Baxter Healthcare Corporation PCA II User manual

TABLE OF CONTENTS
CHAPTER 1 - INTRODUCTION .............................................*..................... l-l
1.1 GENERAL .............................................................................................................. I-l
1.2 FACTORY SERVICE/ASSISTANCE*....................,.......,........................................ 1-l
1.2.1 TechnicalAssistance, Service, and Repairs.
...................................................... 1-I
1.2.2 Parts and Service Related Business.................................................................. l-1
1.2.3 TechnicalRepairAssistance Hotline ................................................................. 1-i
CHAPTER 2 - THEORY OF OPERATION ....................................................2-l
2.1 MECHANICAL ASSEMBLIES ............................................................................... 2-l
2.1.I Drive MechanismAssembly .............................................................................. 2-1
2.1.2 Pusher BlockAssembly..................................................................................... 2-2
2.1.3 Syringe Holder Assembly.................................................................................. 2-2
2.2 ELECTRONIC CIRCUITS ...................................................................................... 2-3
2.2.1 Microprocessor and Associated Circuits ...........................................................
2-3
2.2.1.1 Microprocessor ............................................................................................ 2-3
2.2.1.2 Custom Integrated Circuit ............................................................................ 2-4
2.2.2 RAM ..................................................................................................................
2-5
2.2.3 Program Cartridge (ROM) .................................................................................
2-5
2.2.4 RealTime Clock ................................................................................................
2-5
2.2.5 SYSOKand Latching Reset Circuit...................................................................
2-5
2.2.6 Motor Drive Circuit ............................................................................................ 2-6
2.2.7 Keypad..............................................................................................................
2-6
2.2.8 LCD Panel.........................................................................................................
2-6
2.2.9 AudibleAlarm ....................................................................................................
2-7
2.2.10 Printer Output ....................................................................................................
2-7
2.2.11 Power Supply .................................................................................................... 2-7
2.2.12 Charger Circuit ..................................................................................................
2-7
2.2.13 On/Off Circuit .................................................................................................... 2-7
2.2.14
Power Supply Circuit.. ....................................................................................... 2-8
2.3
SENSING ELEMENTS AND CIRCUITS .............................*...............*.*.....*.......... 2-8
2.3.1 Door Sensor .................................................................................*..*.................
2-8
2.3.2 LockSensor ......................................................................................................
2-8
2.3.3 5 mL and End of Syringe Sensors .................................................................... 2-8
2.3.4 Occlusion Sensor .............................................................................................. 2-9
2.3.5 Syringe Plunger Capture Sensor ...................................................................... 2-9
2.3.6
Leadscrew Gear Sensor ................................................................................... 2-9
.
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TABLE OF CONTENTS
CHAPTER 3 - INITIAL INSPECTION AND DAMAGE CHECK ....................3-1
3.1 GENERAL .............................................................................................................. 3-1
3.2 INITIAL INSPECTION AND DAMAGE CHECK ..................................................... 3-1
3.3 INSPECTIONS ....................................................................................................... 3-I
CHAPTER 4 - FUNCTIONAL TESTS ...........................................................4-1
4.1
4.2
4.3
4.4
4.5
4.6
4.7
4.0
4.9
POWER-UP ............................................................................................................ 4-2
AlTENTlON LIGHT ............................................................................................... 4-2
PUSHER BLOCK ................................................................................................... 4-2
SYRINGE HOLDER ............................................................................................... 4-3
OCCLUSION SENSING ......................................................................................... 4-3
5 ML ALARM .......................................................................................................... 4-4
END OF SYRINGE ALARM ................................................................................... 4-4
FLOW RATES AND DELIVERY VOLUMES .......................................................... 4-5
AC POWER KIT (OPTIONAL) ............................................................................... 4-5
CHAPTER 5 - ROUTINE MAINTENANCE ...................................................
5-I
5.1 GENERAL .............................................................................................................. 5-1
5-2 CLEANING AND DISINFECTING .......................................................................... 5-1
5.3 LUBRICATION ....................................................................................................... 5-1
CHAPTER 6 - TROUBLESHOOTING AND REPAIR ...................................6-1
6.1 GENERAL .......................................................................*...................................... 6-1
6.2 TROUBLESHOOTING ........................................................................................... 6-I
6.2.1
Board Exchange................................................................................................ 6-l
6.2.2 Toolsand Equipment......................................................................................... 6-2
6.2.3 Troubleshooting Tips ......................................................................................... 6-2
6.2.4 System Error Codes.......................................................................................... 6-6
CHAPTER 7 - DISASSEMBLY/ASSEMBLY PROCEDURES ......................7-1
7.1 GENERAL ..........................................................................................................‘... 7-1
7.2 DISASSEMBLY PROCEDURES ............................................................................ 7-1
7.2.1 Syringe Cover ................................................................................................... 7-2
7.2.2 Rear Case Half Assembly ................................................................................. 7-3
7.2.3
Battery Door Assembly......................................................................................
7-4
7.2.4 Mechanism Assembly ....................................................................................... 7-5
7.2.5 Front Switch PlateAssembly.............................................................................
7-6

TABLE OF CONTENTS
7.2.6
7.2.7
7.2.8
7.2.9
7.2.10
7.2.11
7.2.12
7.2.13
7.2.14
7.2.15
7.2.16
Patient Control Connector ................................................................................. 7-7
MPU Circuit Board ............................................................................................ 7-8
Case Cover Assembly....................................................................................... 7-9
Keypad............................................................................................................ 7-l 0
Syringe Holder ................................................................................................ 7-l 0
Mechanism Circuit Board................................................................................ 7-I 1
5mL/EOS SwitchAssembly............................................................................. 7-12
Motor Assembly............................................................................................... 7-13
Syringe Block.................................................................................................. 7-l 4
Pusher BlockAssembly................................................................................... 7-l 5
Guide Rods ..................................................................................................... 7-l 6
7.3 MECHANISM REASSEMBLY PROCEDURES .................................................... 7-17
7.4 SYRINGE BLOCK ALIGNMENT .........................................................................
7-19
7.4.1 Syringe BlockAlignment ................................................................................. 7-l 9
7.4.2 Limit Distance Calibration ............................................................................... 7-I 9
7.4.3 Syringe BlockAdjustment ............................................................................... 7-l 9
7.5 5 MUEOS ADJUSTMENT .,,~......,.,..............,........................‘,.............................
7-20
APPENDIX A - SCHEMATICS AND WIRING DIAGRAMS .....................,... A-l
A.1 GENERAL .......................................................................*...................................... A-l
APPENDIX B - CIRCUIT BOARD ASSEMBLY DRAWINGS ..................,... B-l
B.l GENERAL ................................*................*.........................*....*............................. B-l
APPENDIX C - REPAIR PARTS ...................~.....................‘........................ c-1
C.l GENERAL .............................................................................................................. C-l
C.2 ASSEMBLY PART LISTINGS ................................................................................ C-l
c.2.1 Syringe Cover ................................................................................................... c-2
c.2.2 Rear Case Half.................................................................................................. c-3
C.2.3 Labeling and Miscellaneous Hardware ............................................................. c-4
C.2.4 Front Case Half Parts........................................................................................ C-6
C.2.5 Front PanelAssembly ....................................................................................... C-8
C.2.6 Mechanism Assembly ..................................................................................... C-l 0
C.2.7 EOS and 5 mL Switch Assembly..................................................................... C-l 2
C.2.8 Syringe BlockAssembly.................................................................................. C-l 3
C.3 ALPHABETICAL PARTS LIST ............................................................................
c-14
.. .
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TABLE OF CONTENTS
C.4 NUMERICAL PARTS LIST .................................................................................. C-l 7
APPENDIX D - PRODUCT UPDATES ........................................................ D-l
D.l GENERAL .............................................................................................................. D-l
APPENDIX E - MANUAL REVISION NOTICES .......................................... E-l
APPENDIX F - REPAIR HISTORY ..........*................................................... F-l
APPENDIX G - OPERATOR’S MANUAL .................................‘.................. G-l
- iv -

INTRODUCTION Chapter I
1.I GENERAL
This Service Manual has been developed to introduce the Biomedical Technician to the
PCA II Pump. This manualwill providea basic understanding of the internal workings of the
Pump,functional test procedures,complete assembly/disassemblyinstructions,troubleshoot-
ing, and parts list.
NOTE
Except for the procedures and part replacements included in this
document, nodisassembly or repair should be attempted.
Baxter Healthcare provides a one-year limited warranty for each PCA II Pump. If a Pump
requires warranty service, callBaxter Healthcarefor repair.Unauthorized repairing of a Pump
before the warranty has elapsed voids the warranty.
1.2 FACTORY SERVICE/ASSISTANCE
If factory service isdesired, Pumps may be returned to Baxter Healthcare for repair.
Toexpedite repairs,callfor areturn authorization numberbefore shippingany Pumpto Baxter
Healthcare.
1.2.1 Technical Assistance, Service, and Repairs:
Fortechnical assistance, parts ordering, and service return authorization, contact the Baxter
Healthcare Service Center:
1.2.2 Parts and Service Related Business:
I-800-343-0388
1.2.3 Technical Repair Assistance Hotline:
I-800-634-4602
1-l

Chapter I INTRODUCTION
THIS PAGE INTENTIONALLY BLANK
-
1-2

THEORY OF OPERATION Chapter 2
2.1 MECHANICAL ASSEMBLIES
/-
2.1. I Drive Mechanism Assembly
The drive mechanism assembly is held between the Pump case halves and includes the
syringe holder (l), DC motor and gearbox (2), pusher block assembly (3), lead screw and
gear assembly (4), mechanism circuit board (5) and various sensing systems (described
later inthis section under Sensing Elements and Circuits).
Fluid is delivered from the syringe by the action of the pusher block on the plunger of the
syringe. The pusher blockis advanced bythe action of the lead screw on the half-nut inthe
pusher blockassembly.The leadscrew isturned bythe DC motor through a gearbox integral
with the motor and a pair of pinion gears, one welded to the gearbox shaft with the other
attached to the leadscrew. The Motor Drive Circuit providescontrol and delivery rate of the
fluids and is described later inthis chapter.
Figure2-I Drive MechanismAssembly (out of case)

Chapter 2 THEORY OF OPERATION
2.1.2 Pusher Block Assembly
The pusher block assembly is captured between the stainless steel guide rods (1) of the
mechanism assembly. The pusher block extends through the opening between the case
halveswhere it engages the plunger of the syringe.Squeezing the release lever (2) against
the main support performs two functions. It allowsthe assembly to be moved freely up and
down the guide rod by mechanically de-couplingthe half-nut from the lead screw (3), and it
disengagesthe pusher block assemblyfrom the syringe plunger.
Figure 2-2 PusherBlockAssembly
2.1.3 Syringe Holder Assembly
The syringe holderassembly is connected to the drive assembly. It is designed to holdthe
Baxter@Prefilled50 cc, BD 60 cc, or Monoject’ 60 cc plastic syringes. Use of other syringes
will result in incorrect delivery rates.
1 Sherwood
2-2

THEORY OF OPERATION Chapter 2
2.2 ELECTRONIC CIRCUITS
-
2.2.1 Microprocessor and Associated Circuits
The MPU circuit board (1) is mounted on the inside of the front case cover on top of (and
covers)the LCD displayboard (2). External switches, sensors, and inputs are providedto the
MPU circuit board via direct connection and cabled input.
Figure2-3 MPU Circuit Board Location
2.2.1.1 Microorocessor
The Motorola 68HCi 1A 1 microprocessor controls the functions of the Pump. It provides a
high performance single-chip microcontroller with Electronic Erasable Programmable Read
Only Memory (EEPROM), 16-bittimer, Serial Communication Interface (SCI), Serial Periph-
eral Interface (SPI), and an 8-bitAnalog-to-Digital (A/D) converter. The 4 MHz crystal results
in a I MHz E clock at pin 5.
The microprocessor controls the motor through ports PA3-PA6. It communicates through a
bufferto the printer port.The MPU reads variousanalog signalsthrough buffer U14. The bus
interface of the MPUto system RAM U3, program cartridge (ROM), real-time clock Ul, liquid
crystal display (LCD) and quadrature decoder IC U6 isthrough buffers U18, 19and U20. The
custom IC U4 provides bus decoding and logicto interface the MPU to the keypad and sen-
sors described later inthis chapter.
2-3

Chapter 2 THEOWOF OPERATION
At power up, the microprocessor conducts a number of Pump self-tests. Among these tests
are;a check ofthe watchdog circuit to ensurethat the functional program code is intact; test
of RAM for full functionality; test of the A/D converter by sensingthe voltage at PE3, pin 49
which ensuresthat the power supply iscorrect. If anyof the self-tests fail, the microprocessor
will halt and the audio alarm will sound continuously.
2.2.1.2 Custom Integrated Circuit
Thecustom IC U4performs severalfunctions. Itgeneratesthe System Reset,providesphysical
memory mapping, provides additional digitalI/O ports for the microprocessor and contains a
watchdog circuitthat will reset the microprocessorifthe software failsto continuallywrite to it
at a predetermined time interval.
System Reset (RESET/, pin 43) can be asserted by several different sources. At power on,
the charge time of Cl 0 through R20 providesa period of delaywhere the system is held in
reset through U4 pin 3, this allows the power supply voltage to stabilize before running the
MPU. PWR-ERR/ is a signal that will cause a System Reset to occur if the over/under
detector circuit senses that the power supply voltage is either above 6.OVor below 4.55V.
Resetwill alsobe asserted ifthe program cartridge is not installedor as previously described
ifawatchdog time-out occurs. RESET/ resetsthe microprocessor (disablingits output ports,
includingthe motor drivesignals), disablesthe motor through the SYSOKcircuit, deselects all
peripheral ICs and disables the custom ICs output ports as well. RESET/ also causes the
buzzerto sound continuously acting through U2 and CR2.
Physicalmemory mapping is based onthe address generated bythe microprocessor andthe
R/W signal. Additionally, READ/ and WRITE/ strobes are generated to operate the ROM,
RAM, and realtime clock.
The digital I/O ports on the custom IC pass digital signals to and from the microprocessor.
Most inputs are protected from static discharge by IOOKohm series resistors. INOO-03and
OUTOO-03are used to decode the front panel keypad in a matrix fashion. The mechanism
sensors EOS/, 5ML/, and OCCL (inputs IN1O-l2) are usedto trigger the End of Syringe, 5 mL
andOcclusion alarms respectively. IN13 is usedto detect closure ofthe patient switch andis
debouncedbyRAI 3cand C6 aswell as insoftware. OUT10 is usedto activate the sensor for
the door through Q4. OUT11 activates the displayand, via Q3 and inverter Tl ,the electrolu-
minescent backlighting. SYSOKCLK and OUT12 are part of the SYSOK circuit described
later inthis chapter. OUT20 and OUT21 activatethe front panel Attention and Power LEDs,
respectively.
Thewatchdog circuit is a safety feature designedto guard against lossof motor control inthe
eventthat software does not execute properly. It compares the 32 Hz clock provided by Ui 2
to a write of a specific address by the microprocessor. If the two events are not properly
synchronized,a system reset is generated.
2-4

THEORY OF OPERATION Chapter 2
2.2.2 RAM
8K bytes of system RAM are provided by U3 and an additional 256 bytes are located inside
the microprocessor. U3 is powered from VRAM and continues to store data even when the
Pump isturned off, and upto 20 minutes with the batteries removed. This allows for recalling
and printingpatient information even after the Pump hasbeen turned off.
2.2.3 Program Cartridge (ROM)
The Program Cartridge containsthe software codethat operates the Pump. It isaccessedvia
connector J15 on the MPU board. It has a capacity of 64K bytes. The custom IC allows
accessto most locations not used by other devices.
2.2.4 Real Time Clock
The real-time clock Ul provides data and time information to the microprocessor. It is pow-
ered by VRAM and continues to operate even when the Pump is turned off, and up to 20
minutes with the batteries removed.
2.2.5 SYSOK and Latching Reset Circuit
The System OK (SYSOK) and latching reset circuit performs severalfunctions. It provides
the SYSOK signal, a meansto test the functionality of the watchdog circuit and a means to
latchthe RESET/ signal. The System OK (SYSOK)circuit prevents the microprocessor from
driving the motor until severalof the following events havetaken place:
1) Poweron reset hasexpired
2) Thewatchdog hasbeentested byallowingittotime outthe firsttime the microprocessor
is started at power up.
Unless both of the above events have occurred the SYSOK flip flop UQa will not go high
signifying that the system has been properly initialized. The SYSOK signal UQa, pin 6 is
gated with MPOWER to form the PWM signalwhich is used to drive the motor. As long as
SYSOK islow, PWM is inhibited. Power On reset is usedto initializethe circuit at power up.
The PowerOn resetsignalisfurther delayedbyR23/C25andinvertedbyUl 1to form PWR-UP
PWR-UP keepsthe SYSOKflipflops UQband Ui 5 cleareduntil power on reset has expired.
.Thewatchdog test isperformed by purposefullycausingthe software notto service the watch-
dog ifWDOG-TST is low (itsinitializedstate after power up). Beforethe watchdog times out
the microprocessor clocks UQpin 9 high setting WDOG-TST high by manipulating OUT-12
and INSEL/. The watchdog will then time out resetting the microprocessor which then starts
again. On the second start sequence the software sees that WDOG-TST is high and ser-
vices the watchdog inthe normal fashion. OUT-1 2 and INSEU are manipulated againwhich
causes U15, pin 5 to clock high. This signifies that the watchdog test has successfully ex-
ecuted. Any additional resets at after this point will clock U15b thereby latching the RESET/
signal.
2-5

Chapter 2 THEORY OF OPERATION
2.2.6 Motor Drive Circuit
The microprocessor controls the motor through three output ports: MENABLE, MBRAKE,
and MPOWER. Primary motor motion feedback is provided by an encoder internal to the
motor powered by microprocessor port MENCOD and monitored by quadrature decoder U6.
Leadscrew positionfeedback is providedthrough the REED input.
MENABLE is on (high) whenever the motor is active. Its primary function is to supply a
ground path to run the motor. It has a secondary function in that its absence can disable
operation of the motor inthe event of the failure of the MPOWER signal or transistor.
MPOWER is a pulsatile signal which is AC coupled through C 17 and enabled by SYSOK
through U8a onthe MPU board. Renamed PWM, itpasses to the Mechanism boardwhere it
controls the constant current driver transistor Q9. This in turn drives Ql 1, which provides
powerto the motor.In addition,the motor power iscontrolled bythe normally closed occlusion
switch SW1, which opens during an occlusion.
MBRAKE causes Ql 0 onthe Mechanism boardto short across the motor windings and halt
the motor between pulses. It also provides brakingaction during bolusand dose deliveryfor
better motor control.
The motor contains a 12count quadrature encoder. Its outputs, ENCA and ENCB, are pro-
cessed bythe quadrature decoder U6 onthe MPUboard. The 15kHz clockfrom U7,disabled
byCTRRST when the motor is not movingto reducepower consumption, sets the digitalfilter
frequency of U6. U6 contains a 12 bit counter that counts up or down depending on the
phasing of ENCA and ENCB, and is monitored bythe microprocessor through the address/
data bus. The microprocessor periodicallyclears the counter via the ENCRST/ signal. The
motor drivetransistors Q8, Q9, and Ql 1are tested at power on and then periodically
while in operation to ensure that none are shorted. If this test fails, a system error alarm
results.
2.2.7 Keypad
Thefront panelkeypad is decoded in a matrix fashion by the microprocessor via the custom
IC.
2.2.8 LCD Panel
The 64x 84 dot matrix LCD panel is controlledbythe microprocessor via the address / data
bus. To conserve battery power, it is blanked usingthe DISPLAY output of the custom IC.
DISPLAYalsoturns on Q3, which in turn powersvoltage inverter Ti , which excites the elec-
troluminescent lamp that backlights the LCD.
2-6

THEORY OF OPERATION Chapter 2
2.2.9 Audible Alarm
The audiblealarm isactivatedby eitherthe AUDIO signalfrom microprocessor port pin 24 or
bythe system reset signal RESET/through U2 and CR2. This ensures the alarm will sound
ifthe watchdog times out.
2.2.10 Printer Output
The printer port uses the serialport within the microprocessor. All linesare buffered andhave
transient absorbers with series resistors to provide protection from electrostatic discharge.
This serial port does not conform to RS-232, therefore, the Printer Adapter must be used if
printer capability is desired.
2.2.II Power Supply
The power supply consists of a switching regulator, a linear regulator and bypass FET,a
charger battery relay and an on/off circuit. Each of these subsystems are located on the
Mechanism Board (Figure 2-l).
2.2.12 Charger Circuit
-- A relayisusedto switch between battery power andthe AC wall charger power. When the AC
adapter isplugged in, the relay switches closingthe normally open connections between the
AC adapter voltage and the power supply circuitry (VBATF). This also places a reverse
biased diode in series with the positive battery input. This reverse biased diode prevents
current from the AC charger from charging alkaline batteries. Charging current for NICAD
batteries is provided through F2, CR11 and R222 to the charge ring of the battery stick.
Reverse battery protection is provided by CR7 and Fi. If batteries are installed in reverse,
CR7 becomes forward biasedand causes reverse current to open polyswitch Fi .
2.2.13 On/Off Circuit
Input voltage from the Charger circuit VBATTF is switched to the remainder of the power
supply via FET Qi. U205, a linear regulator, provides a constant supply for RAM backup
while the mainpower supplyis switchedoff. C2 providesa short duration reservoir supplyfor
RAM backup while the batteries are being, changed. Ql isturned on when the On button is
pressed insidethe syringe cover. This applies the battery voltage to the gate of Q6 which
provides a ground path for U2 turning it on. U2 provides a -5V signal to the source of Q13
turning it on which then turns on QI. The presence of 5V at the cathode of CR4 keeps Q6
turned on thereby keepingthe power supply turned on. Pressing the OFF button applies5V
to the gate of Q5 after a delaydetermined by RI 02/C9, which turns Q6 off. By reversingthe
turn-on processthis turns the power supply off.The RI 02/C9 delay allows the microproces-
sor some time to shut down in response to XIRQ/ output from U2 pin 8.
2-7

Chapter 2 THEORY OF OPERATION
2.2.14 Power Supply circuit
The switching regulator Ul is used to boost the inputvoltage when the battery voltage falls
below5V Whenthe batteries arefresh, power issuppliedthrough diodeCR1. Asthe battery
voltage falls below SV,the switching regulator takes over to maintainvoltage at 5V U202, a
linear regulator, is used to keep the power supplyoutput voltage at 5V when the switching
regulator is not boosting voltage and the batteries are supplying more than 5V. FET Q201 is
usedto bypassthe linearregulator when the switchingregulator ison,to minimizethe voltage
dropwhen the linearregulator isnot needed. Q201can beturned on byeither oftwo sources.
REG-BYP is a signalfrom the MPU which turns onQ201 through Q204. The A/D converter
within the MPU monitors the output of Ui via signalV-641 the software can then determine
when to switch in and out U202. The second way Q201 can be turned on is by voltage
detector U203. The AC adapter voltage CHG-MON is input to the voltage detector chip
through a voltage divider network R212/R213. If the voltage at U203 pin 3 goes above 1.3V
signifyingthat the AC adapter isinplacethe bypassFETQ201 isforced on. A second portion
of U203 is usedto monitor the battery voltageVBATTF.This isdone through another voltage
divider network R220/R221, and ensures that the power supply does not turn on automati-
callyvia Cl0 remaining charged and keepingQ6 on if the batteries are quickly removed and
reinstalled. A diodevoting network selects betweensources ofVRAM. The two diodes CR1 0
and CR9 ensurethat the higherof the two suppliesare used.
2.3 SENSING ELEMENTS AND CIRCUITS
2.3.1 Door Sensor
The Pumpsenses that the door is closed bythe proximity of a magnet imbedded inthe door.
This is done using a Hall effect switch mounted inthe front case half. The output, DOOR, is
read by the microprocessor at PE5, pin 46. Toconserve battery power, the sensor is acti-
vated by the microprocessor via the HALLON/ signalonlywhile it is being read.
2.3.2, Lock Sensor
The closure of the door lock on the front panel is sensed by a microswitch mounted to the
backof the front panel. The signal is read bythe microprocessor at PE7, pin 50. A transient
absorber andseries resistor are provided for protectionfrom electrostatic discharge.
2.3.3 5 mL and End of Syringe Sensors
Twomicroswitches are mounted on a bracket attachedto the mechanism assembly to sense
the locationof the pusher blockassembly.
2-8