09
Chest Piece Bottom
All electronic stethoscopes manufactured by Rudolf Riester have the same basic
structure.
The stethoscope consists of two elements:
1. Chest piece
2. Cable with plug (USB plug with straight cable or 3.5mm stereo plug with spiral
cable)
3. Operation and Function
3.1 Introduction
The ri-sonic PCP-USB / ri-sonic PCP-1 chestpiece can be used with a general
PC.
The device / PC that supplies power must comply with IEC 60950.
ri-sonic PCP-USB
The ri-sonic PCP-USB stethoscope is intended for use with a standard PC, mobi-
le devices (with USB port) and appropriate app or software, which is not included.
The ri-sonic provides sound data as specified. The user must check whether the
line data of the sensor matches the requirements of the PC, mobile device, app
or software.
The ri-sonic PCP-USB Stethoscope consists of a hardware element, the PCP-
Chest Piece. The PCP-USB Chest Piece contains an embedded piezo sensor,
audio amplifier Analog to Digital Converter (ADC) and Encoder to create a di-
gitized stream, plus a USB interface to send that data to the PC. The ri-sonic
PCP-USB Chest Piece derives its operating voltage from the 5v lead of the USB
interface to the PC.
ri-sonic PCP-USB Chest Piece Block Diagram and Assembly. The ri-sonic PCP-
USB Chest Piece assembly consists of a Printed Circuit Board Assembly (PCBA),
a piezo element (PE), enclosure pieces and a USB cable, which is attached to
the PCBA.
The PCBA provides an amplifier and an IC that includes an Analog to Digital
Converter (ADC), a Encoder and a USB interface. The operating voltage for the
circuitry on the PCBA is obtained from the 5vdc lead of the USB interface to the
PC to which the ri-sonic PCP-USB is connected during service. The block dia-
gram for the circuitry on the PCBA is shown in the following figure.
The block before the Amplifier provides impedance matching and protection from
external transients.The circuitry is placed on a small round printed circuit board
(PCB). The following figure shows a physical representation of components on
the PCB.
The cable is attached to the PCBA which is then mounted inside the chest piece
assembly along with the piezo element (PE). The following figure shows a cross-
section of a physical representation of ri-sonic PCP-USB Chest Piece assembly.
ri-sonic PCP-1
The ri-sonic PCP-1 stethoscope is intended for use with a standard PC, mobile
devices (with Microphone port) and appropriate app or software, which is not in-
cluded . The ri-sonic brings its performance data. The user must check whether
the line data of the sensor match the requirement of the PC, mobile devices,
app or software.
The only non-generic hardware element in the ri-sonic PCP-1 Stethoscope sys-
tem is the ri-sonic PCP-1 Chest Piece. High Level Schematic Diagrams of ri-so-
nic PCP-1
The ri-sonic PCP-1 Chest Piece assembly consists of a Printed Circuit Board
Assembly (PCBA), a piezo element (PE), an Enclosure Top piece, an Enclosure
Bottom Piece and a cable.
The PCBA provides the amplifier circuitry to bring the signal level from the PE
up to the approximate
level that would come from an electret microphone. The gain if the amplifier is
not critical since the
amplifier in the PC to which the PCP-1 Chest Piece is attached would have a
variable gain amplifier.
Just as an electret microphone gets its operating voltage from the Microphone
