Elunit - System for isolated organs , Belgrade, Serbia , devices for research
 Questions?  office@elunit.co.rs

Elunit in magazines
Research in
October 2010.


to customer needs


Others about us
"The successful cooperation of the Department of Pharmacology and Toxicology, Faculty of Veterinary Medicine with the company Elunit last for many years. Elunit has produced most of the devices used in the laboratory department of pharmacological and physiological studies on preparations of mammalian or parasitic nematodes and trematodes. Some of advantages that Elunit provides are: being able to quickly modify the system components depending on the specifics of the experiment, as well as fast and efficient maintenance."
       Prof.Dr. Saša Trailović

       Faculty of Veterinary       Medicine, Belgrade


Srpski  English

System for isolated organs

System for isolated organs 

Two channel software regulated System
for testing on isolated organs

Two-channel software-regulated system for testing isolated organs provides conditions of the experiment, electrical impulses for stimulation and accurate registering of the acquired signals. For all necessary given conditions to be fulfilled, it consists of the following components:

  1. Thermostated bath systems (volume 20L)
  2. Pinch valve system for filling and emptying small tissue baths with prarations
  3. Isometric transducer
  4. Bridge amplifier for force measurement
  5. Electronic stimulator
  6. Electrodes for electrical fild stimulation
  7. User program, software

1. Tissue Bath Systems Tissue Bath Systems are classical organ bath products for "in vitro" investigations of tissue strips or rings. Thermostated bath systems (volume 20L) with two tissue bath, enables the achievement of stable and uniform temperature of 25-45 oC. The required temperature is achieved by two-step system of water heating in the bathroom with two heater and microprocessor control of temperature. The same temperature in all parts
Tissue Bath Systems

Tissue Bath Systems

of the water bath is achieved by continuous mixing of water by the engine and propeller with speed reduction In thermostated water baths were placed two small tissue baths with a nutritional solution for isolated organs.

2. Filling solution in the tissue bath as well as leaking is regulated by electric valve system with software control. Opening and closing of valves is done by clicking the mouse on the operator panel of primary software used for recording of contractions.

Filling solution in the tissue bath

3. Isometric transducers are designed for precise measurement of force of isometric muscle
Isometric transducers
contractions.Muscle contraction force conducted on the console is transformed into an appropriate electrical signal through the meters-stretch, that they are properly connected in to Witston bridge. This electrical signal is conducted on an electronic amplifier through which the pen-recorder or some other device, can record the size and shape of the resulting signal.

4. Signal enhancing system from the transducer is constructed as a two channel enhancer with an operational enhancer for multiple degrees. Thus enabling that the small electrical signal received from the transuser can be sufficiently enhanced for them to be processed further.

Signal enhancing system from the transducer

5. The purpose of the electro stimulator  is for acquiring electrical impulses for the stimulation of isolated organs through adequate electrodes. It is constructed as a two channel generator of rectangular impulses with possibility of changing the impulse parameters. Parameters that can be changed are: amplitude of impulse stimulation, scope of impulse, impulse period, duration of the impulse stimulation package, and the intermission between impulse stimulation packages. Size of voltage, current and other parameters is regulated in such a way to enable contractions of the tested substance. All parameters relating to the enhancing system and the stimulation parameters are regulated by a on the computer mouse.

The field of electro-stimulation
6. The field of electro-stimulation depends on the type of electrodes (plate, ring ..) and their geometry (parallel, angle ...). We produce all types and sizes of electrodes that are required in investigations on isolated organs.

7. Command software, as graphic interface is simple for the user considering it is intuitive and does not require special training. It can be used by persons that have used perconal computers on the
Command software
elementary level. Basic groups of graphic presenters and commands include: numerical presenters, command keys and sliders and tools for graphic diagrams. Commands are acquired by the key pad or by a click on the mouse. Numerical presenters show present values of measured values (force, time position on the diagram, intermission duration of tested values, frequency and impulse stimulator duration). Command keys are used to chose the work regime of the

electric stimulators, opening and closing of valves, marking of time events, opening or inviting archived numeric ASCI files, etc.
Nimerical function switch is used to chose the presentation time diagram window and calibration. Sliders are used to enter chosen parameters and values of electro stimulators: frequency, duration of impulse – pause, amplitudes of exiting level of voltage on the electrodes.
Time diagram of force change is continuous considering that the program is in continuous contact with the hardware (on-line managing). Tools for working with the diagram enable the analysis of the wave shape and they are: markers, zoom, numerical cursors, size of the time-window, etc. Saving the flow of the acqured data is in the numeric file for purpose of documenting or later processing and analysis. Advanced processing, post processing, is possible through another software such as Excel, Matlab, and the like. Importing of the time-diagram is possible directly to the text processor as MS Word by simple paste-copy tool for the purpose of a report or documentation.
Time diagram of force change

Considering that the unit represents an "embedded solution", the base consists of a microcontoler which makes an analog-digital conversion of the enhanced signal and through a communication driver ( serial RS 232 ili USB port ), sends data to the PC. On the other hand, computer sends data and managing commands for operationg of the subassembly of the generator of electrical impulses, stimulator, as well as commands for opening-closing of imput-output electromagnetic valves of the experimental chamber. Stimulator components are programable timers and digital-analog convertors. As the graphic user interface of virtual instruments represents software substitute for the front pannel of the classical instrument, it enables efficient interaction between the user ant the application.
Certain parts of the software regulated system for testing on isolated organs and improvement of the existing systems incurred during the project – technical development for 2008/2009. Financed by the Ministry of Science of the Republic of Serbia. The whole project was accomplished at the Faculty of Veterinary Medicine in Belgrade, which was the bearer of the project.