Alpha MED Scientific MED64 User manual

MED64 System
(MED64-Basic/Quad II/Allegro)
Manual

i
Table of Contents
1. Introduction ……………….. 1
2. Configuration of the MED64 System ……………….. 1
2.1. Part names and functions ……………….. 1
2.1.1. MED64 Main Amplifier ……………….. 1
2.1.2. MED64 Head Amplifier ……………….. 2
2.1.3. Accessories of the MED64 Main Amplifier ……………….. 3
2.1.4. Accessories of the MED64 Head Amplifier ……………….. 3
3. Setup of the MED64 System - procedure common to Basic, Quad II, and Allegro ……………….. 3
3.1. Considerations for the position of devices ……………….. 3
3.2. Power source ……………….. 4
3.3. Setup of the MED64-Basic ……………….. 5
3.3.1. Part names and functions of the MED Connector ……………….. 5
3.3.2. Connections among devices ……………….. 5
3.3.3. Positioning of the terminal of the MED Connector ……………….. 6
3.3.4. Electric shield with aluminum foil ……………….. 6
3.3.5. Preparation for the noise check – attaching the MED Probe ……………….. 7
3.3.6. Maintenance of the MED Connector ……………….. 7
3.4. Setup of the MED64-Quad II ……………….. 9
3.4.1. Part names and functions of the MED Duet Connector ……………….. 9
3.4.2. Connections among devices ……………….. 9
3.4.3. Positioning of the terminal of the MED Duet Connector ……………….. 10
3.4.4. Preparation for the noise check – attaching the MED Probe16 ……………….. 10
3.4.5. Maintenance of the MED Duet Connector ……………….. 11
3.5. Setup of the MED64-Allegro ……………….. 12
3.5.1. Part names and functions of the MED Multi-well Connector ……………….. 12
3.5.2. Connections among devices ……………….. 12
3.5.3. Positioning of the terminal of the MED Multi-well Connector ……………….. 13
3.5.4. Preparation for the noise check – attaching the MED Multi-well Probe ……………….. 14
3.5.5. Maintenance of the MED Multi-well Connector ……………….. 14
4. Noise check by operating the Mobius - procedure common to Basic, Quad II, and Allegro ……………….. 15
5. Combining with a perfusion system ……………….. 16
5.1. Position of the Minipuls 3 and power supply ……………….. 17
5.2. Installing MED Perfusion Cap Kit to the Minipuls 3 ……………….. 17
5.3. Connection between MED Thermo Connector and MED Perfusion Cap Kit ……………….. 17
5.4. Fixing the droppers to the dropper stand ……………….. 18
5.5. Adjusting the height for the inlet/outlet pipes in the MED Perfusion Cap ……………….. 18
5.6. Connecting the gas tubing to the gas port of MED Perfusion Cap ……………….. 19
5.7. Grounding platinum wire of the MED Perfusion Cap ……………….. 19
5.8. Running the Minipuls 3 ……………….. 19
5.9. Noise check by operating the Mobius ……………….. 19

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6. Abnormal noise ……………….. 19
6.1. Noise check point ……………….. 19
6.2. Noise relating to installation ……………….. 20
6.3. Noise relating to perfusion ……………….. 22
6.4. Identification of cause when a malfunction of the device is suspected ……………….. 23
7. Appendix ……………….. 25
7.1. Specification ……………….. 25
7.1.1. MED64 Main Amplifier [MED-A64MD1A] ……………….. 25
7.1.2. MED64 Head Amplifier [MED-A64HE1S] ……………….. 26
7.1.3. MED Connector ……………….. 27
7.1.4. MED Duet Connector ……………….. 27
7.1.5. MED Multi-well Connector ……………….. 27
7.1.6 Data Acquisition PC ……………….. 27
7.2. Explanation of the technology ……………….. 29
7.2.1. Signal acquisition by the MED64 system ……………….. 29
7.2.2. Electric stimulation by the MED64 system – Applying current to the micro electrode array ……………….. 29
7.2.3. Stimulus artifact and biphasic stimulation ……………….. 30
7.2.4. Stimulus intensity and electrolysis ……………….. 30
7.2.5. About the stimulus interval ……………….. 30

1
1. Introduction
◆ The MED64 System is a micro electrode array (MEA) system commercialized for the first time in the world in 1997. Since then,
the MEA system has been widely used in the United States and the EU for basic research in the fields of the central nervous
system and the cardiovascular system. Nowadays, its application to screening for drug discovery is rapidly spreading, thanks to
its highly evaluated excellent operability and efficiency.
◆ The system use a MEA with 64 planar electrodes arrayed in a pattern (MED probe) on a glass substrate. Users can acquire
extracellular potential simply by placing a tissue slice or by culturing cells on these electrodes. Current stimulation can be
applied through any electrode selected by software. Unlike a glass capillary electrode, the MED64 system requires no
troublesome operations to measure spontaneous activity or evoked response and no special training for electrophysiological
experiment is necessary. The system allows for accurate and easy measurements even by unexperienced researchers.
◆ The electrodes are made of platinum black or carbon nanotube with impedance 7 to 10 kΩ, the lowest impedance among
similar products on the market. The system is substantially free from external noise, thanks to its low impedance electrodes. It
needs no special environment/facility for electrophysiological experiment, such as a shield box, and it can be placed on a
laboratory desk for stable, daily measurement with no need for noise elimination.
2. Configuration of the MED64 System
The MED64 System consists of the following units. The number of biological specimens from which simultaneous measurements
can be made depends on the type of the Connector onto which the MED Probe is mounted.
The MED64 Head Amplifier has connection terminals dedicated for all types of Connector, which allows the user to switch the
system easily by changing the type of Connector to be connected. The extracellular potentials detected by the recording electrodes
of the MED Probe are amplified 10 times by the MED64 Head Amplifier and then further amplified (varied) by the MED64 Main
Amplifier before analog to digital conversion. The obtained digital signals are sent through the USB cable to the data acquisition PC
system, where data recording and analysis are performed online using the MED64 Mobius, which is the dedicated MED64 System
control software. (Recorded data can also be analyzed offline.)
MED64 Head Amplifier
MED64 Main Amplifier
Data acquisition PC
Control software
“Mobius”
MED Probe
MED Connector
MED Probe16
MED Duet Connector
MED Multi-well Probe
MED Multi-well Connector
Head stage for MEA
MED64-Basic
MED64-Quad II
MED64-Allegro

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2.1. Part names and functions
2.1.1. MED64 Main Amplifier
【Front】
➊POWER ….. To switch ON/OFF of the power.
【Back】
➊INPUT ….. An analog input terminal to input signals from the MED64 Head Amplifier. It is connected to the OUTPUT of the
MED64 Head Amplifier via the 68-pin SCSI cable.
➋OUTPUT ….. An analog output terminal to connect an external device (MED Feedback Stimulator etc.)
➌DIO 1、2、3 ….. Digital input/output terminal to connect MED64 Multiplexer.
➍F1 STIMULUS OUTPUT ….. An output terminal of stimulus pattern signal from F1 stimulator. It is connected to F1 STIMULUS
INPUT of the MED64 Head Amplifier via the BNC cable.
➎F2 STIMULUS OUTPUT ….. An output terminal of stimulus pattern signal from F2 stimulator. It is connected to F2 STIMULUS
INPUT of the MED64 Head Amplifier via the BNC cable.
➏CONTROL OUTPUT ….. An output terminal of stimulation channel signal. It is connected to CONTROL INPUT of the MED64
Head Amplifier via the round-pin cable.
➐SIGNAL GND ….. A ground terminal to connect a lead for grounding.
➑USB ….. It is connected to a USB terminal of the data acquisition PC via the USB cable.
➒DC INPUT ….. To connect to a power adaptor cord.
2.1.2. MED64 Head Amplifier
【Front】
➊Power ….. To switch ON/OFF of the power.
➋STIMULUS CURRENT ….. The output current is doubled by moving the lever toward x2.
【Back】
❶
❶
❷
➌
➌
➌
❹
❺
❻
❼
❽
❾
❶
❷
❶
❶
❶
❶
❷
➌
❹
❺
❻
❼
❽
❼

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➊INPUT 1-16CH、17-32CH、33-48CH、49-64CH
….. Analog input terminals to input signal from the MED Duet Connectors or the MED Multi-well Connector. Those are connected
to the output terminals of the either via the 20-pin SCSI cable. Keep ➋INPUT opened (unconnected) when connecting the
cables (Do not connect at the same time.)
➋INPUT ….. An analog input terminal to input signal from the MED Connector. It is connected to the output terminal of the MED
Connector via the 68-pin SCSI cable. Keep the all ➊INPUT opened (unconnected) when connecting the cables (Do
not connect at the same time.)
➌OUTPUT ….. An analog output terminal to connect the INPUT terminal of the MED64 Main Amplifier via the 68-pin SCSI cable.
➍F1 STIMULUS INPUT ….. An input terminal of stimulus pattern signal to connect the F1 STIMULUS OUTPUT of the MED64 Main
Amplifier via the BNC cable.
➎F2 STIMULUS INPUT ….. An input terminal of stimulus pattern signal to connect the F2 STIMULUS OUTPUT of the MED64 Main
Amplifier via the BNC cable.
➏CONTROL INPUT ….. An input terminal of stimulation channel signal. It is connected to CONTROL OUTPUT of the MED64 Main
Amplifier via the round-pin cable.
➐SIGNAL GND ….. A ground terminal to connect a lead for grounding.
➑DC INPUT ….. To connect to a power adaptor cord.
2.1.3. Accessories of the MED64 Main Amplifier
➊Power adaptor ➋68-pin SCSI cable (50cm) ➌BNC cable ➍Round-pin cable ➎USB cable
2.1.4. Accessories of the MED64 Head Amplifier
➊Power adaptor
3. Setup of the MED64 System - procedure common to Basic, Quad II, and Allegro
Thanks to the excellent electrode impedance (impedance of 50 µm electrode is 10 kΩ in frequency range 1 kHz) of the MED Probe,
which is the sensor of the MED64 System, the MED64 System offers several technological advantages:
1) Less influence by external noise (hum noise, etc.)
2) Very low Johnson noise (baseline noise) at about several µV
3) The MED Probe/Connector can be installed at a place physically distant from the amplifier (e.g., inside of an incubator with
100% humidity) via a 2 m connection cable, without being affected by noise or attenuation of the signal acquired.
A faraday cage or vibration isolation table that is typically necessary for an electrophysiological experiment is not necessary for the
MED64 System, but the MED64 System should be set up on a stable table without vibrations, such as a laboratory desk. A desk of
about 100 cm width and 75 cm depth is necessary. For the user’s convenience, a larger desk is preferable. The power adaptor
connected to the amplifier, etc., serves as a magnetic field-derived noise source. When the MED64 System is set up on a desk
against a wall, make space for the cord between the wall and the desk and place the adaptor on the floor in order to place the
power adaptor at a distance from the amplifier and other components (the desk must not be fixed to the wall). Alternatively, a space
is necessary to ensure sufficient distance between the MED64 System and the power adaptor.

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3.1. Considerations for the position of devices
Considering the position of the SCSI cable that connects the Input Terminals of the MED64 Head Amplifier and the MED
Connector, place the MED64 Main Amplifier on the MED64 Head Amplifier (not essential). Place the display monitor on the MED64
Main Amplifier with the PC and the power strip arranged on the right or left side and the MED Connector on the opposite side to
provide sufficient space on the MED Connector side so that the user can perform an experiment easily on the MED Connector side.
Do not place the power adaptor or other electronic devices close to the connection terminals on the back of the amplifiers.
- Layout sample 1
- Layout sample 2
Above is an image of the ideal positions of the components. The user can perform an experiment easily when there is a sufficient space
next to or at the back of the laboratory desk with the power strip on the floor (as shown in Layout Sample 2). If the MED64-Quad II is to
be used in combination with four perfusion systems, a larger space will be necessary.
3.2. Power source
Connect all the 3-terminal power plug (MED64 Main Amplifier, MED64 Head Amplifier, data acquisition PC, etc.) to one power strip
connected to a wall outlet with the ground terminal (do not use an outlet on the desktop rack because it is often not grounded
properly). Do not connect devices that are not necessary for the MED64 System to the power strip or to the wall outlet to which
the MED64 System and other components are connected. Place the power cable and the power adaptor at a distance from the
amplifier, the MED Connector and the 68-pin SCSI cable.
Space for cables on the back of the amplifier
MED Connector
Mouse
Keyboard
PC
Display monitor
Power strip (on the PC)
Power adaptor
60 cm
120 cm
Amplifier (front)
Amplifier (back)

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3.3. Setup of the MED64-Basic
3.3.1. Part names and functions of the MED Connector
【Top unit】 【Base plate】 【Accessory】
➊Output terminal ….. To connect to INPUT of the MED64 Head Amplifier via the accessory, the 68-pin SCSI cable.
❷Fixation screw ….. To fix the fitted top unit and the base plate with a MED Probe attached.
❸Contact pin ….. To contact with the MED Probe terminal to read signals.
❹Ground wire with an bagworm clip ….. To connect to a platinum wire with a perfusion cap when a perfusion system is used.
❺68-pin SCSI cable (2 m) ….. A conductive cloth tape and ground wire are wound on the cable.
3.3.2. Connections among devices
➊Connect the INPUT terminal of the MED Main Amplifier and the OUTPUT terminal of the MED Head Amplifier, using the 68-pin
SCSI cable (50 cm).
➋Connect the F1/F2 STIMULUS OUTPUT of the MED64 Main Amplifier and F1/F2 STIMULUS IMPUT of the MED64 Head
Amplifier, using the BNC cables.
➌Connect the CONTROL OUTPUT terminal of the MED64 Main Amplifier and the INPUT terminal of the MED64 Head Amplifier,
using the round-pin cable.
❶
❷
❷
❸
❹
❺
❻
❼
❼
Display monitor
PC
MED64 Head Amplifier
MED64 Main Amplifier
❶
❹
❺
❷
❷
❸

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➍Connect the output terminal of the MED Connector and the INPUT terminal of the MED64 Head Amplifier, using 68-pin SCSI
cable.
➎Connect the ground wire wound on the 68-pin SCSI cable to the SIGNAL GND terminal of the MED64 Head Amplifier.
➏Connect the USB port (type-B) of the MED64 Head Amplifier and the USB port (type-A) of the data acquisition PC (USB2.0 is
preferable), using the USB cable
➐Connect the power adaptor cables to both amplifiers.
Note1: The 68-pin SCSI cable is wound with a conductive cloth tape and an uncoated lead is wound on it. If the other side of the
lead is free, the conductive cloth tape may serve as an antenna that collects electric noise and may cause noise. Make sure
that the other side of the lead is connected to the SIGNAL GND terminal of the MED64 Head Amplifier (to use the
conductive cloth tape as an electric shield).
Note2: In order to prevent noise, use the SIGNAL GND terminal of the MED64 Head Amplifier for single-point grounding when
the peripheral devices are grounded.
Loosen the screw of SIGNAL GND terminal to lead the ground wire into the hole (left), then thighten to fix it (right) 。
3.3.3. Positioning of the terminal of the MED Connector
Place the MED Connector with its output terminal and the 68-pin SCSI cable on the right side. In this position, the left top of the
MED Probe is assigned to ch 1 and the right bottom is assigned to ch 64. The orientation of the MED Probe is important because
the electrode number of the MED Probe is defined by the contact pins of the MED Connector.
Correspondence between the contact pin of the MED Connector and the electrode number: correspondence from the contact surface side with
the output terminal on the right (left panel) and correspondence with the MED probe terminal (right panel). R indicates the reference electrode.
ch 1
ch 64
ch 56
ch 8
R1
R2
R3
R4
ch 1
ch 64
ch 56
ch 8

7
Correspondence between the MED Connector output terminal and the electrode number. R indicates the reference electrode.
3.3.4. Electric shield with aluminum foil
If a noise check reveals that external electric noise is affecting the MED Connector, the noise may be avoided by placing a sheet of
aluminum foil under the MED Connector and using a lead to connect the aluminum foil sheet and the SIGNAL GND terminal of
the MED64 Head Amplifier for grounding.
A sheet of aluminum foil serves as an electric shield by grounding. Magnetic field-derived noise cannot be prevented by an electric shield.
Note: Although the MED Connector is made from aluminum, its surface is coated and insulated from the aluminum foil. Make
sure that the aluminum foil is grounded to the SIGNAL GND terminal of the MED64 Head Amplifier when a sheet of
aluminum foil is placed under the MED Connector, even if the baseline noise level is within an acceptable range. Without
grounding, the aluminum foil serves as an antenna to collect electric noise and may generate unexpected noise.
MED64-Basic after setup. In this example, the laptop PC is used for a data acquisition PC system.
3.3.5. Preparation for the noise check – attaching the MED Probe
Loosen the fixation screw of the MED Connector to remove the top unit.
Fixation
screw
Top unit
Base plate
Fixation
screw

8
On the base plate, place the MED Probe filled with saline, such as aCSF or PBS holding the ring chamber of the MED probe or the
end of the glass substrate. Pay attention so as not to touch the terminals. If any waterdrop, medium or smudge is on the terminal,
wipe the terminal with a Kim wipe before setting the MED Probe. Subsequently, place the top unit on the MED Probe and fix with
a fixation screw.
Note1: Loosen/tighten both screws little by little at the same time. When the screws are sufficiently loosened/tightened, they can
be completely loosened/tightened one by one. If only one screw is completely tightened/loosened without
tightening/loosening the other screw, the second screw cannot be inserted perpendicular to the hole.
Note2: Do not touch the contact pin of the MED Connector with bare hands. If sebum of the hand attaches to the pin, contact
impedance between the contact pin and the terminal of the MED Probe will increase and may cause noise. Pay attention
so as not to spill liquid (saline, medium etc.) on the MED Probe after it is set. Prevent liquids from coming into contact
with the contact pin.
About the details of noise check, refer to p.19 “Noise check by operating the Mobius - procedure common to Basic, Quad II, and
Allegro”. Also, for the details of operating the Mobius refer to “MED64 Mobius Tutorial.” Refer to the relevant application note for
the preparation of specimens used for the experiment.
3.3.6. Maintenance of the MED Connector
A printed circuit board onto which 68 contact pins contacting the terminal of the MED probe are soldered is fixed by screws to
the top unit of the MED Connector. Spring-loaded pins are used as contact pins and keeping the surface of the pins clean is
important for the maintenance of the MED Connector. If any abnormal noise is found at a particular electrode and noise persists
on that electrode even when the orientation of the MED Probe is changed, the noise may be caused by deformation (crushing)
due to the wear of the contact pins associated with everyday use or dust or sebum on the contact pins. In the latter case, the
noise may be reduced by wiping the contact pin by pushing the eyeglass cleaner cloth on the pin. Do not use ethanol because
the contact pin is filled with lubricant for the spring. The printed circuit board needs to be replaced (paid repair) in the case of
malfunction due to wear of the contact pin associated with everyday use or malfunction due to salt (perfusion solution or media)
attached on the pin.
When the elasticity of the pin
decreases, irreversible contact
failure occurs.

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3.4. Setup of the MED64-Quad II
3.4.1. Part names and functions of the MED Duet Connector
【Front】 【Back】
【Accessories】
➊Insertion slot of the MED Probe16
➋Screw hole ….. To fix the MED Duet Connector onto the MED Thermo Base (MED-CPB02).
➌Ground wire with an bagworm clip ….. To connect to a platinum wire with a perfusion cap when a perfusion system is used.
❹Output terminal ….. To connect to the INPUT terminal of the MED64 Head Amplifier via the 20-pin SCSI cable.
❺20-pin SCSI cable (2 m x 4) ….. A conductive cloth tape and ground wire are wound on the cable (the specification is different
from the 20-pin SCSI cable for the MED Multi-well Connector).
❻Test board ….. A PCB with multiple resistors to check the baseline noise level of the whole system and its environment.
❼Ground wire with an bagworm clip ….. To hold four ground wires from four 20-pin SCSI cables together and connect them to
the SIGNAL GND terminal of the MED64 Head Amplifier.
3.4.2. Connections among devices
➊Connect the INPUT terminal of the MED Main Amplifier and the OUTPUT terminal of the MED Head Amplifier, using the 68-pin
SCSI cable (50 cm).
➋Connect the F1/F2 STIMULUS OUTPUT of the MED64 Main Amplifier and F1/F2 STIMULUS IMPUT of the MED64 Head
Amplifier, using the BNC cables.
➌Connect the CONTROL OUTPUT terminal of the MED64 Main Amplifier and the INPUT terminal of the MED64 Head Amplifier,
using the round-pin cable.
❶
❶
❷
❸
❸
❹
❹
❺
❻
❼
❷

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➍Connect the output terminals of the MED Duet Connectors and the INPUT terminals of the MED64 Head Amplifier, using 20-pin
SCSI cable.
➎Connect the ground wire wound on the 20-pin SCSI cable to the SIGNAL GND terminal of the MED64 Head Amplifier.
➏Connect the USB port (type-B) of the MED64 Head Amplifier and the USB port (type-A) of the data acquisition PC (USB2.0 is
preferable), using the USB cable
➐Connect the power adaptor cables to both amplifiers.
Note1: The 20-pin SCSI cable is wound with a conductive cloth tape and an uncoated lead is wound on it. If the other side of the
lead is free, the conductive cloth tape may serve as an antenna that collects electric noise and may cause noise. Make sure
that the other side of the lead is connected to the SIGNAL GND terminal of the MED64 Head Amplifier (to use the
conductive cloth tape as an electric shield).
Loosen the screw of SIGNAL GND terminal to lead the ground wire into the hole (left), then tighten to fix it (right). Because it is difficult to put
four ground wires through the hole of the SIGNAL GND terminal, use the ground wire with a bagworm clip to hold them together
Note 2: In order to prevent noise, use the SIGNAL GND terminal of the MED64 Head Amplifier for single-point grounding when
the peripheral devices are grounded.
3.4.3. Positioning of the terminal of the MED Duet Connector
A circuit board is incorporated into the top unit of the MED Duet Connector of two types, with one type corresponding to the 2 x
8 array MED Mini Probe and the other to the 4 x 4 array MED Mini Probe. Replace the top unit with the one compatible with the
MED Mini Probe to be used and place and secure it on the base plate with the fixation screws.
2 x 8 array 4 x 4 array
Correspondence between the MED Duet Connector output terminal and the electrode number. R indicates the reference electrode; N is not
assigned.
Type D (2 x 8)
Type B (4 x 4)
Base plate
Screw
ch1
ch9
ch8
ch16
ch1
ch13
ch4
ch16

11
3.4.4. Preparation for the noise check – attaching the MED Probe16
Insert the terminal of the MED Mini Probe filled with saline, such as aCSF or PBS into the insertion slot gently and horizontally,
holding the ring chamber of the MED Mini probe or the end of the glass substrate. If any waterdrop, medium or smudge is on the
terminal, wipe the terminal with a Kim wipe before setting the MED Mini Probe.
Note1: Pay attention so as not to spill liquid (especially saline) on the MED Mini Probe after it is set. Prevent liquids from coming
into contact with the contact pins.
Note2: The test boards for a noise check are supplied with the MED Duet Connector as accessories, but it is recommended to
perform a noise check using an unused MED Mini Probe (with no electrode detachment) filled with saline to check the
influence of external noise from the installation environment. This is because the test board, which is designed to act as a
resistor, is less susceptible to external noise with different frequency characteristics.
About the details of noise check, refer to p.19 “Noise check by operating the Mobius - procedure common to Basic, Quad II, and
Allegro”. Also, for the details of operating the Mobius refer to “MED64 Mobius Tutorial.” Refer to the relevant application note for
the preparation of specimens used for the experiment.
3.4.5. Maintenance of the MED Duet Connector
The contact pins, of 18 pins per well, constitute the area where the MED Duet Connector comes into contact (reads signals from)
the MED Mini Probe terminal. If abnormal noise is observed at a particular electrode even when a noise test is performed with the
test board, the noise may be caused by a contact pin being depressed onto the printed circuit board side or by dirt being
attached to the pins. In the latter case, remove the top unit from the base plate and wipe the contact pins with a Kim wipe
moistened with 70% ethanol by gently wiping from front to back. If any contact pins are rusted, damaged, or detached from the
printed circuit board for whatever reasons, the printed circuit board needs to be replaced (a paid-for repair).
3.5. Setup of the MED64-Allegro
3.5.1. Part names and functions of the MED Multi-well Connector
【Front】 【Back】
❶
❷
❸
❸
❹
❸
❹
❸
❹
❸
❹
❸
Contact pin
Printed circuit board

12
【Accessories】
➊ Insertion slot of the MED Multi-well Probe
➋Ground terminal ….. To connect the SIGNAL GND terminal of the MED Head Amplifier using the accessory ground wire with a
bagworm clip.
➌Screw hole ….. To fix the MED Multi-well Connector onto the MED Thermo Base (MED-CPB02).
➍Output terminal ….. To connect to the INPUT terminal of the MED64 Head Amplifier via the 20-pin SCSI cable.
❺20-pin SCSI cable (2 m x 4) ….. To connect the output terminal and the INPUT terminal of the MED64 Head Amplifier (the
specification is different from the 20-pin SCSI cable for the MED Duet Connector).
❻Test board ….. A PCB with multiple resistors to check the baseline noise level of the whole system and its environment.
❼Ground wire with a bagworm clip ….. To connect the ground terminal of the MED Multi-well Connector and the SIGNAL GND
terminal of the MED64 Head Amplifier.
3.5.2. Connections among devices
➊Connect the INPUT terminal of the MED Main Amplifier and the OUTPUT terminal of the MED Head Amplifier, using the 68-pin
SCSI cable (50 cm).
➋Connect the F1/F2 STIMULUS OUTPUT of the MED64 Main Amplifier and F1/F2 STIMULUS IMPUT of the MED64 Head
Amplifier, using the BNC cables.
➌Connect the CONTROL OUTPUT terminal of the MED64 Main Amplifier and the INPUT terminal of the MED64 Head Amplifier,
using the round-pin cable.
➍Connect the output terminals of the MED Multi-well Connector and the INPUT terminals of the MED64 Head Amplifier, using
20-pin SCSI cable.
➎Connect the ground terminal of the MED Multi-well Connector and the SIGNAL GND terminal of the MED64 Head Amplifier,
using the ground wire with a bagworm clip.
➏Connect the USB port (type-B) of the MED64 Head Amplifier and the USB port (type-A) of the data acquisition PC (USB2.0 is
preferable), using the USB cable
➐Connect the power adaptor cables to both amplifiers.
❺
❸
❻
❸
❼
❸
❶
❸
❷
❸
❷
❸
❸
❸
❹
❹
❹
❹
❺
❻
❼
❼

13
Note: The ground terminal of the MED Multi-well connector must be grounded to the SIGNAL GND terminal of the MED64 head
amplifier. If not grounded, it will be affected by external noise.
3.5.3. Positioning of the terminal of the MED Multi-well Connector
The electrode number will be assigned as the below when place the MED Multi-well Connector with its output terminal and the
20-pin SCSI cable on the right side.
MED-P5NF30 MED-P5N811

14
Correspondence between the MED Duet Connector output terminal and the electrode number. R indicates the reference electrode; N is not
assigned. The pin alignment is divided in the center to correspond the adjacent two well while using the MED-P5N811.
3.4.4. Preparation for the noise check – attaching the MED Multi-well Probe
Insert the terminal of the MED Multi-well Probe filled with saline, such as aCSF or PBS into the insertion slot gently and
horizontally, holding the well chamber of the MED Multi-well probe or the end of the glass substrate. If any waterdrop, medium
or smudge is on the terminal, wipe the terminal with a Kim wipe before setting the MED Multi-well Probe.
Note1: The terminal comes into contact with the contact pins of the MED Multi-well Connector. Attachment of chloride or a
fingerprint may cause deterioration of the contact pins.
Note2: If liquid is spilled and comes into contact with the contact pins, contact failure may occur. In particular, pay attention so as
not to spill saline.
About the details of noise check, refer to p.19 “Noise check by operating the Mobius - procedure common to Basic, Quad II, and
Allegro”. Also, for the details of operating the Mobius refer to “MED64 Mobius Tutorial.” Refer to the relevant application note for
the preparation of specimens used for the experiment.
3.4.5. Maintenance of the MED Multi-well Connector
The contact pins, of 72 pins per well, constitute the area where the MED Multi-well Connector comes into contact (reads signals
from) the MED Multi-well Probe terminal. If abnormal noise is observed at a particular electrode even when a noise test is
performed with the test board, the noise may be caused by a contact pin being depressed onto the printed circuit board side or
by dirt being attached to the pins. In the latter case, remove the top unit from the base plate and wipe the contact pins with a
Kim wipe moistened with 70% ethanol by gently wiping from front to back. If any contact pins are rusted, damaged, or detached
from the printed circuit board for whatever reasons, the printed circuit board needs to be replaced (a paid-for repair).
Terminal
Contact pin
Printed circuit board

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4. Noise check by using the Mobius - procedure common to Basic, Quad II, and Allegro
Tun on the power of the amplifiers, the data acquisition PC, and the display monitor. Start the Mobius by double clicking the Mobius
icon on the desktop. Select Workflow > New > From Template on the menu bar and then select 64MD1_1280x1024 or
64MD1_1920x1080, depending on the resolution of the display monitor.
Note: Do not start other software during the data acquisition because it may place an unexpected load on OS and cause it to freeze
or to force a shutdown. Especially, you need to pay attention to software running background, such as anti-virus software. Do
not connect to the Internet, because it may place an unexpected load due to the communication and cause it to freeze or to
force a shutdown.
In addition, open the Basic_recording folder and select and call up “Noise_check.moflo” as the template workflow. The default
conditions for data acquisition are shown below. Do not change these setting conditions as they serve as reference for the noise
level check of the MED64 System.
Input Range (mV): 5.0、Low cut freq (Hz): 1、High cut freq (Hz): 10000
Note: To call up Noise_check.moflo, the workflow communicates with the MED64 Main Amplifier via the USB cable. If the Amplifier
is not turned on, a pop-up window appears with an error message, as shown in the right figure.
Click the 64ch display tab to display the 64ch display window. Click the play button (playback button) to start data acquisition
without outputting a data file. Once the button is clicked, a pop-up window appears saying “Please wait while the amplifier is
calibrated,” but the pop-up window disappears when a few minutes of the calibration is completed and the Mobius automatically
starts data acquisition with the waveform of the baseline noise displayed on the 64ch window.
The ideal baseline noise level is about ±5-8 µV peak-to-peak. If the baseline noise shows an amplitude greater than the value, take
measures against the noise, with reference to p.19 “6. Abnormal noise.”
Play button

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Normal baseline noise.
5. Combining with a perfusion system
This section explains the procedure for setting up a perfusion system when the MED64 System is used in combination with it. The
perfusion system recommended to be used in combination with the MED64 System consists of the following:
1) MED Perfusion Cap Kit 【MED-KCAP01TU】
2) Peristaltic Pump 【Mini Pulse III Model 312 / MP-2, Gilson】
Note: When a perfusion pump is used, read the pump’s product manual thoroughly and follow the instructions. Set up the MED64
System properly before setting up the perfusion system.
The MED Perfusion Cap Kit is designed to be used with Minipuls 3. If a perfusion pump other than Minipuls 3 is used, change the
tubing configuration to one that is suited to the perfusion pump before use. (Please note that the operation of the MED64 System
cannot be guaranteed if it is used in combination with pumps other than Minipuls 3 for the MED Perfusion Cap Kit.) Extra droppers
and leads for grounding are supplied as accessories for the MED Perfusion Cap Kit, as shown in the figure on the next page.
MED Perfusion Cap Kit
Dropper stand
Spare droppers
Ground wire
Bubbling flask
MED Perfusion Cap
Outlet dropper
Inlet dropper
Gas port
Fixation
screw
Outlet pipe
Inlet pipe
Platinum wire
20 ms
25 µV
Fixation
screw

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5.1. Position of the Minipuls 3 and power supply
The Minipuls 3 itself serves as a magnetic noise source. If it is suspected that it is affecting the baseline nose level, place it away
from the amplifier, the MED Thermo Connector, and the 68-pin SCSI cable, considering its distance from the devices. Connect the
three-terminal plug of the power cable of the Minipuls 3 to the same power strip into which the amplifier is plugged.
5.2. Installing MED Perfusion Cap Kit to the Minipuls 3
Unlock the 2-channel (upper and lower) locking bars of the Minipuls 3 and loosen the compression cams. Wind the flow tubes of
the MED Perfusion Cap Kit around the rollers and fix the tubes by catching the tube hook with the plastic part. Pay attention to the
orientation of the flow tubes so that the perfusion solution properly runs from the liquid supply side to the drainage side along
the rotation direction of the rollers (clockwise or counterclockwise). The example in the figure below shows that the flow tubes are
wound so that the lower (white) compression cam is on the drainage side, while the upper (black) compression cam is on the
liquid supply side.
In the area of the flow tubes to which the compression cams apply pressure, adjust the winding so that both the flow tubes are
horizontal around the center of the upper and lower compression cams and then press the compression cams onto the tubes and
fix them with the locking bars. Make sure that the adjustment screws of the locking bars are completely loosened when fixing the
tubes.
5.3. Connection between MED Thermo Connector and MED Perfusion Cap Kit
The MED Thermo Connector contains an in-line tube (or pipe). Connecting the inlet tube (pipe) to the in-line tube (or pipe)
enables the perfusion solution to flow through and to be warmed.
Adjustment screw
Data Acquisition PC
MED64 Head Amplifier
MED64 Main Amplifier
Mini Pulse III
MED Thermo Connector
Compression cam
Locking bar