Service Manual
169 Pages
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Service Manual
Synergy Systems EMG and EP Systems Part Number: 040W003-E
Manufacturer:
European Authorised Representative:
VIASYS Healthcare
VIASYS Healthcare GmbH
5225 Verona Road, Building 2 Madison, WI USA
Leibnizstrasse 7 97204 Hoechberg
53711-4495
Germany
Tel: +1 608 273 5000
Tel: (49) 931-4972-308
or:
Fax: (49) 931-4972-62308
+1 800 356 0007
Fax: +1 608 441 2004 Email: [email protected]
Email: [email protected]
www.viasyshealthcare.com The Synergy range of multimedia EMG/EP systems has been designed and manufactured by Viasys Healthcare, an international company that has always had an enviable reputation for innovation and quality of its products. VIASYS Healthcare has been certified by KEMA as an approved medical devices manufacturer as meeting the requirements of BS EN ISO 9001, BS EN ISO13485 and the Medical Devices Directive (93/42/EEC). The Synergy range of multimedia EMG/EP systems has been independently tested and successfully approved to the following medical safety standards: IEC 60601-1, EN 60601-1, UL 2601-1, CAN/CSA-C22.2 No. 601.1, JIS T 0601-1 or JIS T 1001/1002, IEC 60601-1-1, EN 60601-1-1, JIS T 0601-1-1, IEC 60601-1-2, EN 60601-12, IEC 60601-2-40, EN 60601-2-40. The Synergy range of multimedia EMG/EP systems is CE Marked in accordance with the European Council Directive 93/42/EEC concerning medical devices. The Synergy range of multimedia EMG/EP systems bears the ETL Listing Mark, which is a Nationally Recognised Testing Laboratory (NRTL) Mark in the United States and Canada. Indicates that this product comes under the provisions of EU Directive 2002/96/EC on waste electrical and electronic equipment (WEEE) and that this unit was placed on the th market after 12 August 2005. This directive covers EOL (End-of-Life) disposal. Within the EU, at end-of-life, this product may only be disposed of through a government approved collection scheme or treatment facility. If in doubt contact your local VIASYS Healthcare representative.
Copyright All rights reserved. This manual contains proprietary information which is protected by copyright and may not be copied in whole or in part except with the prior written permission of VIASYS Healthcare. The copyright and the foregoing restrictions on the copyright use extend to all media in which this information may be preserved. This copy of the User Manual shall be used only in accordance with the conditions of sale of VIASYS Healthcare or its distributors. VIASYS Healthcare makes no representations or warranties of any kind whatsoever with respect to this document. VIASYS Healthcare disclaims all liabilities for loss or damage arising out of the possession, sale or use of this document.
Medelec and TECA are registered trademarks of VIASYS Healthcare in the UK and other countries. EMG LivePlay™ and LongTrace™ are trademarks of VIASYS Healthcare. Microsoft Office, Windows and NetMeeting are registered trademarks of Microsoft Corporation. Intel Pentium and Centrino are registered trademarks of INTEL Corporation.
CAUTION: Federal Law restricts this device to sale by or on the order of a physician.
Synergy Systems Service Manual
Table of Contents Table of Contents ...iv 1. Introduction ...8 1.1
The Synergy products ...8
2. Regulations and safety ... 16 2.1
Standards ...16
2.2
Warning to users...16
2.3
Electrical stimulus output of Synergy ...17
2.4
Special instructions for use...17
2.5
Information on the output waveforms of the electrical stimulators ...17
2.6
Electrical stimulating electrodes ...18
2.7
Cleaning ...18
2.8
Symbols and their definition...20
2.9
Warning symbols ...21
3. Technical overview Synergy N2 and T2 systems...22 3.1
Outline and scope of overview ...22
3.2
The PC ...23
3.3
The Patient Interface Unit ...23
3.4
Patient Interface Unit Overview ...24
3.5
Amplifier electronics...27
3.6
Stimulator electronics ...29
3.7
DC - DC Converter...32
3.8
Patient Interface Unit Connections ...33
4. Technical overview Synergy N and T series... 36 4.1
Scope of Plinth overview ...36
4.2
The PC ...37
4.3
The Plinth ...38
4.4
Overview of the headboxes 2, 5 &10 Channel...42
4.5
The Control Panel & Electrical Stimulators...48
4.6
The EP Stimulator (Optional) ...49
4.7
IOM Stimulator ...51 iv
Table of Contents
4.8
Plinth Connections ...58
4.9
Peripheral Connectors ...60
5. Patient safety checks for N2 and T2 systems...61 5.1
Equipment Required... 61
5.2
Initial Checks for all Systems ...61
5.3
Signal Input Checks for all Systems ... 62
5.4
Internal EMG Stimulus Output checks for all Systems...63
5.5
Notebook System Electrical Safety Tests ... 65
5.6
Enclosure leakage current - Normal condition ...66
5.7
Patient Leakage Current Tests ...67
5.8
Patient Leakage Current Tests for External EMG Stimulator Probe ...69
5.9
Patient Auxiliary Current (Patient Amplifier inputs and Internal Stimulator)... 69
5.10 Patient Auxiliary Current (Patient Amplifier inputs and External Stim Probe) ...70 5.11 Safety Checks EMG Internal Stimulator...71 5.12 Safety Checks EMG External Stimulator Probe ...72 5.13 Tower System Electrical Safety Tests ...73 5.14 Electrical Leakage Current Tests ... 73 5.15 Enclosure leakage current - Normal condition ...75 5.16 Patient Leakage Current Tests ...76 5.17 Patient Leakage Current Tests for External EMG Stimulator Probe ...77 5.18 Patient Auxiliary Current (Patient Amplifier inputs and Internal Stimulator)... 78 5.19 Patient Auxiliary Current (Patient Amplifier inputs and External Stim Probe) ...79 5.20 Safety Checks EMG Stimulator...79 5.21 Safety Checks EMG External Stimulator Probe. ... 81
6. Patient safety checks for Synergy N and T series systems ... 82 6.1
Equipment Required... 82
6.2
Initial Checks for all Systems ...82
6.3
Signal Input Checks for N and T series Systems ...83
6.4
Internal EMG Stimulus Output checks for N and T series Systems ... 84
6.5
EP Stim Checks for N and T series Systems ...86
6.6
N and T series System Electrical Safety Tests...87
6.7
Electrical Leakage Current Tests ... 88
6.8
Enclosure leakage current - Normal condition ...90
6.9
Patient Leakage Current Tests ...91
6.10 Patient Leakage Current Tests for External EMG Stimulator Probe...92 6.11 Patient Auxiliary Current (Patient Amplifier inputs and Internal Stimulator)... 93 v
Synergy Systems Service Manual
6.12 Patient Auxiliary Current (Patient Amplifier inputs and External Stim Probe) ...94 6.13 Safety Checks EMG Stimulator...95 6.14 Safety Checks EMG External Stimulator Probe. ...96 6.15 Patient safety checks IOM systems...97
7. N2 and T2 system functional checks ...108 7.1
Equipment Required...108
7.2
System Connection ...108
7.3
System Checks ...109
7.4
CD-ROM Drive Checks...110
7.5
Patient Amplifier Checks ...110
7.6
Trigger / Gain / Sweep Control Checks ...111
7.7
Amp Cal Mode ...112
7.8
Temperature Probe Checks ...112
7.9
Patient Interface Unit Internal EMG Stimulator Checks ...112
7.10 EMG Stimulator Probe Checks ...114 7.11 Speaker Checks ...115 7.12 Footswitch Checks...116 7.13 Temperature Probe Input check ...116 7.14 Parallel & Serial Port Checks...117 7.15 Networking Checks (Suite System Only) ...118
8. N and T series system functional checks...120 8.1
Equipment Required...120
8.2
System Connection ...120
8.3
System Checks ...121
8.4
CD-ROM Drive Checks...122
8.5
Patient Amplifier Checks ...122
8.6
Trigger / Gain / Sweep Control Checks ...124
8.7
Amp Cal Mode for 2 channel amplifiers ...125
8.8
Calibration and filter check for 5 or 10 channel amplifiers ...126
8.9
Temperature Probe Checks ...126
8.10 Control panel EMG Stimulator Checks ...126 8.11 EMG Stimulator Probe Checks ...128 8.12 Systems with 2 External EMG Stim Probes ...129 8.13 EMG Speaker Checks ...129 8.14 Triple Footswitch Checks ...130 8.15 Single Footswitch Checks ...130 vi
Table of Contents
8.16 Triggering in / out for external sources and I/O Interface (option)...131 8.17 Temperature Probe Input check ...133 8.18 Parallel & Serial Port Checks...133 8.19 Networking Checks (If you have more then one system) ...134 8.20 EP Stim Checks ...135 8.21 IOM Systems ...136
9. Fault finding ... 151 9.1
Notebook System With PIU: Fault Finding ...151
9.2
Tower System With PIU Fault Finding ...153
9.3
Suite System With PIU: Fault Finding ...156
9.4
Notebook System With Plinth: Fault Finding...156
9.5
Tower System With Plinth: Fault Finding...159
9.6
Fault Finding Network Problems With Synergy N and T Series Systems ...162
10. Servicing...163 10.1 Servicing Warnings ...163 10.2 Patient Interface Unit ...163 10.3 Synergy Plinth Unit ...163 10.4 Warranty of PCs ...163 10.5 Notebook PC ...163 10.6 Tower System ...164
11. Customer options and spares ...165 11.1 Common Hardware Spares and Software to all systems...165 11.2 Spares for N2 AND T2 systems ...166 11.3 Spares for N and T series systems...167
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Synergy Systems Service Manual
1.
Introduction
This Service Manual gives you detailed servicing information for the Synergy systems. For further information, refer to the following:
Information
Use
Part Numbers
Installation Manual
First time use
040W004
User Guide
For day-to-day use. Includes descriptions of the hardware
040W009
Synergy Online Help
Quick reminder of test methods in Synergy software
N/A
Reference Manual
System configuration and application information, more detailed and alternative test methods
040W002
Administrator's Guide
For advice on networking and patient data protection
040W024
Accessories Catalogue
For details of accessories
Note: The following terminology and conventions are used in this Service Manual: Description
Meaning
Push Next
Push a knob or button on the control panel, PIU or amplifier
Press <Enter>
Press a key on the keyboard
Click on Average
Click on a function key on the screen
Select Acquisition Setup…
Select an item from a menu
1.1
The Synergy products
The Synergy systems are 2/5/10-channel neurodiagnostic systems, which provide facilities for Electromyography (EMG), Nerve Conduction Studies (NCS), Evoked Potential (EP) recordings and Intra-Operative Monitoring (IOM), for a range of clinical applications. Synergy is available as Synergy N2 and T2 (PIU based, 2 channels, suitable for NCS and EMG only) and the Synergy N and Synergy T Series (Plinth based, 2, 5, and 10 channels, suitable for NCS, EMG, EP and IOM).
8
Introduction
Synergy N2 and Synergy T2 These systems comprise a Notebook or Tower PC, together with a PIU (integral 2-channel amplifier and electrical stimulator). Synergy N2
Synergy T2
The systems comprise the following standard and optional items:
Item
N2
Multimedia Notebook PC with internal Network Card, modem, CD Read-Writer, medical grade psu, Microsoft Windows and Office, Synergy software
T2
Multimedia Tower PC with internal Network Card and CD Read-Writer, keyboard, mouse, Microsoft Windows and Office, Synergy software
CRT monitor or LCD monitor Single footswitch * see 2/5/10 channel EMG/EP PIU with integral 2-channel amplifier and electrical stimulator * Deluxe Stimulator Probe * Desk mount for PIU Mains isolating transformer module Temperature probe Trolley and arm
Backplate for Trolley
Arm and desk mount
Carry case Printer PC to PC Network cable External loudspeaker = standard; = optional
* see below for more detail
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Synergy Systems Service Manual
Patient Interface Unit The Patient Interface Unit (PIU) provides single control operation for setting essential parameters during a patient examination.
A B C D E F
Stim Next Volume Sensitivity
This switch toggles Stimulus ON and OFF. If Acquire is ON, pressing this switch has no effect. Press this switch to move to the next site in NCS and EMG tests. Rotate this switch to change the level of the audio output of the input signal. Set it to zero for no audio output. Rotate this switch to adjust the display sensitivity of the selected trace or traces. If no trace is selected (to deselect a trace click away from it), the sensitivity of all the traces in the current test is changed. Socket for Deluxe Stimulator Probe Sweep Duration Rotate this switch to adjust the acquisition sweep duration for the active trace(s). Once data has been acquired you can also increase or decrease the sweep duration for selected traces.
G H I J
Erase Press this switch to erase the selected trace or traces. This enables you to collect a fresh set of data in the same store. Socket for footswitch Fn1 Programmable via the Display menu to control Marke r, Trigger or Cursor. Fn2 Programmable via the Display menu to control Averager On/Off, record cursor, trigger polarity, EMG Staging.
K L M
Stim Duration Acquire ON Acquire Single
N O P Q R
Stim Intensity Use this switch to adjust the amplitude of the stimulus. Stim Intensity is displayed in the Toolbar. On / off Socket for Temperature Probe Ground socket DINs and inputs for electrode connections
S
Internal stimulator connections
Rotate this switch to adjust the duration (pulse width) of the stimulus. Press this sw itch to set acquire ON. Press it again to set Acquire OFF. Press once to deliver a stimulus and acquire a response. If you hold down this switch for more than 1 second, Acquisition is locked on. Press again to stop Acquisition.
Deluxe Stimulator Probe Your system will have a choice of two types of stimulators. One stimulator is internal with an output on the PIU or control panel. The second stimulator is the Deluxe Stimulator Probe. On PIU systems, if the Deluxe Stimulator Probe is connected, then the internal stimulator is disabled.
The Deluxe Stimulator Probe enables you to control the following: A
Stim ON / OFF
B C
Next switch Stimulus Polarity
D E
Stim Intensity / Acquire Stim Duration Up / Down
Push to deliver a stimulus without acquiring data. This button turns the stimulus ON and OFF. If all stimuli are OFF when you push the button, stimulus is set ON. If Acquire is ON, pushing this button has no effect. Push to move to the next site and start a new acquisition. Push to change the polarity of the stimulus: the positive probe tip changes to negative and the negative probe tip changes to positive. Note that the positive probe tip has its LED lit. Rotate to adjust the amplitude of the stimulus. Stim Intensity is displayed in the Toolbar. Push to deliver the stimulus and acquire the data. Push the up (left) or down (right) button to increase or decrease the duration (pulse width) of the stimulus.
With the adjustable head, you can modify the Deluxe Stimulator Probe for paediatric use:
10
Introduction
1. Unscrew the probe tip C (next to the locking button A). 2. Screw this tip into position B. Note: Do not force the probe tips when you move them. Always slide down on the locking button before you attempt to release them.
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Synergy Systems Service Manual
Synergy N and Synergy T Series These systems comprise a Notebook or Tower PC together with a Plinth, patient side control panel, and 2, 5, or 10-channel amplifier. Synergy N Series
Synergy T Series
The systems comprise the following standard and optional items: Item
N Series
Multimedia Notebook PC with internal Network Card, modem, CD Read -Writer, DC to DC adapter, Microsoft Windows and Office, Synergy software
T Series
Multimedia Tower PC with 15” OR 18” flat panel display, internal Network Card and CD Read -Writer, keyboard, mouse, Microsoft Windows and Office, Synergy software
Plinth * 2/5/10 channel amplifier *
Control panel
Deluxe Stimulator Probe *see 2 channel EMG section
Footswitch ( Single or triple) * Desk mount for amplifier
Mains isolating transformer module
Temperature probe
Trolley and arm Arm and clamp
Rolling case
Printer PC to PC Network cable
I/O Interface Unit
Patient Side Head box
IOM Stimulator Extension Surgeon Footswitch
= standard; = optional
* see below for more detail
Plinth The Plinth contains connections to the amplifier, stimulators and PC interfaces. It links together the PC, amplifier, control panel and accessories. It also has connections to power the Notebook. Rear of Plinth
Left side of Plinth
12
Introduction
Rear of Plinth:
Left side of Plinth:
A
O I
On/Off switch
L
Speaker for EMG
B
Mains lead connector
M
EMG
EMG external speaker interface
C
DC to DC power adaptor for connection to Notebook
N
EMG
Headphones for EMG
D
PC
Connection to PC Audio (yellow)
O
EP
Microphone for Auditory EP *
E
Footswitch interface (orange)
P
EP
Auxiliary input for Auditory EP *
F
Control panel interface (brown)
Q
EP
Headphones for Auditory EP *
G
External trigger port
H
PC USB interface
I
Two interfaces for up to two Deluxe Stimulators or a single IOM Stimulator (light grey)
Visual EP LED goggles interface *
J
Amplifier interface (black)
Visual EP monitor interface *
K
Functional earth connection
Right side of Plinth (not shown):
Speaker for EMG Front of Plinth (not shown): Green light
Indicates the Plinth has power * These connections are blanked off on EMG-only systems
Control panel The control panel provides a single control operation for setting essential parameters during a patient examination. It includes a mouse capability.
A B
Fn1 Fn2
Programmable via the Display menu to control Marker, Trigger or Cursor. Programmable via the Display menu to control Averager On/Off, record cursor, trigger polarity, EMG Staging.
C D
Volume Sensitivity
E
Next
Rotate to change the level of the audio output of the input signal. Set it to zero for no audio output. Rotate to adjust the display sensitivity of the selected trace or traces. If no trace is selected (to deselect a trace click away from it), the sensitivity of all the traces in the current test is changed. Push to move to the next site in NCS and EMG tests.
F
Sweep Duration
G H
Erase Acquire ON/OFF
I
Acquire Single
J
Stim B
K L M N
Green light Stim On/Off Stim Duration Stim A
Indicates the control panel has power. Push to toggle Stimulus On and Off, without acquiring. If Acquire is On, pushing this button has no affect. Rotate to adjust the duration (pulse width) of the stimulus. Rotate to adjust the amplitude of the internal stimulus. Stim Intensity is displayed on the tool bar and also on the Status Panel.
O P Q R
Internal Stimulus Inputs Right button Pointing device Left button
Push to open a menu Push to move pointer on screen. Push to select
On rear of control panel
Removable clip for attachment of the control panel to a bedside, blanket, desk, keyboard on mouse tray of the trolley
Rotate to adjust the acquisition sweep duration for the active trace(s). Once data has been acquired you can also increase or decrease the sweep duration for selected traces. Push to erase the selected trace or traces. This enables you to collect a fresh set of data in the same store. Push to set acquire ON. Press it again to set Acquire OFF. Push once to deliver a stimulus and acquire a response. If you hold down this button for more than 1 second, Acquisition is locked on. Push again to stop Acquisition. Rotate to adjust the amplitude of the external stimulus, the Deluxe Stimulator. Stim Intensity is displayed on the tool bar and also on the Status Panel.
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Synergy Systems Service Manual
Amplifier 2 channels
A
Two-channel Touchproof connectors Sensitivity Control
The two-channel Amplifier has 2 positive, 2 negative and 1 neutral 1.5mm touchproof connections. Use this to adjust the display sensitivity of the selected trace or traces. If a trace is not selected, the sensitivity of all the traces in the current test is changed. Push this button to show impedance levels. The impedance level (<2, 4, 8, 16, 32 and >32 Kohms) is shown for each input when the appropriate button is pressed.
B C
Impedance check ON button Two-channel Impedance Check indicators
D E F
Amplifier ON/OFF switch Temperature Probe Input Sweep Duration Control
Use this to switch the amplifier ON and OFF. An input for a temperature monitoring probe. Use this to adjust the acquisition sweep duration for the selected trace(s). Once data has been acquired you can also increase or decrease the sweep duration for selected traces. If no trace is selected (deselect a trace by clicking away from it) all traces are affected.
G H I
Trigger Control 2 DIN sockets Ground socket
Use this to set the trigger level for signal trigger mode. The trigger level takes effect when you select signal trigger acquisition mode.
Amplifier 5 channels
The five/ten-channel Amplifier has twenty 1.5mm connections: 12 cephalic in 10-20 format, 6 non-cephalic and 2 neutral.
A
Five-channel Touchproof connectors Temperature Probe Input
B
Sensitivity Control
C
Sweep Duration Control
D
F
Impedance Pass Level Up/Down buttons Five-channel Impedance Check indicators Amplifier ON/OFF switch
Use this to adjust the display sensitivity of the selected trace or traces. If a trace is not selected, the sensitivity of all the traces in the current test is changed. Use this to adjust the acquisition sweep duration for the selected trace(s). Once data has been acquired you can also increase or decrease the sweep duration for selected traces. If no trace is selected (deselect a trace by clicking away from it) all traces are affected. These are used to set the impedance level. The Impedance Check indicator is illuminated for any channel that fails the impedance check.
G H I
Trigger Control 2 DIN sockets Ground socket
E
An input for a temperature monitoring probe.
These are the LEDs for the inputs. With the amplifier on, the LEDs indicate which electrodes are in use. When Impedance is on, the LEDs indicate high impedance if they are lit. Use this to switch the amplifier ON and OFF. Use this to set the trigger level for signal trigger mode. The trigger level takes effect when you select signal trigger acquisition mode.
14
Introduction
Footswitch There is a single and triple footswitch available. The single footswitch has function C Acquire only. (Single footswitch not shown.)
A
Programmable
B
Next
C
Acquire
The function of this switch is specific for each test. If you have the optional Test Configuration Wizard, you can configure this switch. Click the footswitch icon in the toolbar to display the function you have allocated to this footswitch. For NCV and Needle EMG tests: Push once to move to next store. For EP tests only: Push once to move to next run. Push once to deliver a stimulus and acquire a response. If you hold down this switch for more than 3 seconds Acquisition is locked on. Push again to stop acquisition.
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Synergy Systems Service Manual
2.
Regulations and safety
2.1
Standards
The entire Synergy system complies with EN 60601-1, the European standard for medical electrical equipment: For type of protection against electrical shock
Class 1
For degree of protection against electrical shock
Type BF
For degree of protection against harmful ingress of liquid
Ordinary (no protection)
For the mode of operation
Continuous
For the degree of safety of application in the presence of a flammable
Not suitable
anaesthetic mixture with air or with oxygen or nitrous oxide
EP Headphones The EP Headphones connector is designated solely for use with type BF isolated headphones to comply with EN60601-1, UL2601-1 and CSA C22.2 No. 601.1.
LED goggles The LED goggles connector is designated solely for use with type BF LED goggles, as supplied by VIASYS Healthcare.
Amplifiers The amplifier connector is designated solely for use with type BF amplifiers, as supplied by VIASYS Healthcare.
Stim probes The stimulator probe connectors are designated solely for use with type BF stimulator probes, as supplied by VIASYS Healthcare.
Control panel (including stimulator) The Control panel connector is designated solely for use with a type BF control panel including stimulator, as supplied by VIASYS Healthcare.
2.2
Warning to users
1
It should be noted that it is the user responsibility to ensure that conformance to EN 60601-1 Type BF, UL2601-1 and CSA C22.2 No. 601.1 patient isolation requirements are to be maintained when patient connected equipment or accessories not supplied by VIASYS Healthcare are used with VIASYS Healthcare equipment.
2
If any mains powered equipment, for example printers, video monitors or other medical equipment, is to be connected to Synergy to form a medical electrical system then the requirements of standard EN60601-1-1 (Medical Electrical Equipment, Part 1. General requirements for safety, Section 1.1 Collateral standard: Safety requirements for (medical electrical systems)) must be complied with to ensure patient and operator safety is maintained. For further information please refer to the Synergy Installation Manual.
16
Regulations and safety
2.3
Electrical stimulus output of Synergy
Max intensity:
300V constant voltage (pulsed) or 100mA constant current (pulsed)
High range:
0 - 300V or 0 - 100mA
Low range:
0 - 75V or 0 - 25mA
Duration:
0.02 - 1ms per pulse
Repetition rate:
0.06 - 200 pulses/second
2.4
Special instructions for use
Ensure that Synergy is not powered up before plugging in the amplifier. To disconnect the amplifier: Ensure that Synergy is not powered up. Switch ON the instrument before connecting patient electrodes. Disconnect all patient electrodes before switching OFF. Do NOT use electrical stimulators for the direct stimulation of exposed nerves unless the stimulator output has been set to the Low range. A patient with an implanted electronic device, for example a cardiac pacemaker, should not be subjected to electrical stimulation unless specialist medical opinion has first been obtained. Disconnect ERG electrodes (i.e. gold-foil, carbon-fibre and corneal electrodes) from the amplifier before using the facility for impedance checking. Alternatively you may disable the impedance checking of these electrodes using the Impedance Check Setup dialog. Accidental contact should be avoided between electrodes connected to the amplifier and stimulator connectors but not applied to the patient and other conductive parts including protectively earthed parts.
2.5
Information on the output waveforms of the electrical stimulators
The output waveform is a square pulse. The ratio of pulse interval (seconds) to pulse duration (seconds) is prevented from falling below a value of 20:1 to limit the maximum average energy delivered to the patient. The d.c. component is dependent on the pulse duration (t) and the pulse repetition frequency (prf). In constant voltage mode the d.c. component (Vdc) is given by: Vdc = Vpk x t T, where Vpk is the pulse amplitude in volts, t is the pulse duration in seconds and T is the interval between pulses in seconds (T = 1 prf, with the prf in Hz). In constant current mode the dc component is given by: Vdc = Ipk x R x t T, where Ipk is the pulse amplitude in milliamperes and R is the resistive part of the load impedance in kilo-ohms. A d.c. component in the output may be avoided if the biphasic stimulation mode is selected. This outputs alternate positive and negative pulses of equal amplitude and duration resulting in zero net charge delivered to the patient. The effect of load impedance on the stimulus output is as follows: In constant voltage mode the output voltage will be as demanded provided that the output current limit of 100mA is not reached. Once the current limit operates the output voltage will fall from the value demanded to a value given by 100mA x the load impedance. In constant current mode the output current will be as demanded provided that the output voltage limit of 300V is not reached. Once the output voltage limit is reached the output current will fall from the value demanded to a value given by 300V the load impedance. 17
Synergy Systems Service Manual
The range of load impedance for which the output voltage or current is as demanded is as follows: In constant voltage mode the maximum load is infinity (open circuit), the minimum load is given by the demanded voltage 100mA. So for example the minimum loads at 1V, 10V, 100V and 300V outputs are 10ohms, 100ohms, 1000ohms and 3000ohms respectively.
2.6
In constant current mode the minimum load is zero (short circuit), the maximum load is given by 300V the demanded current. So for example the maximum loads at 1mA, 10mA, 50mA and 100mA are 300kilo-ohms, 30kilo-ohms, 6kilo-ohms and 3kilo-ohms respectively.
Electrical stimulating electrodes
Electrical stimulators must be used only by appropriately medically trained and qualified personnel. Electrodes must never be positioned so that electrical current flows across the heart (transthoracic stimulation), i.e. never apply a positive electrode to one limb and a negative electrode to any other limb. Keep the positive and negative stimulating electrode sites in close proximity. When stimulating for long periods there may be a risk of damage to tissue under the stimulating electrodes due to the d.c. component in the stimulator output. The biphasic stimulation mode may be used to avoid a d.c. component in the output. This outputs alternate positive and negative pulses of equal amplitude and duration resulting in zero net charge delivered to the patient. Surface electrodes must make good electrical contact with the skin surface. Notes: Current densities for any electrodes exceeding 2mA r.m.s./cm 2 may require the special attention of the operator. Electrical stimulating electrodes supplied by the manufacturer can operate at the maximum output of the Synergy. WARNING! Connection of a patient to high frequency electrosurgical equipment and to Synergy simultaneously may result in burns at the sites of stimulating and recording electrodes. Damage may also occur to the electrical stimulator and amplifiers. However, Synergy includes protection components to reduce the risk of this happening. WARNING! Operation of Synergy in close proximity (for example 1 metre) to shortwave or microwave therapy equipment may produce instability in the electrical stimulator output.
2.7
Cleaning
WARNING: Switch OFF and unplug the instrument before cleaning. The casing, panels and screen may be cleaned using a cloth moistened with water and detergent, except for flat panel displays, which require special wipes. Do not allow any liquid to enter the case of the instrument. The instrument may also be cleaned using a low-pressure air-line or a vacuum cleaner with an appropriate attachment. Do not use propanone (acetone) on any part of the instrument. The instrument must not be autoclaved or sterilised by any means. Ideally, the Stimulator probe tips should be cleaned with warm soapy water prior to the use of 70% isopropyl alcohol (IPA) as a disinfectant, as per manufacturer's instructions.
18
Regulations and safety
The non-slip mat under the printer may be cleaned with warm soapy water. You are advised to carry out cleaning as specified above as and when required.
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Synergy Systems Service Manual
2.8
Symbols and their definition
Information
Connections
Warning symbol. See page 21 for details
Connection complies with EN60601-1 for Type BF defibrillation proof equipment
Input/output interface
Connection complies with EN60601-1 for Type BF equipment
EP video monitor
Amplifier
Stimulus Stimulus duration
External switches (footswitches)
/s
Stimulus repetition rate
Output
Display Sensitivity
Patient ground
Sweep Duration
-
Trigger
Stimulus Probe
Trigger - falling edge
EMG
External speaker-EMG audio
+
Trigger - rising edge
Headphones - EMG audio
Alternating current (ac)
EMG
Universal Serial Bus
Z
Direct current (dc)
Digital input/ Output
Temperature Probe
LED goggles
PC
PC audio
Impedance check
Earth (ground, functional)
EP
EP audio headphones
Input
Control panel
Switches
I
Power rocker switch, ON position
O
Power rocker switch, OFF position
Non Power switch, ON position
Non Power switch, OFF position
PC connections See the documentation supplied with the PC.
20