Comparison of outcomes for routine versus American Heart Association-recommended technique for blood pressure measurement (CORRECT BP): a randomised cohort study.

Background: Optimal clinical care, diagnosis and treatment requires accurate blood pressure (BP) values. The primary objective was to compare BP readings taken while adhering to American Heart Association (AHA) guidelines to those typical of routine clinical care. Specifically studied: the combined effect of feet flat on the floor, back supported, and arm supported with cuff at heart level, while adhering to other guideline recommendations. Methods: In this prospective, randomised, three-group cohort study, a modified cross-over design was applied in a primary care outpatient office setting in Columbus (OH, USA). Eligible participants were adults (aged ≥18 years) with an arm circumference of ≥18 cm and ≤42 cm who did not have a renal dialysis shunt or a previous or current diagnosis of atrial fibrillation. 150 recruited volunteers meeting the inclusion criteria were randomly randomised into the three groups. Group methodologies were BP readings taken on a fixed-height exam table followed by readings taken in an exam chair with adjustable positioning options (Group A), readings taken in the reverse order, chair then table (Group B), and both sets of readings in the exam chair (Group C). A rest period occurred before each set of readings. Group C was included for the purpose of obtaining an independent estimate of the order effect. The order in which the two types of readings (table vs chair) were taken was randomised. The primary outcome was the difference between the mean of three BP readings taken on the table and the mean of three readings taken in the chair. Findings: Between September and October, 2022, 150 participants were enrolled in the study; all 150 of whom completed testing: 48 in Group A, 49 in Group B, 53 in Group C. The mean systolic/diastolic BP (SBP/DBP) of readings taken on the table (Group A first readings, Group B second readings) were 7.0/4.5 mmHg higher than those taken in the chair (Group A second readings, Group B first readings); both statistically significant, p < 0.0001. These findings show that AHA-recommended positioning-feet flat on the floor, back supported, arm supported with the BP cuff at heart level-results in substantially lower BP values than improper positioning. The mean SBP/DBP of the first set of readings taken on the chair were 1.6/0.6 mmHg higher than for the second set of readings (Group C, included to estimate order effect). Interpretation: The observed benefit of proper positioning is sufficient to change the BP classification of several million patients from having hypertension to not having hypertension and therefore avoiding medication and/or intense follow-up. Funding: Midmark Corporation, Versailles, Ohio, USA.

Statistical considerations for testing automated sphygmomanometers in special patient populations.

The International Standards Organization 81060-2:2018 is the current global Standard for the validation of automated sphygmomanometers. It specifies the requirements for clinical studies on the general population, as well as additional requirements for special populations, which might have physiologic characteristics that affect the accuracy of blood pressure measurements. This paper summarizes the statistical methodology behind the sample size required to test automated sphygmomanometers in these special populations and specifically addresses the pregnant patient population.

Validation of the A&D UM-212BLE monitor according to ISO 81060-2, 2018: a device with clinically important programmability.

OBJECTIVE: The objective of this report was to describe the validation of the A&D UM-212BLE automated oscillometric sphygmomanometer to the ISO 81060-2, 2018 protocol. The device is specifically designed for enhanced office and out-of-office programmability. METHODS: A combined pediatric ( n = 35) and adult ( n = 50) population was studied at Clinmark LLC in Louisville, Colorado, USA. Same-arm sequential testing was performed following the ISO 81060-2, 2018 requirements. Five cuffs were tested with a total arm circumference range from 12 to 50 cm. Reference readings were done by two blinded observers performing simultaneous auscultation. RESULTS: For validation of Criterion 1 the mean ± SD (mmHg) of the device minus the reference differences were 3.94 ± 6.89 for SBP and 2.09 ± 6.68 for DBP. Both passed the Standard limits for Criterion 2; the systolic(S)SD achieved was 5.56 (5.70 permitted) and the diastolic(D)SD was 6.01 (6.62 permitted). All other Standard requirements were met. CONCLUSIONS: The UM-212BLE passed all requirements. The features that make this device clinically superior include settings for automated office BP, variable pressure inflation, dual measurement modes (oscillometry, auscultation), the wide range of cuffs tested, automated irregular heartbeat detection, and full validation in a pediatric population. The inclusion of all of these features makes the UM-212BLE a highly attractive device for both office and out-of-office BP estimation.

Validation of the Aktiia blood pressure cuff for clinical use according to the ANSI/AAMI/ISO 81060-2:2013 protocol.

OBJECTIVE: Assess the accuracy and precision of the Aktiia initialization oscillometric upper-arm cuff device (Aktiia SA, Neuchâtel, Switzerland) for home blood pressure (BP) monitoring in the general population according to the American National Standards Institute / Association for the Advancement of Medical Instrumentation/International Organization for Standardization (ANSI/AAMI/ISO) 81060-2:2013 standard. METHODS: Three trained observers validated BP measurements performed using the Aktiia cuff versus BP measurements performed using a standard mercury sphygmomanometer. Two ISO 81060-2 criteria were used to validate the Aktiia cuff. Criterion 1 evaluated, for both SBP and DBP, whether the mean error between BP readings performed by the Aktiia cuff and auscultation was ≤±5 mmHg, and whether the SD of the error was ≤8 mmHg. Criterion 2 assessed whether, for the SBP and DBP of each individual subject, the SD of the averaged paired determinations per subject of the Aktiia cuff and of the auscultation met the criteria listed in the table of Averaged Subject Data Acceptance. RESULTS: Mean differences between the Aktiia cuff and the standard mercury sphygmomanometer (criterion 1) were 1.3 ± 7.11 mmHg for SBP and -0.2 ± 5.46 mmHg for DBP. The SD of the averaged paired differences per subject (criterion 2) was 6.55 mmHg for SBP and 5.15 mmHg for DBP. CONCLUSION: Aktiia initialization cuff complies with the requirements of the ANSI/AAMI/ISO guidelines and can be safely recommended for BP measurements in the adult population.

Validation of the A&D UA-651 Plus/UA-651SL Plus automated sphygmomanometer according to the ISO 81060-2, 2018 and ISO 81060-2 Amendment 1, 2020, which resulted in the currently pending Amendment to Amendment 1.

In 2020 the ANSI/AAMI/ISO published Amendment 1 to the 81060-2 Standard. The purpose was to try to address issues relating to the distribution of subjects with respect to limb size ranges. It also required a new plot showing the limb circumferences on the x-axis and the device minus reference errors on the y-axis (Alpert plot). The study reported here showed inadequacies of the Amendment if significantly overlapping cuffs were to be tested. The innovative approach led to the testing of 135 subjects. Requirements for blood pressure (BP), arm circumference, and gender were fulfilled. The standard same arm sequential protocol was used. Criterion 1 calculations gave a mean ± standard deviation (SD) device minus manual BP values of 0.22 ± 7.90 mmHg for systolic BP and -0.68 ± 7.36 mmHg for diastolic BP. The maximum allowed mean value for either measurement is 5.0 mmHg. The SD values for Criterion 2 were 6.03 mmHg for systolic BP (maximum allowed 6.95) and 6.47 mmHg for diastolic BP (maximum allowed 6.90). All results passed the Standard requirements. This study demonstrated inadequacies of Amendment 1 and led to the development of an Amendment 2, still in the process of finalization. The new Amendment corrects the issues with significantly overlapping cuffs and "wide-range" cuffs. The A&D UA-651 Plus/UA-651SL Plus BP monitors and the five cuffs not only passed the requirements of 81060-2:2018 and Amendment 1 but also a revised and more rigorous protocol with more subjects involved. These devices and cuffs can be used with confidence.

Validation of the STEP deflation algorithm of the Midmark IQvitals Zone Vital Signs Monitor: part of a novel clinical ecosystem.

OBJECTIVES: Assess the accuracy of the Midmark IQvitals Zone Vital Signs Monitor STEP deflation algorithm according to the ANSI/AAMI/ISO 81060-2 Standard. METHODS: A total of 85 subjects completed the testing protocol. All standard requirements for gender, blood pressure (BP) values, and arm circumferences were met. Manual auscultation was performed by testers blinded to the device; the manual BP values were compared to the device readings. RESULTS: The Standard Criterion 1 data analyses showed mean ± SD device minus manual BP values of 1.22 ± 6.3 mmHg for SBP and -1.67 ± 6.09 mmHg for DBP. The SD values for criterion 2 were 5.06 mmHg (SBP) and 4.98 mmHg (DBP). CONCLUSIONS: The device passed all Standard requirements. The Midmark IQvitals Zone device has features to improve accuracy and reduce or eliminate transcription errors and inaccuracy from improper patient positioning.

Evaluating the impact of motion artifact on noninvasive blood pressure devices.

Most automated sphygmomanometers use oscillometric algorithms. Motion, either patient-based or environmental, will affect the ability of a device to record an accurate blood pressure (BP). Members of the Association for the Advancement of Medical Instrumentation (AAMI) Sphygmomanometer Committee have been studying this problem for more than a decade. The AAMI TIR44 was the first publication to address the challenges of motion tolerance. The concepts described in TIR44 have led to the development of a draft of ISO 81060-4, a new standard for testing devices for which the manufacturer wishes to claim motion tolerance. The current ISO 81060-2 addresses both stress testing and 24-hour ambulatory BP monitoring. Recent publications have reported on testing of devices in response to voluntary and involuntary patient motion. The ISO 81060-4 will address testing in the presence of patient transport by ground, fixed-wing, and rotary (helicopter) ambulances. The protocol will utilize noise profiles recorded under those three conditions. The profiles will be digitally stored on a library with free access. The proposed testing will be performed using patient simulators introducing the noise library files into known BP oscillometric envelopes. The specifications of the data capture and playback devices are specified, as is the evaluation statistical testing. The authors expect that the final draft will be published in 2020.

Accuracy testing of a new optical device for noninvasive estimation of systolic and diastolic blood pressure compared to intra-arterial measurements.

OBJECTIVE: The objective of this study was to compare the systolic (S) and diastolic (D) blood pressure (BP) estimations from a new optical device at the wrist with invasive measurements performed on patients scheduled for radial arterial catheterization in the ICU. Optical signals were automatically processed by a library of algorithms from Aktiia SA (OBPM - optical blood pressure monitoring algorithms). METHODS: A total of 31 participants from both sexes, aged 32-87 years, were enrolled in the study (NCT03837769). The measurement protocol consisted of the simultaneous recording of reflective photoplethysmographic signals (PPG) from the cuffless optical device and the reference BP values recorded by a contralateral radial arterial catheter. From the 31 participants, 23 subjects whose reference data quality requirements were adequate were retained for further analysis. The PPG signals from these patients were then automatically processed by the Aktiia OBPM library of algorithms, which generated uncalibrated estimates of SBP and DBP. After the automatic assessment of optical signal quality, 326 pairs of uncalibrated SBP and DBP determinations from 16 patients were available for analysis. These values were finally transformed into calibrated estimations (in mmHg) using arterial catheter SBP and DBP values, respectively. RESULTS: For SBP, a mean difference (±SD) of 0.0 ± 7.1 mmHg between the arterial catheter and the optical device values was found, with 95% limits of agreement in the Bland-Altman method of -11.9 to + 12.2 mmHg (correlation of r = 0.87, P < 0.001). For DBP, a mean difference (±SD) of 0.0 ± 2.9 mmHg between arterial catheter and the optical device values was found, with 95% limits of agreement in the Bland-Altman method of -4.8 to + 5.5 mmHg (correlation of r = 0.98, P < 0.001). CONCLUSION: SBP and DBP values obtained by radial artery catheterization and those obtained from optical measurements at the wrist were compared. The new optical technique appears to be capable of replacing more traditional methods of BP estimation.

Validation of the Welch Allyn Home blood pressure monitor with professional SureBP algorithm with a special feature of accuracy during involuntary (tremor) patient movement.

BACKGROUND: Current blood pressure (BP) measurement guidelines recommend certain patient requirements, especially keeping still for 5 min. Some patients cannot comply. My colleagues and I have reported accurate performance of the Welch Allyn SureBP algorithm for BP estimates during voluntary patient motion. No validation studies for involuntary patient movement (tremor) BP readings have been reported. This paper reports the validation of the Welch Allyn Home BP monitor, the 1700 Series, which contains that same SureBP algorithm, and the results of tremor testing as well. This device has multiple clinical advantages. PATIENTS AND METHODS: Eighty-five patients (49 females) were studied using the ANSI/AAMI/ISO 81060-2, 2013 requirements. Three sizes of cuffs were included. The tremor experiments used a simulator programmed to frequency and amplitude of oscillometric impulses typically seen in patients with diseases causing tremors. This is the first protocol developed for this clinical scenario. The device uses an inflation-based algorithm, reducing discomfort and cycle times. RESULTS: The mean±SD for the device minus manual readings per ISO Criterion 1 were -2.93±6.64 mmHg for systolic BP and -2.453±5.48 mmHg for diastolic BP. The tremor testing was performed at low, normal, and high BP simulations. The device recorded a BP value for every cycle tested. The errors (device minus manual BP estimates) were quite low. CONCLUSION: The Welch Allyn Home BP monitor is accurate in the presence of involuntary patient motion (tremor). Clinicians can have a high level of confidence in the use of a self-measurement device, which operates using the same algorithm as contained in the 'professional grade' family of devices.

Accurate blood pressure during patient arm movement: the Welch Allyn Connex Spot Monitor's SureBP algorithm.

BACKGROUND: Current blood pressure (BP) measurement guidelines specify patient requirements, including being still. Some populations of patients cannot comply. A new International Organization for Standards is being developed to test devices that claim tolerance to transport-induced motion artifacts. This study proposes the first protocol to assess BP device accuracy in the presence of patient-induced motion. PARTICIPANTS AND METHODS: Forty healthy volunteers (23 males) participated. The device tested was the Welch Allyn Connex Spot Monitor (CSM) using the SureBP algorithm. A reusable cuff was placed on the left arm. During inflation/deflation cycles the participant performed pronation/supination movements of the left forearm every 5 s. The CSM readings during motion were compared to the average of manual resting auscultatory estimations immediately before and after each motion cycle (bracketing). RESULTS: The CSM recorded a BP reading on the first cycle in 37 participants. It displayed a reading in all 40 participants with one repeat cycle in the other three. The mean±SD for the device minus the manual BP values was 0.9±7.3 mmHg for systolic BP and -3.4±7.9 mmHg for diastolic BP. CONCLUSION: This study represents a proposal for an automated BP device assessment in the presence of patient-induced motion. The CSM device, which uses an inflation-based algorithm, routinely produced BP values that closely matched auscultatory values bracketed immediately before and after the motion-associated cycle. The CSM should be of significant clinical value in populations in whom resting 'still' readings are not usually feasible, such as pediatric and geriatric patients, and patients in pain from injury or illness.

Validation of the Welch Allyn Pro BP 2000, a professional-grade inflation-based automated sphygmomanometer with arrhythmia detection in a combined pediatric and adult population by ANSI/AAMI/ISO standard testing.

OBJECTIVE: The Welch Allyn Pro BP 2000, an automated sphygmomanometer, was subjected to ANSI/AAMI/ISO testing. PATIENTS AND METHODS: The protocol used was the same-arm sequential procedure described in the ANSI/AAMI/ISO 2013 Standard. Eight-eight (53 adults and 35 children aged 3-12 years old) patients completed testing successfully. Arm circumferences ranged from 15 to 49.5 cm. Seven different cuff sizes were used, including two long cuffs. RESULTS: All requirements for age, sex, blood pressure (BP), and cuff sizes were fulfilled. The mean±SD was -2.8±6.37 mmHg for systolic BP for criterion 1 and -3.6±6.14 mmHg for diastolic BP. The SD for criterion 2 were 5.29 for systolic BP and 5.75 for diastolic BP. All data passed the Standard's requirements. CONCLUSION: The Pro BP 2000 uses an accurate inflationary algorithm. The time for each inflation/deflation cycle is short, thus improving patient comfort. There is also arrhythmia detection to caution the use of BP values obtained during irregular heart rhythms. The algorithm for the professional-grade Pro BP 2000 is also contained in the Home BP 1700, targeted for home use. This encourages out-of-office self-measurement. The healthcare professional can be confident that the values obtained at different sites are comparable.

Accurate blood pressure measuring devices: Influencing users in the 21st century.

Hypertension is now recognized as a major global cause of morbidity and death. All decisions relating to the epidemiology, diagnosis, and management of hypertension are dependent on being able to measure blood pressure accurately. Scientists have developed protocols to assess the accuracy of blood pressure-measuring devices, but little attention has been given to informing users which devices are accurate and inaccurate. This article identifies a recipient audience of researchers, clinicians, and scientists, the public, healthcare executives and administrators, and consumer and regulatory bodies, and discusses how best to communicate the results of device accuracy to these groups with the aim of improving the accurate measurement of blood pressure.

Validation protocols for blood pressure measuring devices in the 21st century.

Blood pressure (BP) is a vital sign and the essential measurement for the diagnosis of hypertension. Therefore, its accurate measurement is a key element for the evaluation of many medical conditions and for the reliable diagnosis and efficient treatment of hypertension. In the last 3 decades prestigious organizations, such as the US Association for the Advancement of Medical Instrumentation (AAMI), the British Hypertension Society, the European Society of Hypertension (ESH) Working Group on BP Monitoring, and the International Organization for Standardization (ISO), have developed protocols for clinical validation of BP measuring devices. All these initiatives aim to standardize validation procedures and establish minimum accuracy standards for BP monitors. Unfortunately, only a few of the BP measuring devices available on the market have been subjected to independent validation using one of these protocols. Recently, the AAMI, ESH, and ISO experts agreed to develop a single universally acceptable standard (AAMI/ESH/ISO), which will replace all previous protocols. This major international initiative has been undertaken to best serve the needs of patients with hypertension, a public interested in cardiovascular health, practicing physicians, scientific researchers, regulatory bodies, and manufacturers. There is an urgent need to influence regulatory authorities throughout the world to make it mandatory for all BP measuring devices to have undergone independent validation before approval for marketing. Efforts need to be intensified to improve the accuracy of BP measuring devices, further optimize the validation procedure, and ensure that objective and unbiased validation data become available.

The Accutension Stetho, an automated auscultatory device to validate automated sphygmomanometer readings in individual patients.

The aim of this report is to describe a new device that can validate, by automated auscultation, individual blood pressure (BP) readings taken by automated sphygmomanometers.The Accutension Stetho utilizes a smartphone application in conjunction with a specially designed stethoscope that interfaces directly into the smartphone via the earphone jack. The Korotkoff sounds are recorded by the application and are analyzed by the operator on the screen of the smartphone simultaneously with the images from the sphygmomanometer screen during BP estimation. Current auscultatory validation standards require at least 85 subjects and strict statistical criteria for passage. A device that passes can make no guarantee of accuracy on individual patients. The Accutension Stetho is an inexpensive smartphone/stethoscope kit combination that estimates precise BP values by auscultation to confirm the accuracy of an automated sphygmomanometer's readings on individual patients. This should be of great value for both professional and, in certain circumstances, self-measurement BP. Patients will avoid both unnecessary treatment and errors of underestimation of BP, in which the patient requires therapy. The Stetho's software has been validated in an independent ANSI/AAMI/ISO standard study. The Stetho has been shown to perform without difficulty in multiple deflation-based devices by many manufacturers.

Accuracy of Blood Pressure Measurement Devices in Pregnancy: A Systematic Review of Validation Studies.

The accurate measurement of blood pressure (BP) in pregnancy is essential to guide medical decision making that affects both mother and fetus. The aim of this systematic review was to determine the accuracy of ambulatory, home, and clinic BP measurement devices in pregnant women. We searched Ovid MEDLINE, The Cochrane Library, EMBASE, CINAHL EBSCO, ClinicalTrials.gov, International Clinical Trials Registry Platform, and dabl from inception through August 3, 2017 for articles that assessed the validity of an upper arm BP measurement device against a mercury sphygmomanometer in pregnant women. Two independent investigators determined eligibility, extracted data, and adjudicated protocol violations. From 1798 potential articles identified, 41, that assessed 28 devices, met the inclusion criteria. Most articles (n=32) followed a standard or modified American National Standards Institute/Association for the Advancement of Medical Instrumentation/International Organization for Standardization, British Hypertension Society, or European Society of Hypertension validation protocol. Several articles described the results of validation studies performed on >1 device (n=7) or in >1 population of pregnant women (n=12), comprising 64 pairwise validity assessments. The device was validated in 61% (32 of 52) of studies which used a standard or modified protocol. Only 34% (11 of 32) of the studies wherein the device was successfully validated were performed without a protocol violation. Given the implications of inaccurate BP measurement in pregnant women, healthcare providers should be aware of and try to use the BP measurement devices which have been properly validated in this population.