Medical Devices Sanity: NIHON KOHDEN Life Scope PT (BSM-1700 Series) Transport Monitor and Data Non-Continuity

Category: NIHON KOHDEN Life Scope TR (BSM-6000 series), Life Scope PT (BSM-1733, BSM-1753, BSM-1763, BSM-1773), Life Scope Telemetry, Life Scope J (BSM-9101) bedside monitor, Nihon Kohden SpO2 algorithm type, semi-quantitative Waveform, Host Monitor, MULTI connectors, discontinuous seamless monitoring, IntelliVue X2, patient monitoring

In this knowledge-sharing record we examined the history and performance of the Life Scope BSM-1700 series transport monitors, noting the total absence of realtime data streaming during patient transport. The BSM-1700 monitor when changing from role of input unit of a host monitor to being an independent transport monitor should not compromise critical central monitoring connectivity at the system level.

Life Scope PT (BSM-1700 series) Transport Monitor

The Life Scope PT is a 5.5-inch transport monitor transformed from a multi-parameter Input Unit designed initially for configured Life Scope TR (BSM-6000 series) bedside monitors, and its use later extended to Life Scope J (BSM-9101) bedside monitor, Life Scope G9 (CSM-1901) bedside monitor, Life Scope G5 (CSM-1500 series) bedside monitors, and Life Scope G7 (CSM-1700 series) bedside monitors. The transport monitor was realized by the addition of touch-screen, storage memory and rechargeable battery to the multi-parameter input unit, doing away the need to attach it to a monitor during patient transfer; this means the Life Scope PT transport monitor can also act as an Input Unit for the mentioned bedside monitors, known as the Host Monitor. The design is an adaptation to imitate the Philips IntelliVue MMS X2; and because it is not a system design from scratch, something important at the system level is missing and the details will be discussed later in this same article.

Configured Input Units made into a Transport Monitors imitating Philips IntelliVue MMS X2

Before the Life Scope PT transport monitor, Nihon Kohden offered three types of Input Units used by Life Scope TR (BSM-6000) bedside monitors for export. The AY-663P Input Unit uses NIHON KOHDEN SpO2 algorithm while AY-653P Input Unit offers Nellcor OxiMax SpO2 algorithm, and the AY-633P Input Unit offers Masimo SET SpO2 algorithm. The AY-663P Input Unit is however, not marketed in the US market.

Similarly configured input units with different SpO2 algorithms

On the other hand, there are four models of Life Scope PT (BSM-1700 series) transport monitors, namely

1. BSM-1773 transport monitor (Nihon Kohden older SpO2 algorithms)

2. BSM-1763 transport monitor (Nihon Kohden current SpO2 algorithms)

3. BSM-1753 transport monitor (OEM SpO2 board supplied by Nellcor)

4. BSM-1733 transport monitor (OEM SpO2 board supplied by Masimo)

Life Scope PT transport monitor with telemetry transmitter

The only difference among the four models is the SpO2 algorithms.

The four types of Life Scope PT transport monitors

The two models (BSM-1773 and BSM-1763) on the left make use of Nihon Kohden SpO2 algorithms and their main difference being the version of SpO2 algorithm. It should be clear the SpO2 algorithm for the USA market and ex-USA market are not the same version, the latest version is refrained from use in the USA market.

The remaining two models on the right, namely BSM-1733 and BSM-1753 are using SpO2 OEM boards supplied by Masimo and Nellcor respectively.

Some sales people are very excited about the bigger screen of Life Scope PT in the market but there is little knowledge why the configured multi-parameter Input Units of Life Scope TR (BSM-6000 series) bedside monitors are so different and big that its sides can accommodate a 5.7 inch screen?

Why are the Input Units of Life Scope TR so big?

The shown input unit is in fact, heavily loaded with patient-monitoring hardware inside, and avoided for mention in product communication to the market, intentionally done to hide the fact the input units are configured.

Many internal hardware are not made clear in product communication to the market

The prominent feature of the AY-663P Input Unit (or Life Scope PT transport monitor) is the utilization of yellow MULTI-parameter sockets. These MULTI sockets do not accept ordinary measurement cables but only measurement cables that have NIHON KOHDEN parameter codes embedded in their yellow plugs. The end result of using flexible connector sockets means less connector sockets on the monitor; although the advantage of the Multi-parameter sockets is claimed to be flexible, but in reality, the shortage of connector sockets makes for inflexible monitoring!

Concept of the Multi-parameter Unit (MPU)

NIHON KOHDEN had identified five types of analog hardware that can be linked to the MULTI-parameter sockets (from the inside) and to make use of these hardware, a cable with the correct code on its plug must be inserted into one of the MULTI-parameter sockets. These cables with coded plugs are collectively cited as Smart Cables by the manufacturer and the codes are also known as parameter codes. Each MULTI-parameter socket selects only one channel of the hardware, except for Temperature allowing two channels of hardware to be selected.

A measurement cable with a correct code in its plug can make use of any of the internally configured hardware shown here

The configured hardware using the Smart Cables are grouped into an electronic block known as MULTI-parameter Unit (MPU), complete with a small number of yellow MULTI-parameter sockets.

It is the hardware rule that all MULTI-parameter sockets must be able to do IBP monitoring, each socket comes with its own exclusive IBP hardware to adhere to this rule. The term "exclusive" means said IBP hardware is not intended for shared-use.

A MULTI-parameter socket makes use of its own exclusive IBP hardware when a measurement cable with an IBP code is plugged into it; for non-IBP monitoring, the socket can access a common pool of Temperature, Cardiac Output, Thermistor Respiration and FiO2 hardware pre-configured in the MULTI-Parameter Unit, which are designed for sharing.

Many are puzzled by the contents of the MULTI-parameter Unit, whose design has many hardware sharing limited MULTI-parameter sockets, this is because it was originally devised to solve the problem of limited panel space to mount all needed connector sockets. When panel space is enough to accommodate all the necessary connector sockets, it is obviously a waste of money to adopt this design.

Principle of operation

To reiterate,
A functional MULTI-parameter socket always come with its own exclusive one-channel IBP hardware, it means a user can tell the number of IBP monitoring hardware channels delivered with a monitor just by counting total number of available yellow MULTI-parameter sockets.

This being a hardware rule, and the key word is "functional" because a non-functional MULTI-parameter socket may not need to care about the capability to do IBP monitoring, such a socket can be found on the CardioLife TEC-5600 series defibrillators and this socket cannot do IBP monitoring, it is a fake MULTI-parameter socket and can only be used as a serial port for mainstream CO2 kit sets.

Given the large amount of hardware in the MULTI-parameter Unit block, more MULTI-parameter sockets should be added whenever possible, to make good use of the hardware that would otherwise be idling; this is actually done by using an external expansion box filled with MULTI-parameter sockets (plus associated IBP amplifier hardware).

The additional sockets are added using analog interface, and limited to a maximum four MULTI-parameter sockets, to avoid signal deterioration caused by voltage drop and noise.

Variations to the basic theme

There are variations to the basic theme, such as doing without use of external expansion box, or increasing the number of MULTI-parameter sockets in the MULTI-parameter Unit, or reducing the hardware configured in the Multi-parameter Unit.

In the AY-663P, AY-653P, AY-633P Input Units (or Life Scope PT transport monitors), 3 channels of IBP amplifiers, 2 channels of Temperature, one channel each of Thermistor Respiration, FiO2 and Cardiac Output are configured for use by Smart Cables.

As the hardware in the input units are extensive, they were designed to work with external expansion boxes which can add two or four MULTI-parameter sockets to make use of the idle hardware in the input units.

NIBP, SpO2, ECG and two channels of Temperature are configured using dedicated measurement cables. They are not part of the MULTI-parameter Unit.

The digital hexadecimal code is stored in an EEPROM chip mounted on a small flexible PC board electrically wired to the pins of the cable plug. It is not difficult to make the Smart Cables but they are being priced highly by the manufacturer; only the common IBP cable can be sourced from China suppliers at a reasonable price.

A parameter code is stored in the plug of the measurement cable

One MULTI-parameter socket can select two Temperature hardware channels.

Each MULTI-parameter socket can take two channels of Temperature measurements

The MULTI-parameter sockets are additionally diverted to serve as digital serial ports

As explained earlier, the design concept of MULTI-parameter Unit was to solve the problem of limited panel space, further reduction of sockets could be achieved by using the MULTI-parameter sockets as serial ports. This being an easy task since there is no need for additional internal analog hardware and the digital serial signals from the serial kit sets just go straight to the monitor main unit.

Currently, mainstream CO2, 2nd SpO2, BIS and NMT hardware are self-contained digital serial kits using the MULTI-parameter sockets only as a link to the monitor, to save on connector sockets. We must be clear when use of MULTI-parameter sockets as serial ports is not to solve the problem of limited panel space, the cost cannot be justified.

Shown below is the original label for the yellow MULTI socket, indicating the five specific hardware and also serving as serial port for mainstream CO2 serial kits; the purpose of this arrangement was to minimize the number of sockets being used on a limited panel space.

The original label for the yellow MULTI-parameter sockets when they were first used

The use of Smart Cables does not upgrade a configured monitor to be modular

A yellow MULTI-parameter socket by itself does not automatically mean all the five types of mentioned parameters are available for measurements; it still depends on whether what hardware are actually being placed inside for selection.

Additional parameter capability can be added using serial kit sets or via interfaces to external equipment.

When a model is not equipped with FiO2 hardware internally, no amount of yellow MULTI sockets is going to provide this measurement capability. The amount of configured hardware linked to each multi-parameter socket varies, so is the system support for serial kits and external interfaces.

Examples of configured hardware and serial kits using Smart Cables

It is the built-in hardware that determine the parameter capability; and in the case of serial kit sets, the system software. This of course, is the same description as a configured patient monitor

Actual internal hardware and system support for serial kits varies for each multi-parameter unit

It is obvious monitors with input units using Smart Cables are still configured monitors. The only advantage of using Smart Cables is to allow sharing of connector sockets, which are of negligible hardware cost; on the other hand, the cost needed to make use of Smart Cables is way far higher! It does not make logical sense, and we should look out for the ulterior motivation behind its use.

Notice the captured value from using Smart Cables is negative for users

Take a closer look at the AY-663P Input Unit shown below, it needs at least ten sockets for carefree use but the manufacturer can only provide three yellow MULTI-parameter sockets for time-sharing use. 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 connector sockets, why would anyone need such a skewed input unit?

The reason AY-663P Input Unit cannot come with more MULTI-parameter sockets is because only three IBP amplifier hardware are specified for design of the input unit. Since each MULTI-parameter socket comes with its own one-channel IBP hardware, the manufacturer cannot provide more than three MULTI-parameter sockets. Notice the two channels of Temperature hardware in the shown input unit are not making use of the yellow MULTI-parameter sockets for connections, this is to provide relief to the three yellow MULTI-parameter sockets which are not enough for use.

A skewed input unit delivering pain of not having enough connector sockets

The BIS, Second SpO2, ETCO2 and NMT parameters are self-contained kit sets with processed digital serial data using the input unit only as a link to the monitor, they have no reason to queue for the scarce yellow MULTI-parameter sockets.

What value can the users capture from using input units that come with deficiency of connector sockets? The first vehement complaint from users is always the yellow MULTI sockets are not enough for use!

Next comes the unconvincing offer to add more yellow MULTI-parameter sockets to supplement the inadequate three on the AY-663P Input Unit, using an external box (AA-674P) which comes with four MULTI-parameter sockets.

The link from AA-674P expansion box to AY-663P is an analog interface, not digital; as such, only a maximum of four MULTI-parameter sockets can be added, limited by signal deterioration caused by voltage drop and noise pickup.

Shown below is 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 a satellite box with four supplementary MULTI-parameter sockets (AA-674P) that can also link to hardware already configured in the AY-663P Input Unit.

The AA-674P box makes up for four missing sockets but at the same time adds four channels of IBP hardware

It is obvious the AY-663P Input Unit can never be sold without the AA-674P expansion box, and the manufacturer should have designed an input unit with enough connector sockets in the first place, but there is a reason for wanting to do it. The purpose is to imitate the scalability process of patient-monitoring parameters when MULTI-parameter sockets are being shown visually added to the input unit; the manufacturer is however, adding sockets, and not patient-monitoring parameters. A bedside monitor using AY-663P Input Unit and AA-674P expansion box is not modular in design.

Users must distinguish the difference between scalability of the MULTI-parameter connector sockets and scalability of patient-monitoring parameters

We should be clear, the scalability of patient-monitoring parameters is the one being sought after by the market, not scalability of usable connector sockets. The act of adding four MULTI-parameter sockets using the AA-674P expansion box also means adding four channels of IBP hardware to what are already configured in the AY-663P Input Unit; do you need seven channels of IBP hardware? This is how Life Scope TR bedside monitor got its maximum ability to do seven channels of IBP monitoring; it is either three channels of IBP monitoring using AY-663P alone or seven channels of IBP monitoring using both AY-663P and AA-674P, but the AY-663P Input Unit can never be sold alone because of the massive deficit of connector sockets.

Users are told the AY-663P Input Unit must be supplied with AA-674P expansion box as standard to meet the number of sockets needed, but this is not the real reason and users are unknowingly accepting seven mandatory built-in IBP hardware. This is not scalability of patient-monitoring parameters!

The limitation of only four additional MULTI-parameter 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!

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.

Only share the expensive hardware, not the cheap sockets

Philips modular monitors

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.

The Philips MMS modules (initiated by Hewlett Packard) are however additionally capable of being linked to a real-time measurement data network using Ethernet

Remember the HP Agilent M3/M4 portable monitor?

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

On the contrary, NIHON KOHDEN failed to realize a workable Measurement Network and the Life Scope TR Input Units do not have IP addresses for networking. There is no way to scale monitoring parameters or sharing expensive modules using 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 measurement LAN

If you are still harboring the misconception there are monitoring hardware embedded in the NIHON KOHDEN Smart Cables, we show here, beyond any doubt, there is absolutely no active electronics in the Smart Cables.

The marketing messages "New Modular Technology" and "The Module is in the cable!" are mere imaginations of people without the necessary electronics knowledge.

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.

The continued repetitions of an assertion without offering any proof does not make it the truth!

This is just assertion without offering any proof

Chip makers need huge demand to justify each of their products, so which chip manufacturer is supplying NIHON KOHDEN the variety of analog chips given the extremely low volume in demand? If we were to open up the plug of a Smart Cable, what do we see? A small PC board is seen attached to some pins of the yellow plug.

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

The PC board confirms a cheap digital EEPROM chip is being used to code the Smart Cable.

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

If we were to open up the plug of a compatible IBP cable from China suppliers, what do we see? It is the same thing, a plug with a 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 with a 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 requires FDA registration. Can you find any stand-alone Smart Cables registered with US FDA as a medical device?

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 and not the passive Smart Cable.

Irrefutable Proof the IBP amplifier hardware is configured internally, an important fact withdrawn from later monitor manuals

The Life Scope BSM-2301 bedside monitor was launched before the Life Scope TR bedside monitors, and the Service Manual is clear on the design; 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, launched before the Life Scope TR bedside monitors.

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

Can you see the IBP amplifier and thermistor respiration hardware are internal components of the Life Scope BSM-2301 monitor?

The MULTI-parameter socket doubles as a serial port without any need for internal monitoring hardware, only as a link to the monitor. In the block diagram below, the processed digital serial data from a CO2 kit set goes straight to the digital microcontroller APU (Analog-block Processing Unit) and is forwarded to the DPU. For a parameter using the internal analog hardware, the analog signal needs to pass through an Analog-Digital converter before going to the APU for digital processing.

Relevant page in the combined Service Manual for BSM-2301A, BSM-2301K, BSM-2303K, BSM-2304A

You should know by now the three IBP amplifier hardware inside the AY-663P Input Unit or Life Scope PT transport monitor is the reason they can each perform three channels of IBP monitoring.

Knowing there are three built-in IBP amplifier hardware inside the AY-663P Input Unit easily allows us to conclude the rest of the configured hardware after confirming all parameters that can be measured by the input unit.

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

First we filter out the parameters using self-contained serial kit sets, and they are mainstream CO2, 2nd SpO2, BIS and NMT hardware for the AY-663P Input Unit.

We can conclude the patient monitoring hardware in the AY-663P Input Unit to be:

NORMAL BLOCK
(The hardware using dedicated sockets and ordinary measurement cables)
- 2 channels of Temperature
- ECG
- SpO2
- NIBP

MULTI-PARAMETER UNIT BLOCK with three MULTI-parameter sockets
(The hardware only use Smart Cables for connections)
- 3 channels of IBP (3 MULTI sockets = 3-ch IBP)
- 2 channels of Temperature (1 MULTI socket = 2-ch TEMP)
- Cardiac Output
- FiO2
- Thermistor Respiration
< Self-contained kit sets using Multi-parameter sockets as serial ports>
- BIS, 2nd SpO2, mainstream CO2 and NMT

These configured hardware in the Multi-parameter Unit of AY-663P is the reason for its size

In the AA-674P expansion box, each of the four MULTI sockets makes use of its own IBP hardware when a IBP Smart Cable is plugged in; for the other four parameters, the sockets can access and make use of the Temperature, Cardiac Output, FiO2 and Thermistor Respiration hardware already configured in the Multi-parameter Unit of AY-663P Input Unit.

The hardware in the AA-674P expansion box

Instead of using AA-674P expansion box, the additional four MULTI-parameter sockets 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-parameter sockets to the AY-663P Input Unit or Life Scope PT transport monitor is the use of 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.

There is no proper viability assessment to pick the Smart Cables as a product selling point, and it is leading customers into having an unrealistic expectation of what the Smart Cables can actually deliver. The apparent flexibility of the MULTI sockets is in reality an adoption with negative captured value for the users.

Origin of the MULTI-parameter Unit (MPU) design

In the 1990s, when developing the first digital modular monitor, the development team encountered a problem of insufficient front panel space for connector sockets on the first digital multi-parameter module being made. The Smart Cables were originally devised only to resolve a product issue.

At the time NIHON KOHDEN was responding to an important emerging trend of using a high-density digital multi-parameter module as basic building block for modular monitors. In analog modular monitors, only single parameter modules were produced by NIHON KOHDEN. When designing the first digital modular monitor, the company discovered the critical care market had already moved to using a digital multi-parameter module with higher density of electronic components as a basic building block for modular monitors.

NIHON KOHDEN wanted to follow the trend by offering the first digital multi-parameter module, and the first digital multi-parameter module made by the company was named the Saturn module. However, putting a lot of hardware into the Saturn module also means more panel space needed for connector sockets.

The Saturn module was intended to be physically small in size

The solution from NIHON KOHDEN for panel space limitation of Saturn module was to introduce a MULTI-parameter Unit with many hardware sharing two yellow sockets for common use.

The Saturn module turned to sharing two modified connector sockets as solution to the constraint of space for more sockets

In the Saturn module, the hardware are divided into two blocks, a normal block and a MULTI-parameter Unit.

ORDINARY BLOCK
(These hardware make use of dedicated sockets and ordinary measurement cables)
- ECG
- SpO2
- NIBP

MULTI-PARAMETER UNIT with two yellow sockets
(These hardware only use Smart Cables for connections)
- 2 channels of IBP (2 MULTI sockets = 2-ch IBP)
- 4 channels of Temperature (2 MULTI sockets = 4-ch TEMP)
- Cardiac Output
- FiO2
- Thermistor Respiration
< Self-contained kit sets using Multi-parameter sockets as serial ports>
- mainstream CO2

Huge amount of configured hardware in the Saturn module

The MULTI-parameter Unit design has many hardware sharing only two MULTI-parameter sockets, this is to solve the problem of limited panel space.

More MULTI-parameter sockets are of course needed to make good use of the hardware that would otherwise be idling. This is done by using an external expansion box filled with MULTI-parameter sockets, each with its own IBP amplifier hardware.

Analog solution of adding more sockets, not monitoring parameters

The additional sockets are added using analog interface, and limited to a maximum four MULTI-parameter sockets, to avoid signal deterioration caused by voltage drop and noise.

The image gives an impression of scalability but this is scalability of connector sockets, and not the scalability of monitoring parameters that is being sought after by the market. All necessary hardware are already configured in the Saturn module except for additional IBP amplifier which must always come with each MULTI-parameter sockets.

A MULTI-parameter socket makes use of its own IBP hardware when a Smart Cable with an IBP code is plugged into it; for the other four parameters, the sockets are linked to the common pool of Temperature, Cardiac Output, Thermistor Respiration and FiO2 hardware already embedded in the the MULTI-parameter Unit of Saturn module.

It is the hardware rule that all MULTI-parameter socket must be able to do IBP monitoring, each socket has its own IBP hardware that is not shared

The extension Smart module is therefore a 2-channel IBP box adding two MULTI-parameter sockets for use by the Saturn module. Remember, the analog interface limits the number of Smart modules that can be added to the Saturn module to two, making a total of four additional Multi-parameter sockets.

The MULTI-parameter sockets were additionally allowed to be diverted to act as a costly digital serial ports so that mainstream CO2 digital serial kit sets can also use it; we must remember this is for purpose of minimizing connector sockets on the Saturn multi-parameter module, as it does not make sense outside this context.

The mainstream CO2 comes in the form of a self-contained serial kit set, and has no need for the MULTI-parameter Unit.

Keep in mind, a yellow MULTI-parameter socket is a high-cost serial port when it does not select any internal hardware

MULTI-parameter socket poorly utilized as a costly serial port

The initial arrangement was only for mainstream CO2 serial kit sets, but later extended enthusiastically to BIS kit set, 2nd-SpO2 kit set, APCO kit set, NMT kit set etc., whose motivation is highly questionable given this greatly increases the interface cost compared to a plain serial port.

The use of Smart Cables for serial communication does give a false illusion of mighty MULTI-parameter sockets but the capabilities are in reality coming from the system software.

Make no mistake, the serial kit sets are self-contained and whether a particular kit set is supported depends on the system software, not on the type of connector sockets being used.

To reiterate, there is no difference if you connect digital serial data to the monitor using Smart Cables or ordinary serial cables

This is how you connect the BIS processor kit to a yellow MULTI socket

Using Smart Cables for serial interface means an unnecessary jump in demand for more yellow MULTI-parameter sockets and there is no technical need for the serial kit sets to use the yellow MULTI-parameter sockets. Putting things into perspective, most patient monitoring parameters cannot be made into self-contained serial kits; for example, the AE-918P Neuro Unit or a strip chart recorder cannot be linked to a yellow MULTI-parameter socket as serial kit as shown. They are connected as external devices to a monitor.

The AE-918P Neuro unit and recorder module are examples that cannot make use of the yellow MULTI sockets

The MULTI PARAMETER UNIT is an official term found in the service manual

The Saturn module, together with two satellite boxes adding 4 channels of IBP to the Saturn module is shown below. The four MULTI-parameter sockets on the satellite boxes can also access the MPU of the Saturn module. Together, six IBP channels and six shared-use MULTI-parameter sockets are available to the users.

The sockets on the satellite boxes compensate for the missing connector sockets on the Saturn module

The two Modular Monitors that made use of the Saturn module were failures

The two modular monitors that could make use of the first Multi-parameter Module (Saturn module) made by NIHON KOHDEN were Life Scope S (BSS-9800) bedside station and Life Scope M (BSM-9510) bedside monitor; the software supporting the network infrastructure exchanging digital measurement data between the Saturn module and main units was unfortunately, not reliable and both modular monitors ended up as failures.

Life Scope S (BSS-9800) bedside station was a digital modular monitor

Lower-end Life Scope M bedside monitor was using a (6-slot) built-in module rack. The Life Scope M (BSM-9510) bedside monitor has lower processing power compared to the Life Scope S bedside station.

From the US FDA records, you could tell that Life Scope S and Life Scope M monitors were not launched in the US market

The two monitors were found lacking before they could be marketed in the USA market.

The cause of the failure for Life Scope S and Life Scope M modular monitors was the problematic network infrastructure needed by modular monitors for data exchange between modules and main unit. This resulted in Life Scope S bedside station functioning only as a limited monitor while the Life Scope M bedside monitor had to be withdrawn from the market due to insufficient processing power.

There were two digital real-time data network infrastructures used by BSS-9800 Life Scope S bedside station. The software supporting the Ethernet network linking patient monitors to the Central Nurse Station proved stable but the software supporting the network linking the modules to the main units of BSS-9800 bedside station/ BSM-9510 bedside monitor was unreliable and further development work on the network infrastructure was stopped to avoid incurring unbearable losses.

The exchange of measurement data between main unit and modules was the problem

The product failures were huge financial losses incurred at a time when the company was already suffering badly from poor sales due to the lack of digital technology know-how.

NIHON KOHDEN gave up solving the communication problem between main unit and modules

Failure to succeed in the measurement data-exchange network infrastructure meant NIHON KOHDEN was downgraded to be a manufacturer only capable of making configured patient monitors

To avoid being seen as a failure, the manufacturer continued to promote the Multi-parameter Unit with socket boxes as options, without access to an exchange network for measurement data. The Input Unit and expansion box of Life Scope TR bedside monitor is only the equivalence of Life Scope S modular monitor's Saturn module and extension. The rest of the other modules are being solved by using external device interface, a truly configured monitor.

A Life Scope TR bedside monitor has to depend on external device interface for expansion

A standalone BSM-1700 monitor can only have Telemetry or wired Ethernet link to the Central Monitor

Note a BSM-1700 monitor can only link to a central monitor using telemetry or wired Ethernet when not acting as an input unit. It is important to know the BSM-1700 transport monitor cannot communicate directly with a Central Monitor via WiFi. Though the BSM-1700 monitor can make use of a telemetry transmitter, there is no way to mount the optional ZS-900PK transmitter when the monitor is operating as an Input Unit to a host monitor.

Life Scope PT has no user benefit in a stand-alone operation

A stand-alone BSM-1700 monitor (i.e. when not acting as input unit to a host monitor) can be connected to a Central Nurse Station via the LS-NET real-time data network using wired Ethernet provided by the SC-170R AC Cradle.

Shown below is how a BSM-1700 monitor resting on an SC-170R AC Cradle is connected to the LS-NET patient monitoring network. The Ethernet socket is at the rear of the cradle and it is mandatory to protect the patient with an Ethernet isolation unit when connecting to a network.

The SC-170R AC Cradle does not make sense outside of Japan

When a BSM-1700 monitor is placed on a SC-170R AC Cradle, its function is only an ordinary stand-alone monitor but the price of a purpose-built BSM-1700 is twice that of an ordinary monitor with equivalent monitoring capability. Apart from cost, there is another problem.

Outdated Clinical Network Protocols

The failure of the two modular monitors (BSS-9800, BSM-9510) was a big setback to developments efforts, as many experienced engineers were being sidelined. The clinical network protocols, which define behaviors for communications on the network connecting bedside monitors and central monitors, is now only in maintenance mode and lacking new initiatives.

The Life Scope Real-time patient monitoring Ethernet Protocols only work when the monitors do not move from place to place. Before the SC-170R, the monitors were always fixed to each location and patient would only be transferred from one monitor to another. With the advent of the SC-170R, the assumption no longer holds true and the old protocols need a fundamental revamp to accommodate patients moving together with their monitors while maintaining links to a central monitor.

Thus, the SC-170R AC Cradle is only meaningful for telemetry use in Japan where there is government subsidy for monitors making use of telemetry, one of entry barrier for foreign competitors. The SC-170R AC Cradle provides the power for a BSM-1700 monitor placed on it, as well as charging its internal battery for transport use. There is no similar subsidy system for telemetry monitor outside of Japan.

This means although a BSM-1700 monitor placed on a SC-170R AC Cradle is easily released mechanically by a lever, the BSM-1700 monitor cannot be used as a "PICK AND GO" monitor due to the outdated LS-NET clinical networking protocols.

The manufacturer had reported there would be patient location confusion at the Central Nurse Station for such a setup.

Life Scope PT placed on a SC-170R AC Cradle causes confusion when used with a Central Monitor!

In the above monitoring setup with a Central Monitor, the Central Monitor would still remember the last bed locations even if the patients (together with the Life Scope PT monitor) had been swapped between BED ONE and BED TWO. This is serious matter.

Below shows part of the relevant Note to sales teams. There is no indication that the company is capable of fixing it yet.

Do not link the AC Cradle to a central monitor

The LS-NET patient monitoring protocol is outdated

The LS-NET network protocols need an upgrade

The Philips IntelliVue MMS X2

The Philips IntelliVue MMS X2 is similarly a transformation of MMS (multi-measurement server module) into a compact monitor with display and battery, primary purpose to link an MMS module to a patient and follow the patient's movement. In fact IntelliVue MMS X2 was released much earlier than BSM-1700, so there was no reason the project leader of BSM-1700 was unaware of this important need.

IntelliVue MMS X2 was launched long before BSM-1700

When the IntelliVue MMS X2 is connected to a host monitor, it has the option of wired Ethernet or WiFi via the host monitor OR through its own wireless telemetry transceiver to link with the Central Station. To maintain network continuity when the IntelliVue MMS X2 changes from being a MMS to transport monitor, it must choose the wireless telemetry option only. When the IntelliVue MMS X2 is assigned to a telemetry transceiver at the Central Station, patient identity is by the telemetry transceiver, thus the host monitor is automatically paired to it. The IntellieVue MMS X2 and Host Monitor together are recognized as one telemetry device to the central station.

During patient transfer, the IntelliVue MMS X2 disconnects from host monitor and operates as an independent transport monitor but communication link between MMS X2 and central station is not broken since telemetry transceiver in inside the IntelliVue MMS X2.

In addition, consider the patient arrives at a new location, the new host monitor is now paired to the IntelliVue MMS X2's telemetry transceiver monitored at the central station. Such patient transfer is truly seamless at the system level.

The telemetry transceiver in the IntelliVue MMS X2 is the token for tracking the patient

The Phillips Telemetry System

The official name for current Philips telemetry system is IntelliVue Instrument Telemetry System (IIT) and this is a newer generation bi-directional communication system operating in groups of channels within the 2.4GHz ISM band utilizing frequency hopping algorithm.

Frequency hopping technology originated from electronic warfare and is a technique to avoid enemy eavesdropping or high-power CW jamming by continuously switching the transmitting frequency (and therefore the receiving frequency). In healthcare, there is no enemy determined to jam you in every move so you do not have to anticipate the enemy. It is an adapted version to improve real-time performance in a crowded band since the 2.4GHz ISM band is a real radio waves jungle today. In the US market, Philips also offers the same IIT system using the protected WMTS bands in line with FCC initiative. This is done easily by replacing the internal ISM adapter (for International market) with WMTS adapter.

The telemetry transmitter is not always mountable on the Life Scope PT monitor

Despite the fact BSM-1700 monitor has a wireless option using a ZS-900PK telemetry transmitter to link to the Central Station, the telemetry transmitter cannot be attached to the BSM-1700 when it is acting as an Input Unit to a host monitor. This is because the concept of BSM-1700 as a transport monitor for the Life Scope TR was an after-thought.

The initial idea was to follow GE Marquette

The initial design was to follow GE Marquette way, transferring the input unit from Life Scope TR bedside monitor (BSM-6501 or BSM-6701) to a compact 10.4-inch Life Scope TR (BSM-6301) to fulfill the transport role.

The original way was to use Life Scope TR 10.4 inch model as transport monitor

This naturally extends to the Data Acquisition Unit (DAU) which is a repeater interface between input unit and monitor.

The BSM-6000 series main unit was designed long before Philips introduced the idea of turning input unit into a transport monitor

Thus, although the BSM-1700 monitor has a wireless option using a ZS-900PK telemetry transmitter to link to the Central Station, there is no room to attach the telemetry transmitter when BSM-1700 is acting as an Input Unit to a host monitor as illustrated.

A telemetry transmitter cannot be attached to a BSM-1700 series monitor when it is on the DAU

To attach a telemetry transmitter onto a BSM-1700 monitor requires the service of a qualified technical staff, it is therefore impossible for a BSM-1700 to change from being an Input Unit to a Transport Monitor with telemetry connectivity at short notice.

This means the telemetry transmitter can only be used on BSM-1700 monitor operating as a stand-alone monitor, which obviously will be an over-priced monitor and an unlikely installation.

BSM-1700 series monitors are not priced for stand-alone telemetry use

In the above image, the BSM-1700 monitor is equipped with a ZS-900PK telemetry transmitter linking to a Telemetry Central Monitor.

This is the misleading "continuous monitoring while wirelessly transmitting patient data and waveforms to a central monitor" mentioned in the brochure for use as a standalone monitor, which is meaningless to the target market outside of Japan.

Why is this description so out of context?

It is reminded the BSM-1700 does not have a built-in power unit and in telemetry mode cannot be charged directly from an AC outlet, the SC-170R AC Cradle or special external charger is additionally needed for its proper operation.

Problem exists at the system level because following Philips was an after-thought

The idea of turning the Input Unit on a host monitor into a Transport Monitor was not conceived yet when BSM-6000 series monitor was first designed, it was considerable time after Philips had introduced the IntelliVue MMS X2 that Nihon Kohden decided to copy the idea.

Life Scope PT has a serious problem of radio silence during patient transport when copying the Philips way. The image below illustrates a LIFE SCOPE BSM-1700 sitting on a Data Acquisition Unit (DAU) and connected to a Life Scope TR (BSM-6000) series host monitor. The BSM-1700 monitor in this setup is acting as an Input Unit only and master control is on the host monitor. The BSM-6000 monitor as host monitor not only provides DC Power to charge BSM-1700's internal battery, it also provides the Ethernet path (either wired or WiFi depending on BSM-6000 setting) to the Central Monitor.

Life Scope PT as Input Unit to a host monitor will turn into a transport monitor when detached

When BSM-1700 is removed from the host monitor, it can no longer use the latter's Ethernet path to the Central Monitor but it does not have its own path to the Central Monitor after leaving the host monitor. We had mentioned earlier that the BSM-1700 series monitors does not have WiFi ability.

Radio silence means it is impossible to have seamless monitoring at the central monitor

The communication link can only be re-established after the Transport Monitor is attached again to another Host Monitor as Input Unit. Upon re-attaching back to another host monitor, the patient data stored in the Life Scope PT during the transport period will then be synchronized to the Central Monitor.

Removing a BSM-1700 monitor as Input Unit on a DAU turns it offline to the Central Monitor

Critical central station surveillance is therefore not available for the BSM-1700 transport monitor during patient transfer from one host monitor to another. There is a critical missing specification at the system level.

The BSM-1700 relies on built-in memory to store the patient data during transport and only able to upload it to the Central Station via a Host Monitor after the transfer is completed.

Seamless data review though available at the Central Monitor, it does not equate seamless monitoring

The Central Station can be updated only after the BSM-1700 transport monitor is eventually linked to another Host Monitor as Input Unit. This synchronization will make the data on the Central Station seamless but it is not seamless monitoring.

As a comparison, Draeger does not need to change IP because their concept is not "from Input Unit to Transport Monitor".

>> See Draegar's "Pick And Go" Concept.

The dangerous use of uncertain semi-quantitative CO2 measurements and 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 have never been able to offer benefits of integrated sidestream CO2 measurement. You can check this point on the sales brochures that are readily available on the internet.

The inability to integrate the sidestream CO2 unit into the patient monitor main unit

The adoption of semi-quantitative mainstream CO2 measurement 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 semi-quantitative measurement is adopted, the method is not commonly seen and many are not aware of the risks of obtained CO2 readings from the semi-quantitative CO2 kit sets, and to make matter worse, the semi-quantitative measurements are also being made used of to display a flawed continuous CO2 waveform.

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

How to remove a relatively big disposable adapter from the two tiny transducers after use?

When the sensors become smaller, it also means the disposable adapter becomes relatively much bigger as seen in this below picture. When trying to remove the disposable adapter from the transducers, it is difficult to separate the two because of the latching mechanism. A small size transducer means anything that latches onto it must be even smaller.


It is not easy to separate the disposable adapter from the Cap-ONE transducers after use

When removing disposable adapter from the mini sensors, users tend to just pull from the cables and this action quickly weakens the joint holding the sensors and cables. The action will cause stress to the two joints and quickly degenerate the performance of the transducers. This means the transducers are unlikely to last.

Users just doing the inevitable

Shown below is another TG-900P etCO2 kit set (order code P903) that makes semi-quantitative CO2 measurements on 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 with traditional mainstream transducer

Do the users know semi-quantitative CO2 measurements are only estimations??

To save costs, the semi-quantitative kit sets do not make measurement during the inspiration phase. The important point is there is a measurement duty cycle and it is as shown; there is no way to know the actual CO2 measurements during the inspiration phase because CO2 measurements are not made.

Semi-quantitative means there is a duty cycle, and measurements are 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.

It is impossible for users to know if measurements are reliable when they cannot tell if CO2 is present during inspiration!

Measurements are invalid when CO2 is present during inspiration, but CO2 is not measured during this period

As seen from the duty cycle, there is no measurement being made during the inspiration phase, how does the manufacturer assure measurement accuracy? The specified measurement tolerance has no meaning for the users!

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.

Since the users are also not alerted on screen there is no CO2 measurement being made during the inspiration phase, they are unknowingly made to take on 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 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 possible for the manufacturer to display a 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 end tidal CO2 (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.

What you should know about fully-quantitative type miniaturized mainstream CO2 sensor

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

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.

The fragile miniaturized CO2 sensor is clearly of poor design, and easily broken

The key point is, it does not last