Vigileo原理與準(zhǔn)確性

1、測定心率測定心率 通過波形的上升通過波形的上升來識別心跳來識別心跳 從心跳的時間周從心跳的時間周期計算出心率期計算出心率校準(zhǔn)血管的差異性校準(zhǔn)血管的差異性 (順順應(yīng)性和阻力應(yīng)性和阻力) 從人口統(tǒng)計學(xué)資料中評從人口統(tǒng)計學(xué)資料中評估不同病人的差異性估不同病人的差異性 通過血壓數(shù)據(jù)和波形分通過血壓數(shù)據(jù)和波形分析評估動態(tài)的改變析評估動態(tài)的改變基于生理學(xué)原理基于生理學(xué)原理, 脈搏壓脈搏壓(PP)和每搏量和每搏量(SV)成比例成比例 應(yīng)用統(tǒng)計分析計算應(yīng)用統(tǒng)計分析計算PP特特性性 在每一次心跳的基礎(chǔ)上進(jìn)在每一次心跳的基礎(chǔ)上進(jìn)行計算行計算APStdevCO = HR * Sd(AP) * 每秒采樣血壓100次

2、每搏量的改變會使得脈搏壓相應(yīng)的改變 準(zhǔn)確測量整個脈搏周期的壓力，并計算其標(biāo)準(zhǔn)差 動脈壓標(biāo)準(zhǔn)差Sd(AP) 脈搏壓(PP) 每搏量(SV) 每搏量（SV）計算取20秒平均值PP SV收收縮壓縮壓SBP舒舒張壓張壓DBP20 sec.20 sec. SV 變異度 Std(BP) SV 變異度 Std(BP)20 sec.因此，對一個不變的血管狀況 05010015020025030000.0050.010.0150.020.0250.030.0350.040.0450.05PressureCompliance05010015020025030000.0050.010.0150.020.0250.0

3、30.0350.040.0450.05PressureCompliance05010015020025030000.0050.010.0150.020.0250.030.0350.040.0450.05PressureCompliance05010015020025030000.0050.010.0150.020.0250.030.0350.040.0450.05PressureComplianceFemaleMaleAge 20Age 50Age 80Elasticity of the vessel 年齡和性別與血管順應(yīng)性相關(guān) 高血管順應(yīng)性降低血壓變異度Sd（AP）及PP 2101max1P

4、PPPALPCP, mmHgCv,(P) cm2.mmHgP0P1P1CvmaxCvmax/2A, cm2P, mmHgP0P0+P1P1AmaxAmax/2FemaleMaleAmaxP0P14.1272-0.89*Age57-0.44*Age5.6276-0.89*Age57-0.44*Age血管順應(yīng)性血管順應(yīng)性 10maxarctan15 . 0PPPAPALangewouters GJ, et al, The static elastic properties of 45 human thoracic and 20 abdominal aortas in vitro and the p

5、arameters of a new model. J Biomechanics. 1984;17:425-435 運算法則尋找影響血管特性的動脈壓的特征性變化(i.e., ap, MAP, Skewness, Kurtosis) 這些改變包括在SV的計算中斜率斜率:反映血管順應(yīng)性反映血管順應(yīng)性MAP反映反映外周阻力外周阻力峰態(tài)峰態(tài)區(qū)分血壓采樣點區(qū)分血壓采樣點Arterial pulse pressure waveform moments均值 變異度斜率 (a measure for lack of symmetry) 峰態(tài) (a measure of how peaked or flat a

6、 sample distribution is from normal distribution 10111NkavgpkPNP 1022211NkavgppPkPN 103311NkpavgpPkPN 104411NkpavgpPkPN對絕大多數(shù)病人來說，對絕大多數(shù)病人來說， 從主動脈弓到外周動脈，收縮壓遞增，從主動脈弓到外周動脈，收縮壓遞增， 而血流量而血流量遞減遞減 動脈壓力動脈壓力 流量流量 Recorded immediately after coronary bypass2 hours after coronary bypassWeighted Skewness = 1.1Weig

7、hted Skewness = 0.1Weighted Kurtosis = 0.024Weighted Kurtosis = 0.071Different hemodynamic conditions in the same patientChanges in Vascular ToneTAPAPLangMAPPCBSAHRf43,.,)(,一旦各因素相關(guān)性確定，相關(guān)順應(yīng)性計算 變量矩陣建立，建立在血壓數(shù)據(jù)上的 SV就算就可以實現(xiàn).CO = PR * SVwhereSV = * apTAPAPLangMAPPCBSAHRf43,.,)(,一旦各因素相關(guān)性確定，相關(guān)順應(yīng)性計算 變量矩陣建立，建

8、立在血壓數(shù)據(jù)上的 SV就算就可以實現(xiàn)0 1 2 3 4 5 60 1 2 3 4 5 6Horswell JL, et al, Arterial Pressure-Based Method of Continuous Cardiac Output Monitoring Accurately Follows Trends in Cardiac Output During and After Surgery, presented at SCCM 2006.Pressure (mmHg)Pressure (mmHg)Pulse RateStroke VolumeVascular ToneMAP 升高

9、而CO 維持不變脈搏率每搏量血管特性改變Identical CO values with significant different arterial pressuresMcGee WT, et al, Validation of a Continuous Cardiac Output Measurement Using Arterial Pressure Waveform, poster at the ISICEM, Brussels, 2005 Key CCO ICO FloTrac脈搏率每搏量血管特性改變Key CCO ICO FloTracHorswell JL, et al, Art

10、erial Pressure-Based Method of Continuous Cardiac Output Monitoring Accurately Follows Trends in Cardiac Output During and After Surgery, presented at SCCM 2006.Pulse RateStroke VolumeVascular ToneConclusions: This novel arterial pressure cardiac output algorithm provides cardiac output assessments that agree satisfactorily for clinical purposes with intermittent and