Capnograph Mainstream — Biomedical Instrumentation & Clinical Sensing

Abstract — Capnograph Mainstream

Capnograph Mainstream: Biomedical Engineering, Medical Electronics & Bio-Signal Modeling Integrated Clinical Investigation: Bio-Sensors · Analog Front-Ends (AFE) · Diagnostic Waveforms · DSP Algorithms · ~7098 Words Chapter 1: Electrophysiological Foundations, Action Potentials & Clinical Significance 1. School of Biomedical Engineering and Health Sciences, Universiti Teknologi Malaysia (UTM), Skudai, Malaysia 2. Institut Jantung Negara - Universiti Teknologi Malaysia (IJN-UTM) Cardiovascular Engineering Center, Universiti Teknologi Malaysia (UTM), Skudai, Malaysia The study of carbon dioxide expiration is called capnometry. The graphical representation of capnometry is called capnography. There is a growing interest in the usage of capnography as the usage has expanded toward the study of metabolism, circulation, lung perfusion and diffusion, quality of spontaneous respiration, and patency of airways outside of its typical usage in the anesthetic and emergency medicine field. The parameters of the capnograph could be classified as carbon dioxide (CO 2 ) concentration and time points and coordinates, slopes angle, volumetric studies, and functional transformation of wave data. Up to date, there is no gold standard device for the calculation of the capnographic parameters.

Sensor Interfacing & Analog Front-End Conditioning

Capnography digitization using the image processing technique could serve as an option. From the algorithm we developed, eight identical breath waves were tested by four investigators. The values of the parameters chosen showed no significant difference between investigators. Although there were no significant differences between any of the parameters tested, there were a few related parameters that were not calculable. Further testing after refinement of the algorithm could be done. As more capnographic parameters are being derived and rediscovered by clinicians and researchers alike for both lung and non-lung-related diseases, there is a dire need for data analysis and interpretation. Although the proposed algorithm still needs minor refinements and further large-scale testing, we proposed that the digitization of the capnograph via image processing technique could serve as an intellectual option as it is fast, convenient, easy to use, and efficient.

Bio-Signal Waveform Analysis & Simulation Findings

Figure 1: Diagnostic Medical Waveform & Bio-Potential Clinical Trace for Capnograph Mainstream Capnometry is the expirometric study of the carbon dioxide gas. Although it is used interchangeably with “capnography,” “capnometry” means only the measurement of carbon dioxide (CO 2 ) in respiratory gas without a continuous written record or waveform ( 1 ). The device in which both the capnometry and capnography are measured is called the capnometer. The capnometer is capable to sample both the time-based and volume-based signal ( 2 ). Time-based capnography is an expirogram that plots the expired CO 2 partial pressure against a continuous duration of time ( 2 , 3 ).

Scope & Clinical Applications

• Real-time multi-parameter vital signs telemetry (ECG, Heart Rate, SpO2, Temperature, Respiration)
• Low-noise Analog Front-End (AFE) conditioning with active Driven Right Leg (DRL) 50 Hz cancellation
• Digital signal processing in MATLAB: Pan-Tompkins QRS detection, FIR/IIR notch, and Continuous Wavelet Transforms
• Finite element tissue bio-electromagnetics and orthopedic mechanical simulations in COMSOL & ANSYS
• Complete Arduino firmware .INO sketches, circuit schematics, and university dissertation reports