Welch Allyn LC101 CO2 Module - User Manual - Manual (Page 11)

LC101 CO
2
Module OEM Implementation Manual Section 1 - Functional Description
Welch Allyn OEM Technologies Confidential Page 11
O
2
/N
2
O/desflurane
O
2
/N
2
O/desflurane compensations account for the effects that these gases have on the IR
absorption characteristics of CO
2
molecules. Refer to Appendix A Software Procedures for a
description of this effect and a recommendation for enabling these compensations.
The O
2
/N
2
O/desflurane compensations are OFF by default and may be enabled or disabled via a
host system command.
BTPS
Often the clinician’s intent is to determine the CO
2
levels within the patient’s lungs where gas
exchange is taking place. BTPS compensation corrects for the environmental differences
between the measurement site (i.e. the bench) and “deep lung” CO
2
.
The BTPS compensation is ON by default and may be enabled or disabled via a host system
command.
Hardware Components
LC101 Main Board
The LC101 Main Board provides the interface to the host system, manages power requirements,
calculates measurements, and regulates pump flow.
The functional components of the Main Board include
• 68HC11 microprocessor with external memory
• reset circuit
• primary power supplies
• analog to digital (A/D) converter
• digital to analog (D/A) converter
• source hybrid
• pressure transducers
68HC11 Microprocessor
The microprocessor controls feedback to the pump and to the temperature and pressure
transducer. The microprocessor also provides the communication interface to the host system
and interfaces to the external A/D and D/A converters and sensor EEPROM memory. An internal
multiplexed A/D converter is used for digital conversion and for monitoring some of the power
supplies for fault determinations.
All address decoding is performed by a microprocessor. The software code is stored in FLASH
memory and is supplemented by an external static RAM chip. The boot mode of the
microprocessor is used to install new software into the FLASH device.