title: A new noninvasive device for continuous arterial blood pressure monitoring in the superficial temporal artery.
abstract: Continuous recording of arterial blood pressure (ABP) has many applications in cardiovascular physiology, but existing alternatives rely on measurements performed in the fingers or radial artery. Peripheral recordings have significant differences from central ABP regarding the pattern of the waveform and corresponding systolic and diastolic values. To address the need for noninvasive measurements closer to the ascending aorta, a new device was constructed to measure ABP in the superficial temporal artery (STA) using photoplethysmography and the arterial volume clamping technique. The optoelectronic circuitry to generate the photoplethysmogram is contained in a specially designed probe placed over the STA and kept in place with a head frame. The prototype (STAbp) also includes original designs for the pneumatic, electronic, signal processing, control and display sub-systems. A self-calibration feature regularly updates the photoplethysmogram operating point to improve accuracy. The performance of the STAbp was compared against the Finapres in 19 healthy subjects. At rest, the bias (SDd) was -23.1 (15.05), -10.8 (13.83) and -12.4 (12.93) mmHg for systolic, mean and diastolic pressures respectively, without significant differences in drift between the two devices. The 99% bandwidth (SD) for the spectral distribution of ABP waveforms was 5.3 (1.46) Hz for STAbp and 6.8 (0.73) Hz for the Finapres (p < 0.01). Handgrip manoeuvre showed a very similar response to the Finapres, including the rapid return to baseline on release. The new STAbp device has considerable potential as a new tool for clinical and research applications where continuous recording of more central ABP is advantageous compared to peripheral alternatives.
authors.affiliation: Department of Medical Physics, University Hospitals of Leicester NHS Trust, Leicester Royal Infirmary, Leicester LE1 5WW, UK. kong.chin@uhl-tr.nhs.uk
authors.forename: K Y
authors.initials: KY
authors.lastname: Chin
authors.forename: R B
authors.initials: RB
authors.lastname: Panerai
mesh_terms: D000328:Adult; D062186:Arterial Pressure / Q000502:physiology*; D001795:Blood Pressure Determination / Q000295:instrumentation* / Q000379:methods*; D003971:Diastole / Q000502:physiology; D005260:Female; D018737:Hand Strength / Q000502:physiology; D006321:Heart / Q000502:physiology; D006801:Humans; D007537:Isometric Contraction / Q000502:physiology; D008297:Male; D017156:Photoplethysmography; D011674:Pulse; D012815:Signal Processing, Computer-Assisted; D013057:Spectrum Analysis; D013599:Systole / Q000502:physiology; D013699:Temporal Arteries / Q000502:physiology*