NIHON KOHDEN Life Scope PT (BSM-1700 Series) Transport Monitor (PART TWO)

 

 

 

Project Leader turned to Magic Show

to create a "modular" monitor

About 9 years after the launch of modular Life Scope S Bedside Station, a new Life Scope J (BSM-9101) purporting to be a modular bedside monitor was released for export.

 

Instead of working on a new measurement LAN as replacement, what we saw was a bizarre attempt to hide the missing technology platform essential for modular monitors. The Corporate Director spearheading the Life Scope J bedside monitor project was finally asked to step down from the board in 2006, and had to leave the company because of the seriousness of his incompetence (this happened before June 29, 2006).

 

From subsequent behavior, we know the manufacturer had already crossed the Rubicon, and there was no turning back on Life Scope J bedside monitor. The show just had to go on.

 

 

 

Life Scope J (BSM-9101) Bedside Monitor was finally released in June 2007 (after what was an unusually long delay, apparently as a result of new information curtailment policy and staying vague).

 

The processing main unit for Life Scope J bedside monitor was MU-910R, complete with an AY-920PA Input Unit similar in structure to the Saturn module. The Saturn module was housed in a module rack but AY-920PA Input Unit was not; it meant AY-920PA Input Unit does not need the yellow MULTI sockets.

 

 

The AY-920PA Input Unit follows the Saturn multi-parameter module, containing huge amount of hardware and continued to use an internal MPU with yellow flexible MULTI sockets. Unlike the Saturn module, the MPU of AY-920PA Input Unit has four yellow MULTI sockets instead of two.

 

Given the many hardware in the MPU, these four yellow MULTI sockets are not enough for use, but the manufacturer needed to show scalability, so an external AA-910P expansion box was offered to add four more physical sockets in the form of yellow MULTI sockets.

 

Since four yellow MULTI sockets are not enough, the AA-910P is not really an option but mandatory add-on; it would be cheaper to put all the MULTI sockets in the AY-920PA Input Unit.

 

 

The patient monitoring hardware inside the AY-920PA Input Unit are divided into a conventional block and an MPU block. The conventional block uses dedicated sockets and ordinary measurement cables while the MPU block makes use of Smart Cables with different parameter code for different hardware.

CONVENTIONAL BLOCK

- 2 channels of Temperature

- ECG

- SpO2

- NIBP

MPU BLOCK with four MULTI sockets

- 4 channels of IBP

- 6 channels of Temperature [3 MULTI sockets = 6-ch TEMP]

- Cardiac Output

- Thermistor-method Respiration

- FiO2

- [MULTI sockets as serial ports] Mainstream CO2, 2nd SpO2, BIS and NMT 

Note:

Other options such as Sidestream CO2, Multi-gas, EEG etc., are connected using external device interface, and not via MULTI sockets.

 

The configured Life Scope J Bedside Monitor was

masquerading as a modular monitor

The market communication was meticulously executed to portray Life Scope J (BSM-9101) bedside monitor as a modular monitor when the manufacturer is fully aware it is a true-blue configured monitor.

 

Life Scope J bedside monitor appears to be a modular monitor in this brochure image

In above brochure image, Life Scope J (on the right) shown using 12 yellow MULTI sockets was an impossible configuration because the interface between AY-920PA Input Unit and AA-910P expansion box is analog, the number of yellow sockets that can be added must be limited to four to avoid signal degradation. There was obvious intention to hide the fact only four MULTI sockets can be added using an external box. If 12 MULTI sockets are realized, it also means 12 channels of IBP; we should be reminded this is a patient monitor, not a diagnostic polygraph system.

 

This is a fake configuration, since AY-920PA Input Unit can only make use of one AA-910P expansion unit

In the next picture, you can see the AY-920PA Input Unit was designed in a shape that when combined with the recorder make Life Scope J (BSM-9101) bedside monitor (left) closely resemble the Life Scope S (BSS-9800) bedside station with a 8-slot module rack filled with modules (right).

 

Life Scope J bedside monitor was configured while Life Scope S bedside station was modular

In other words, Life Scope J bedside monitor was specially designed in appearance to look like an updated version of the Life Scope S bedside station.

The components making up a Life Scope J (BSM-9101) bedside monitor system is shown in next picture. The connection from MU-910R Main Unit to AY-920PA Input Unit is using the same connector type utilized by BSS-9800 bedside station; the old modular racks can therefore theoretically be daisy-chained to the AY-920A Input Unit.

Why offer the module rack that caused the failure of both Life Scope S bedside station and Life Scope M bedside monitor? The shown module rack and old modules are not merchantable since there was no longer any new module under development!

 

Life Scope J Bedside Monitor is not a bona fide modular monitor

 

The purpose of the questionable module racks and old modules were there for the powerful association of Life Scope J with modular monitors in the minds of the intended audience (including foreign employees). It was a powerful way to get the audience to nod their heads when making claim that the Life Scope J is a modular monitor. It was indeed a magic show.

Without offering a new network infrastructure for measurement data, connecting to the old module rack was just a pretense, and can no longer be feigned after they were discontinued without replacement.

 

There was no replacements for the discontinued module rack and modules

The Input Unit and expansion box of Life Scope J bedside monitor is only the equivalence of Life Scope S modular monitor's Saturn module and expansion boxes.

 

Life Scope J bedside monitor has to depend on external device interface for real expansion

Without a measurement LAN network, The Life Scope J (BSM-9101) Bedside Monitor main unit cannot reach any individual module, including the recorder. If you inspect the connection, the recorder can only be connected to the main unit by direct wire. External device interface on the AY-920PA Input Unit or on MU-910R Main Unit links to third party devices to add more monitoring parameters, in addition to using serial kit sets. It is just like any configured patient monitor in the market.

Life Scope TR Bedside Monitors

 

After Life Scope J monitor, NIHON KOHDEN went on to develop the Life Scope TR (BSM-6000 series) monitors; they are versions of Life Scope J bedside monitor using a built-in display, instead of an external display. The development team continued to shy away from the difficult task of working on a new measurement LAN to do away with the yellow MULTI sockets as camouflage. Life Scope TR was thus a decision to continue investing in weakness, throwing good money after bad. Life Scope G9, Life Scope G5 and Life Scope G7 bedside monitors inherit the input units from the Life Scope TR series bedside monitors.

 

In other words, the magic show continues.

 

Life Scope TR main unit can hold one input unit plus an attached expansion box

Since the Life Scope PT transport monitors are versions of Life Scope TR Input Units with a screen, so let's take a closer look at the AY-663P Input Unit (using Nihon Kohden SpO2 algorithm) which is shown below. These same input units are made use of by replacement models, Life Scope G5 series (CSM-1501, CSM-1502) bedside monitors.

 

It needs at least ten physical sockets for carefree use but the manufacturer can only provide three yellow MULTI sockets on a ratio of 3/10 availability ratio. This means only three of the ten connectable cables can plug into the input unit at any one time. The input unit is so short of physical sockets, why would anyone need such a skewed input unit? This is actually worse than the Life Scope VS bedside monitors, and obviously incomplete.

 

A skewed input unit delivering pain of insufficient physical connection sockets

Notice the two channels of Temperature hardware in the shown input unit are not making use of the MULTI sockets for connections, this is to provide relief to the three MULTI sockets which the designers know too well, are far from enough.

 

The BIS, Second SpO2, ETCO2 and NMT parameters are self-contained kit sets with processed digital serial data using the MULTI sockets as pass-through paths to the monitor, they have no reason to queue for the scarce yellow MULTI sockets. It was done merely to show the flexibility of the MULTI sockets.

 

The image below shows a Life Scope TR bedside monitor main unit (on the right) with the input unit (AY-663P) on the immediate left of its side. On the extreme left is the satellite box with four additional MULTI sockets (AA-674P) that can be integrated to the MPU of the AY-663P Input Unit.

 

The AA-674P box adds four physical connection sockets together with four channels of IBP hardware to AY-663P input unit

 

Since AY-663P Input Unit is incomplete without the AA-674P expansion box, why didn't the manufacturer just design an input unit with the intended seven MULTI sockets?

 

Like Life Scope J bedside monitor, the manufacturer wanted to show scalability by taking out some of the needed physical sockets in the Input Unit and placed them in an optional expansion box. This odd arrangement is to imitate the scalability process of adding patient-monitoring parameters when identical yellow MULTI sockets are being shown visually added to the input unit. However, we should know the manufacturer is only adding sockets, and not patient-monitoring parameters.

What the market really wants is scalability of patient-monitoring parameters, not more or less flexible sockets.

It is clear the three physical MULTI sockets on the AY-663P Input Unit are not enough for use, which means the customers have to buy the AY-663P Input Unit and AA-674P expansion box as a mandatory requirement. The act of adding four MULTI sockets using the AA-674P expansion box also adds another four IBP hardware to the three already configured in AY-663P Input Unit. Do you really need seven channels of IBP hardware? This is indeed quite rare a requirement, and you should not be buying more than what you need.

 

The limitation of four additional MULTI sockets also means it is not possible for the AY-663P Input Unit to make use of two AA-674P expansion boxes; be sure to ask for a field demonstration to verify the truth if any salesman insists on this possibility. By the way, that means eleven channels of IBP monitoring!

 

When placing the Life Scope PT transport monitor on a DAU unit, four additional MULTI sockets are made available on the JA-694PA DAU. The Life Scope G5 bedside monitor can also make use of the AA-174P expansion unit, noting expansion sockets cannot be more than four.

 

Four yellow MULTI sockets can be found on JA-694A DAU

 

Sharing must make economic sense

 

Elaborate time-sharing should be applied to things that are expensive (high in demand, an asset), and not worth the efforts for things that are cheap (high in supply, a commodity) like a connector socket or a switch!

 

The next picture shows Philips time-sharing one channel bio-amplifier hardware between IBP and Temperature measurements, and there was no sharing of connector socket; this is exactly the opposite of what Nihon Kohden is doing. The said manufacturer merely ensures physically it is not possible to make use of both the PRESS and the TEMP socket at the same time, and the objective is to make it possible for the same hardware to be used for different purpose at different time.

 

This design optimizes the use of expensive hardware, not the cheap sockets

 

 

Case Study

 

The AY-663P Input Unit together with AA-674P expansion box corresponds to a Philips MMS module with an extension. These are operating at the configured level, not modular, and the extension or expansion are made using analog interface.

 

 

The MMS modules are capable of further linking to a

real-time measurement LAN (Ethernet) network for expansion

 

While the Philips MMS modules can be upgraded using analog extensions, each also has an IP address for linking onto the digital Measurement Ethernet LAN network, allowing direct communication between the main unit and each module. Scalable monitoring is achieved by slotting individual modules into a module rack linked to the Measurement LAN Network; in the same way, expensive modules can be shared.

On the contrary, NIHON KOHDEN failed to realize a working digital Measurement LAN Network. 

 

The Input Units of Life Scope G5 series monitors do not have IP addresses for digital networking. There is no way to scale monitoring parameters or sharing expensive modules using digital networking, only via serial kit sets or linking to independent devices using custom interfaces.

 

The Philips MMS module (and extension) serves as the basic module and can be expanded using a digital measurement LAN

Smart Cables and the yellow flexible MULTI sockets

do not make a modular modular

A yellow flexible MULTI socket by itself does not automatically mean all the five types of mentioned parameters are available for measurements; it still depends on which hardware are decided for placement inside the MPU for selection by Smart Cables. The amount of hardware specified must be placed in the MPU before leaving the factory.

 

Additional monitoring parameter capability can be added to an MPU using serial kit sets, supported by system software. However, not all patient monitoring parameters can be added using self-contained serial kit sets. For example, the AE-918P Neuro Unit or strip chart recorder cannot be linked to MPU as a serial kit set.

 

When an MPU is not equipped with FiO2 hardware internally, no amount of MULTI sockets is going to provide this measurement capability. The amount of configured hardware placed in each MPU varies, so is the system software support for serial kits and external devices. A summary of a few monitors using one to three flexible MULTI sockets are shown in below table. They are just like any configured monitor.

 

 

Examples of configured hardware and serial kit sets using MULTI sockets

The costs needed to make use of Smart Cables are high, and the customers are paying to be led into having an unrealistic expectation of what the Smart Cables and MULTI sockets can actually deliver.

 

Messages such as "New Modular Technology" and "The Module is in the cable!" are just the wild imaginations of people without the necessary electronics knowledge. These are unsubstantiated marketing messages and the manufacturer should not have condoned it.

 

What do the manufacturer mean by this statement? 

It started with the Life Scope TR (BSM-6000) series monitors in the USA market and gradually adopted officially for International markets. These are precise statements.

Remember, the constant iteration of the same assertion while avoiding to provide any proof does not make it the truth!

 

This is just wild assertion without offering any proof

 

Which chip manufacturer is willing to take a big loss to supply NIHON KOHDEN the variety of analog chips given the extremely low volume in demand? When we opened up the plug of a Smart Cable, we found a small PC board being soldered to some pins of the yellow plug (as shown).

 

A small PC Board is soldered to some pins of the yellow connection plug

 

Upon inspection, the PC board confirms a cheap non-volatile digital EEPROM chip is being made used of to custom code each Smart Cable.

 

A cheap digital EEPROM chip was what we found inside the yellow Smart Cable plug

The same thing can be found in the plug of a compatible IBP cable from China suppliers, they just copied the digital code defined by NIHON KOHDEN.

 

 

Under US FDA rule, a cable is only a cable if it does not change the signal that passes through it. A Smart Cable embedded with a non-volatile digital hexadecimal code is just a cable and does not change a signal passing through it, but if it has an amplifier it becomes a medical device and definitely requires FDA registration. Can you find any stand-alone NIHON KOHDEN Smart Cable registered with US FDA as a medical device? We do not.

 

Make no mistake, when the Smart Cables are used with serial kit sets, such as mainstream CO2 kit sets or the NMT AF-101P kit set, the registration is for the active serial kit set (just like any other manufacturers) and not the passive Smart Cable.

 

Below service screen shows the MPU knows what cable is being inserted by reading the parameter codes in the plugs. MP1 is identified as an IBP measurement cable, MP2 as a Temperature measurement cable, while MP3 has blank reading (no sign of any measurement cable). The "loop check" shows error for MP1 and MP2 because the two measurement cables do not have any transducer attached.

 

 

The older manuals (before June 2007)

have the details

The details are no longer shown on later manuals, so we take a look at Life Scope BSM-2301 bedside monitor which was launched in 2001; the Service Manual is clear on the design, and manuals for later models stop providing such information.

 

The major move to curb details in manuals started from Life Scope J (BSM-9101) Bedside Monitor, which was launched in June 2007. The Life Scope TR bedside monitors obviously do not provide such details, since it was launched in April 2008 after Life Scope J monitor.

In BSM-2301 service manual, you can see the IBP and thermistor-method respiration are internal hardware inside the Life Scope BSM-2301 monitor. These hardware are clearly shown being linked internally to the MULTI socket, and to make use of either hardware, a Smart Cable with the valid code must be plugged into the MULTI socket.

 

The block diagram also tells us the MULTI socket of Life Scope BSM-2301 monitor cannot measure Temperature because there is no Temperature hardware internally linked to it, and the sole Temperature amplifier hardware is dedicated to an external jack. The observation is confirmed by the label for the yellow MULTI sockets indicating PRESS/ CO2/ RESP, i.e. no TEMP. This diagram clearly shows there is no reason for any amplifier hardware to be placed inside the NIHON KOHDEN Smart Cables.

 

This manual confirms the IBP amplifier and thermistor-method respiration hardware are internal components of the Life Scope BSM-2301 monitor

 

The block diagram also shows the path of the serial data packet, bypassing the internal analog hardware and going straight to the digital APU (Analog-block Processing Unit).  For a parameter using the internal analog hardware, the analog signal needs to be converted to digital before it can go to the APU for digital processing.

 

The huge amount of hardware inside the AY-663P Input Unit

is the reason for its size

 

The patient monitoring hardware inside the AY-663P Input Unit are divided into a conventional block and an MPU block. The conventional block uses dedicated sockets and ordinary measurement cables while the MPU block makes use of Smart Cables with different parameter code for different hardware.

 

CONVENTIONAL BLOCK

- 2 channels of Temperature

- ECG

- SpO2

- NIBP

MPU BLOCK (three MULTI sockets)

- 3 channels of IBP [3 MULTI sockets = 3-ch IBP]

- 2 channels of Temperature [1 MULTI socket = 2-ch TEMP]

- Cardiac Output

- FiO2

- Thermistor-method Respiration

- [MULTI sockets as serial ports] BIS, 2nd SpO2, mainstream CO2, NMT 

 

The hardware in the MPU block

In the AA-674P expansion box, each MULTI socket comes with its own IBP hardware and can access the common hardware pool in the MPU of AY-663P Input Unit.

 

The hardware in the AA-674P expansion box

Instead of using AA-674P expansion box, the additional four MULTI can also be arranged horizontally using the AA-174P expansion box. This is the version used by Life Scope G5 bedside monitor.

 

The hardware in the AA-174P expansion box are similar to AA-674P expansion box

Another way to add four MULTI sockets to the AY-663P Input Unit or Life Scope PT transport monitor is the JA-694P Data Acquisition Unit. It is of course not possible to add more than four sockets in total due to the interface limitation.

 

 

Beware the Lurking Dangers of

Reading Estimated CO2 Values presented as Actual CO2 Values

 

The adoption of semi-quantitative mainstream CO2 measurements by NIHON KOHDEN was to reduce cost and its simplicity also help in miniaturization of the transducers. The first solution offered by Nihon Kohden was the 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 (P907) has very small sensors because of the adoption of semi-quantitative measurements; the method is not commonly seen and many are not aware of the risks of CO2 readings from the semi-quantitative CO2 kit sets. To make matter worse, the semi-quantitative measurements are also being fed to display a flawed continuous CO2 waveform on screen to users.

 

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 using a traditional mainstream CO2 sensor. The TG-901T3 kit set (order code P906) is the same thing but using a non-coded connection plug. The medical devices from same manufacturer that make use of semi-quantitative CO2 kit sets for patient CO2 measurements and waveform include:

- Life Scope patient monitors

- Vismo patient monitors

- Cap-STAT OLG-2800

- CardioLife defibrillators

- Neurofax EEG machines etc.

 

Nihon Kohden semi-quantitative CO2 kit sets using traditional mainstream transducer

Semi-quantitative CO2 measurements

are not a cheap alternative to quantitative CO2 measurements

  

To save costs, the semi-quantitative kit sets do not make measurement during the inspiration phase. The measurement duty cycle is as shown in below image.

 

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

 

Semi-quantitative measurements are also of low-accuracy type, performed using one IR detector instead of the usual two to save cost.

 

Contrasting, quantitative measurements delivers high accuracy for critical care. To ensure the necessary high accuracy, quantitative measurement employ two IR detectors for simultaneous CO2 measurements at different wavelength for results comparison. CO2 measurements are also being made continuously, which means it can be fed to display a waveform on screen.

 

Quantitative measurements employ two detectors to make continuous measurements 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 measurements using semi-quantitative method no longer holds true once CO2 is present during the inspiration phase. This is because the actual CO2 levels can be much higher.

 

In other words, it is an acknowledgement that:

 

1. The measured CO2 value is not the true CO2 level,

 

2. The true CO2 level = [measured CO2 value + x]

where x is an unknown CO2 value carried forward from the inspiration phase. Only when x = zero will the measured CO2 value reflect the true CO2 level.

 

It is unprofessional to specify a measurement tolerance

when there is an unknown in the equation

 

This is not professional specifications

 

As seen from the duty cycle, there is no measurement being made during the inspiration phase, how do the users verify the measured CO2 value is the true CO2 level?

 

The specified measurement tolerance is conditional on this assurance and the CO2 values shown to users are therefore wrong and misleading! Each semi-quantitative CO2 measurement is in fact only an estimation, because the users have no way to tell if the value of x is indeed zero. It is only assumed to be zero by the manufacturer.

In addition, since the users are not alerted on screen that there is no CO2 measurement being made during the inspiration phase, they are unknowingly made to take on unnecessary risks.

 

 

Semi-quantitative measurements are only for selective uses with known risks

 

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 to estimate the value of etCO2 for airway tube placement confirmation. It cannot be a feed for continuous waveform display.

 

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

It is a flawed continuous CO2 waveform when fed by a source

that does not have the ability to make continuous measurements

 

The manufacturer ended up carelessly displaying a flawed continuous CO2 waveform using semi-quantitative measurement kits that do not have ability to make continuous measurements. This is unacceptable, as the manufacturer is subjecting the monitored patients and users to dangerous misinterpretation risks.

 

When there is no measurement being made during the inspiration phase, the displayed CO2 level is forced by the manufacturer to a clean zero by design. Is the manufacturer aware that a zero CO2 reading on the waveform means zero measured value, not that you are not measuring? This is basic professional knowledge.

 

Note the end tidal CO2 (etCO2) value shown in below picture is not alerted as "estimated etCO2" only.

 

A flawed CO2 waveform with non-measurement intervals reflected as zero measured CO2 value

The dangerous assumption

that expiratory upstrokes always start from zero CO2 level

 

Below image confirms it is dangerous to assume the CO2 level during the inspiration phase is always zero.

 

Dangerous assumption the manufacturer is making

 

Check the latest updated table to make sure you only use quantitative method for critical measurements and to display a true CO2 waveform on the screen.

 

Use only quantitative method for waveform display; the quantitative TG-950P (P905) shown here was already discontinued.

 

What you should also know about

fully-quantitative type miniaturized mainstream CO2 sensors

 

The TG-907P CO2 Sensor kit (order code P909) shown in above table is declared as using quantitative method; the sensor was designed for non-intubated adult/ neonatal CO2 monitoring. Nihon Kohden is thus offering this as an alternative to sidestream CO2 technology.

 

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!

 

Common defects of a TG-970P CO2 sensor kit (P909), reflecting an impractical design.

The fragile miniaturized CO2 sensors are clearly of poor design,

and easily broken

 

The key point is, it does not last

 - END -