Cuff width alters the amplitude envelope of wrist cuff pressure pulse waveforms

Abstract

The accuracy of noninvasive blood pressure (BP) measurement with any method is affected by cuff width. Measurement with a too narrow cuff overestimates BP and measurement with a too wide cuff underestimates BP. Automatic wrist cuff BP monitors use permanently attached narrow cuffs with bladders about 6 cm wide. Such narrow cuffs should result in under-cuffing for wrist circumferences larger than 15 cm. The objective of this qualitative study was to show that a narrow wrist cuff results in increased BP values when a cuff pulse amplitude ratio algorithm is used. According to the algorithm used in this study, systolic pressure (SBP) corresponds to the point of 50% of maximal amplitude; for diastolic pressure (DBP) the ratio is 70%. Data were acquired from 12 volunteers in the sitting position. The mean wrist circumference was 18 cm. The acquired cuff pulse data were used to compute SBP, mean pressure (MAP) and DBP. The mean values for a 6 cm cuff were SBP = 144 mmHg, MAP = 104 mmHg and DBP = 88 mmHg. The values for a 10 cm cuff were SBP = 128 mmHg, MAP = 93 mmHg and DBP = 78 mmHg. The reference BP values were SBP = 132 mmHg, MAP = 96 mmHg and DBP = 80 mmHg. All narrow (6 cm) cuff BP values were higher than wide (10 cm) cuff or reference BP values. The results indicate that wider wrist cuffs may be desirable for more accurate and reliable BP measurement with wrist monitors.

Development of a Public Database of Raw Data From a Blood Pressure Cuff

“…For example, cuff width for 20 cm wrist circumference is 8 cm. Our previous study [10] showed the effect of under-cuffing on accuracy and reliability of wrist cuff BP devices. Investigators interested in wrist cuff BP determination should take this into account.…”

The impact of arm circumference on noninvasive oscillometric blood pressure referenced with intra-aortic blood pressure

“…The cuff size influences the accuracy of noninvasive BP measurement not only in brachial, but in wrist [11], or even in toe BP measurements [12]. As the cuff size may result in differences between peripheral and central BP readings [13], the cuff size should be selected correctly for noninvasive central BP measurement.…”

New Hemodynamic Parameters in Peri-Operative and Critical Care—Challenges in Translation

“…Besides aiding in making observations on regulation mechanisms, the large number of studies has also contributed to identifying technology requirements for measurement of arterial properties. Device characteristics such as PPG sensor contact impact on PTT [ 65 ], hydrostatic effects [ 66 ], BP cuff size/shape/design properties [ 67 , 68 , 69 ], different cuff inflation strategies [ 60 , 70 ], and measurement of cardiac factors [ 71 ] have been investigated, and processes for validating devices have been improved [ 66 ]. Motion artifacts and signal-to-noise ratio have also been thoroughly investigated [ 72 ].…”

“…In addition to this, many sensor effects are not fully understood or characterized. PPG contact pressure, cuff size and placement, and wrapping tightness have recently been found to affect signal quality and interpretability [ 65 , 67 , 68 , 69 , 72 ]. In certain cases, even sensor effects of invasive measures such as arterial lines can make the data unusable (e.g., inaccurate damping).…”