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

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