Technical SeminarTEC-5500 Series Defibrillator
Contents
Features Board/Unit location and Block Diagram Screens for
Maintenance Troubleshooting Case StudyNihon Kohden 2008
FeaturesAC and battery power (Ni-MH) operation 5.7 inch color
TFT-LCD Synchronized cardioversion AED (Automated External
Defibrillation) 50 mm width thermal array recorder External pacing
(TEC-5531) External paddles, internal paddles disposable pads
Options: 5 lead-ECG, SpO2, etCO2 or AUX out, TEC-5500: Voice
prompt/Sound recording in SD card2/36
Board/Unit Location
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Block Diagram - General
Patient ECG signal Peripheral controls Defibrillation energy
path
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Block Diagram - OverallMain key board
CPU board
Mother board
Key board
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Parameters Signal Processing
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ECG Signal ProcessingECG signals are input through either the
Electrodes or Paddles. Through ECG connection cordPatient ECG
signal from ECG electrodes
LEAD ECG floating circuit
ECG signals from the electrodes are input through the LEAD ECG
floating circuit. ECG signals are selected in the ECG MPX as lead
signals. The lead signal (Lead I, II, III, aVR, aVL, aVF to V) is
selected by the user. This lead information is sent from the Main
CPU to the Sub CPU.
ECG MPXSelected Lead ECG signal
The ECG Amplifier circuit consists of the following.i)
Differential amplifiers - This circuit amplifies differential
(biological) signals and reduces common mode signals (AC
interference)High-cut and Low-cut filter - The frequency response
is from 0.05 to 150 Hz for input through ECG connection cable 0.05
to 30 Hz when High-cut filter (System Maintenance screen
Configuration) and AC filter are set to ON Notch filter - To check
if noise is caused by AC interference Signal generator To generate
test and calibration waveforms
ECG Amplifier TC, Reset, AC Filter, Test wave, Cal
ii)
iii)
Analog ECG signals
iv)
SUB CPU
The Sub-CPU receives the signals from the ECG Amplifier. The
Sub-CPU converts the analog ECG data to digital data and sends it
to Main CPU as parallel data through the Main FPGA. The QRS
detection, Heart rate count, VF analysis for AED are performed by
the Main CPU.
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ECG Signal ProcessingThrough PaddlePatient ECG signal from
Paddle
Paddle ECG floating circuit
ECG signals from the paddles are input through the Paddle ECG
floating circuit.
The lead signal in this case is fixed to the paddle lead (Apex
to Sternum) . ECG MPXPaddle Lead ECG
The Amplifier circuit consists of the following.i)
ECG Amplifier TC, Reset, AC Filter, Test wave, Caliii) iv)
ii)
Differential amplifiers This circuit only amplifies potential
difference between two electrode. High-cut and Low-cut filter The
frequency response is from 0.5 to 20Hz for input through external
paddle Notch filter To check if noise is caused by AC interference
Signal generator To generate test and calibration waveforms
Analog ECG signal
SUB CPU
The Sub-CPU receives the signals from the ECG Amplifier. The
Sub-CPU converts the analog ECG data to digital data and sends it
to Main CPU as parallel data through the Main FPGA. The QRS
detection, Heart rate count, VF analysis for AED are performed by
the Main CPU.
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SpO2 Signal ProcessingSpO2 signals are input through the SpO2
probes
SpO2SpO2 signal from patient
probe/adapter
The Red and Infrared signals are detected through the detector
and are sent to the DSI Interface Unit/DSI/AUX Out Interface unit
as serial data
Serial data
DSI Interface Unit /DSI/AUX Out Interface UnitSerial data
Sends the serial data (SpO2 value, PR (Pulse Rate) and pulse
waveform data) to the FPGA.
FPGA
Converts the received serial data to parallel data and sends it
Main CPU.
MAIN CPU
Displays the SpO2 value, PR and pulse waveform data.
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CO2 Signal ProcessingCO2 signals are input through the CO2
sensorCO2CO2 signal from patient
Sensor kitSerial data
The Infrared signals are detected through the detector and are
sent to the DSI Interface Unit/DSI/AUX Out Interface Unit as serial
data
DSI Interface Unit /DSI/AUX Out Interface UnitSerial data
Sends the serial data (etCO2 value, PR and CO2 waveform data) to
the FPGA.
FPGA
Converts the received serial data to parallel data and sends it
to the MAIN CPU.
MAIN CPU
Displays the etCO2 value, PR and CO2 waveform data.
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Status Control ProcessStatus signals are fed back to the Main
CPU via the Main input port The status are then output to the LEDs
through the Main output port
Legends : Input signals Output signals
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Leads Off DetectorPatient ECG signal from Electrodes
Lead ECGfloating circuit
ECG signals from patient are fed through the ECG electrodes to
the Lead ECG floating circuit
Leads off detector
This circuit continuously detects if any ECG leads have come
off
Leads Detection status
Main Input port
The ECG leads status are sent to the Main Input port
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Paddle Contact IndicatorPatient ECG signal from Paddle
Paddle ECGfloating circuit
ECG signals from patient are fed through the Paddles electrode
to the Lead ECG floating circuit
Paddle contactDetector When both Discharge buttons are not
pressed, the paddles electrodes pick up the patients physiological
signal. From this picked up signal, Main Input the
electrode-to-skin contact resistance can be determined
port to Main CPU
Main Output portPaddle contact status
The paddle contact status is sent from Main Output port to the
LED status on the External paddle
LED status onExternal Paddle
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Peripheral Control ProcessPeripherals are controlled from the
FPGA. These include LCD unit, Audio and Recorder controls
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LCD control process
Main CPU
Sends the waveform data and measurement data to the FPGA.
FPGA
Converts the data to display data and sends it to the LCD.
RGB output to the LCD unit
LCD Unit
Displays the display data on LCD.
LCD Inverter
Converts the DC power to AC power to light the LCD
backlight.
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Audio control processMain CPU Requests the voice prompt or sound
to to the FPGA.
FPGA
Sends the sound signal to the Voice CPU.
Voice CPU
Sends the voice data to the Sound Amplifier as an analog
signal.
Sound Amplifier
Amplifies the voice signal or sound signal and sends it to the
Speaker.
Speaker
Outputs the voice signal or sound signal.
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Recorder control processMain CPU Sends the waveform data or
measurement data to the FPGA.
FPGA
Converts the waveform data and measurement data to the recording
data and sends to the thermal head. Generates the motor driving
signal (pulse) for the Motor Driver.
Motor Driver
Drives the Stepping Motor.
Stepping Motor
Fees the recording paper. A stepping motor rotates by an exactly
angle with a pulse from the motor driver IC.
Thermal head
Records the recording data.
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Defibrillation Control Process
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HV Circuit Charging/Discharging
External relay Opens and closes the connection between the
Paddle ECG input circuit and pacing output circuit, and the HV
charging circuit. When the Charge button is pressed, the set of
relay switches closes to the connection between the DC/DC converter
and HV capacitor for charging. When the Discharge buttons are
pressed simultaneously, the set of relay switches closes the
connection between the HV capacitor and Patient
Step-up transformer - DC/DC converter that provides the voltage
charge the HV capacitor. This block receives the start charging
signal from the Sub CPU, and outputs the control signal to the
switching FET that switches on or off the HV stepup transformer
Internal relay Used to disarm the capacitor when a fault is
detected, the capacitor is in charged condition for more than 40
seconds (default setting, can be changed in Charge hold time), or
when the rotary switch is set to Disarm. In this situation, the
internal relay closes the circuit to discharge the stored energy of
the HV capacitor
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High Voltage CircuitThe energy charging is controlled by the HV
circuit. It has the following functions.1. Generates a high voltage
to charge the energy in the high voltage capacitor 2. Controls
energy charging and discharging 3. HV Fail Safe Circuit- Monitors
the voltage of the HV Capacitor comparing with the selected energy
to avoid overcharging. - Attenuates the voltage of the HV
Capacitor. - Outputs the voltage reading to the Main CPU via the
Main PLD. Main CPU in turn halts the HV process via the HV Fail
Safe Circuit.
4. Calculates TTR (Transthoracic Resistance) from integration of
discharge current change - The change of magnetic flux in the
primary winding induces the voltage in thepickup coil (secondary
winding). - The voltage at the secondary winding is integrated. Sub
CPU calculates the TTR and delivered energy according to the
integrated value.
ActiBiphasic Innovation - TEC-5500
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High-voltage Capacitor
Protection from sudden failure of capacitor by segmentation of
dielectrics and thin lead connection of cell capacitors
Dielectrics
Thin Lead
Electrode (metal)
4,530 small cells21/36
Damage protection by self cutoff
Screens for Maintenance
Basic ChecksSetup
Report Setup - Defibrillation Report/Event List Report Battery
Test HV Capacitor Test Recorder Test Report History (Instrumnt
Report) Check Hardware22/36
System Setup
System Maintenance
Battery Test Screen
Press the Reset key to delete the previous battery test history
when the battery is replaced.Test result Description Action
Battery OK XXX% (Capacity XXX%:100%, 80% 70%) Battery WEAK XXX%
Capacity XXX%: 60%, 50%)
Capacity is enough.
Battery operation is available anytime. When the defibrillator
is not used, always do trickle charging. Battery operation is
available only when the battery is fully charged. The time to
replace the battery is coming soon. It is recommended that the
battery be replaced with a new one. Only AC operation is available.
Immediately replace the battery with a new one.
Capacity has decreased under 70%.
Replace battery XXX% (Capacity XXX%: 40%, 0%)
Capacity has decreased under 50%.
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TroubleshootingThe following repots are useful for
troubleshooting.
Defibrillation report (Setup screen Report Setup Defib) Setting
and waveforms when discharge operation is performed. Event list
report (Setup screen Report Setup Event List) Instrument operation
history Instrument report (System Setup screen Report History
Instrument report) Error code, battery test and HV capacitor test
result We can know what error occurred and what the operator was
doing from the reports.24/36
Case StudyPower on problem
Problem: The defibrillator does not turn on when the Energy/Mode
Select control (rotary knob) is set to the position other than the
OFF position.
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Power on problem
Cause: When the AC power cord is connected to AC outlet on the
wall, if the AC power lamp and battery charge lamp are lit, the
power unit is operative. Check if you can hear the click sound by
pressing any of the key switches on the front panel. There is the
click sound: LCD or LCD inverter is faulty. No click sound: Faulty
power circuit on the mother board. Solution: Replace the faulty
board or unit.26/36
Battery Test Stops
Problem: Battery test stops. Battery was too hot.
Normal example
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Battery Charge Time-out
Cause: The battery temperature exceeds 60C. When the battery
temperature exceeds 60C, the battery test stops and the battery
check result appears on the screen. Then, the message appears to
prompt you to fully charge the battery by tuning the Energy/Mode
select control to OFF position. This is normal operation.
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A512 HV Error
Problem: A512 error is displayed and energy cannot be charged.
The sub CPU monitors the output of the HV unit. When the output of
HV unit does not match the control signal, this error is displayed.
Block diagram Error code
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A512 HV Error
Possible Causes:Connection cable between Biphasic HV unit and HV
capacitor. Connection cable between Biphasic HV unit and CPU board.
HV capacitor Biphasic HV unit
Solution: Replace any of the above failed parts.
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Energy Discharge Test Failure 1
Problem 1: When discharge test is performed in the paddle
holder, the Test fail message appears. Problem 2: When the paddle
is placed in the paddle holder, paddle contact LED turns red.
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Energy Discharge Test Failure 1
Cause:Resistance of the resistor in the Test Load Board is
changed or the resistor is damaged due to test discharge.
Solution:Replace resistors. Test Load Photo
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Energy Discharge Test Failure 2
Cause: Test electrode plate is rusted. Solution: Clean or
replace the plate.
Rusted paddle electrode due to remaining paste
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Out of Paper Error
Problem:The Out of paper message appears even when paper is
loaded normally and magazine door is tightly closed.
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Out of Paper Error
Cause: Faulty open/close detection sensor of the paper magazine
door
Solution: Replace the micro-switch (448053 AV404461).
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