A generalized transfer function predicted radial and digital artery pressure waveforms from the digital volume pulse with an average root mean square error of 4.4+/-2.0 and 4.3+/-1.9 mm Hg.
Observational (n=60)
Can a generalized transfer function accurately relate the noninvasive digital volume pulse to the peripheral pressure pulse across different blood pressure states?
A generalized transfer function can accurately predict peripheral pressure pulse waveforms from noninvasive digital volume pulse recordings, independent of hypertension or nitroglycerin administration.
Effect estimate: RMSE 4.4+/-2.0 mm Hg (radial) and 4.3+/-1.9 mm Hg (digital)
The digital volume pulse can be recorded simply and noninvasively by photoplethysmography. The objective of the present study was to determine whether a generalized transfer function can be used to relate the digital volume pulse to the peripheral pressure pulse and, hence, to determine whether both volume and pressure pulse waveforms are influenced by the same mechanism. The digital volume pulse was recorded by photoplethysmography in 60 subjects (10 women, aged 24 to 80 years), including 20 subjects with previously diagnosed hypertension. Simultaneous recordings of the peripheral radial pulse and digital artery pulse were obtained by applanation tonometry and a servocontrolled pressure cuff (Finapres), respectively. In 20 normotensive subjects, measurements were obtained after the administration of nitroglycerin (NTG, 500 microgram sublingually). Transfer functions obtained by Fourier analysis of the waveforms were similar in normotensive and hypertensive subjects. In normotensive subjects, transfer functions were similar before and after NTG. By use of a single generalized transfer function for all subjects, the radial and digital artery pressure waveforms could be predicted from the volume pulse with an average root mean square error of 4.4+/-2.0 and 4.3+/-1.9 mm Hg (mean+/-SD) for radial and digital artery waveforms, respectively, similar to the error between the 2 pressure waveforms (4.4+/-1.4 mm Hg). The peripheral pressure pulse is related to the digital volume pulse by a transfer function, which is not influenced by effects of hypertension or NTG. Effects of NTG on the volume pulse and pressure pulse are likely to be determined by a similar mechanism.
Millasseau et al. (Fri,) conducted a observational in Hypertension (n=60). Generalized transfer function vs. Direct measurement (applanation tonometry and Finapres) was evaluated on Root mean square error between predicted and measured radial and digital artery pressure waveforms (RMSE 4.4+/-2.0 mm Hg (radial) and 4.3+/-1.9 mm Hg (digital)). A generalized transfer function predicted radial and digital artery pressure waveforms from the digital volume pulse with an average root mean square error of 4.4+/-2.0 and 4.3+/-1.9 mm Hg.