Technical Seminar: Electrocardiograph (ECG) Ecg-K Ecg- K・ECG- K

 

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Technical Seminar  Electrocardiograph(ECG) ECG-9620K ECG-9620 K ECG-1250 ECG1250K K ECGECG-1350 1350K K ・

 

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Table of Contents 

NIHON KOHDEN Service Policy



Introduction of ECG-9620 ECG-9620K/ K/1250 1250K/ K/1350 1350K K

 

Block Diagram ECG Waveform Acquisition

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Two Approaches to Find the Trouble - How to Troubleshoo Troubleshoott 

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Maintenance Schedule

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Case Study – Study  – Hands-on Session

“You “Y oucan canget getused usedto tothe theinstrument instrumentthrough throughthis thissem seminar!!” inar!!”

 

 

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NIHON KOHDEN Service Policy • Our service policy is to replace the faulty unit, board, or damaged mechanical part with a new one. • We do not support component level repair of  the multi-layered units or boards.

Because… Because…  

 

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NIHON KOHDEN Service Policy ・

・

Impossible to repair multi-layered boards without special tools, high degree of repair  skills. Quality of the component level repair cannot be guaranteed for multi-layered boards.

 

Introduction – Introduction  – Latest ECGs

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ECG-1350 ECG1350K K

NIHON KOHDEN ECG

ECG-1250 ECG1250K K

ECG-1550K

ECG-9620 ECG9620K K

 

ECG-9620 9620K K Introduction - ECG-

>120 min battery operation! Just 2.7 kg!

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ECG-1250 1250K K Introduction - ECG-

Color 5.6 inch LCD! >60 min battery operation! Just 2.0 kg!

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ECG-1350 1350K K Introduction - ECG-

Color 5.6 inch LCD! Great 12 ch printing!

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Block Diagram - Composition

Control Board

ECG-9620 ECG9620K K

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Two primary boards inside    

Block Diagram - Composition

ECG-1250 ECG1250K/ K/1350 1350K K

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Two primary boards inside    

Block Diagram – Diagram  – ECGECG-9620 9620K K

Control Board

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Block Diagram – Diagram  – ECGECG-9620 9620K K

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Block Diagram – Diagram  – ECGECG-1250 1250K/ K/1350 1350K K

 

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Block Diagram – Diagram  – ECGECG-1250 1250K/ K/1350 1350K K

 

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ECG Waveform Acquisition Analog processing

 Amplifies analog   analog signals   signals

A/D conversion

Converts the signals into digital   digital

Digital processing

Filtering: Reduces artifact by computation

10010010 01110110 10110010     ・

・

ECG waveform acquisition flow: 1. Simultaneously acquires 12 12 lead ECG waveforms. waveforms. Lead signals I and II, V1 to V6 V6 are generated by differential amplifiers.  2. The lead signals are converted to digital signals. 3. Digital signals are filtered to reduce artifact with DSP. DSP. 4. Filtered digital signals are analyzed and and recorded.

Measurement and analysis

Recording

ECG-9620 ECG9620K/ K/1250 1250K/ K/1350 1350K K  

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Technologies Technolog ies for Analysis & Recording Conventionall Method With EMG filter: Conventiona Digitized

 AC filter  Drift filter 

EMG filter 

ECG analysis Recording

NIHON KOHDEN Method:

Digitized

 Averaging

ECG analysis

 AC filter  Drift filter  EMG

NIHON KOHDEN ECG can use the EMG filter (highcut filter) to record the ECG waveforms. However, this may cause ECG waveform distortion.  distortion.  For ECG analysis, The cardiograph averages the QRS dominant waveforms for each lead. This process is very effective to minimize minimi ze artifact on the waveform.

filter 

Recording

ECG-9620 ECG9620K/ K/1250 1250K/ K/1350 1350K K  

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Main Board

/Control Board

(ECG-1250 (ECG1250& &1350 1350K) K)



(ECG-9620 (ECG9620K) K)

Internal circuit protection  protection  The patient cable provides 20 M ohm or higher input impedance for each electrode to protect the internal circuit from excessive voltage caused by static energy or defibrillation discharge.



Lead I and II, and V1 to V6

Lead signals are generated by differential amplifiers. A dither signal (white noise) is added to the lead signals to improve low level signal distortion in A/D conversion. 

The signals are  converted to digital signals at the sampling rate A/Dlead conversion conversion  of 8000 samples per second for simultaneously processing 12 lead ECG waveforms. 

ECG-9620 ECG9620K/ K/1250 1250K/ K/1350 1350K K  

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Main Board

/Control Board

(ECG-1250 (ECG1250& &1350 1350K) K)



Heart rate calculation:  QRS is detected from leads II, V1 and V5. 



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(ECG-9620 (ECG9620K) K)

For the real time display, the heart rate is calculated every 2 seconds by averaging the latest six waveforms (5 R-R intervals). For the heart rate recorded on the ECG analysis result, the heart rate is calculated by the dominant waveforms for each lead by averaging the ECG waveforms for ECG analysis.

This filter reduces components High-cut filterthe (EMG filter):of 25 Hz, 35 Hz or higher signals such as EMG. Body movement noise can be reduced.

ECG-9620 ECG9620K/ K/1250 1250K/ K/1350 1350K K  

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Main Board

/Control Board

(ECG-1250 (ECG1250& &1350 1350K) K)



(ECG-9620 (ECG9620K) K)

FPGA 

Electrode detachment detection  Electrode detachment is detected when an overflow or  underflow of A/D conversion value appears in each lead.



Display Control

The LCD is controlled by a LCD controller in FPGA. 

CPU (Software) 

Created Lead III, aVR, aVL and aVF by calculation III = II – II – I aVR = - (I + II)/2 aVL = I - II/2 aVF = II - I/2

ECG-9620 ECG9620K/ K/1250 1250K/ K/1350 1350K K  

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Main Board

/Control Board

(ECG-1250 (ECG1250& &1350 1350K) K)

(ECG-9620 (ECG9620K) K)

ECG-9620 ECG9620K/ K/1250 1250K/ K/1350 1350K K  

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Main Board

(ECG-1250 (ECG1250& &1350 1350K) K)

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ECG-1250K/ K/1350 1350K) K)   A/D converter in the CPU (Only on ECG-1250 

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The 1ch of the converter detects the temperature of the thermal head and inside of the cardiograph.

The 2nd ch of the converter detects the battery voltage. The 3rd and 4th ch of the converter handle external input signals .

ECG-1250K/ K/1350 1350K) K)  Battery voltage detection (Only on ECG-1250

In battery operation, the battery voltage is displayed in 3 colors.   

Light in green: green: At least 15 minutes. Or more when fully charged. Light in yellow: yellow: Power will be lost soon. Blink in orange: orange: Power will be lost within a minute.

ECG-1250 ECG1250K/ K/1350 1350K K  

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Main Board

(ECG-1250 (ECG1250& &1350 1350K) K)



Thermal head temperature detection by CPU  CPU   If the surface of the thermal head temperature exceeds 70 degrees Celsius or higher ,the following error message appears and recording stops.

“Overheating,wait “Overheating, wait5 5minutes.”   (Only on ECG-1250 ECG-1250K/ K/1350 1350K) K)

ECG-1250 ECG1250K/ K/1350 1350K K  

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Power Board 

Power supply     

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12 V DC switching regulator  5 V DC linear regulator  3.3 V DC/DC regulator  24 V DC/DC regulator for stepping motor driver  (ECG-1350K only) 24 V DC/DC regulator for thermal head

Tuning off the several power supplies  supplies  Software shutdown: When the POWER key is pressed.



 Automatic power off : When there is is no key operation for 3 minutes in battery operation

ECG-1250 ECG1250K/ K/1350 1350K K  

Power board connector on main board CNJ055: ECG-1250K No.

Signal name

ECG-1250 ECG1250K/ K/1350 1350K K

CNJ051: ECG-1350K No.

Signal name

1

CHG_C (Battery charging LED Cathode)

1 to 3

24 V_MOT

2

ACLED (AC lamp ON signal)

4 to 6

5V

3

PSWON (Power key is pressed)

7 to 8

12 V

4

CHG_A (Battery charging LED Anode)

9 to 14

3.3 V

5

nAC/DC_DET (AC Power detection)

15 to 24

GND

6

nPOFF_OUT (Power off command from CPU)

25

 Not connected

7

MOTOR_ENB (Motor start)

26

GND

8

PWOVER (Power board overheat

27

nAC/DC_DET (AC Power detection)

9

GND

28

MOTOR_ENB (Motor start)

10

 Not connected

29

PSWON (Power key is pressed)

11 to 18

GND

30

PWOVER (Power board overheat)

19 to 21

3.3 V

31

CHG_C (Battery charging LED Cathode)

22

5V

32

nPOFF_OUT (Power off command from CPU)

23 to 24

12 V

33

ACLED (AC lamp ON signal)

25 to 28

24 V_TH

34

CHG_A (Battery charging LED Anode)

Battery connector on power board No.

Signal name

1 2

TO_BATT THERM

3

AGND

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CNJ411: CNJ41 1: Thermal head connector on main board No.

Signal name

1 to 3

 Not connected

4 5 to 9

5V AGND

10 to 13

VH

 

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Power Board

ECG-9620 ECG9620K K  

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Sometimes…   Sometimes… We might ask you to measure signals from parts on the boards. Please get ready to use a multi-meter anytime.

 

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Question to you When you get troubles on the ECG, how do you handle?

 

Two approaches approaches to find the trouble Automatic Approach

ECG

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Human Approach

 

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 Automatic Approach

ECG

 

ECG-9620 ECG9620K K

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System Error  (System Information) • During the startup, the ECG automatically checks the internal system.

• If failure is detected, system information and error history are printed out and all the operations are stopped.

• After  After printing the system information information and error history history,, the power of the ECG is automatically turned off.

 

ECG-9620 ECG9620K K System Error  (System Information)

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ECG-9620 ECG9620K K (System Information) System Error 

 

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ECG-9620 ECG9620K K (System Information) System Error 

 

ECG-1250 ECG1250K/ K/1350 1350K K System Error  (System Information) • During the startup, the ECG automatically checks the internal system.

• If failure is detected, all the keys and LEDs do not work.

•Turn off off the power once, and turn on the power again.

•The system information is printed out.

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ECG-1250 ECG1250K/ K/1350 1350K K System Error  (System Information)

 

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System Error  (System Information)

Report the error to NIHON KOHDEN!

 

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Human Approach

ECG

 

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Human Approach

• Take the following steps to find the trouble. Step1 Step1:: Check the block diagram Step2:: Use troubleshooting table Step2 Step3:: Try system test Step3

 

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How to Troubleshoot: Troubleshoot: Step1 Check the block diagram first. - Understand the overall architecture of the device.

 

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How to Troubleshoot: Troubleshoot: Step2 Use troubleshooting tables on service manual. - Major troubles are listed in the manuals.

 

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How to Troubleshoot: Troubleshoot: Step3 Try “System “SystemTest” Test” to understand the device condition.

What is “System Test” ?

 

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How to Troubleshoot: Troubleshoot: Step3 •  All NIHON KOHDEN KOHDEN ECGs have have a program called “System “SystemTest” Test” to diagnose the current condition of your device. • Try the “System “SystemTest” Test” to identify the possible causes of the problem.

Let’s try…  try… 

 

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How to Troubleshoot: Step3 But how ? 

To call up the “System Test Level 1”, press the POWER key while pressing the FEED/MARK key.

 

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How to Troubleshoot: Step3 But how ? 

To call up the “System Test Level 2”, press the POWER key while pressing the FEED/MARK key & AUTO/MANUAL key.

 

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How to Troubleshoot: Step3             

Demonstration waveform Recorder test Thermal head test Key test Memory test LCD/LED test Electrode input test ECG input circuit test USB test Initialize system settings Display internal information Display model information … 

 

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How to Troubleshoot: Step3         

Demonstration Recorder  Key Memory LCD/LED test “Inputunit” “Input unit”   “Calibration”   “Calibration” Communication … 

 

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Maintenance Schedule • Periodic replacement is required. - Battery pack - LCD - Built-in lithium battery on control/main board - Thermal head - Feeding motor 

ECG-9620 ECG9620K/ K/1250 1250K/ K/1350 1350K K  

ECG-9620 ECG9620K K

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Maintenance Schedule 

Battery pack: 



After one year operation

If battery operation time is less than 30 minutes, it is time to change.

LCD:

After 15,000 hours(625 days)

The above time is when the initial screen brightness is reduced to half.



Built-in lithium battery:

After 7 years

When the battery power is low, the time is not accurately recorded and the system setup restores it to the default factory settings.

 

ECG-1250 ECG1250K/ K/1350 1350K K

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Maintenance Schedule 

Battery pack:  



After one year or when battery operation time is reduced to half 

ECG-1250K: More than 60 minutes continuous recording ECG-1350K: More than 30 minutes continuous recording

LCD:

After 75,000 hours(3,125 days)

The above time is when the initial screen brightness is reduced to half. 

Built-in lithium battery:

After 6 years

When the battery power is low, the time is not accurately recorded and the system setup restores it to the default factory settings.

 

ECG-9620 ECG9620K K

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Maintenance Schedule 

Thermal head: After 50 km continuous recording When the thermal head wears out, the recording density gets weaker due to missing dots.

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Feeding motor: After 1,000 h(417 days) continuous operation When the motor wears out, the recording paper may feed unevenly or at unstable speed.

 

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ECG-1250 ECG1250K/ K/1350 1350K K Maintenance Schedule 

Thermal head: After 30 km continuous continuous recording When the thermal head wears out, the recording density gets weaker due to missing dots.



Feeding motor: When the motor wears out, the recording paper may feed unevenly or at unstable speed.  

ECG-1250K: After 1,000 hours continuous recording ECG-1350K: After 3,000 hours continuous recording

 

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Case Study – Study  – Hands on Session

 

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Trouble: “V6 “V 6 waveform waveformis isweaker.” weaker.”   

Trouble:  Trouble:   Printed waveforms of I, II, III, aVR, aVF, aVL, V1 to V5 are OK. However, only V6 is weaker signal amplitude on the paper.

H o w c a n y o u i d e n t i fy fy t h e c a u s e ?  

 

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Trouble: “V6 “V 6 waveform waveformis isweaker.” weaker.”   

Possible - Breaking Causes: of the cable(disconnection) might be the cause? - Something is wrong with V6 channel on the A/D converter? - Signal is coming but not amplified correctly?

 

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Troubleshooting



Demonstration waveform Recorder test Key test Memory test LCD/LED test

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“Electrode input test”  

   

    

“ECG input circuit test”   USB test Initialize system settings Display internal information Display model information



… 

 

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Troubleshooting   

Demonstration Recorder  Key

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Memory LCD/LED test

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“Input unit”  

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

“Calibration”    Communication



… 



 

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Please…   Please… Sometimes,we Sometimes, wereceive receivetrouble troublereports reportswhich whichonly onlysay say“Broken”… “Broken”…

 

How can we identify the cause without information?

 

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Please…   Please… Describe the situation of the trouble as much as possible in

“ServiceRequest “Service RequestForm”!!! Form”!!!  

 

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For distributo distributors rs We recommend you to check the following distributor Web.

http://www.nihonkohden.com/distributors/me/    

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Questions?