Critikon Dinamap Plus Vital Signs Monitor tear-down

[ealex]

Hello

I've bought this thing as defective from ebay, mainly for the plasma display. It's outer case was smashed - it seemed it took a nasty fall.
The "defect" was fixed just by re-seating all boards - the fall pulled out one of the control boards, the system detected it and stopped booting.

It's quite an interesting design, with a lot of hardware and software safety features - electrical protection for the patient and software safety so it either works 100% or not at all.

This is the service manual - some design hints and full schematics. The system seems to be designed around 1990's - chip dates are from 1993 / 1992

The service manual: http://www.frankshospitalworkshop.com/equipment/documents/ecg/service_manuals/Critikon_Dinamap_Plus_Vital_Signs_Monitor_-_Service_manual.pdf
Higher resolution images: https://drive.google.com/open?id=0B0CB5A9yU03XU0VpOUZaaTAwdVk&authuser=0

I don't know how to embed an attached image, so i'll make a post for each board and include an image as large as i can attach.


The main board:

This board contains all the control logic, display signal generator and uart interface.
The interesting chips are:
MC68302 Mcu , datasheet: http://cache.freescale.com/files/32bit/doc/ref_manual/MC68302UM.pdf
   - MC68000 core
   - secondary communication controller ( RISC cpu )
   - DRAM controller and a ton on peripherals ( ISDN voice or data terminal )
it seems to be clocked at 16Mhz

4x TC551001 - 128kB, 85nS static RAM made by Toshiba
   - 2 of them are used by the MCU
   - the other 2 are used by the video controller
   
HD63484CP98 video controller, http://pdf.datasheetcatalog.com/datasheet_pdf/hitachi-semiconductor/HD63484-4_to_HD63484Y98.pdf
   - advanced CRT controller, 9.8MHz pixel clock - the display needs a 12MHz pixel clock so i don't know how it's working
   - a lot of acceleration features like drawing, sprites, character generator, etc
   - up to 2MB of video memory
   - connected to the plasma display via 4 lines: HSync, VSync, Data, PixelClock
   
HN27C4096 256K*16bit UV erasable EPROM, http://pdf.datasheetcatalog.com/datasheets/166/165230_DS.pdf
   - holds the code
   - i'll try to read the firmware and post it here
   - ceramic PLCC case, i don't recognise the manufacturer's logo
   
ML2009 - micro linear logarithmic gain / attenuator block http://pdf.datasheetcatalog.com/datasheet/MicroLinearCorporation/mXuwwtw.pdf
   - 20 pin PLCC case

ML2036 - serial input sine wave generator with gain control http://pdf.datasheetcatalog.com/datasheet/MicroLinearCorporation/mXqwuvw.pdf
   - it's near ML2009 and some op-amps, also next to the speaker connector
   - they generate the audio output - this thing is loud - very loud and got a lot of acoustic signals

DS1284QN - RTC and watchdog http://pdf.datasheetcatalog.com/datasheet_pdf/dallas-semiconductor/DS1284_to_DS1284QN.pdf
   - got a crystal next to it
   - watchdog timer
   - 50 bytes of user ram
   - 0.5uA current draw from the battery input
   - parallel interface
   - 28 pin PLCC case

MAX172   - 12bit ADC and voltage reference http://pdf.datasheetcatalog.com/datasheet/maxim/MAX172.pdf
   - SAR ADC
   - parallel interface
   - 10uS conversion time

MAX358 analog multiplexer http://pdf.datasheetcatalog.com/datasheet/maxim/HI-508A-MAX359.pdf
   - dual supply
   - some on-chip protection features: over voltage detection, etc
   - it measures the power supplies and some other system voltages
   
MAX695 microprocessor supervisor
   - voltage monitor
   - power on reset generator
   - watchdog timer
   - battery back-up power switching

the white labelled chip might be a CPLD / FPGA glue logic - it's serial number is unreadable.
a nice Tadiran 3.7V primary cell, that is still in spec. 3.66V

The board seems to be 4 layer, only the top side is populated
there is an interesting logo etched on the bottom side, under the battery : an 'atom' symbol with 'FCC02" inside, like this one:
http://upload.wikimedia.org/wikipedia/commons/thumb/e/e5/Schematicy-atom.svg/683px-Schematicy-atom.svg.png

[ealex]

The second board measures blood pressure and O2 concentration.
It's almost all analog with some DAC's and interface stuff
The pressure sensor is a MPX2050 temperature compensated and calibrated sensor with differential output. http://cq-dx.ru/upload/pdf/M/MPX2050.PDF
Next to it there is a DG211 quad analog switch and a N5532 op-amp
The DAC is a MX7226, 8 bits with 4 channels, with parallel interface. http://pdf.datasheetcatalog.com/datasheet/maxim/MX7225-MX7226.pdf
Next to it there is a REF02C 5V refference: http://pdf.datasheetcatalog.com/datasheets/120/351644_DS.pdf

Other that that there are some DG508 8 channel analog switches.

The SpO2 side is isolated with some opto-couplers and the 3 transformers. The 2 one that are close together seem to be for analog signals.
The one on the side of the board forms an isolated power supply. There is a big isolation gap in the ground plane around this sections and a thick metal shield on the back
This board is connected to a pneumatic control board that's got another pressure sensor used as a safety over-pressure sensor and disconnect switch.
The pump is "Made in Germany", membrane type, an adjustable balancing counter-weight, and a big motor with replaceable brushes.

[ealex]

The ECG board is designed as a stand alone unit.
It's powered by a Burr-Brown PWR1726 power block - 1.5W, unregulated, +/-15V dual output http://pdf.datasheetcatalog.com/datasheets/400/359616_DS.pdf
The data link is made via 2 HP branded otocouplers that isolate a simple serial port
The board got it's own CPU - a Hitachi HD63B03Y 8 bit CMOS Mcu with an external EPROM.
Next to it is the main ADC - ADC1251 12 bit + sign ( 13 bits ), self calibrating, in a ceramic DIP case. http://pdf.datasheetcatalog.com/datasheet/nationalsemiconductor/DS011024.PDF
Some other intersting parts:
   MAX664: programable voltage regulator http://pdf.datasheetcatalog.com/datasheet/maxim/MAX663-MAX666.pdf
   LP2951:   voltage regulator http://pdf.datasheetcatalog.com/datasheet/nationalsemiconductor/DS008546.PDF
   AD631:   instrumentation amplifier http://pdf.datasheetcatalog.com/datasheet/analogdevices/789405427AD621_b.pdf
   MAX333: precision quad analog switch http://pdf.datasheetcatalog.com/datasheet/maxim/MAX333.pdf
   MAX358: fault protected analog multiplexer http://pdf.datasheetcatalog.com/datasheet/maxim/HI-508A-MAX359.pdf
   TLE2021: precision operational amplifiers http://pdf.datasheetcatalog.com/datasheet2/a/0szy8d0yf6jeu4ozdt1hjosz0i3y.pdf
   a Takamisawa relay, some 1k, 0.05% Vishay resistors and a ton of Wima film caps.

The input section is protected by the 2 neon bulbs, big carbon resistors and a lot of diodes.
This board has a complete metal shield.
Sniffing the serial port should be interesting - the unit can run by itself as an ECG front end.

[ealex]

The display is made by LOHA corp and it's also got a Planar label. It's a passive matrix plasma display with a 320x256 resolution. It lights bright orange with a long after glow. The pixels are big - the display area is 95x75mm and the outer dimensions are 130x110mm.
It's build with 2 stacked boards.
The lower one is the power supply board - it provides ~ 90V for the actual display.
There are some parts whose function i don't understand: SNJ5407 open collector hex. buffers and a AM27S19A 128 bits PROM.
Both of them are in ceramic dip cases.

The second board contains the row and column drivers on the bottom and the plasma glass on the top.

[ealex]

The power supply is built in 2 stages: 1 section gets from 220 to 14 ( if i remember properly ) and the second one makes all internal voltages.
The 14V output is used to charge an external lead-acid battery.
Both sections are built with isolated converters -> there is a dual isolation layer from mains to the internal voltages and a 3-rd one on each board that is electrically connected to the patient.
The next pictures show how the boards fit together and the unit powered up

[SeanB]

Seen newer ones in hospitals here, nice to see how they look inside.

[bktemp]

I doubt the display is a plasma display. It looks more like a electroluminescent display.

[ealex]

it might be, i'm also not sure. I though of "plasma" when i saw the grids and the HV supply + some burn-in that is visible when the panel is on.
i could not find any data sheet - just some other ebay listings that label it as "electro luminescent".
still a nice display to make a pong game on it's got  a long after glow.

[mikeselectricstuff]

Yes, definitely EL

[Mashpriborintorg]

Thanks for the teardown, I missed one similar item on ebay a few months ago, was very cheap first the price  finally climbed too high... so instead I picked up a "Datex Ohmeda Capnomac" anesthesia monitor, another cool piece of shit packed with science inside 

[Mashpriborintorg]

There, I am waiting for my Critikon Dinamap plusmonitor    Paid 25 euros for it, shipping from Germany included. Unknown condition, seems to have some case damage according to the photos. All the info here and in the service manual will be very usefull I guess