- 學位論文
開發假體血壓校正系統以驗證即時低壓式血壓量測裝置
Development of the phantom blood pressure calibration system for validation of real-time continuous low-pressure blood pressure measurement device
摘要
血壓(blood pressure)與血壓波型為臨床評估心臟功能的指標。一般非侵入式量測方式，如振盪式血壓量測法，目前皆無標準校正工具可供市售儀器進行校正，因此本研究開發假體血壓校正系統，以供振盪式血壓量測進行校正，同時利用假體血壓校正系統可以調整、輸出不同舒張壓與收縮壓以提供血壓量測裝置進行校正。 同時，本研究整合本實驗室已有的非侵入式連續血壓量測系統[1]，將數位處理晶片(DSK5510) 以及PID控制工程的幫浦控制加入系統，建構振盪法血壓量測與連續血壓量測兩種血壓量測功能，並以上述假體模擬系統進行兩種血壓量測功能校正。 本研究實測分為三方面，第一部份整合振盪法血壓量測功能與床邊監視器血壓量測結果進行比對的自我測試。量測十位受測者，每位受測者量測兩次。結果顯示，使用本系統與床邊監視器量測得平均血壓與舒張壓差異大多數在10 mmHg以內，但收縮壓有較多差異超過10 mmHg，整體來說本系統與床邊監視器在收縮壓、舒張壓與平均血壓量測結果相比較，在統計上皆有顯著差異(p<0.001)。 第二為利用建構假體模擬系統改變其輸出舒張壓與收縮壓以測試假體模擬系統使用在振盪法血壓量測裝置表現。結果顯示，當假體模擬系統設定收縮壓、舒張壓與平均血壓分別為139 mmHg、60 mmHg與86 mmHg時，本研究振盪法血壓量測機制量測值分別為132.4±5.32 mmHg、48.4±2.80 mmHg與94.5±5.48 mmHg。床邊監視器量測值分別為143.6±1.51 mmHg、88±1.05 mmHg與105.4±1.17 mmHg。由結果可知，在本研究系統量測，收縮壓與平均血壓與假體模擬設定較接近，而舒張壓有偏低現象。在床邊監視器量測，在收縮壓有與假體模擬設定較接近，在平均血壓與舒張壓皆有過高現象。整體來說，雖然兩種儀器量測值皆有不同大小差異，但在統計上不管是在收縮壓、舒張壓與平均血壓皆與假體模擬系統有統計上的顯著差異。 第三部份為利用假體模擬系統測試連續血壓量測系統對於不同設定表現。結果顯示，假體模擬系統固定收縮壓提高舒張壓時，連續血壓振幅量測會有下降趨勢。反之，當假體模擬系統固定舒張壓提高收縮壓時，連續血壓振幅量測會有上升趨勢。但當同時調整舒張壓與收縮壓時，血壓振幅會根據舒張壓與收縮壓的互相抵銷而有不固定上升與下降。 經由上述三種實際量測結果顯示，本研究已成功開發一假體血壓校正系統，可提供非侵入式振盪式血壓量測裝置進行校正。同時，可利用此假體血壓校正系統進行連續血壓量測裝置的相關測試。未來改進方向包括:假體血壓校正系統的材質、管路與控制，以提供更精準、更擬真的血壓模擬。同時，利用假體血壓校正系統驗證、改進振盪法血壓量測與連續血壓量測之參數設定與功能。
並列摘要
Blood pressure and blood pressure waveform are indicators for clinical evaluation of heart functions. The physiological reaction mechanism will influence the changes of blood pressure and blood pressure waveform. There is no calibration tool for commercial device using common non-invasive blood pressure measurement method, such as auscultation and oscillation. Thus, this study develops the phantom blood pressure calibration system (PBPCS) to calibrate the non-invasive measurement oscillomatric devices. Additionally, this system can adjust and output different basic blood pressure (diastolic pressure) and flow (systolic pressure) in order to provide proper setting for the calibration of blood pressure measurement devices. At the same time, this research integrates the custom made non-invasive continuous blood pressure system from this laboratory [1] with the real-time digital signal processing chips and the PID controller for pump control into one complete system. The constructed system has two blood pressure measurement capabilities: oscillometric blood pressure measurement and continuous blood pressure measurement. and use the phantom blood pressure calibration system to adjust the two kind of blood pressure meters. This research have three aspects, the first part compares the blood pressure measurements of integrated device using oscillometric blood pressure measurement method and bedside monitor (Spacelabs). This experiment measures ten subjects and repeat twice measurements for each subject. Results demonstrate that the most of the difference of mean pressure and diastolic pressure between the integrated device and the bedside monitor are less than 10 mmHg. However, lots of the systolic pressures differs more than 10 mmHg. Over all, there are significant differences on systolic pressure, diastolic pressure and mean pressure obtained by the integrated device and the bedside monitor. And, the correlation coefficient is 0.867. The second aspect is to assess the performance of the PBPCS in oscillometric blood pressure measurement by adjusting and outputting different basic blood pressure (diastolic pressure) and flow (systolic pressure). Results demonstrate that when the settings of PBPCS for systolic, diastolic and mean pressure are 139 mmHg, 60 mmHg and 86 mmHg, respectively, the measured results of the integrated device are 32.4±5.32 mmHg, 48.4±2.80 mmHg and 94.5±5.48 mmHg, respectively. On the other hand, the measured results of the bedside monitor are 143.6±1.51 mmHg, 88±1.05 mmHg and 105.4±1.17 mmHg, respectively. These results indicate that the systolic pressures and mean pressures from the integrated device are adjacent to the PBPCS setting. However, the integrated device underestimates the diastolic pressures. On the other hand, the bedside monitor overestimates the diastolic and mean pressures. Nevertheless, there are significant differences between PBPCS settings and measurements from both devices. The third part of this research is to use the PBPCS to evaluate the continuous blood pressure measurement system under different settings. The results demonstrate that when the PBPCS keeps systolic pressure constant and elevates the diastolic pressure, the blood pressure pulse wave has the tendency to decrease in amplitude. On the other hand, when the PBPCS keeps diastolic pressure constant and elevates the systolic pressure, the pulse wave amplitude increases. When the PBPCS adjusts systolic and diastolic pressures at the same time, due to the combined effect of changes in diastolic and systolic pressures, the change of pulse wave amplitude is uncertain. By way of the preceding results of three experiments, this research develops the PBPCS to calibrate the non-invasive blood pressure measurement devices successfully. At the same time, it can be used for related tests of continuous blood pressure measurements system. In the future, there are several improvement can be made including: the material of the phantom, pipeline and control mechanism of the PBPCS in order to provide more realistic and more accurate blood pressure simulation. At the same time, the PBPCS can be used to validate and test the parameters setting for oscillometric blood pressure and continuous blood pressure measurements.