Impedance Testing Device MEA-IT Manual
Information in this document is subject to change without notice. No part of this document may be reproduced or transmitted without the express written permission of Multi Channel Systems MCS GmbH. While every precaution has been taken in the preparation of this document, the publisher and the author assume no responsibility for errors or omissions, or for damages resulting from the use of information contained in this document or from the use of programs and source code that may accompany it.
Table of Contents 1 1.1 1.2 Introduction About this Manual Welcome to the Impedance Testing Device 1 1 2 2 2.1 2.2 2.3 Important Information and Instructions Important Safety Advice Guarantee and Liability Operator's Obligations 3 3 4 4 3 3.1 3.2 3.3 Setting up the MEA-IT Hardware Installing the MEA-IT Software Compatible Microelectrode Arrays 5 5 7 8 4 4.1 4.2 Impedance Measurements Mounting the MEA MEA-IT Software Controls 4.2.1 Introduction 4.2.2 Overview 4.2.
1 Introduction 1.1 About this Manual This manual comprises all important information about the first installation of the hardware and software, and about the daily work with the instrument. It is assumed that you have already a basic understanding of technical and software terms. No special skills are required to read this manual.
Impedance Testing Device MEA-IT Manual 1.2 Welcome to the Impedance Testing Device MEA-IT The impedance testing device MEA-IT for microelectrode arrays with 60 electrodes allows an easy monitoring of MEA electrode impedances. The measurement process is controlled by the software MEA-IT. On a virtual MEA layout the impedance of each electrode is displayed in an intuitive color code. It is possible to save the data after each measurement to a database file and to export the data in ASCII format .
2 Important Information and Instructions 2.1 Important Safety Advice Warning: Make sure to read the following advice prior to install or to use the device and the software. If you do not fulfill all requirements stated below, this may lead to malfunctions or breakage of connected hardware, or even fatal injuries. Warning: Obey always the rules of local regulations and laws. Only qualified personnel should be allowed to perform laboratory work.
Impedance Testing Device MEA-IT Manual 2.2 Guarantee and Liability The General conditions of sale and delivery of Multi Channel Systems MCS GmbH always apply. The operator will receive these no later than on conclusion of the contract. Multi Channel Systems MCS GmbH makes no guarantee as to the accuracy of any and all tests and data generated by the use of the device or the software. It is up to the user to use good laboratory practice to establish the validity of his findings.
3 Setting up the MEA-IT 3.1 Hardware The MEA-IT is a very compact and portable device for measuring electrode impedances on microelectrode arrays (MEA) with MEA-IT software. The measurements are transmitted to the connected computer via universal serial bus (USB 2.0 Full Speed). Thus, it is possible to use any computer as a data acquisition computer, also a laptop. The device does not need an own power supply.
Impedance Testing Device MEA-IT Manual The two triangular front edges of the device can be moved outwards and inwards to open and close the MEA-IT device, respectively. Two sockets are provided to connect an Ag/AgCl ground electrode. Important: You always have to connect an Ag/AgCl silver wire even though you like to measure a MEA with internal reference electrode. Otherwise the impedances are too high.
Setting up the MEA-IT 3.2 Installing the MEA-IT Software System requirements Software: One of the following Microsoft Windows ® operating systems is required XP (Service Pack SP 3), Vista or Windows 7 (32 or 64 bit), English and German versions supported with the NT file system. Other language versions may lead to software errors. Hardware: You can operate the MEA-IT device with any computer with an USB 2.0 port.
Impedance Testing Device MEA-IT Manual 3.3 Compatible Microelectrode Arrays Currently, the MEA-IT is available for MEAs with 60 electrodes only. Contacting units for different layouts are under development. Please contact Multi Channel Systems MCS GmbH for detailed information. Each MEA is classified by its type and its individual serial number, which is engraved on the back side of the MEA. The name of the specific MEA defines its parameters: 100/10iR-Ti, for example.
Setting up the MEA-IT Table of microelectrode arrays, currently available for impedance testing device MEA-IT.
4 Impedance Measurements 4.1 Mounting the MEA Open the upper part of the device by moving the triangular edges of the lid outwards. The lid swings open. Before inserting the MEA note its layout and the individual serial number. Please see chapter "Compatible Microelectrode Arrays". Insert the MEA carefully into the provided area in the middle. Make sure that the MEA is correct orientated. Close the device by pressing down the lid and moving the triangular edges of the lid inwards.
Impedance Testing Device MEA-IT Manual Grounding the MEA Fill the MEA dish with a conducting solution, usually PBS (phosphate buffered saline) or with ACSF (artificial cerebral spinal fluid for rats and mice). The impedance of an electrode also depends on the hydrophilic properties of the electrode. If an electrode is hydrophobic, the measured impedance will be too high. Ground the MEA with the included Ag/AgCl pellet. There are two identical sockets provided to connect the ground electrode.
Impedance Measurements 4.2 MEA-IT Software Controls 4.2.1 Introduction The MEA-IT software controls the impedance measurements with the MEA-IT device. Each MEA is identified by its individual serial number, and all measurements for each MEA are stored in a database file. A current impedance measurement can be compared to any previous one stored in the database in order to identify changes in electrode impedance over time.
Impedance Testing Device MEA-IT Manual 4.2.2 Overview The MEA-IT main window opens. See below for an overview of the MEA-IT software control.
Impedance Measurements Header In the header the serial number S/N of the MEA-IT device is displayed. You can find the serial number additionally on the rear panel of the device or in “Info”. Click the "Preferences" button. The following dialog has three tabs. Under "Database" the user can change the selected path for the database file. Click the "Export" button. It is possible to select the layout for the ASCII export.
Impedance Testing Device MEA-IT Manual Click the "Ranges" button. In the "Ranges" tab, the default settings for the evaluation of a MEA can be changed. The MEA-IT software uses default reference values to evaluate whether a measured impedance is all right or out of the acceptable range for the selected electrode type. This evaluation is displayed in an intuitive color code. To change the default reference parameters, select a layout and click on the reference value you want to modify.
Impedance Measurements Click the "Help" button of the header for using the online help. Click the "Info" button of the header. The "About MEA-IT" dialog shows the serial number of the MEA-IT device and the actual MEA-IT software and firmware version. MEA Identification Line The MEA Identification line shows the “Layout” and the individual "MEA-ID", usually the serial number engraved on the back side of each MEA.
Impedance Testing Device MEA-IT Manual Main Controls The main control buttons allow to "Load" an old measurement and "Save" the current one to the database. The "Measurement" and "Cancel" buttons start and interrupt the impedance measurement. With the "Export" function, the results of a current or loaded measurement can be exported in ASCII format. The layout of the ASCII file can be selected in the "Preferences" dialog.
Impedance Measurements Legend The “Legend” describes what you see in the virtual MEA layout: The color coded MEA electrodes with the value of the measured impedance in black letters in the front, and the electrode names in white letters in the back. To evaluate a MEA, you can compare the measured impedances to individual reference values for each electrode type. Good and bad electrodes will be color coded according to the limits shown in the legend. It is also possible to highlight outliers.
Impedance Testing Device MEA-IT Manual 4.2.3 Running a Measurement Note the serial number and type of the MEA, and mount it in the correct orientation in the MEA-IT device (please read chapter "Mounting the MEA"). Open the MEA-IT software and click the button "Measure" in "Main Controls" to start a measurement. The "Select MEA" dialog appears. Please type the serial number of the MEA into the "MEA-ID" in the drop down box.
Impedance Measurements Click "OK" to start the measurement. The electrodes are measured one by one and the exact values of the measurements are written in black letters inside the electrodes, and also in the log file in column "Impedance". The color code is activated only when comparing with previous measurements or when the check box “Show Outliers” is enabled. Otherwise the color of the electrodes remains grey. Click the "Cancel" button to stop a measurement.
Impedance Testing Device MEA-IT Manual When comparing previous measurements with actual measurements, the impedance of the older measurement is displayed in the upper right corner of each electrode in the Virtual MEA Layout. It is possible to switch between the different evaluation and comparison options without running a new measurement.
5 Troubleshooting 5.1 Troubleshooting Most problems occur seldom and only under specific circumstances. In most cases, it is only a minor problem that can be easily avoided or solved. If the problem persists, please contact your local retailer. The highly qualified staff will be glad to help you. Please inform your local retailer as well, if other problems that are not mentioned in this documentation occur, even if you have solved the problem on your own.
Impedance Testing Device MEA-IT Manual 5.3 Technical Support Please read the "Troubleshooting" part of the manual or help first. Most problems are caused by minor handling errors. Contact your local retailer immediately if the cause of the trouble remains unclear. Please understand that information on your hardware and software configuration is necessary to analyze and finally solve the problem you encounter.
6 Appendix 6.1 Technical Specifications The MEA-IT-System is a device for impedance testing of microelectrode arrays. Warning: The device may only be used together with microelectrode arrays from Multi Channel Systems MCS GmbH, and only for the specified purpose. Damage of the device and even fatal injuries can result from improper use. Do not open the data acquisition box and do not change hardware configuration as it could lead to improper behavior of the system.
Impedance Testing Device MEA-IT Manual 6.2 Contact Information Local retailer Please see the list of official MCS distributors on the MCS web site. User forum The Multi Channel Systems User Forum provides the opportunity for you to exchange your experience or thoughts with other users worldwide. Mailing list If you have subscribed to the Mailing List, you will be automatically informed about new software releases, upcoming events, and other news on the product line.
