013/02/automatic-greenhouse-control-system.html

The code files can be found here:
https://www.dropbox.com/sh/ip306uavm7jpekg/xQuoUjSmEJ/Green%20house%20control

Unfortunately there comes little to no documentation with the file, thus one have to dig through the source code files to understand the program.

You can contact me for further questions.

Automatic greenhouse control system

My brother is a farmer and he owns a couple of green houses. The greenhouses are computer controlled; depending on light intensity and temperature in each green house, the computer system lifts or closes the window panels to keep the temperature constant and safes the plants from too much heat or cold. The control system my brother uses is a very well established system. The only drawback is, that it costs a fortune. So my brother came up to me and asked me, if I can figure out a cheaper solution. Well, and there we go with my concept that is less than 100USD...

Overview about the conceptional system showing light and temperature sensors (left), the micro-controller board (middle) and the control output (left, LEDs for illustration) which will be connected to the greenhouse window lifting system

Micro-controller board used in this concept project; Arduino Leonardo

Ok, so how does it work? I am using temperature sensors (LM35) and light sensors (LPR) to detect the actual temperature and light intensity in the greenhouses. - In the current example I am controlling two greenhouses and therefore there are two light sensors and two temperature sensors-. The electronic signals are sent from the sensors to the micro-controller board (Adruino Leonardo). The board processes the signals and sends the data to the computer that is connected via USB micro plug.

GUI showing actual temperature and light values as well as temperature and light criteria used in the algorithm to control the greenhouse window panel and ensure constant temperature in the greenhouse

I have used Python to create a Graphic User Interface (GUI) that presents the sensor values and the history of the sensor values via Diagram.

Recorded temperature and light (light less than 3klx, thus not visible in the chart) history

Recorded temperature and light (light less than 3klx, thus not visible in the chart) history

I have implemented several algorithms that check temperature and light intensity in order to verify if a greenhouse window panel must be opened or closed. After processing the input signals, electronic impulses are sent from the computer back the the micro-controller which then sends opening or closing signals to the window panel control system. (Here simulated with LEDs) 

LEDs are used to simulate the window panel control.

  

Servo position control via PC

Image of experimental setup. The PC control panel sends a signal to the micro-controller board and changes the position of the servo

The position of a servo can be controlled with a Micro-Controller (MC) board that recieves singals from the PC. This picture shows an example setup that I created to control the servo position with a PC control panel. When the slider is moved in the control panel, a digital signal is generated and sent to the MC via USB connection. The MC processes the signal and sends an equvalent electronic impulse to the servo. Thus the servo changes position according to the electrical signal. For this example I used Python and the Tkinter (GUI) library to create the control panel and Arduino's sketch tool to program the MC.
A real-time video of the application can be found at: http://www.youtube.com/watch?v=cI-eiEtxchc
The scrip and sketch for the MC data can be found at: https://www.dropbox.com/sh/ip306uavm7jpekg/uiElcgcgWg/Servo%20positioning%20control%20from%20PC