摘要
傳統血氧濃度機基於以微處理器作為核心訊號處理器，其配合之類比數位轉換器(ADC)多採用8~12位元低解析度之轉換器。由於血氧濃度計算需測量雙波長之紅外光與紅光之交流訊號與直流訊號之比值，由於交流訊號甚至會與直流訊號之強度相差約一千倍，為滿足最低訊雜比與提升訊號處理解析能力，故傳統血氧濃度機會以類比電路實現交流訊號分離，並進行放大與濾波，形成四通道訊號電路架構。 由於現今數位訊號處理器與高解析度類比數位轉換器在價格與功能整合性極具優勢，故本論文以24位元類比數位轉換器進行血氧濃度計前端電路簡化設計，除了可有效降低傳統類比電路之複雜度，藉由高位元類比數位轉換，亦能得到清晰之訊號細部特徵。 本論文同時實現傳統12位元血氧濃度計，並將24位元高解析度ADC，架構於傳統血氧濃度計解調後之直流訊號，並藉由血氧濃度模擬器輸出在固定血氧值之條件下，血液灌流量(PI)由20%~0.2%之訊號，透過兩套電路擷取之訊號，並配合相同之訊號處理程序所得之血氧值，證實24位元ADC架構除了能取代複雜之交流訊號處理電路外，處理低PI之血氧訊號能力亦優越於傳統電路。 本論文同時以24-bit ADC系統評估不同光亮度對Spo2的影響，及血氧濃度和心率的穩定性測試，並複製三台相同系統測試其再現性。 本論文依據量測系統擷取之訊號，及各項統計之數據資料，24-bit ADC血氧濃度計，對血氧模擬器標準差約為0.247、心跳標準差0.314，複製三台進行波型的比較相關度可達到0.99
並列摘要
pulse oximeter in the traditional microprocessor-based machines as the core signal processor, with the analog to digital converter (ADC) with 8 to 12 bits over a low resolution of the converter. As the calculation of oxygen concentration to be measured with dual-wavelength red light of the exchange infrared signals with the DC-signal ratio, due to exchange signals with the DC signal or the strength difference of about a thousand times, in order to meet the minimum signal to noise ratio and improve signal processing analytical capabilities, so the traditional analog circuit oxygen concentration of the opportunity to exchange signals to achieve separation, and zoom and filter, the formation of four-channel signal circuit architecture. As the current digital signal processors and high-resolution analog to digital converter integrated in the strong competitive advantage in price and features, this thesis to 24-bit analog to digital converter front-end circuit for pulse oximeter to simplify the design, in addition to effectively reduce the traditional analog circuit complexity, by high bit analog to digital conversion, the signal can also be clear and detailed features. The paper also of traditional 12-bit pulse oximeter, and 24-bit high-resolution ADC, the traditional pulse oximeter structure after DC signal demodulation and simulator output by oxygen concentration at a fixed oxygen value conditions, blood perfusion (PI) from 20% to 0.2% of the signal, the signal through two sets of circuit extraction and processing with the same signal from the oxygen values, confirmed that in addition to 24-bit ADC architecture replace the complicated communication signal processing circuit, the handling capacity of low-PI of the oxygen signal is also superior to the traditional circuit. The thesis in both 24-bit ADC system, the evaluation of different brightness effects on Spo2, oxygen saturation and heart rate and stability testing, and copy the three tested the same system reproducibility. In this thesis, the measurement system based on the signal acquisition, and various statistical data ,24-bit ADC pulse oximeter, oxygen simulator on the standard deviation of about 0.247, the standard deviation of 0.314 heartbeat, copy three to wave Comparison of correlation up to 0.99