Yes, before the TEC-7700 series defibrillators were
allowed for sales in Japan, Nihon Kohden had incredibly gone on to launch another
Acti-Biphasic TEC-5500 series defibrillators for export sales in August 2004.
Why was the need to launch the TEC-5500 series when it was crystal clear the TEC-7700 series
application with Regulatory Authority would take time for
approval? This made the urgent launch of TEC-5500 highly suspicious and illogical.
We only learned later that for some unknown reasons, the manufacturer had surreptitiously decided not to continue with the original waveform! |
This was the series later found to have
Acti-Biphasic waveform flipped vertically upside down from that of the TEC-7700 series and it was
happening right before Japan MHLW granted approval for the TEC-7700 series.
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CardioLife
TEC-5500K series started to be exported from August 2004, when Japan
MHLW had not approved the sales of CardioLife TEC-7700 series |
The Timeline
|
Export
of CardioLife TEC-5500K series started in August 2004, more than one
year before Japan MHLW actually approved the TEC-7700 series |
The reason CardioLife TEC-5500 series defibrillators were quickly approved for sales in Japan was based on the principle of
declared substantial equivalence with the newly-approved TEC-7700 series |
Current TEC-5600 series, TEC-8300 series output waveform are similar to TEC-5500 series defibrillators, how about submission documents for foreign regulatory approval
which are all based on the TEC-7700K series? We also could not help wondering if the domestic and export versions of the Acti-Biphasic shock energy are currently identical?
A
prestigious University Hospital in Taiwan was the first to find the polarity of TEC-5500K output
waveform inverted from the original shown on the manual
In the image below,
we were greatly puzzled to learn of an adverse report from a competent Biomedical
Engineering Team in National Taiwan University Hospital (Taipei City) that the polarity of measured
waveform from two tested CardioLife TEC-5500K series defibrillators were inverted
(i.e. opposite in polarity) from what the manuals had described. The tests were a result of investigation after a serious performance failure incident. The investigation raised many questions and only the IEC60601-2-2:2002 electrical safety compliance was put to rest.
There
was no doubt since they had tested both models TEC-5521K (S/N 09xx4) and
TEC-5531K (S/N 05xx4) to arrive at the same conclusion; the suffix K is
for export models using English language as interface (for example the suffix J is for Japan domestic models),
indicating more than 9000 units of TEC-5521K and more than 5000 units of TEC-5531K had been produced before the two tested units respectively.
Detailed
comparison was also done with defibrillators from another manufacturer
(Philips) using the same testing equipment (Fluke Impulse 7000DP with 7010 Selectable Load) and the polarity was consistent with the manual descriptions of Philips.
This
was an input from professionals that the Acti-Biphasic output waveform
from the CardioLife TEC-5500K series defibrillators starts with a
negative polarity and ends with a positive polarity; it is the exact
opposite of what were shown on the operator and service manuals. As far
as we know, there is no known manufacturer with a biphasic waveform that
starts with a negative polarity, NIHON KOHDEN is unique in this
approach but there is no clinical research done to validate its use on
patients!
The
next image showed the illustration from another distributor (Thailand)
sending in a Nihon Kohden defibrillator analyzer AX-103VK (OEM device)
for repair.
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The AX-103VK defibrillator analyzer has a discharge waveform output on the rear panel for oscilloscope display |
The
analyzer was concluded by their technical staff to be defective because
the display on the oscilloscope was inverted; the analyzer was of
course working fine. Said Thailand distributor is top distributor who had sold the highest number of CardioLife TEC-7700K series defibrillators in the world and knew too well what is the "Correct Graph", confident of the defect conclusion. The
conclusion turned out to be erroneous because the service manual wrongly informed them a TEC-5500K series
defibrillator has similar output as a TEC-7700K series defibrillator.
Guess what? someone has the audacity to ask the distributor staff to "just flip the APEX/ STERNUM connections"!
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Changing "Evaluation machine" from a TEC-7700K defibrillator to a TEC-5500K defibrillator
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Does the inverted waveform only apply to production batches meant for export? |
What could be the reason for the sudden change of mind? Was it due to copyright pressure? Does the inverted waveform only apply to export models since Japan MHLW solely approved the TEC-7700 series version?
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The
declared current flow direction of NIHON KOHDEN Acti-Biphasic shock
energy is the one on the left while we discovered actual biphasic flow
is the one shown on the right
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The clinical trial data cited to regulatory authorities is based on the
TEC-7700 series defibrillators for all Acti-Biphasic defibrillators,
including the TEC-5500 series, TEC-8300 series and latest TEC-5600 series.
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There were only some clinical data from TEC-7700 series defibrillators
|
When the discharge waveform is flipped upside down, the TEC-7700 series clinical data cited becomes irrelevant
It is serious matter if the actual output waveform is different from the
manual descriptions, as well as any inaccurate description documents
submitted together with operator/ service manuals to regulatory authorities.
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Change in current direction demands fresh clinical trial and validation |
As
a responsible company with a Corporate Social Responsibility
(CSR) policy in place, NIHON KOHDEN must act fast and should have by now
long recalled all Acti-Biphasic defibrillators from the market.
The Acti-Biphasic defibrillation output of AED-2100 series is seen avoiding the original waveform in a different way
The
AED-2100K defibrillator was announced for export from October 2009 (Signal SE.C-19), it retained many features and appearance of the Cardiac Science OEM models except the proprietary output waveform.
CardioLife
AED-2100K is exported to many parts of the world, albeit in small
quantity; exception seems to be Taiwan and South Korea. It is not
exported to the US market where it does not have US FDA clearance for
the use of the Acti-Biphasic output waveform.
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CardioLife AED-2100K seen distributed in Taiwan |
The
model AED-2100K did not have a screen display, which a later model was
added in January 2012 with this feature. A more compact and lower-cost AED-3100 has now replaced AED-2100 series with some small changes.
The
defibrillation success stories of AED-9200 and AED-9231 in Japan are
routinely cited to sell later models but this is a misrepresentation |
The
newer
CardioLife AED-1200K series and AED-3100 are not authorized to use the
STAR biphasic waveform and had nothing to do with earlier OEM models in
terms of defibrillation technology.
The
defibrillation success stories of AED-9200 and AED-9231 in Japan are
routinely cited to sell later models but this is a misrepresentation
that should be dropped immediately; the success stories cannot be linked
to the latest AED-3100 defibrillator! Unlike the STAR biphasic defibrillation output, the Acti-Biphasic defibrillation output employed by CardioLife AED-3100 defibrillator does not meet US FDA approval for use in the USA market.
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AED images from Japan |
How can a user view the "Acti-Biphasic" output waveform from a defibrillator? |
The QP-551VK defibrillator report viewer software can be used on a PC or laptop to review event recorded by any CardioLife defibrillator, including the AED-2100K defibrillator.
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The defibrillator report viewer can be used to review events recorded by a NIHON KOHDEN defibrillator
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Below
shows a review screen of an AED-2100 event using the QP-551VK software; the event was recorded using a simulator with TTR
value of 49 ohm.
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Notice the output waveform of AED-2100 is the same as older TEC-2200K which discharges a monophasic output waveform |
The
output waveform of AED-2100 series (and AED-3100) are the same as the monophasic
defibrillator TEC-2200K series AED defibrillators released in May 1997 |
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The TEC-2200K series with its monophasic discharge waveform dated April 1995
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Be warned that a mono-phasic defibrillation must be able to deliver a 360J shock energy |
In the TEC-2200K series manual mode, the monophasic defibrillator energy storage has the following choices:
25J, 50J, 100J, 150J, 200J, 300J or 360J
When
arrhythmia requiring defibrillation is detected in the semi-automatic mode, the defibrillator will
automatically charge to the energy according to the following defibrillation sequence:
First Defibrillation: 200J
Second Defibrillation: 300J
Third Defibrillation: 360J
This is consistent with American Heart Association recommendation for monophasic defibrillator, which Nihon Kohden is allowed to sell in the US market.
And why are the operator/ service manuals not reflecting the shape we had observed? |
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Output waveform expected from AED-2100K shown on user manual |
We should pause and think about the seriousness of the points raised on the Acti-Biphasic defibrillation output.