Validation of the Omron M7 (HEM-780-E) oscillometric blood pressure monitoring device according to the British Hypertension Society protocol

BACKGROUND: The Omron M7 (HEM-780-E) is an automated oscillometric upper arm blood pressure monitor for the professional and home use markets. The aim of this study was to validate the accuracy of this device according to the British Hypertension Society (BHS) and the Association for the Advancement of Medical Instrumentation (AAMI) SP10 validation criteria. METHODS: Participants were recruited until a total of 85 were obtained that filled the blood pressure ranges specified by the BHS protocol. Recruitment to the study was from the general medical and specialist clinics and from the staff at Guy's and St Thomas' Hospital in London, UK. Nine sequential same-arm blood pressure readings were taken from each participant by two trained observers, alternating between a mercury reference sphygmomanometer and the Omron M7 (HEM-780-E). The differences between the reference and test device readings, for both systolic and diastolic pressures, were compared with BHS and AAMI criteria to determine the outcome of the study. RESULTS: The Omron M7 (HEM-780-E) is graded 'A' for systolic and 'A' for diastolic blood pressures according to the BHS criteria. The mean (standard deviation) of the difference between the observer and the device measurements was 0.75+/-6.5) mmHg for systolic and 1.33+/-5 mmHg for diastolic pressures. The device, therefore, also satisfies the AAMI SP10 standard for the study population, which requires differences of <+/-5 (8) mmHg. CONCLUSION: The Omron M7 (HEM-780-E) achieved an 'A/A' performance classification under the BHS criteria and passed the AAMI requirements for the study population. It can be recommended for professional and home-use in this population.     

Accuracy of the Omron RX-M, an automated blood pressure measuring device, measuring blood pressure at the wrist, according to a modified British Hypertension Society protocol

OBJECTIVE: To determine the accuracy of the Omron RX-M, a device measuring blood pressure oscillometrically at the wrist. METHODS: In 89 subjects (mean age 55+/-14 years) blood pressure measurements at the wrist with the Omron RX-M were compared to sequential blood pressure measurements with a mercury sphygmomanometer at the (same) upper-arm and to simultaneous measurements with the Omron HEM-705 CP at the opposite arm.Measurements with analyzed according to the British Hypertension Society (BHS) - protocol 1993, to the protocol of the Association for the Advancement of Medical Instrumentation (AAMI) and (retrospectively) to the new 'International Protocol'. RESULTS: Mean differences (+/-SD) between the measurements with the mercury sphygmomanometer and the Omron RX-M were -7.5+/-8.4 mmHg for diastolic blood pressure (DBP) and -2.5+/-12.2 mmHg for systolic blood pressure (SBP), thus not fulfilling the AAMI-criteria (< or =5+/-8). According to the BHS-criteria a grade D was achieved for both DBP and SBP. Compared to the Omron HEM 705 CP results were -6.3+/-7.1 for DBP (grade D) and -4.1+/-12.7 for SBP (grade D). The Omron RX-M also failed to pass the new 'International Protocol' in phase 1. CONCLUSION: Although easy to use, based on this study the Omron RX-M can not be recommended to determine blood pressure accurately.     

Evaluation of the Schiller BR-102 ambulatory blood pressure system according to the protocols of the British Hypertension Society and the Association for the Advancement of Medical Instrumentation.

OBJECTIVE: To evaluate the Schiller BR-102 monitor for ambulatory blood pressure measurement according to the protocols of the British Hypertension Society (BHS) and the Association for the Advancement of Medical Instrumentation (AAMI). DESIGN: The BHS protocol is divided into two parts. Part I, which is the part applicable to this study, comprises the main validation procedure and has five phases: before-use device calibration; in-use (field) phase; after-use device calibration; static device validation; and report of evaluation. METHOD: Three Schiller BR-102 recorders passed the before-use device calibration test, after which they entered the in-use (field) assessment phase during which the three recorders were each worn by 10 subjects for 24 h, after which calibration was again assessed. Because there was no difference in results of calibration testing among the three devices, one was selected randomly and the main validation test was carried out on 85 subjects with a wide range of blood pressures both for the auscultatory mode and for the oscillometric mode using the Sphygmocorder. The results were analysed according to the BHS grading system from A to D. The data were also analysed according to the standard of the Association for the Advancement of Medical Instrumentation (AAMI), which stipulates that the mean difference between the test device and the standard shall be 160/100 mmHg) the Schiller BR-102 was less accurate in the high pressure range for diastolic blood pressure but more accurate for systolic blood pressure, achieving A/C grading, while satisfying the AAMI criteria both for systolic and for diastolic blood pressure in the auscultatory mode. In the oscillometric mode the device performed less accurately in the high-pressure range, achieving grade D/C, while failing to satisfy the AAMI criteria both for systolic and for diastolic blood pressure. The means+/-SD of the first mercury sphygmomanometer measurements were 143+/-32 mmHg for systolic blood pressure and 88+/-21 mmHg for diastolic blood pressure. Acceptability to subjects was good and the manufacturer's manual was satisfactory. CONCLUSION: On the basis of these results, the Schiller BR-102 can be recommended for ambulatory blood pressure measurement in clinical practice using the auscultatory mode, but the oscillometric mode, which operates only if the device fails in the auscultatory mode, does not provide accurate measurements.     

Validation of the Omron M5-I, R5-I and HEM-907 automated blood pressure monitors in elderly individuals according to the International Protocol of the European Society of Hypertension

OBJECTIVE: This study aimed at verifying the accuracy of three automated electronic oscillometric blood pressure measuring devices, namely Omron M5-I (home use upper arm monitor), R5-I (home use wrist monitor) and HEM-907 (professional use upper arm monitor) according to the European Society of Hypertension International Protocol in elderly individuals. METHODS: Sequential measurements of systolic and diastolic blood pressure were obtained in 33 participants (aged >or=75 years) using the mercury sphygmomanometer (two observers) and each of the tested devices (one supervisor). A standard adult cuff was always employed during the study because all participants had an arm circumference compatible with such a cuff. According to the European Society of Hypertension validation protocol 99 couples (three pairs per patient) of test device and reference blood pressure measurements were obtained during phase 1 (15 participants studied) and phase 2 (a further 18 participants) for each electronic monitor. RESULTS: All devices successfully passed the validation study with a mean (+/-SD) device-observer difference for systolic and diastolic blood pressure of 0.2+/-3.6/0.2+/-3.9 mmHg (Omron M5-I), -1.5+/-6.2/-0.7+/-3.7 mmHg (Omron R5-I), and 0.1+/-5.1/-1.9+/-4.2 mmHg (Omron HEM-907). SD of the mean difference was lower and thus the precision was better for diastolic than for systolic blood pressure, and for the Omron M5-I than for the other two devices. CONCLUSIONS: According to the results of the validation study based on the European Society of Hypertension International Protocol the Omron M5-I, R5-I, and HEM-907 may be recommended for clinical use in elderly individuals, without atrial fibrillation or frequent ectopic beats.     

Validation of two devices for self-measurement of blood pressure by elderly patients according to the revised British Hypertension Society protocol: the Omron HEM-722C and HEM-735C.

BACKGROUND: The validation of self-measurement devices for clinical use by elderly patients has been recommended. The Omron HEM-722C device has recently been validated according to the British Hypertension Society (BHS) protocol for use for general populations and the Omron HEM-735C is a new fully automatic device with a high capacity for storage of measurements that is integrated with a personal computer. OBJECTIVE: To perform a clinical validation for use by elderly people of the Omron HEM-722C and HEM-735C devices according to the revised protocol of the BHS and the criteria of the Association for the Advancement of Medical Instrumentation (AAMI). METHODS: We carried out a main validation test according to the revised BHS protocol for validation procedures for special groups on two groups of 30 subjects aged more than 65 years (29 men and 31 women), 11 of 30 with systolic blood pressures (SBP) <110mmHg, 10 of 30 with SBP >200 mmHg, 15 of 30 with diastolic blood pressures (DBP( <70 mmHg and 10 of 30 with DBP >110 mmHg. The results were graded according to the BHS system from A to D. RESULTS: The Omron HEM 722C achieved an overall A/A grading and satisfied the AAMI criteria for accuracy whereas the Omron HEM-735C achieved an overall B/A grading and satisfied the AAMI criteria for accuracy. The sphygmomanometer measurements were 147 +/- 31/79 +/- 15 and 144 +/- 30/78 +/- 15 mmHg (means+/-SD) respectively, for the models 722C and 735C. The average differences between mercury sphygmomanometer and HEM-722C readings for SBP and DBP were, respectively, 0.76+/-5 and 0.41+/-8 mmHg; those for HEM-735C were, respectively, 0.24+/-8 and 0.9+/-8 mmHg. Readings of the HEM-722C device differed by less than 5 mmHg for 76% of systolic readings and 96% of the readings differed by less than 10 mmHg. Diastolic measurements differed by less than 5 mmHg for 71% and less than 10 mmHg for 71 and 87% of all readings. Readings of the HEM-735C device differed by less than 5 mmHg for 68% of systolic readings and 74% of the readings differed by less than 10 mmHg. Diastolic measurements differed by less than 5 mmHg in 74% and less than 10 mmHg in 88 and 87% of all readings. CONCLUSIONS: On the basis of these results, for elderly subjects both self-measurement devices (Omron HEM-722C and HEM-735C) satisfied the validation criteria of the BHS and therefore can be recommended for the clinical measurement of blood pressure in elderly patients.     

Quality Control and Validation of Oscillometric Blood Pressure Measurements Taken During an Epidemiological Investigation

This study aims to validate blood pressure (BP) values measured by an oscillometric BP monitor and seek possible calibration methods if discrepancies exist.Noninvasive BP measurement outcomes were determined using an oscillometric BP monitor (Omron HBP-1300) versus a mercury sphygmomanometer (standard device). Two percent of subjects enrolled in an epidemiological investigation were systematically sampled in this study. Intraclass correlation coefficient (ICC) was used to evaluate measurement reliability, paired t-test was used to evaluate trueness, and linear regression was used for calibration. The Association for the Advancement of Medical Instrumentation (AAMI) standards and British Hypertension Society (BHS) protocols were used for validation quality assessment.Both mercury sphygmomanometer (standard device) and oscillometric BP monitor (test device) displayed high reliability. A significant difference in systolic blood pressure (SBP) was observed between devices. SBP calibration was achieved by using an effective linear regression model (B = 0.803 and constant = 19.592, P < 0.001). The calibrated model was corroborated by verification samples (P = 0.120) and was found to pass AAMI standards and BHS protocol requirements.Calibrated SBP measurements from the Omron HBP-1300 device were valid. Use of a combination of statistical methods, such as ICC for reliability assessment as well as paired t-test for trueness evaluation can be used to validate data from the oscillometric BP monitors.     

Validation of the SAA-102 home blood pressure monitor according to the protocols of the European Society of Hypertension, the Association for the Advancement of Medical Instrumentation and the British Society of Hypertension

OBJECTIVE: To determine the accuracy of a new oscillometric home blood pressure (BP) monitor for arm BP measurement, the SAA-102, developed by the Sensacare Company. DESIGN: Evaluation of the SAA-102 was performed using validation protocols of the European Society of Hypertension (ESH), the Association for the Advancement of Medical Instrumentation (AAMI), and the British Hypertension Society (BHS). METHODS: The SAA-102 monitor was assessed on 33 participants according to ESH requirements, which are based on four zones of accuracy differing from the mercury standard by 5, 10, 15 mmHg or more. Then the oscillometric monitor was tested on 85 participants according to AAMI criteria which require a mean device-observers discrepancy within 5+/-8 mmHg. Finally, the electronic device was evaluated on 93 participants according to BHS requirements, which are based on five phases: before-use calibration, in-use assessment, after-use calibration, static device validation and report of the results. RESULTS: The SAA-102 passed all phases of the ESH international protocol for both systolic and diastolic blood pressure (SBP and DBP). The SAA-102 passed also AAMI criteria for SBP and DBP. The mean discrepancy between the SAA-102 and observers was 0.1+/-4.6 and -2.7+/-5.2 mmHg, for SBP and DBP, respectively. According to BHS protocol, the oscillometric monitor achieved final grading of A/A for SBP and DBP, respectively. CONCLUSION: These data show that the SAA-102 device satisfies ESH, AAMI, and BHS protocols for both SBP and DBP and may be recommended for everyday use for BP monitoring at home and in clinical practice.     

Validation of A&D UA-767 device for the self-measurement of blood pressure

BACKGROUND: The validation of self-measurement devices has been recommended. Automatic monitor A&D UA-767 (A&D Company, Ltd, Tokyo, Japan) is well known and widely used, but not tested according to the Association for Advancement of Medical Instrumentation (AAMI) and British Hypertension Society (BHS) recommendations. OBJECTIVE: To perform a clinical validation for use by adults of the A&D UA-767 device according to the criteria of the AAMI and a modified BHS protocol. METHODS: The test concerned 101 subjects (57 men and 44 women) aged 15-85 years with arm circumferences of 22-39 cm, a systolic blood pressure (SBP) range of 89-206 mmHg, and a diastolic blood pressure (DBP) range of 53-122 mmHg. For each subject, three readings of the UA-767 were compared with simultaneous auscultatory measurements by two trained independent observers who used a mercury manometer and dual stethoscope. The results were graded according to the BHS (1990 and 1993) and AAMI recommendations. RESULTS: Observers showed close agreement, with mean differences of 1.1+/-2.4 mmHg for SBP and -0.7+/-2.0 mmHg for DBP. The proportion of values agreeing to within 5, 10 and 15 mmHg were 93, 100, and 100% for SBP and 97, 100, and 100% for DBP for the two observers. The sphygmomanometer measurements were 132+/-24/79+/-14 mmHg (mean+/-SD). The average difference between the mercury sphygmomanometer and A&D UA-767 readings for SBP and DBP were, respectively, -0.4+/-5.4 and -0.4+/-4. 8 mmHg. The proportion of values agreeing to within 5,10, and 15 mmHg were 82, 94, and 98% for SBP and 80, 95, and 98% for DBP for the observers and device (A/A grade for BHS). CONCLUSIONS: For an adult population, the A&D UA-767 device for the self-measurement of blood pressure satisfied the AAMI criteria, achieved a BHS grade of A/A and can therefore be recommended for monitoring blood pressure in home and clinical conditions by patients with mild-to-moderate arterial hypertension.     

Evaluation of three devices for self-measurement of blood pressure according to the revised British Hypertension Society Protocol: the Omron HEM-705CP, Philips HP5332, and Nissei DS-175

OBJECTIVE: We evaluated three devices for self-measurement of blood pressure - the Omron HEM-705CP, the Philips HP5332 and the Nissei DS-175 - according to the revised protocol of the British Hypertension Society (BHS). The results were also analysed according to the criteria for accuracy of the revised standard of the Association for the Advancement of Medical Instrumentation (AAMI). DESIGN: The revised BHS protocol is divided into two parts. Part I, the part applicable to this study, comprises the main validation procedure and has five phases: Before-use device calibration; in-use (field) phase; after-use device calibration; static device validation; report of evaluation. METHODS: Three models of each device passed the before-use device calibration test, after which they entered the in-use phase, which involved use of the three recorders for a month; inter-device calibration was assessed again at the end of the month. There was no difference in calibration testing between the three models of each device, and therefore one of each was selected randomly; the main validation test was carried out in 85 subjects with a wide range of pressures, and the results were analysed according to the BHS grading system from A to D. RESULTS: The Omron HEM-705CP achieved an overall B/A grading and fulfilled the AAMI accuracy criteria; the Philips HP5332 achieved an overall C/A grading and failed the AAMI accuracy criteria for measuring systolic pressure; the Nissei DS-175 achieved an overall D/A grading and failed the AAMI accuracy criteria for measuring systolic pressure. When the BHS and AAMI criteria were applied to tertiles of pressure (low-pressure range < 130/80 mmHg; medium-pressure range 130-160/80-100 mmHg; high-pressure range > 160/100 mmHg) all three devices were less accurate in the high-pressure range: the Omron HEM-705CP achieved C/B grading while continuing to fulfil the AAMI criteria; the Philips HP5332 dropped to D grading for systolic pressure and the Nissei DS-175 achieved a lower D grading for systolic pressure. The mean and standard deviation of the first mercury sphygmomanometer measurements were 148+/-35/88+/-22 mmHg. Acceptability by the users was good and the manufacturer's manual was satisfactory for all three devices. CONCLUSIONS: On the basis of these results, the Omron HEM-705CP was the most accurate of the three devices tested, achieving Grade B for systolic and Grade A for diastolic pressure, as well as fulfilling the AAMI criteria for accuracy for both systolic and diastolic pressure. It can therefore be recommended for the clinical measurement of blood pressure and is the first inexpensive device to satisfy the accuracy criteria of these protocols.     

Validation of the Finometer device for measurement of blood pressure in black women

The improved Finapres apparatus, known as the Finometer, measures finger blood pressure noninvasively on a beat-to-beat basis and gives waveform measurements similar to intra-arterial recordings. The Finometer measures brachial pressure and corrects for finger pressure accordingly. It also corrects for the hydrostatic height of the finger with respect to the heart level. The objective was to validate the Finometer according to the revised British Hypertension Society (BHS) protocol and the criteria of the Association for the Advancement of Medical Instrumentation (AAMI). We carried out a main validation test using a subject group of 102 black women, which was also divided into smaller groups, namely 24 hypertensives, 25 obese normotensive and 35 lean normotensive women. Finometer and mercury sphygmomanometer blood pressure (BP) measurements were taken early in the morning before breakfast, after the subjects stayed overnight in a research unit. Within the whole subject group, the Finometer satisfied the AAMI criteria for accuracy and achieved an overall A/B grading according to the BHS criteria. The sphygmomanometer measurements were 128+/-20/78+/-12 mmHg compared to 130+/-20/78+/-11 mmHg for the Finometer. The average differences between the mercury sphygmomanometer and Finometer readings for systolic and diastolic BP were, respectively, -1.83+/-6.8 and 0.88+/-7.5. Systolic readings of the Finometer device differed by less than 5 mmHg for 64%, by less than 10 mmHg for 86% and differed by less than 15 mmHg for 96% of all readings. A total of 63% of all diastolic readings of the Finometer by less than 5 mmHg, 85% by less than 10 mmHg and 94% of all readings differed by less than 15 mmHg. On the basis of these results, the Finometer device satisfied the validation criteria of AAMI and received an A/B grading according to the BHS protocol. It can therefore be recommended for measurements in the clinical set-up and for research purposes.     

Clinical evaluation of the efficacy of the Braun PrecisionSensor oscillometric wrist blood pressure monitor for use on adults versus auscultation as defined by ANSI/AAMI SP10-1992

OBJECTIVE: To evaluate the overall performance of a new oscillometric wrist blood pressure monitor (Braun PrecisionSensor, Braun GmbH, Kronberg, Germany) as defined by the ANSI/AAMI SP10-1992 guidelines, and to analyze the data for the optimized selection of the algorithm that derives the blood pressure values from the oscillometric blood pressure curves. METHODS: The clinical trial was a multi-center, open, within-subject evaluation. Repeated sequential blood pressure measurements were taken on the left wrist using the Braun PrecisionSensor, and on the left upper arm using a T-tube stethoscope and a mercury sphygmomanometer as a standard auscultatory blood pressure measurement device. The reported results are based on a sample of 86 adult male and female subjects (57% female, 43% male). Three sets of measurements with each of both devices were evaluated for each individual. RESULTS: Close agreement was obtained between both observers in compliance with the ANSI/AAMI SP10-1992 guidelines. The mean values of the differences between the Braun PrecisionSensor and the mercury sphygmomanometer were 0.1mmHg for systolic and 1.9mmHg for diastolic blood pressure. The standard deviations were 7.1mmHg for systolic and 7.0mmHg for diastolic blood pressure. The use of an optimized algorithm improved the accuracy of the Braun PrecisionSensor, after which the standard deviations were 6.1mmHg for systolic and 6.3mmHg for diastolic blood pressure. CONCLUSIONS: The Braun PrecisionSensor satisfies the Association for the Advancement of Medical Instrumentation's efficacy and safety criteria for both systolic and diastolic blood pressures with both algorithms analyzed.     

对腕式电子血压计的准确性评价

目的评价欧姆龙HEM-6001型电子血压计的准确性并分析影响准确性的因素。方法151名试验对象,年龄范围19~78岁,平均年龄50±16岁。臂围20~40cm,腕围12.5~23cm。静息收缩压(SBP)范围85~192mmHg,舒张压(DBP)范围52~118mmHg,其中男性81名,女性70名。按水银柱式血压计、欧姆龙HEM-7000、水银柱式血压计、欧姆龙HEM-6001、水银柱式血压计的顺序测定同一侧上臂的血压。结果欧姆龙HEM-6001、HEM-7000型电子血压计均与水银柱式血压计所测血压值相关性较好,用BHS标准评估分别达到C/B级和B/A级。两者与听诊法测量的血压(SBP/DBP)差值分别为:0.59±8.92/0.43±7.34mmHg(HEM-6001)和-0.79±7.65/1.27±6.05mmHg(HEM-7000)。HEM-6001型的测量差值与臂围大小呈正相关(RSBP=0.315,P<0.01;RDBP=0.245,P<0.01),与腕围大小也呈正相关(RSBP=0.237,P<0.01;RDBP=0.183,P<0.05);HEM-7000型的测量差值与臂围大小不相关(RSBP=-0.066,P>0.05;RDBP=-0.022,P>0.05),与腕围大小也不相关(RSBP=0.098,P>0.05;RDBP=0.033,P>0.05)。结论臂围与腕围特别粗或细的人在使用腕式电子血压计时要注意到臂围和腕围对测量结果的影响。     

Evaluation of the overall efficacy of the Omron office digital blood pressure HEM-907 monitor in adults.

BACKGROUND: Non-invasive self blood pressure monitoring has become increasingly popular. To assure the accuracy of devices used for this purpose, all need to be validated independently prior to marketing. The objective of this study was to assess the accuracy of the HEM-907, a new semi-automatic, non-invasive, oscillometric blood pressure monitoring device specifically designed to be used in the clinic or physician's office setting. METHODS: Blood pressure measurements taken employing this device were compared with the results obtained by two experienced observers using a mercury sphygmomanometer on 100 subjects and patients (384 measurements). The limits of agreement were calculated for the device compared with the results of the two observers according to the standards of the Association for the Advancement of Medical Instrumentation (AAMI). RESULTS: The agreement between the two observers was -0.36+/-2.32mmHg for systolic blood pressure and 0.02+/-2.42mmHg for diastolic blood pressure. The agreement between the device and the observers was 1.56+/-4.42mmHg and 3.49+/-4.61mmHg for systolic and diastolic blood pressure respectively. CONCLUSIONS: The Omron HEM-907 satisfied the AAMI criteria for accuracy for a non-invasive blood pressure monitoring device.     

Wrist blood pressure-measuring devices: a comparative study of accuracy with a standard auscultatory method using a mercury manometer

BACKGROUND: In this study, we compared two wrist blood pressure-measuring devices, the Omron RX and the Nissei WS-310, against a mercury manometer. METHOD: A total of 152 subjects attending an out-patient hypertensive clinic were recruited from a randomized blood pressure survey, 87 patients (mean 44.4 +/- 14.5 years of age) being selected according to the Association for the Advancement of Medical Instrumentation/British Hypertension Society standards. Device validation was assessed through the use of sequential same-arm readings compared with readings taken using a mercury sphygmomanometer by the two trained observers. RESULTS: There were no differences between the observers and the monitors for diastolic readings (2.8 +/- 4.8 mmHg for the Omron and 4.2 +/- 6.4 mmHg for the Nissei) according to the Association for the Advancement of Medical Instrumentation standards. The largest standard deviations -- 8.3 mmHg for the Omron and 8.8 mmHg for the Nissei, respectively -- were seen for systolic readings recorded by the observers and the monitors. According to the British Hypertension Society standards, the Omron achieved an A grade for diastolic readings and a B grade for systolic readings within 5 and 10 mmHg. The Nissei monitor achieved an A grade for diastolic readings and a B grade for systolic readings within 5 and 10 mmHg. CONCLUSION: Patients found the wrist oscillometric devices that we tested to be comfortable and easy to use. These devices are appropriate for measuring diastolic blood pressure according to the standards, but the reliability of both devices decreased when measuring systolic blood pressure.     

Validation of the Omron 637IT wrist blood pressure measuring device with a position sensor according to the International Protocol in adults and obese adults

OBJECTIVE: Wrist blood pressure devices are becoming popular for the self-measurement of blood pressure. Despite widespread use of these devices, there is limited published evidence for their accuracy and reliability. In this study, we assessed the accuracy of the Omron 637IT wrist blood pressure device against the mercury sphygmomanometer in adults and obese adults according to the International Protocol criteria. METHODS: A hundred and thirty-one participants were studied and classified on the basis of the International Protocol range. Blood pressure measurements at the wrist using the Omron 637IT were compared with the results obtained by two trained observers using a mercury sphygmomanometer. Nine sequential blood pressure measurements were taken. Initially, 33 participants with random arm circumferences were selected for the first validation study. Then, the device was evaluated in adults with arm circumferences equal to or higher than 34 cm. During each validation study, 99 measurements were obtained for comparison from the 33 participants. The first phase was performed on 15 participants, and, if the device passed this phase, 18 more participants were selected. RESULTS: Mean discrepancies and standard deviations of the sphygmomanometer device were 0.5+/-6.2 mmHg for systolic blood pressure and 0.1+/-3.7 mmHg for diastolic blood pressure in the adult group. The device passed phases 1 and 2 in 33 participants. Mean discrepancies and standard deviations of the sphygmomanometer device were 1.8+/-6.6 mmHg for systolic blood pressure and 1.6+/-4.7 mmHg for diastolic blood pressure in the obese adult group. The device passed phases 1 and 2 in 33 participants in this group. CONCLUSION: The Omron 637IT passed according to the International Protocol criteria and can be recommended for use in adults and obese adults.     

Evaluation of the Profilomat II ambulatory blood pressure system according to the protocols of the British Hypertension Society and the Association for the Advancement of Medical Instrumentation

OBJECTIVE: To evaluate the Profilomat II monitor for ambulatory blood pressure measurement according to the protocols of the British Hypertension Society (BHS) and the Association for the Advancement of Medical Instrumentation (AAMI). DESIGN: The BHS protocol is divided into two parts. Part I, which is the part applicable to this study, comprises the main validation procedure and has five phases: before-use device calibration; static device validation; and report of evaluation. METHOD:Three Profilomat II recorders passed the before-use device calibration test. They then entered the in-use (field) assessment phase during which the three recorders were each worn by ten subjects for 24-h, after which the calibration was again assessed. Since no difference in calibration testing was observed between the three devices, one was selected randomly and the main validation test was carried out in 85 subjects, who had a wide range of blood pressures, using the sphygmocorder. The results were analysed according to the BHS grading system from A to D. The data was also analysed according to the standard of the Association for the Advancement of Medical Instrumentation (AAMI) which stipulates that the mean difference between the test device and the standard shall be 160/100 mmHg), the Profilomat II was less accurate in the high pressure range, achieving a D/C grading, and failed the AAMI criteria for systolic and diastolic blood pressures. The mean and standard deviation of the first mercury sphygmomanometer measurements were 145+/-34/87+/- 20 mmHg. Subject acceptability was good and the manufacturers manual was satisfactory. CONCLUSION: On the basis of these results, the Profilomat II cannot be recommended for ambulatory blood pressure measurement in clinical practice where accurate measurements are required.     

Inflationary oscillometric blood pressure monitoring: validation of the OMRON-MIT

BACKGROUND: To evaluate the accuracy of the OMRON-MIT, (an automated inflationary oscillometric blood pressure monitoring device) for use in the general population by direct comparison to standard auscultatory mercury sphygmomanometry. DESIGN: Two trained, blinded observers taking simultaneous blood pressure measurements alternating between a mercury sphygmomanometer and the OMRON-MIT. METHODS: The evaluation was carried out according to the revised British Hypertension Society protocol. The validation data was also classified by the American Association for the Advancement of Medical Instrumentation (AAMI). RESULTS: The OMRON-MIT device achieved a BHS grade A for both systolic blood pressure (SBP) and diastolic blood pressure (DBP). It also met the criteria for the AAMI protocol, the mean difference between the MIT and standard was -2.0 +/- 7 mmHg for SBP and -2.0 +/- 6 mmHg for DBP. CONCLUSIONS: Inflationary oscillometry is a valid technique for the measurement of blood pressure. The OMRON-MIT, which uses this technique, is accurate and can be recommended for clinical use in the adult population.     

A simulation-based evaluation of nine oscillometric blood pressure monitors for self-measurement

OBJECTIVE: To evaluate the performance of nine self-measurement oscillometric blood pressure monitors using a simulator. METHODS: For each monitor, simulation data from 48 sets of simulated waveforms with four simulations for each set were used for analysis. The waveforms represent a wide range of blood pressure. The monitor-simulator blood pressure differences were analyzed according to the 1992 Association for the Advancement of Medical Instrumentation (AAMI) and 1993 British Hypertension Society (BHS) protocols, except that corrections were made to take into account simulation variability. One-way analysis of variance was used to compare the differences for various combinations of monitors. The monitors' heart rate readings were compared with the rated accuracy. RESULTS: First, the mean blood pressure differences in general vary from monitor to monitor, the absolute mean differences ranging from 1.2 to 18.2mmHg. This can be partly explained by the likely use of different blood pressure determination criteria. Second, the Omron HEM-711 and HEM-712C gave about the same mean difference for systolic pressure and for diastolic pressure, suggesting that the two monitors may be using the same or approximately the same set of determination criteria. Third, the quantitative assessments for some of the monitors, for systolic or diastolic pressure or both, satisfy the clinical-use accuracy criteria of the AAMI or BHS protocol or both. These assessments alone cannot, however, be used to conclude whether or not any of the monitors fulfils the accuracy requirements of either protocol. Fourth, the corrected standard deviations of the differences range from 1.5 to 16.6mmHg, most of them being substantially less than the 8mmHg limit stipulated in the AAMI protocol. The different standard deviations suggest a varying robustness of the signal-processing methods used by the monitors. Fifth, for 7 out of the 9 monitors, more than 94% of the heart rate readings fall within +/-5% of their reference readings. CONCLUSIONS: The nine monitors in general performed differently with respect to the simulator. The results cannot be used fully to reflect the monitors' performance on human subjects because they were not based on clinical evaluation. Studies that lead to a more realistic simulation of oscillometric blood pressure are needed. Protocols integrating both clinical and simulation-based evaluations need to be developed.     

Comparison of wrist blood pressure measurement with conventional sphygmomanometry at a cardiology outpatient clinic

OBJECTIVE: Oscillometric measurement of blood pressure at the wrist is becoming a widely used method for detection of hypertension and its control by treatment. The objective of the present study was to evaluate accuracy and suitability of wrist measurement in a clinical routine setting. PATIENTS AND METHODS: A series of 333 consecutive patients admitted to our cardiology outpatient clinic were included. Blood pressure was measured at both upper arms according to World Health Organization-International Society of Hypertension guidelines. Oscillometric measurement was performed at the contralateral wrist simultaneously. Blood pressure readings were taken by an oscillometric device applied at the wrist ('Klock'; Industrielle Entwicklung Medizintechnik, Stolberg, Germany) and a conventional mercury sphygmomanometer applied at the upper arm. RESULTS: Seventy-eight patients were excluded due to differences in blood pressure > 5 mmHg between both upper arms or due to 'error' messages of the wrist device. The data of the remaining 255 patients (149 males; mean age, 65 +/- 13 years; range, 18-95 years) are presented. Mean conventional blood pressure was significantly lower compared with the wrist device (137 +/- 20/80 +/- 11 mmHg versus 153 +/- 28/87 +/- 18 mmHg; P < 0.001 and P < 0.001). The mean difference was 16 +/- 25/6 +/- 17 mmHg. In clinical terms, differences in blood pressure exceeding +/-20/+/-10 mmHg reflecting classification of hypertension are considered important. Measurements of 101 (40%) patients were within these limits. Systolic readings of 110 (43%) and diastolic readings of 117 patients (46%) were beyond this scope. CONCLUSION: Due to low reliability of wrist blood pressure measurement, it cannot compete with the upper arm standard procedure. If ever, it should only be used if test readings in an individual comparing wrist and upper arm measurement show differences within a range of +/-20/+/-10 mmHg.     

Validation of the Omron 637IT wrist blood pressure measuring device with a position sensor according to the International Protocol in the elderly

OBJECTIVE: The market for wrist devices for self-measurement is growing and these devices are becoming popular among the patients. Despite widespread use of these devices, there is limited published evidence for their accuracy and reliability in the different patient groups. The objective of this study was to evaluate the accuracy of the Omron 637IT (Omron Healthcare Europe B.V, Hoofddorp, Netherlands) wrist blood pressure device against the mercury sphygmomanometer in the elderly according to the International Protocol criteria. METHODS: Seventy-six patients older than 65 years of age were studied and classified on the basis of the range of the International Protocol. Blood pressure measurements at the wrist with the Omron 637IT were compared with the results obtained by two trained observers using a mercury sphygmomanometer. Nine sequential blood pressure measurements were taken. A total of 33 participants with arm circumference distributed randomly were selected for the validation study. During the validation study, 99 measurements were obtained for comparison in the 33 participants. The first phase was performed on 15 participants, and if the device passed this phase, 18 more participants were selected. RESULTS: Mean discrepancies and standard deviations of the sphygmomanometer device were -0.3+/-6.5 mmHg for systolic blood pressure and 2.8+/-4.8 mmHg for diastolic blood pressure in the study group. The device passed phase 1 in 15 participants. In phase 2.1, from the total 99 comparisons, 66, 87, and 95 for systolic blood pressure and 69, 92, and 97 for diastolic blood pressure were <5, <10, and <15 mmHg, respectively. In phase 2.2, 24 participants had at least two of the differences within 5 mmHg and three participants had no differences within 5 mmHg for systolic blood pressure. For diastolic blood pressure, 24 participants had at least two of the differences within 5 mmHg and three participants had no differences within 5 mmHg. The Omron 637 IT passed the phase 2.1 and 2.2 in the elderly group. CONCLUSION: The Omron 637IT wrist blood pressure device passed according to the International Protocol criteria and can be recommended for use in the elderly.