The Research Of Key Technology About Carboxyhemoglobin Multi-Wavelength Noninvasive Detection Method

Carboxyhemoglobin(COHb) is a kind of human hemoglobin derivatives and the product of carbon monoxide combined with hemoglobin. After inhaled carbon monoxide, the body's hemoglobin rapidly combines with carbon monoxide to form carboxyhemoglobin. The content of carboxyhemoglobin in the human body is closely relative to the amount of carbon monoxide in the air, so the content is the sign used to determine carbon monoxide poisoning. Carbon monoxide poisoning causes the hemoglobin to lose the ability to carry oxygen, tissue hypoxia. Carbon monoxide poisoning is a worldwide common and high incidence disease, but do not have the identifiability clinical symptoms. Therefore, detecting the content of carboxyhemoglobin in human blood has important clinical significance for timely diagnosis of carbon monoxide poisoning and taking timely relief measures.At present, the detection of carboxyhemoglobin is mainly through invasive blood gas analysis method in the clinical. But the invasive method cannot be real-time online monitoring. Therefore, carboxyhemoglobin real-time noninvasive detection methods become inevitable. Real-time continuous noninvasive pulse oxygen saturation measurement technology is mature, widely used in clinical. However, the equipment monitoring carboxyhemoglobin content in real-time continuous non-invasive way is not much, only Masimo products passed the FDA certification in the market. There are no studies in China. Because there are many problems with invasive method, therefore, noninvasive carboxyhemoglobin detection technology has great application space. In this paper, the study of the method about noninvasive carboxyhemoglobin detection based on multi-wavelength spectrum was proposed.In order to achieve real-time, continuous, non-invasive detection of carboxyhemoglobin content, fill the domestic blank of such technology, the subject was proposed. The subject is a study of multi-wavelength noninvasive carboxyhemoglobin detection method, and the method is based on photoplethismograpyh on the existing pulse oximetry monitoring technology platform. The subject through constructing multiple wavelength hardware control system, modular software system and PC software system, to complete the multi-wavelength photoplethismograpyh acquisition and data transmission. And the signals' analysis and feature calculation were preceeded on the PC software system. At the same time, the multi-wavelength pulse oxygen saturation(SpO2) measurement function used to assist the diagnosis of carbon monoxide poisoning disease was added. The real-time monitoring of pulse oxygen saturation and carboxyhemoglobin was realized. The pulse oxygen saturation monitoring and the real-time quantitative assessment of carbon monoxide poisoning were completed. And the calculation method of carboxyhemoglobin content was verified by standardized calibration method of carboxyhemoglobin, based on the hardware system, software platform and algorithm platform of the subject.The invasive experimental verification results showed that test equipment can effectively reflect the overall upward trend of carboxyhemoglobin content, after the subjects inhaled carbon monoxide. The root mean square error of SpCO between test equipment and Masimo reference device is approximately 1.33, correlation coefficient of SpCO between test equipment and Masimo reference device is approximately 0.7948. The root mean square error of SpO2 between test equipment and Masimo reference device is approximately 1.4682, correlation coefficient of SpO2 between test equipment and Masimo reference device is approximately 0.9875. According to the results, the research work in this paper achieved the expected target. The follow-up works are required in measurement range, invasive calibration, special multi-wavelength sensor and the overall system design improvements, in order to improve the applicability of this system.