Operation of the Meditech ABPM-05 device BP5I2241 – 2006.05.25.
Operation of Meditech ABPM-05
The device' intended u e i to equentally mea ure blood pre ure and tore the re ult
over a period of 24 hour , during the normal daily activity of the patient.
ABPM-05 i a battery operated electronic device with a power ource of 2 AA ized batterie
or a NiMH accumulator.
The input of the DC-DC tran former with IC13 witch mode i connected to the power
ource via F2 fu e. It provide a VSTAB voltage of approximately 5V which upplie the IC8
upervi or microcontroller, the LCD1 LCD driver and the two analogou witche IC: IC9 and
IC15. The ame voltage charge the button cell B1 through D2 diode and R12 re i tance.
When there i no operating power ource in the device, the B1 button cell upplie the IC
power need (VORA) of IC6 clock.
The digital part of the mea urement electronic operate from the VKAP voltage, which i the
ame a the VSTAB voltage, but it can be witched off by the IC8 upervi or microcontroller
through OFF ign to the T3 tran i tor. The electronic of pre ure mea urement operate
through VANA power upply, which i created from a VKAP ign by the IC16 fix 4V
tabili ator.
High current con umption component (motor pump and valve ) operate from the VPOWER
voltage. Thi voltage i produced by the IC14 DC-DC tran former and it i u ually 3.6 V, but
the IC1 main microcontroller can increa e it up to 4.6 V via a GEAR ign. The DC-DC
tran former i connected to the power ource via the F1 fu e. It operate only, if the main
microcontroller i witched on via VPEN ign and only if the upervi or microcontroller allow
it through a VPWR ign. In ca e of witching it off, the operation of the motor and the valve
i attached via the T2 FET a well. Thi dual cut off i a afety function, o that it will al o
happen in ca e of any component failure.
The upply (VRXD) of the T4,T5 tran i tor i normally between 4.5 and 5 V. There i an off
mode of the device, when it' „totally” witched off. In thi ca e the upervi or
microcontroller IC8 witche even thi upply off in order to decrea e the current
con umption.
In the stand-by mode of the device, the upervi or microcontroller IC8 regularly read the
tatu of the two pu hbutton of the device, the TIMER interrupt line of the real-time clock
IC6, and the pre ence of any ignal on the optical erial line. If either pu hbutton i pre ed,
or the real-time clock IC6 end a TIMER ignal, or a character i received on the optical
erial line, the upervi or microcontroller IC8 witche the other part of the device on
(VKAP, VANA). Now the device i in on mode.
Then, in thi on mode of the device, the upervi or microcontroller IC8 ha mainly afety
function .
In it on mode, the ABPM-05 device i controlled by the main microcontroller IC1. The main
microcontroller execute the program tored in the IC3 EPROM, and it u e the IC4 external
RAM during runtime, too. It read the current time from the IC6 real-time clock and it et
the real-time clock to end a TIMER ignal after 1 minute. It communicate with the IC6
real-time clock and the IC7 LCD driver through the SCL and SDA of the I2C bu .
The mea urement plan (monitoring chedule) and the re ult (blood pre ure and pul e rate
reading , event marker , ervice and error code ) are tored in the IC5 EEPROM. The main
microcontroller can read and write the EEPROM u ing a imulated I2C bu , but writing ha
to be enabled on the DWP line handled by the upervi or microcontroller IC8, too. Thi can
be accompli hed by ending a command to the upervi or microcontroller.
The main microcontroller IC1 can communicate with the u er’ per onal computer on an
optical erial line. Communication i initiated by the u er’ per onal computer in each ca e.
The ignal ent by the per onal computer through one fiber of a twin pla tic optical cable
are received by the photodiode of the optical connector D3, they reach the receiver ba ed
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