Welch Allyn LC101 User Manual
LC101 CO2 Module
OEM Implementation Manual
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Cop yright © 2002 by Welch Allyn OEM Technologies. Welch Allyn
Module OEM Implementation Man ual
2
®
is a registered tr ademark,
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patents and patents pending. Welch Allyn OEM Technologies is a division of Welch Allyn, Inc.
Disc laimers: Welch Allyn OEM Technologies cautions the reader of this manual:
• This manual may be wholly or partially subject to change without notice.
• All rights are reserved. No one is permitted to reproduce or duplicate, in any form, the
whole or part of this manual without permission from Welch Allyn OEM Technologies.
For inf ormation concerning this document, contact:
elch Allyn OEM Technologies
8500 SW Creekside Place
Beaverton, OR 97008-7107 U.S.A
(503) 530-7900 • Fax: (503) 526-4901
PN 000.91161 Rev. 1, September, 2002
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able of Contents
Section 1
Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Intended Use . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Terminology. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Mainstream vs. Sidestream . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Measuring Principle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Measurement Calculation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Measurement Compensation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Hardware Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
LC101 Main Board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Sidestream Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Section 2
LC101 Module Interface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Power Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
LC101 Main Board. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
LC101 Module Interface Connector. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Watertrap Switch Connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Pump . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Watertrap Receiver . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Watertrap Receiver Switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Exhaust Tubing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Section 3
LC101 Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Zero Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Zero Calibration Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Two-Point User Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Two-Point User Calibration Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
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Section 4
Host/Module Communications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Communication Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
System EEPROM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Packet Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Host Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Mode Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Simple Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Configuration Commands. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Calibration Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
Module Responses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Status Responses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Mode Command Responses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
Simple Command Responses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
Configuration Command Responses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
Calibration Command Responses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Software Protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
Packets. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
Faults . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
Module Resets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
System Behaviors - Dynamic Communications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
Section 5
Pneumatic Operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
Normal Flow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
Pneumatic Events . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
Total Inlet Occlusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
Partial Inlet Occlusion. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
Total Exhaust Occlusion. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
Partial Exhaust Occlusion. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
Barometric Out Of Range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
Unexpected Reverse Flow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
Unexpected Forward Flow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
Internal Disconnects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
Watertrap Receptacle. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
Sensor Inlet/Outlet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
Flow Control Circuitry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
Pump Inlet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
Pump Exhaust . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
Pump Failure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
Low Flow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
High Flow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
No Flow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
Section 6
Regulatory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
IEC 601-1-2 (EN 60601-1-2) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
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OEM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
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Electromagnetic Interference. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
Electromagnetic Susceptibility. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
Compliance Testing Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
ISO 9918 and EN 864 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
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Appendix A
Software Procedures. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
O2/N2O/Desflurane Compensation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
Correction For O2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
Correction For N2O & O2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
Correction For Desflurane . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
Summary of O2, N2O, and Desflurane Compensation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
Percent CO2 Calculation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
Zero Calibration Sequence Example. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
Two-Point User Calibration Sequence Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
Example of Verification Using Dry Gas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
CRC. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
CCITT/CRC Code Calculation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
Software Upgrade . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
Appendix B
EEPROM Memory Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
System EEPROM Map Table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
Appendix C
Error Messages & Recovery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
Advisories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
LC101 Advisories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
Pneumatic System Advisories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
Calibration Advisories. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68
Soft Faults . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
Calibration Faults . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
Sensor Faults . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
System Faults. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72
Appendix D
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Part Numbers and Accessories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
Module Configurations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
Accessories Available From Welch Allyn OEM Technologies. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76
Appendix E
Specifications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77
LC101 Main Board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77
Assembly Drawings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
CO2 Absorber Material Safety Data Sheet (MSDS) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81
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Appendix F
CO2 Developer’s Kit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83
Disclaimer. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83
Software Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84
Initial Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85
Menu Options Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86
CO2 Evaluation Platform . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89
Glossary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91
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Section 1
Functional Description
Intr oduction
The LC101 Module is designed to control and acquire data from an inter nal Welch Allyn OEM
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concentr ation in the patient’s expired respiratory gas can be obtained. The sidestream
2
system includes an internal sidestream CO
The LC101 Module calculates CO
CO
aveform to the host system via a serial communications interface.
2
bench. Utilizing a pump to aspirate the patient sample to the CO
2
bench, electronics and pneumatic components .
2
measurements and respir atory rate and outputs this data with
2
bench, the
2
Intended Use
The LC101 Module is intended f or use as a subsystem within a medical instrument or device.
The Module measures levels of CO
Module has been designed to be used on both intubated and non-intubated patients. The Module
and its accessories should always be used as described in the host system’s operator’s manual
and only for the purpose(s) intended. Areas of intended use include:
• Hospital Intensive Care Units (ICU)
• Hospital Emergency Department/EMS (ED/EMS)
• Surgical Operating Rooms (Anesthesia)
• Hospital Post Anesthesia Care Units (PACU)
• Outpatient Surgical Units
contin uously or intermittently in the sidestream mode. The
2
• Skilled Nursing Facilities / Subacute Care
•Transport (Air, Ground and Sea)
• Home Care / Traditional Health Care
The most common user will be a nurse or skilled healthcare professional (such as an EMT,
paramedic, respiratory therapist, clinical engineer, etc.).
elch Allyn OEM T echnologies
onfi dential
age 7
LC101 CO
Module OEM Implementation Manual
2
Terminology
Capnography is the noninvasive measurement and graphic display of airway CO2 concentration
as a function of time. The resulting waveform is called a capnogram. The evaluation of the
capnogram is useful in the assessment of the adequacy of carbon dioxide exchange in the lungs,
integrity of the patient’s airway, cardiopulmonary function and ventilator function.
76
CO
2
40
(mmHg)
0
Capnogram Components
CD
AB
Time
E
Monitoring of CO2 concentration at the end of expiration (point D) is referred to as End-Tidal CO2
(ETCO2) monitoring.
Mainstream vs. Sidestream
The patient’s expired gas may be sampled either directly off the patient airway external to the
LC101 Module or aspirated from the patient through a cannula into the Module. The method used
is dependent on the patient’s airway status.
Mainstream capnography is typically used on intubated or tracheostomy patients and requires
the use of an external mainstream sensor. Intubation is the process of inserting a tube into the
patient’s trachea to deliver gases to the lungs.
Sidestream capnography is used on patients who are intubated or non-intubated. The patient’s
expired gas is aspirated from the airway and transported to the LC101 Module through a sample
line. The sidestream sample chamber and sensor are embedded within the LC101 Module.
Signal acquisition and measurement calculation are performed by the LC101 Module.
Measuring Principle
CO2 measurement is based on the Infra-Red (IR) absorption characteristics of CO2 molecules.
The CO
present in the sample gas. CO2 gas has a unique absorption band which is related to a CO2
molecule’s composition and mass. CO2 gas concentration is measured by detecting absorption in
this band. Due to the nature of the measurement technique employed, user calibration is
necessary with this system.
sensor uses non-dispersive IR spectroscopy to measure the number of CO2 molecules
2
Page 8 Confidential Welch Allyn OEM Technologies
LC101 CO2 Module OEM Implementation Manual
Section 1 - Functional Description
The basic components of the CO2 sensor (C-Cap bench) include
• IR source
• Dual element IR detector
• optical filter
• non-volatile memory
The IR source emits energy that is directed toward a dual element thermopile IR detector. The
dual element design uses two opposing thermopiles connected in series. As the ambient
temperature changes, the two elements change in similar fashion resulting in an output near
zero. Only one element is exposed to energy from the IR source, resulting in a voltage change
due to only that energy. The detector generates a voltage based on the amount of energy it
receives. In the IR path between the IR source and the detector is an
optical filter which allows
only a specific IR wavelength to pass and the gas sample within the sensor chamber.
Dual Element Thermopile
+
detector
output
element 1
element 2
+
narrowband
IR pass filter
energy
from IR
source
foil cover
CO2 Measurement Method
A temperature sensor is attached to the detector housing for temperature compensation beyond
the thermopile’s designed compensation, including temperature changes in the system
sensitivity. The detector generates a voltage in the mV range and an Op-amp on the circuit board
amplifies the signal.
The non-volatile memory is an EEPROM containing calibration and manufacturing data specific
to the CO
sensor.
2
Measurement Calculation
Measurements provided to the host system by the LC101 Module include ETCO2, Inspiratory
(InsCO2) and respiratory rate (RR). These three measurements are collectively referred to
CO
2
as breath data. A proprietary breath algorithm is used to calculate the breath data.
Breath Algorithm
Welch Allyn OEM Technologies’s breath algorithm incorporates an initial learning period which,
based on certain assumptions of CO
for threshold determinations. A sliding window is used to detect a stable maximum, or ETCO
waveform morphology, establishes CO2 reference points
2
2
value, and a baseline, or InsCO2 value. Thresholds are updated in real time with each breath. A
signal averaging technique is used to calculate the RR based on this set of measurements.
By incorporating these adaptive and signal averaging techniques, the breath algorithm effectively
reports accurate CO
measurements while maintaining a high level of noise immunity.
2
Welch Allyn OEM Technologies Confidential Page 9
LC101 CO2 Module OEM Implementation Manual
Measurement Compensation
IR absorption in the CO2 wavelength band may be affected by a number of factors that alter the
measurement. The LC101 Module automatically compensates for some of these factors
CO
2
while others may be disabled by the host system.
These factors include
•water vapor
• pressure broadening
• gas mixing
•oxygen, nitrous oxide and desflurane or O2/N2O/desflurane
• Body Temperature, ambient Pressure and Saturated with water vapor or BTPS
Water Vapor
Water vapor compensation accounts for the effect that water vapor has on the IR absorption
characteristics of CO
adjusted mathematically to compensate for this effect.
molecules. During normal sidestream operation, CO2 measurements are
2
The host may choose to disable this compensation when performing dry gas measurements in
which the gas does not contain water vapor. Dry gas procedures may include steady state
measurements and calibration procedures. Steady state measurements are performed only
when background CO
of a steady state measurement is measuring the CO
, or CO2 present in the immediate environment, is measured. An example
2
content inside an incubator. Calibration
2
procedures use calibrated gas which is free of water vapor, or dry, as well.
The water vapor compensation is ON by default and may be enabled or disabled via a host
system command.
Pressure Broadening
Pressure broadening compensation accounts for the effect that barometric pressure has on CO2
molecule distribution and is used in both measurement and autorun modes.
The pressure broadening compensation is ON by default and cannot be disabled by the host
system.
Gas Mixing
A small amount of gas “mixing” occurs as the CO2 sample travels through the tubing to the
sample chamber. Gas mixing compensation accounts for the effect that low level gas mixing has
on the baseline, or InsCO2 measurement in both measurement and autorun modes. The gas
mixing, or baseline, compensation is ON by default and can be disabled by the host system.
Page 10 Confidential Welch Allyn OEM Technologies
LC101 CO2 Module OEM Implementation Manual
O2/N2O/desflurane
O2/N2O/desflurane compensations account for the effects that these gases have on the IR
absorption characteristics of CO
description of this effect and a recommendation for enabling these compensations.
The O2/N2O/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 CO2 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” CO2.
The BTPS compensation is ON by default and may be enabled or disabled via a host system
command.
molecules. Refer to Appendix A Software Procedures for a
2
Section 1 - Functional Description
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.
Welch Allyn OEM Technologies Confidential Page 11
LC101 CO2 Module OEM Implementation Manual
Reset Circuit
The first section of a 556 timer is connected to a serial receive data line such that the
microprocessor is forced into reset if the data line is held in a break condition for greater than 10
msec. A second timer section is used to determine if the break condition is maintained for more
than 500 msec.
Holding the receive data line in a break condition for a period of time greater than 10 msec and
less than 500 msec is referred to as a reset.
A hard reset occurs when the break condition is held longer than 500 msec. This condition
forces the microprocessor to enter the boot mode after the break is released.
Power ON, reset and low voltage lockouts are performed by a reset controller. Undervoltage
lockout is set to approximately 4.5 V. On power up, the microprocessor is held in reset for about
100 msec after the supply rises above 4.5 V.
Primary Power Supplies
All primary power supplies run off a single voltage power source and are converted on the Main
Board to various levels. The power source is derived from the (+5 V or +5.75 to +14.5 Vdc) Vin
power supplied by the host system.
A/D Converter
The 8 channel 12 bit serial A/D converter converts the following analog signals into a binary data
stream for the microprocessor: analog waveform from the optical bench, temperature of optical
bench, barometric pressure and pneumatic flow rate.
D/A Converter
The 12 bit serial interface D/A converter provides bench source current selection and bench
detector bias circuit control.
Source Hybrid
The optical bench requires that the IR source be current-regulated. The current-sensing circuitry
is located on a ceramic hybrid module, or source hybrid. A regulator is used that adjusts the
output voltage to maintain a constant current.
Pressure Transducers
The pressure circuitry monitors pressure via transducers in order to compensate for the effect of
pressure variation on the CO
measurement. The transducers include
2
• an absolute pressure transducer which initially provides an ambient pressure
measurement and then continuously monitors internal bench pressures during pump
operation.
•a differential pressure transducer which is used for pump flow regulation.
Due to the use of a single absolute pressure transducer, the ambient pressure
measurement is only updated at power on and watertrap replacement.
Page 12 Confidential Welch Allyn OEM Technologies
LC101 CO2 Module OEM Implementation Manual
Section 1 - Functional Description
Sidestream Components
The functional components necessary for sidestream operation include
• pump
•watertrap and watertrap receiver assembly
• inlet and exhaust tubing
•CO2 sample line
• cannula
The flow control circuitry regulates flow by using a fixed orifice flow sensor that provides
feedback to a circuit that controls power to the pump. A differential pressure transducer
measures the pressure drop across a restrictor and this is used as feedback to adjust the pump
speed. The pump power supply steps down the raw voltage applied to the board to a level
appropriate for maintaining the desired pump flow rate.
The pump connector provides the electrical connection for the pump to the Main Board.
The watertrap receiver assembly connector provides the electrical connection for the
watertrap switch to the Main Board.
Pump
The electrically driven miniature oil-free diaphragm pump is mounted on the Main Board. The
pump draws the sample through the sample line to the sample chamber by creating a vacuum.
Fault states such as exhaust and watertrap occlusions are recognized by the flow control
circuitry. Refer to Section 5, Pneumatic Operation, for additional information on pump function.
Watertrap and Watertrap Receiver Assembly
NOTE The watertrap, watertrap receiver and receiver switch are not included with the LC101
Module and each may be ordered separately from Welch Allyn OEM Technologies or
supplied by the OEM.
The watertrap is a user-supplied cartridge that removes excess moisture in the sample line
before the sample is delivered to the sample chamber. The watertrap includes a built-in shutoff
pellet which is designed to fully occlude once the filter is saturated.
The functional components of the watertrap assembly include the watertrap receiver and
receiver switch.
The watertrap receiver is a receptacle for the watertrap and can be molded by the OEM into the
main housing of the host monitor (or purchased from Welch Allyn OEM Technologies as an
accessory). The external end of the watertrap is connected to the sample line.
The watertrap receiver switch provides a signal that is used for detection of a properly inserted
watertrap into the watertrap receiver before the pump begins operation. This eliminates the
possibility of the user bypassing the watertrap.
Welch Allyn OEM Technologies Confidential Page 13
LC101 CO2 Module OEM Implementation Manual
Inlet and Exhaust Tubing
The internal inlet tubing provides the means to transport the gas sample from the watertrap
receiver to the sidestream bench. The inlet tubing includes the tubing, connectors and a
secondary shutoff pellet. Attachment of the inlet tubing to the watertrap receiver is via a Luer®
connector. A secondary shutoff pellet is attached in line with the inlet tubing to provide additional
backup.
The exhaust tubing provides the means to expel the exhaust gas. A 5 µm screen, or filter, is
positioned in line with the exhaust tubing to muffle, or reduce the pump noise.
CO2 Sample Line and Cannula
The CO2 sample line, or sample line, is used to transport the gas sample from the patient to the
watertrap assembly.
NOTE The sample line is not included with the LC101 Module and may be ordered separately
from Welch Allyn OEM Technologies or other suppliers.
For a non-intubated patient, the sample line connects to a cannula that is positioned on the
patient. A variety of cannulas are available to accommodate patient requirements. Nasal, oral/
nasal and divided cannulas which deliver oxygen and sample CO
simultaneously may be used.
2
NOTE Cannulas are not included with the LC101 Modules and may be ordered separately
from Welch Allyn OEM Technologies or other suppliers.
For an intubated patient, the sample line connects to the patient’s breathing circuit.
Sample connections for both intubated and non-intubated patients are shown below.
Watertrap
Sample line
Watertrap
Sample line
To cannula
Elbow connector
to breathing
apparatus
Typical Connection to Non-Intubated Patient
Typical Connection to Intubated Patient
Page 14 Confidential Welch Allyn OEM Technologies
LC101 CO2 Module OEM Implementation Manual
Section 2
LC101 Module Interface
Power Requirements
Description Typical
Input voltage range 5 V regulated, or +5.75 to +14.50 Vdc
Ripple 100 mV peak-to-peak
Typical non-measurement mode power 570 mW at 8 Vdc
Typical operating power 1.3 W at 8 Vdc
Typical occluded power 1.5 W at 8 Vdc
LC101 Main Board
Description Specification
Dimensions 3.15 in. L x 3.90 in. W x 1.00 in. H
(80.3 mm × 99.3 mm × 25mm)
Orientation No limitations
Weight < 1 lb (454 gm)
Welch Allyn OEM Technologies Confidential Page 15
LC101 CO2 Module OEM Implementation Manual
LC101 Module Interface Connector
The LC101 Module interface connector is a 4-pin connector (Molex P/N 22-11-2042). The host
may use a 4-pin polarized housing (Molex P/N 22-01-3047 with Molex 2759 series terminals) or
equivalent.
Pin Signal Signal Description
Vin
a
input power
1
2 gnd ground
3 TXD data from Main Board to host system
4 RXD data from host system to Main Board
a. The “square” plated through-hole designates pin 1 on the Main Board.
Watertrap Switch Connection
Watertrap switch connection is via a 2-pin Molex connector on the Main Board.
Pump
The pump is mounted on the Main Board. The pump wiring harness is connected to the Main
Board via a 2-pin connector (Molex P/N 22-01-3027).
The pump wiring meets typical insulation standards but does not meet patient isolation
requirements. If the pump must be moved to a different location, patient isolation requirements
must not be compromised. Refer to Section 6, Regulatory, for additional regulatory and safety
information.
Watertrap Receiver
The internal space available in the host monitor must be considered when incorporating the
watertrap receiver into the host system design. To accommodate various OEM dimensions, two
watertrap receivers are offered: long and short. The long watertrap receiver requires more
intrusion into the host monitor but the watertrap does not protrude as far externally from the host
chassis than with the short watertrap receiver.
Page 16 Confidential Welch Allyn OEM Technologies
LC101 CO2 Module OEM Implementation Manual
Section 2 - LC101 Module Interface
Watertrap Receiver Switch
The watertrap receiver switch is wired in the “normally open” configuration.
The watertrap receiver switch connects directly to the Main Board via a wiring harness and
connector. The watertrap receiver switch assembly is equipped with a 2 pin connector (Molex
P/N 22-01-3027) which electrically connects directly to the Main Board at J102.
The watertrap receiver switch wiring meets typical insulation standards but does not meet patient
isolation requirements. When applicable, harness routing must not violate patient isolation
requirements. Refer to Section 6, Regulatory, for additional regulatory and safety information.
Exhaust Tubing
In the event of an exhaust tubing malfunction, gas buildup can occur within the host system.
WARNING To protect against potentially flammable gas buildup, the tubing must be
single-fault protected. Refer to Section 6, Regulatory, for additional regulatory
and safety information.
Welch Allyn OEM Technologies Confidential Page 17
LC101 CO2 Module OEM Implementation Manual
Page 18 Confidential Welch Allyn OEM Technologies
LC101 CO2 Module OEM Implementation Manual
Section 3
LC101 Calibration
The LC101 Module requires periodic user calibration to adjust offset voltages and calibration
constants used by the internal C-Cap bench. There are two types of calibration, each supported
in the LC101 software protocol:
• Zero Calibration
•Two-Point User Calibration
Zero Calibration
The Zero Calibration adjusts the offset voltage used by the C-Cap to generate the CO2 values
and the IR source current. The required frequency of Zero Calibration depends on the amount
and type of usage, and may be typically required every two weeks. The LC101 does not monitor
the elapsed time between calibrations, nor does it alert the host when calibration is needed. It is
up to the host system and the end-user to determine when calibration is required.
The procedure requires the use of clean, dry air (0% CO2) at room/ambient temperature. In
order to provide the 0% CO
used to absorb CO
eliminates CO
Allyn OEM Technologies.
The scrubber is designed to be attached directly to the Welch Allyn OEM Technologies watertrap
by the user before a Zero Calibration. The scrubber is removed after successful calibration. The
scrubber has a shelf life of approximately one year. Although the scrubber is considered reusable, its effective life depends on application and exposure to CO
concentration in the zero reference gas and will alert the host system, when polled for
CO
2
status, if a problem exists with the sample zero gas.
from room air. The scrubber contains a chemical which reacts with and
2
as it is drawn through the scrubber. The CO2 scrubber is available from Welch
2
, an external device, called a “CO2 scrubber” (or CO2 absorber), is
2
. The LC101 monitors the
2
Welch Allyn OEM Technologies Confidential Page 19
LC101 CO2 Module OEM Implementation Manual
To get an accurate calibration, the LC101 needs to be operating for at least 5 minutes in
measurement or autorun mode with the scrubber installed. The LC101 internally monitors the
run time and will not allow a Zero Calibration if the run time requirement has not been met.
The LC101 monitors the calibration progress and provides a “Calibration OK” (or “not OK”)
message to the host system when polled for status. See the LC101 Software Protocol and the
Zero Calibration Commands and Responses for more detail. After a successful Zero Calibration,
the LC101 updates the zero residual offset constants located in the LC101 C-Cap EEPROM
Memory and the IR source current.
Zero Calibration Procedure
Equipment needed:
• watertrap
•CO2 scrubber (or 0% CO2 medical-grade gas source; see the Two-Point User
Calibration procedure for pressurized gas setup)
To Perform a Zero Calibration:
The user is required to apply a 0% CO2 gas, or “zero” gas, during the steps of a Zero Calibration.
To perform Zero Calibration, the user must follow the Original Equipment Manufacturer’s
procedure typically provided in the Operator’s Guide or User Service Manual.
1. Select a well ventilated room to perform the calibration.
2. Make sure the LC101 has been operating for at least 5 minutes prior to the Zero Calibration.
3. Attach the CO2 scrubber to the watertrap inlet according to the CO2 scrubber “Directions for
Use” (or attach a 0% medical-grade gas source). Now let the LC101 operate for one
minute.
4. After approximately one minute, observe the CO2 reading. The CO2 reading should be
between 0.0% - 0.3% with well-ventilated room air.
5. Proceed with the zero gas phase of the calibration as defined by the host system.
6. Disconnect the CO2 scrubber (or gas source) from the watertrap after the zero gas calibration.
Page 20 Confidential Welch Allyn OEM Technologies
LC101 CO2 Module OEM Implementation Manual
Section 3 - LC101 Calibration
Two-Point User Calibration
NOTE Before performing a Two-Point User Calibration, a separate Zero Calibration must be
performed first. It is also recommended that both calibrations be performed at 75ºF in
order to maintain accuracy over the Module’s operating temperature range.
The Tw o-Point User Calibration, or User Calibration, updates two of the gas calculation constants
used to generate the CO
amount and type of usage. Typically it may be required every six months. The LC101 does not
monitor time between calibrations, nor does it alert the host when calibration is needed. It is up
to the host system and the end-user to determine when calibration is required.
To get an accurate User Calibration, the LC101 needs to be operating for at least 5 minutes in
measurement or autorun mode. The LC101 internally monitors the run time and will not allow a
User Calibration if the run time requirement has not been met.
To perform the User Calibration, the host is required to supply a calibration date, a span gas
concentration, and indicate the gas concentration being applied to the LC101 Module (0% or the
span gas).
values. The required frequency of User Calibration depends on the
2
The OEM typically provides a User Calibration Kit to the end user containing a CO2 reference
gas with regulator, scrubber, directions for use, adapter, and tubing.
The LC101 monitors the User Calibration progress and provides a “Calibration OK” (or “not OK”)
message to the host system after successful calibration when polled for status. See the LC101
Software Protocol and the User Calibration Commands and Responses for more detail. After a
successful User Calibration, the LC101 updates the User Calibration History Queues located in
the LC101 C-Cap EEPROM Memory.
Zero and User Calibration dates should be user accessible via a host service screen or other
means.
Welch Allyn OEM Technologies Confidential Page 21
LC101 CO2 Module OEM Implementation Manual
Two-Point User Calibration Procedure
Illustration of gas canister,
regulator and pneumatic circuit
Equipment needed:
• calibration gas canister (8 – 12% CO2, ±0.02%, balance air or nitrogen)
Regulator
Te e
On/Off
10%
CO2
Bal. N2
Free Flow Away
From Monitor Input
Water Trap
To Monitor
Two-Point User Calibration Equipment Setup
• gas valve and non-silicon tubing
• sample elbow or tee
•flow meter
• sample line
•watertrap
•CO2 scrubber (or 0% CO2 medical-grade gas source)
CAUTION Make sure that the tubing used to connect the gas supply to the LC101 does
NOT contain silicon. Silicon tubing absorbs CO
and affects the stability of
2
the gas concentration, thereby reducing the accuracy of the procedure.
Page 22 Confidential Welch Allyn OEM Technologies
LC101 CO2 Module OEM Implementation Manual
Section 3 - LC101 Calibration
To Perform a Two-Point User Calibration:
The user is required to apply a 0% CO2, or “zero” gas, and also apply a gas of known CO2
concentration (referred to as “span” gas) during the various steps of a Two-Point User
Calibration. The user is required to manually enter the value of the Span Gas applied into the
Monitor.
To perform the Two-Point User Calibration, the user must follow the Original Equipment
Manufacturer’s procedure typically provided in the Operator’s Guide or User Service Manual.
(Refer to illustration on
page 22.)
1. Select a well-ventilated room to perform the calibration.
2. Let the LC101 run for at least 5 minutes prior to calibration.
3. For the “Sample Zero Reference Gas” step, attach the CO2 scrubber to the watertrap inlet
according to the CO
scrubber “Directions for Use” (or use a 0% medical-grade gas source).
2
4. Proceed with the zero gas phase of the calibration as defined by the host system. Disconnect CO2 scrubber (or 0% gas source) from the watertrap after the zero gas phase and prior
to the next calibration step.
5. For the “Sample Span Reference Gas” phase of the calibration, provide a medical-grade
gas source with a known CO
concentration between 8% and 12%, regulated to a pressure
2
between 5 and 7 psi.
NOTE Do not apply any pressure directly to the Module inlet or outlet.
6. Introduce a steady stream of CO2 gas. Set and monitor the flow rate to approximately
liter/minute (±10%). To verify flow, place the bleed line of the calibration sample line in a
1
glass of water. If bubbles emerge, gas supply is sufficient. If no bubbles emerge, there is an
insufficient supply of gas.
7. Connect a sample line from the sample elbow, or Tee, as shown above, to the Monitor’s
watertrap inlet. Make sure the bleed line is directed away from the monitor. Allow the refer
ence gas to flow for at least one minute.
8. Sample the Span Reference Gas.
9. After the Two-Point User Calibration steps have been followed, disconnect the LC101 from
the gas supply and test setup.
10. A verification may be performed using the same gas delivery set up. Verify the observed
CO
gas reading is within 3 mmHg or 10%, whichever is greater, of the CO2 value of the test
2
gas supplied. (If not, refer the user to the appropriate troubleshooting information.)
-
Welch Allyn OEM Technologies Confidential Page 23
Troubleshooting
• Make sure that the room is well ventilated. CO2 readings may be elevated in a closed
room.
• Confirm that the calibration gas is of known concentration. If the CO2 readings are
consistently elevated or depressed, the calibration gas may be suspect. Try another
gas source.
• Make sure that the CO2 module was properly set up and operating for the required
minimum period before testing.
• Check for air leaks in the pneumatic tubing and connections. Repair or replace as
needed.
• Confirm that the sample gas flow rate is greater than the CO2 module’s pump flow
rate.
• Confirm that silicon tubing is not used in the procedure (silicon absorbs CO2 which
affects the gas concentration stability and accuracy of the procedure).
LC101 CO2 Module OEM Implementation Manual
Page 24 Confidential Welch Allyn OEM Technologies
LC101 CO2 Module OEM Implementation Manual
Section 4
Host/Module Communications
The LC101 Module is a command driven slave device capable of communicating with a host
system over an asynchronous serial communication line. After the host system commands the
LC101 Module to begin transmission of CO
sends periodic packets without additional intervention by the host system. The host system must
initiate all other communication with the LC101 Module.
waveform and breath data packets, the Module
2
The LC101 Module and the host system are referred to as the “Module” and “host” in the
remainder of this section.
Communication Interface
• 9600 baud rate
• full duplex
• asynchronous using standard non return to zero (NRZ) format.
{1 start bit 7 or 8 data bits even parity 1 stop bit}
• Receive data input (RxD) is the buffered input of a 74HC14. A pull up is provided on
the Module so it can be driven by an open collector source.
•Transmit data output (TxD) is the collector of a 2N4401 transistor driven with a 10 K
base resistor from the output of a 74HC14. A weak pull up is provided to source a
CMOS load.
• Module power and communications are provided at J101.
Welch Allyn OEM Technologies Confidential Page 25
LC101 CO2 Module OEM Implementation Manual
System EEPROM
The system EEPROM contains manufacturing and operational data that is necessary for the
LC101 Module to function. A limited number of these system parameters may be specified by the
OEM. These include
• data format
• start up mode
• initial pump flow rate
The data format options are 7 and 8 data bits (default is 7E1).
The start up mode options are auto run, measurement, standby and fault (default is standby).
The initial pump flow rate option allows the host to specify the default pump flow rate in
milliliters per minute (default is 150 ml/min).
Packet Structure
Transmission of host commands and Module responses is via packets. The following byte
structure represents a packet.
Packet format:
< start of text (STX) 02h
X identifier 1*(ASCII)
n
xx
yy CCITT/CRC code 2*(ASCII)
> end of text (ETX) 03h
ASCII characters have values in the range of 00h to 7Fh. The identifier is case sensitive.
Characters between 00h and 20h are reserved as control characters.
Tr ansmission of all packets starts with a “<” STX control character and ends with a CCITT/CRC
code and “>” ETX control character. Between STX and ETX is an identifier and n bytes of ASCII
data. The length of the packet is defined by the identifier character. Packet length cannot exceed
25 bytes with a maximum of 20 bytes of data allowed. Packets without the STX control character
are ignored. The CCITT/CRC code is calculated on values between STX and CCITT/CRC code.
data n(hex char)
Example:
02h X xxn yy 03h
Page 26 Confidential Welch Allyn OEM Technologies
LC101 CO2 Module OEM Implementation Manual
Section 4 - Host/Module Communications
Host Commands
The host communicates to the Module via commands. These include:
• mode commands to request a change in the operating mode.
• simple commands to request data or a status change. Data is not sent with these
commands.
• configuration commands to specify custom system settings. Data is sent with these
commands.
• calibration commands to request a Zero or User Calibration sequence. Data is sent
with these commands.
Mode Commands
Mode commands allow the host to put the Module into one of the three operating modes.
Host Command Description
<M24> Enter auto run mode
To start automatic sampling and data packet transmission at default
intervals of realtime CO2 waveform and breath data. A watertrap
removal causes the Module to wait for a watertrap insertion. This is
the preferred operating mode since temporary watertrap
removal and replacement is typical in normal operation.
<M23> Enter measurement mode
Same as auto run mode except for sidestream watertrap removals.
Instead of waiting for watertrap insertion, the sensor’s activity is
halted and the Module reverts to the standby mode and requires a
new <M23> host command to restart measurement.
<M21> Enter standby mode
Used when a low power standby state for the Module is desirable.
This prolongs the life expectancy of the IR source, since this component is disabled in this mode.
No more than two mode commands should be issued in any five-second period.
The Module automatically reverts to fault mode if a Module or sensor fault occurs. A fault
message is sent via the status response by the Module to the host when polled for status.
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Simple Commands
Simple commands instruct the Module to send Module data or EEPROM data and to reset the
Module software or reset sensor error.
Host Command Description
<C00> Request and confirm operating mode and Module status
<C20> Request software version
<C21> Request hardware version
<C22> Request ambient barometric pressure
<C23> Request sensor temperature
<C26> Request single CO2 measurement
<C27> Request single breath data packet
<C2E> Request current set flow rate
<C31> Request sensor EEPROM revision #
<C32> Request sensor manufacturer code
<C33> Request sensor serial #
<C3A> Request last calibration date
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LC101 CO2 Module OEM Implementation Manual
Section 4 - Host/Module Communications
Configuration Commands
Configuration commands instruct the Module to temporarily modify specific default settings for
measurement criteria. A new pump flow rate may also be specified. The host does not have to
command the Module into the unprotected mode prior to issuing a new flow rate command.
A description of these commands is included in the following table.
Host Command Description
<Nxx> Change CO2 waveform update rate
Allows the host to specify how often the Module sends a CO2 waveform data packet. The Module generates a CO2 measurement every
31msec. The maximum update rate is 31 msec. The host may program the rate to xx increments, where xx is the number of 31msec
increments per packet.
<Nxx> where xx (ASCII) defines the CO2 waveform update rate
based on the number of 31msec increments.
xx range 00h to FFh
xx default 01h, 31 msec interval
Examples:
<N01> send a CO2 waveform data packet every 31 msec (1 × 31
msec)
<N05> send a CO2 waveform data packet every 155 msec (5 ×
31 msec)
<NFF> send a CO2 waveform data packet every 7.9 seconds
(255 × 31 msec)
<N00> stop sending waveform data
<Axx> Change breath data clear rate
Allows the host to specify how long the Module waits for a new
breath data packet before clearing the breath data (ETCO2 = 00h /
RR = 00h / InsCO2 = 00h).
<Axx> where xx (ASCII) defines the “no breath” timeout in sec-
onds
xx range 10 to 60 s (0Ah to 3Ch)
xx default 0Fh, clear breath data after 15 s of “no breath”
Example:
<A0A> clear the breath data after 10 seconds of “no breath”
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<Oxx> Change breath data update rate
Allows the host to specify how often the Module sends a breath
data packet.
<Oxx> where xx (ASCII) is converted to a 8 bit binary number (yyzz
zzzz) with yy defining how often the breath data is
updated.
If yy = 00 binary, Breath data packet update rate is defined by
zzzzzz, where zzzzzz is in tenths of seconds. The 6
lower bits = (seconds × 10).
to even values.
If yy = 01 binary, Breath data packet update rate is every breath
where zzzzzz = doesn’t matter.
Exception: If the “no breath” condition occurs, data is sent
at 1 second increments.
If yy = 10 binary, Breath data update rate is when the data changes,
where zzzzzz = doesn’t matter.
Exception: If after 15 seconds the breath data has not
changed, data is sent after the next breath. This does not
guarantee a 15 second update; however, if the “no breath”
condition has occurred, the “no breath” timeout takes precedence.
Exception: If the “no breath” condition occurs, data is sent
at 1 second increments.
If yy = 11 binary, Not defined.
Examples
<O05> send a breath data packet at .6 s interval (Odd values
<O40> send a breath data packet every breath
<O80> send a breath data packet every time the data changes
Special case:
<O00> no breath data sent (Note: Continuous CO2 mode would
:
rounded up)
use this command.)
Odd values are rounded up
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