Cardiofish ECG device
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111111 r. | cardiofish High throughput testing method Zebrafish ECG device

ZEBRAFISH ELECTROCARDIOGRAM (ECG) MEASUREMENT IS A VALUABLE TECHNIQUE USED IN CARDIOVASCULAR RESEARCH TO STUDY THE ELECTRICAL ACTIVITY OF THE ZEBRAFISH HEART. ZEBRAFISH, DUE TO THEIR GENETIC SIMILARITY TO HUMANS AND TRANSPARENT EMBRYOS, OFFER A UNIQUE OPPORTUNITY TO OBSERVE AND ANALYZE CARDIAC FUNCTION IN A LIVING ORGANISM. The process involves placing zebrafish embryos or larvae in a specialized chamber with electrodes, enabling the noninvasive recording of electrical signals generat- THE ZF-01 CARDIOFISH SYSTEM IS ONE OF THE MOST UNIQUE DEVELOPMENTS OF OUR COMPANY. ed by the heart. These...

THE SYSTEM INCLUDES TWO MAIN PARTS MECHANICAL PART – BASEPLATE, GILL PERFUSION SYSTEM, MANIPULATORS WITH MEASURING ELECTRODES Manipulator with ECG Electrode ELECTRONICAL PART - LOW-NOISE BROADBAND AMPLIFIER AND DATA ACQUISITION, - MONITORING AND ANALYSING HARDWARE/SOFTWARE UNIT. Manipulator stand Amplifier Reservoire Fish Bath Bath stand Drug administration port Emptying tap MECHANICAL PART While designing the system, we focused on its ability to be easily operated and to be appropriate for long term measurements. Regarding this aim we worked out a compact and easy to use system. CardioFish...

BASEPLATE The measurement scheme is very sensitive to any mechanical noise around the system, therefore we planted the setup to a rigid baseplate on an aluminium structure. This helps to keep the working area clean and gives a solid base to the whole system. GILL PERFUSION SYSTEM During the design of the system, a fundamental requirement was to ensure the stability of the measured Electrophysiology signal. To succeed with this, aim its crucial to assure a stable physiological condition of the fish what could be achieved only by perfusing the gills with saturated water. Two reservoirs for...

ELECTRONICAL PART As a result of a 10 years long development we worked out a complex hardware softwar e processing setup that allows to r ecordandcondition electrocardiographic signals of a zebrafish’s heart that could be an input of several automated data analysing algorithms. The first part of the setup is a dedicated lownoise amplifier that allows to record the signals in nano volt range. The design includes a 50 Hz notch filter that excludes most of the electronic noise that is out of the range of a normal signal. The second part is the Cardiofish software that includes low cut and high...

DATAACQUISITION, MONITORING AND ANALYSING HARDWARE/SOFTWARE UNIT The acquisition and analysis framework are derived from our well validated recording and analysis system (Cardiosys), used for 15 years in cardiac R&D. The data recording and processing system is built around the CardioFish software, which has an inbuilt database architecture, where all the measurement results are automatically stored. ECG RECORDING For ECG recordings both the quick buttons above (5) the monitoring filed and the roll down orders of the menu can be applied (1). The applied filter visualization or the appearing...

OFFLINE EVALUATION The recorded ECG signal can be either evaluated right after the measurements or at any time later. The software provides five different possibilities for so doing. The most typical ECG parameters can be quickly calculated, as well as more complex features however, owing to the wide choice of analysis routines included. One cursor analysis: can be applied to collect the ECG QT analysis: calculating an eligible QT or QTc amplitudes, at user defined cursor value, as well as QT variability (QTv) as a function the ECG signal, and HR values are collected into of RR or HR, in...

In case of all analysis modes different graphs is exportable as an image together or separately with data table in csv format. In raw data table al the notable points and segments/intervals of the electrocardiogram are presented as well as some calculated value for QT analysis like: P value (mV) is recording the highest amplitude ST segment (ms) records the time from the end of of the spread of depolarization through the atrial myocardium from start to finish. • ventricular depolar i zat ion to the s tar t of ventricular repolarization. Q value (mV) is the lowest amplitude which repre- ST...

SCHEMATIC DIAGRAM OF THE SYSTEM The following picture represents the operation of the system: • The liquid enriched with gas goes through the buffer tanks driven by a roller pump then through a cannula before reaching the gills. Fish is placed on a sponge foam in bath, which also keeps the body continuously wet. The excess liquid returns to tank through the outlet. The gas supply of the tanks is provided through valves. Peristaltic pump Drug administration ports Mechanical parts of the system are essential to provide ideal conditions for the fish during the measurement. The system is...

APPLICATIONS MDE Cardiofish system is able to help with function- Milan et al. (5.) were the first to publish and conduct ECG al phenotyping of adult zebrafish working heart with recordings using adult zebrafish. Fish are injected with electrocardiography. This system provides a real pos- a muscle paralysing agent to reduce noise levels pro- sibility for long ECG recording on adult zebrafish with duced by gill motions, and fine needle electrodes are the inbuilt gill perfusion system. With minimal inva- inserted. While ECG measureme nts are taken, the ze- sive technic not only short, few...

200-290 ms which is much closer to the human heart Inward rectifier K+ current (IK1) IK1 was observed in both rate found in children and in adults during isolated adult atrial and ventricular myocytes, but IK1 compared with the mouse. was ≈5 times larger in ventricular myocytes. These ob- Based on work of Nemtsas et al. (4.) shape servations are consistent with findings in mammals (2.). ventricular zebrafish Action Potential (AP) is similar to that of the human heart, and that zebrafish APs are IK1 regulates the late phase of AP repolarization and much closer to human APs than mouse is to...