CardioLife TEC-5600 series defibrillators from NIHON KOHDEN

Category: 日本光電 Cap-ONE mainstream etCO2 semi-quantitative measurement, its inappropriate use for continuous waveform display and the vulnerability of the compact CO2 sensors. CardioLife TEC-7700K series, TEC-5500K series, TEC-5600 series defibrillators and ActiBiphasic output waveform.




 
There are four basic models of the CardioLife TEC-5600 series defibrillators and they are:
 
1. CardioLife TEC-5601 defibrillator
2. CardioLife TEC-5611 defibrillator
3. CardioLife TEC-5621 defibrillator
4. CardioLife TEC-5631 defibrillator
 
It is incomprehensible why the Pacing Unit cannot be offered as an optional item, that it must be assembled in the factory before delivery when other manufacturers can do it. As seen in below table, there are four rigid models to choose from. This is a lower range than the CardioLife TEC-8300K series defibrillators.

CardioLife TEC-5600 series comparison table
 
 
 
It means high inventory cost for distributors and dealers trying to sell the defibrillators!
 
The rigid models implies the lack of designing skills and a burden to users; it is impossible to upgrade a model in the field and a customer must buy a new model if such a need arises.
 
Which of the four models should you keep stock when your competitors only need to keep one?

 
 
There is an optional connection panel with SpO2 and mainstream CO2 socket for all models

The use of a new type yellow connector socket for mainstream CO2 is meaningless
 
In the picture below, it can be seen the connector socket for the mainstream CO2 kit set is different from the previous model, necessitating a new set of accessory even though the transducer is the same old one.

Note the yellow connector socket is an isolated MULTI socket because there is no multi-parameter unit in the TEC-5600 series defibrillators. In other words, it is not a MULTI socket.
 
A CardioLife TEC-5600 defibrillator and its side connectors
 
 
For those who already had bought the mainstream CO2 sensor kit for TEC-5500 series, this is just additional expenditure with no new benefit. The change to using a yellow MULTI socket has negative captured value for such loyal customers.
 
The P903 on the left is for TEC-5600 series while the P906 on the right is for TEC-5500 series. The two are identical except for the connector plug.
 
The CardioLife TEC-5600 series defibrillators have no reason to use a new type socket different from that of the TEC-5500 series.
 
 

WATCH OUT the dangerous use of semi-quantitative estimation data for uncertain measurements and concurrently displaying a flawed CO2 waveform
 
Nihon Kohden lacks sidestream CO2 sampling expertise and buys OEM units to offer them as expensive standalone. The AG-400 CO2 unit as shown, for example, is technology from Oridion Medical. For monitoring such as post-surgery recovery, integration of the sidestream CO2 into the monitor is a mandatory requirement because an external unit requires additional power socket besides necessitating the use of a trolley; for some unknown reason, Nihon Kohden monitors are not known to have sidestream CO2 unit integrated.
 
The inability to integrate the sidestream CO2 unit into the patient monitor main unit


Nihon Kohden solution was to offer miniaturized mainstream cap-ONE TG-920P CO2 sensor kit (order code P907) that can be used on non-intubated patients.
 
The cap-ONE TG-920P CO2 sensor kit (order code P907) has very small sensors because semi-quantitative measurement is adopted, the method is not commonly seen and many are not alerted to the risk of using data from semi-quantitative etCO2 kit sets for critical measurements and true CO2 waveform display.
 

Nihon Kohden cap-ONE P907 (TG-920P) mainstream CO2 sensor kit

 
Shown below is another TG-900P etCO2 kit set (order code P903) that makes semi-quantitative CO2 measurements; the TG-901T3 kit set (order code P906) is the same thing using a different connection plug. The medical devices from same manufacturer that uses semi-quantitative etCO2 kit sets for patient CO2 waveform monitoring have Life Scope patient monitors, Vismo patient monitors, Cap-STAT OLG-2800, CardioLife defibrillators and Neurofax EEG machines etc.
 
Nihon Kohden semi-quantitative etCO2 kit sets
 

An interesting question: Can users accept estimated measurements for patient monitoring?
    
To save costs, the semi-quantitative kit sets do not make measurement during the inspiration phase, the measurement duty cycle is as shown. This means semi-quantitative CO2 measurements are not made continuously.

Semi-quantitative means there is a duty cycle, and measurement is not continuous
 

Semi-quantitative measurement is also of low-accuracy type, performed using one IR detector instead of the usual two to save cost. This is reflected in the measurement tolerance.
 
Contrasting, quantitative measurement delivers high accuracy for critical care. To ensure the necessary high accuracy, quantitative measurement employed two IR detectors for simultaneous CO2 measurements at different wavelength for results comparison. CO2 measurements are also being made continuously.
 
Quantitative measurement employs two detectors to make continuous measurement at different wave-lengths to compare readings for high accuracy

 
NIHON KOHDEN specification for TG-901T CO2 sensor kit shows even the specified low accuracy of CO2 measurement using semi-quantitative method no longer holds true once CO2 is present during the inspiration phase.

This is because actual CO2 value will be more.


As seen from the duty cycle, there is no measurement being made during the inspiration phase; how do the users know specified measurement accuracy is valid?
  
Measurements are invalid when CO2 is present during inspiration, but CO2 is not measured during this period; can you have confidence in the measurements?

 
It should be clear each semi-quantitative CO2 measurement is only an estimation since its accuracy is rendered uncertain by the inability to confirm if CO2 is present during the inspiration phase. The specified measurement tolerance therefore has no meaning for the users!
 
The users are also not alerted on screen there is no CO2 measurement being made during the inspiration phase, and unknowingly made to take an unnecessary risk.
 

Semi-quantitative methodology means cost-effective estimations and the design cannot be used in a general way, only on a selective basis with known risks
 
 
For example, semi-quantitative methodology can be used as a simple estimation tool for obtaining the numerical value of End-tidal Carbon Dioxide level (etCO2).
 
Below picture shows the semi-quantitative method in the way it was intended for, estimating only the etCO2 numerical value for the purpose of airway tube placement confirmation. It is not for continuous waveform display.

A hand-held semi-quantitative etCO2 estimation tool (with SpO2) for airway tube placement confirmation

 
 
How is it feasible to display a true continuous CO2 waveform when the semi-quantitative measurement kits do not have the ability to make continuous measurements?
 
 
NIHON KOHDEN also allows data from semi-quantitative measurements to be displayed on screen with the non-measurement period reset to zero level. The insistence to display a continuous waveform using discontinuous measurement data from semi-quantitative mainstream CO2 estimation kits is unacceptable; the manufacturer is just subjecting the monitored patients and users to dangerous misinterpretation risks.
 
A zero CO2 reading on the waveform means zero measured value. No measurement can only mean a defective sensor, not by design!

Note the etCO2 value shown is also not alerted as estimated etCO2 only.
 
A flawed CO2 waveform with non-measurement intervals reflected as zero measured CO2 value


As seen from the two true CO2 traces below, expiratory upstrokes do not always start from zero CO2 level!
 
Quantitative measurements confirming expiratory upstrokes do not always start from zero CO2 level

  
Check the latest updated table to make sure you only use quantitative method for critical measurements and true CO2 waveform display on screen.
 
Use only quantitative method for waveform display; the quantitative TG-950P (P905) shown here was already discontinued.
 
 

How about fully-quantitative type miniaturized mainstream CO2 sensor?
  
The TG-907P CO2 Sensor kit (order code P909) shown in above table is using quantitative method as declared. This sensor was designed for non-intubated adult CO2 monitoring, as well as neonatal CO2 monitoring. In short, Nihon Kohden is trying not to rely on others for sidestream CO2 sampling expertise.
 
The miniaturized CO2 sensor is easily broken by the bigger and stronger adapter
 
 
In addition to the dead space problem, they had not foreseen miniaturized mainstream CO2 sensors could be easily broken by the disposable adapters. This happened because the disposable adapters are now relatively bigger and stronger!
These are common defects of a TG-970P CO2 sensor kit (P909). The design is impractical.
 

Confirmation that the fragile miniaturized CO2 sensor is of poor design, and easily broken
 
 
Key point is, it does not last



CardioLife TEC-5600 series defibrillators are described as using the Acti-Biphasic defibrillation shock energy

From the operating and service manuals of CardioLife Acti-Biphasic defibrillators, we know the Acti-Biphasic waveform looks like what is shown in below picture.

THE DECLARED WAVEFORM

Declared characteristics of the Acti-Biphasic waveform


The basic concept of a bi-phasic shock energy is to add a negative follow-up phase to the conventional mono-phasic shock to achieve the same defibrillation result using lesser energy
 
 

 
 
The characteristics of NIHON KOHDEN Acti-Biphasic defibrillation can be summarized as:
 
1. First (Launch) Phase
The Acti-Biphasic waveform is seen as operating in an open loop during the first phase (period).
 
- It is a positive truncated exponential pulse with a duration depending on the patient impedance.
- It is of a longer duration than the second period.
 
 
2. Second (Follow-up) Phase
The Acti-Biphasic waveform operates in a closed loop during the second phase. In a closed loop the duration of the width can be deliberately set to a specific duration.
 
- This phase is shorter in duration and of negative polarity.
- The duration in this phase is fixed to a constant 3.4ms duration regardless of patient impedance. How was
the optimal duration of 3.4ms arrived at? It is also not clear how was the maximum energy of 270 Joules concluded?
 
Note the first phase (period) is positive and a wider pulse than the second phase


 
The first to use the Acti-Biphasic waveform were the TEC-7700 series defibrillators
 
 
The first Acti-Biphasic defibrillators

 
 
Output of CardioLife TEC-7700K series is consistent with declared waveform
 

The output waveform of the CardioLife TEC-7700K series on a recorder is as shown below. The recording correctly shows the first phase is a positive pulse.
 

The recording shows the voltage first swings to the top (positive saturation), then to negative saturation after some time; this is fully consistent with the official description of the Acti-Biphasic waveform.
 
Output of CardioLife TEC-7700K series is consistent with the declared description
  

How can we know if the Acti-Biphasic defibrillation shock actually works?
 
The margin of error is high for data from a small 75 investigated cases
 
There is no white paper available. The Acti-Biphasic defibrillators were hurriedly launched (for export) before completion of proper clinical validation and the small sample size of seventy five investigated cases meant a high margin of error; we cannot be sure the Acti-Biphasic defibrillation shock works on patients! The clinical data and methodology fell short of US FDA guide for safety and effectiveness, and Nihon Kohden could have engaged a consultant if they had respected the validation process. The Acti-Biphasic defibrillation shock cannot meet the requirements to be allowed for sales in the US market; note the US FDA 510(K) process could not be used to clear the product since mono-phasic defibrillators are not predicate devices in the market. The often mentioned American Heart Association recommendations are therefore meaningless to Acti-Biphasic defibrillators.

Outside of the US market, we must ask what is the point of buying such critical treatment devices and placing them on standby to save lives? It is so unfair to the patients needing immediate treatment in a life-threatening situation!
 

Biphasic Defibrillation Was In Fact A Game Changer for NIHON KOHDEN

In May 1997 Nihon Kohden released a new defibrillator with a semi-automatic AED mode for export using mono-phasic defibrillation. The details of this TEC-2200K series can be found in the 1997 Product Guide.

The monophasic CardioLife TEC-2200K series was launched for export in May 1997

This was a mono-phasic model using the non-proprietary Edmark single-phase pulse as illustrated and the use of rechargeable battery for energy made it very inconvenient for public use.

Edwark, Single Phase Pulse defibrillation waveform used by monophasic CardioLife TEC-2200K series in 1997

 
Just a few months after the TEC-2200 series was released, Hewlett Packard made announcement to acquire Heartstream Inc. in a stock-swap deal.

Heartstream ForeRunner

 
Biphasic defibrillation waveform was becoming the new preference as it allowed for a smaller and lighter defibrillator design; more importantly it uses less current and this means less damage defibrillation will do to the heart and skin. With the deal with Heartstream, HP acquired the Heartstream biphasic technology and also expanded the line of external defibrillators to include lay responders users. 
 
There was zero interest in the monophasic TEC-2200 series defibrillators offered by Nihon Kohden for ex-Japan market and the products had to be withdrawn from exporting.
 
Unlike the monophasic pulse, biphasic waveform comes in various forms; each type of shape is proprietary and cannot be copied freely. This means the energy envelopes of manufacturers in the market are all different. For some waveform, the manufacturers only recommend a maximum of 200 joules while another can recommend energy as high as 360 joules. Since there is practically no limits to the type of biphasic defibrillation waveform shape a manufacturer could come up with, all manufacturers must justify the use of their proprietary output waveform in some reasonable ways, preferably in accordance with US FDA guide for safety and effectiveness, which calls for clinical research validations.

The global shift to biphasic defibrillation technology was an unexpected market disruption for NIHON KOHDEN
 
 
After more than four years, NIHON KOHDEN remained unable to offer biphasic defibrillators and the company had no choice but to look for a suitable partner with biphasic technology for the Japanese domestic market when the demand for biphasic AEDs emerged. A strategic OEM distribution agreement was announced in January 2002 that Nihon Kohden would market Cardiac Science's line of AEDs under Nihon Kohden's trade name. This arrangement was a big success and many AED-9200 and AED-9231 were sold in Japan as reflected in annual reports and presentations.

NIHON KOHDEN CardioLife AED-9200 and AED-9231 were highlighted to have very good sales in FY2006 financial results presentation


The Cardiac Science STAR biphasic waveform (white paper) was validated by researchers at Cleveland Clinic and Cedars-Sinai Medical Center in accordance with US FDA guides for Safety and Effectiveness
 
It was however impossible for NIHON KOHDEN to get any success outside of Japan since distributors could buy the original models at cheaper prices, directly from Cardiac Science.
 
Instead of licensing the design from Cardiac Science, a few engineers in NIHON KOHDEN quietly started to experiment with biphasic defibrillation on pigs and came up with the proprietary Acti-Biphasic defibrillation shock. It was done with minimal external collaboration, the company thus had great difficulty securing the necessary clinical support to advance the number of investigated cases for proper clinical validation. To date, there is not a single clinical paper published on Acti-Biphasic defibrillation.
 
 
The Absence of Internal Safeguards
 
Before completion of proper clinical validation, the company was bold enough to go ahead with exporting the first newly-designed Acti-Biphasic defibrillators from November 2002, relying solely on reputation of being an existing supplier of mono-phasic defibrillators. The November 2002 export launch was three long years ahead of the date Japan MHLW officially approved its use for the domestic market.
 
The desperate action was taken in response to the rapid changing preference for biphasic defibrillators but the process totally overlooked the seriousness of mandatory successful clinical studies before marketing; the fact that Ministry of Health, Labour and Welfare (MHLW) had not yet approved the sales of TEC-7700 series defibrillators in Japan domestic market reflected the disturbing absence of internal safeguards in corporate conduct.
 
Up to this point, the company had never exported a new product before first launching it in Japan, showing the company was in complete disarray. It is not just loss of credibility in overseas markets as a leading defibrillator exporter from Japan but a ticking time bomb with important issues left unaddressed.
 
Before completion of proper clinical validation, Nihon Kohden began exporting proprietary Acti-Biphasic defibrillators in 2002

Japan Regulatory Authority three (3) long years to grant approval for the TEC-7700 series to be allowed for sales in Japan
 
 
This implied the application was turned down several times and serious doubts by the Regulatory Authority to grant its use. What prompted the decision to clear it after three years' wait is something we should know. By the time of receiving approval to sell in Japan, many CardioLife TEC-7700 series defibrillators were already exported.
 
NIHON KOHDEN was only able to announce the launch of TEC-7700 series defibrillators for sales in Japan market on December 1st, 2005.
 

When the TEC-7700 series defibrillators had not even obtained approval from MHLW to sell in Japan, a new defibrillator series was launched with undisclosed Acti-Biphasic waveform flipped vertically upside down
 

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, without showing any clinical studies done to support its use.
 
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.

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 distributor had sold the highest number of CardioLife TEC-7700K series defibrillators in the world and knew too well 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" to get the polarity right!
 
Changing "Evaluation machine" from a TEC-7700K defibrillator to a TEC-5500K defibrillator

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?
 
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

 
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.
 
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.
 
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 both the TEC-7700 series and TEC-5500 series 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.
 

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.
 
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.
 
The defibrillator report viewer can be used to review events recorded by a NIHON KOHDEN defibrillator

 
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.
 
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
 
The TEC-2200K series with its monophasic discharge waveform dated April 1995
 

 

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?
 

 
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.
 
 
 
The iNIBP box is not incorporated into main unit
 
Recently, we were told by the sales team an external iNIBP BOX has become available as an option to TEC-5600 series defibrillators, we have not seen such a design before and understand NIBP option should be integrated into the TEC-5600 main unit, this is just for meeting tender specification.
NIBP box option for TEC-5600 series



The paddle electrodes cannot be removed for sterilization
 
For sterilization, only the paddle electrodes need to be sterilized but we found the paddle electrodes cannot to be separated from the handles. This means the entire set as shown in the picture needs to be sterilized, it also implied there is no possibility of using disposable internal paddles.
 
Paddle electrodes cannot be separated from the handles for easy sterilization


 Connectivity
 
The TEC-5600 series offers manual Bluetooth communication to a Life Scope bedside monitor but the data just stays at the patient monitor without any onward connectivity concept (since this data cannot be seen at the Central Monitor or Gateway Server).
 
There is No LAN Capability and data transfer is only by using SD card. Defibrillation DATA MANAGEMENT software is also NOT AVAILABLE (*this is different from QP-551VK defibrillator report viewer software).