uniphy PHYACTION 190, Информация о сервисе

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2. THEORY OF OPERATION Service information Phyaction 190 / 190i - Page 5
CHAPTER 2
THEORY OF OPERATION
2.1 Introduction
In this chapter the electronics of the Phyaction 190 will be explained. A description on the level of functional
block diagrams will be used. The electronics will be described in more depth when safety aspects are
concerned.
The Phyaction 190 is a device for ultrasound therapy. The user -the physical therapist- can set a number of
parameters. The parameters are converted in electric signals for the ultrasound unit by a microcontroller. Also
the microcontroller continuously checks whether the ultrasound unit produces the proper amount of ultrasound
energy.
2.2 General block diagram
The block diagram of the Phyaction 190 is shown in figure 2.1. The microcontroller core, shown in the middle of
the diagram, controls the complete apparatus. The user can set most of the parameters with the keyboard,
which is shown at the left of the microcontroller. The intensity of the ultrasound can be set with the intensity
knob, drawn to the right of the microcontroller. The actual parameters and the amount of ultrasound energy
actually being administered to the patient is shown on the graphical display.
The ultrasound unit, drawn under the microcontroller, generates the electrical signal the US-head converts into
ultrasonic vibrations. The 4 mm banana safety socket, drawn close to the ultrasound unit, allows the user to
apply combination therapy when an electrotherapy device is connected to this bus.
2.2.1 The microcontroller core
The microcontroller used in the Phyaction 190 is an 80C552. The 80C552 is an MCS-51 type controller (8051)
with a number of extra features on the chip:
- 256 byte RAM memory (instead of 128 byte in 8051)
- 3 timer / counters (2 in 8051)
- eight channel 10-bit AD converter (N.A. in 8051)
Figure 2.1, Functional block diagram of the Phyaction 190