Validation of the JAMR F1701T (arm type) pressure monitor according to the Association for the Advancement of Medical Instrumentation/European Society of Hypertension/ISO 81060-2:2018 protocol

Abstract

To validate the JAMR F1701T (arm type) blood pressure (BP) monitor according to the Association for the Advancement of Medical Instrumentation/European Society of Hypertension/International Organization for Standardization (AAMI/ESH/ISO) Universal Standard (ISO 81060-2:2018). A total of 90 subjects (male 60 and female 30) were recruited to fulfill the criteria of the AAMI/ESH/ISO Universal Standard (the number, gender, age, limber size, and BP distribution), and sequential measurements of BP, including both SBP and DBP were obtained using the test device and the standard mercury sphygmomanometer. A total of 270 sets of comparison data (three sets of each subject) were obtained and analyzed. According to the validation criterion 1 of ISO 81060-2:2018, the mean ± SD of the differences between the JAMR F1701T and mercury sphygmomanometer BP (systolic/diastolic) readings was 2.06 ± 6.83/−4.84 ± 5.23 mmHg. For criterion 2, the SD of the averaged BP (systolic/diastolic) differences between the JAMR F1701 and reference BP (systolic/diastolic) per participant was 5.62/4.39 mmHg (the requirement was ≤6.43/5.01 mmHg by calculation). The JAMR F1701T met all the requirements of the ISO 81060-2:2018, and can be recommended for clinical and self/home use.

Introduction

Hypertension is a major chronic disease and a most influential risk factor of cardiovascular disease which can lead to cardiac death, the increasing burden of hypertension has become a worldwide problem [¹]. The number of hypertensive populations aged 30–79 had nearly doubled from 1990 to 2019 which reached nearly 1278 million in 2019 all over the world [²]. However, the treatment and control rates are low compared to the high morbidity, especially in low- and middle-income countries [²]. A blood pressure (BP) monitor is a simple tool to screen hypertension and can be used to evaluate BP control, both of which can reduce the risk of cardiovascular disease events [³]. Since the use of mercury sphygmomanometers is limited by skill, mercury pollution, and inconvenience, guideline recommend using the automated upper-arm cuff devices to measure BP in the clinic and at home (home blood pressure monitoring, HBPM) [⁴]. To make appropriate decisions, the accuracy of the device is critical, which should be validated according to standardized protocols [^5,6].

From this standpoint, we assessed the accuracy of the JAMR F1701T (arm type) BP monitor according to AAMI/ESH/ISO Universal Standard (ISO 81060-2:2018).

Material and methods

Participants

This study was approved by the ethics committee of the Shenzhen Hospital, University of Chinese Academy of Sciences (Shenzhen, China), and carried out in the hospital, with written informed consent obtained from every participant. Since individuals with a wide range of upper-arm circumference and BP should be needed according to the standardized protocols (ISO 81060-2:2018), participants were recruited from volunteers and patients with or without antihypertensive drugs. There are two criteria for inclusion, one is that the subject should be older than 12 years, and the other is that the subject’s upper-arm circumference is between 22 and 42 cm. We excluded participants with arrhythmia, those whose Korotkoff sound [fifth phase (K5)] is not audible which leads to unclear DBPs, those who spoke or moved during the entire procedure, those with great variations in BP of >12/8 mmHg, and those with variations in BP >4 mmHg which measured by two investigators in the meantime.

Devices

The JAMR F1701T (Shenzhen Jamr Technology Co. Ltd, Danyang, Jiangsu Province, China) (Fig. 1) is an automated oscillometric BP monitor (arm type) for clinical use and HBPM. The device has only one size cuff ranging from 22 to 42 cm which can cover most people’s size, and its dimensions are approximately 121 mm × 109 mm × 52 mm (width × height × depth), it weighs about 556 g (including a cuff), the measurable pressure ranges from 0 to 280 mmHg and pulse rate values from 40 to 170 beats. The device’s memory capacity of measurements is 120 sets of two different people, it allows two users to log in, measure BP, and store data, respectively.

Fig. 1: The JAMR F1701T device. The range of the arm circumference is 22–42 cm. BP, blood pressure.

To fulfill the family’s desire of knowing the data remotely, the device develops a Bluetooth function specifically, from which the data of BP can be transferred to the phone’s app. This study showed the app’s data, both on iPhone and Android phone, is 100% consistent with the test device’s data. The data on the phone can be reserved for 5 years.

Validation procedure

To conduct this study, six observers with certificates of Good Clinical Practice (GCP) were retrained strictly in mercury BP measurement, and they were trained in the testing procedures and the operational approach of the test device with two supervisors additionally who also obtained the certificates of GCP before the research initiation. Each participant should have a rest sitting on a chair and be taught not to talk or move during the research with their both feet flat on the floor, and then one simulation test (mercury sphygmomanometer) should be conducted to confirm that the observers could normally listen the Korotkoff sound [especially the fifth phase (K5)] to determine the SBP and DBP before the test, two observers used a double stethoscope (Y tube) simultaneously and recorded their data, respectively, they were blinded to each other while the measurement. Only when the Korotkoff sound met the criteria will the next step be taken, following with BP measurement using a mercury sphygmomanometer (two observers and four groups of readings) and test device alternatively (one supervisor and three readings). The supervisor measured the subject’s arm size before the test and checked the two observer’s data, the supervisor also checked whether the data received on the app was consistent with the data displayed by the test device, to test the consistency of data of the app and the test device on different mobile operating systems, 45 × 3 (half subjects × readings) sets of data on Android phone and the same sets of data on iPhone. At least 1 min should be paused between two measurements. We also record and verify the performance of the test device through this study.

Data analysis

Data were expressed as mean ± SD, for each participant, the mean of each group BP measured by two researchers was calculated as reference data. The Bland–Altman scatter plots were also used to display the agreement between the test device and the reference sphygmomanometer.

Results

According to ISO protocol, 90 participants were analyzed from the 106 recruited individuals. 16 individuals were excluded for several reasons which are presented in Table 1. The requirements for number, gender, age, limber size, and BP distribution were fulfilled according to ISO 81060-2:2018 [⁶], which are shown in Tables 2–4. The data (including 90 subjects and 270 sets of comparison data) of validation analysis is shown in Table 5, the differences between the JAMR F1701T and mercury sphygmomanometer BP (systolic/diastolic) readings were 2.06 ± 6.83/−4.84 ± 5.23 mmHg. For criterion 2, the SD of the averaged BP (systolic/diastolic) differences between the JAMR F1701 and reference BP per participant was 5.62/4.39 mmHg (the requirement was ≤6.43/5.01 mmHg by calculation). This means the test device passed both the validation criteria 1 and 2. Bland–Altman scatter plots of the electronic sphygmomanometer (test device) and reference sphygmomanometer BP differences against their average are shown in Fig. 2a and b.

Table 1 - Enrollment of subjects

	Number of subjects
Recruited	106
Excluded	16
Reasons for exclusion
The arm circumference is less than 22 cm	8
Observer 1 or 2’s judgment reading of SBP or DBP at the same time >4 mmHg	4
Reference blood pressure variability (>12/8 mmHg for systolic/diastolic)	1
Subjects not cooperate (speaking or moving during the measurement)	3
Included in analysis	90

BP, blood pressure.

Table 2 - Gender, age, limb circumference distribution (n = 90)

	Mean ± SD	Range
Sex (male/ female)		60/30
Age (years)	42.5 ± 13.87	20–77
Limb circumference (cm)	28.0 ± 20.5	22–41.5

Table 3 - Limb size distribution

Limb size distribution (cm)	22–24.5	22–27	22–32	>32–42	>37–42	>39.5–42
Proportion (%)	18.89	40	60	40	24.44	13.33

Table 4 - Distribution of reference blood pressure measurements

SBP (mmHg)	≤100	≥160	≥140
	10.0%	5.5%	24.44%
DBP (mmHg)	≤60	≥100	≥85
	5.5%	14.44%	42.22%

Table 5 - Efficacy evaluation of blood pressure measurement

		Achieved
	Pass requirement	SBP	DBP
Criterion 1 (270 BP pairs)
Mean BP difference (mmHg)	≤5	2.06	−4.84
SD (mmHg)	≤8	6.83	5.23
		Pass	Pass
Criterion 2 (90 subjects)
SD (mmHg, systolic/diastolic)	≤6.43/5.01	5.62	4.39
		Pass	Pass
Result		Pass

BP, blood pressure.

Fig. 2: Scatter diagram of SBP (a) and DBP (b) of electronic sphygmomanometer and reference sphygmomanometer. BP, blood pressure.

There is no malfunction of the test device during the whole study, and as mentioned above, the data of the test device can be sent to the app of the phone through Bluetooth, there was no error comparing the data of the test device and the data on the app. This means the test device worked very well.

Discussion

The research showed that the test device (JAMR F1701T) fulfilled the validation criteria of the AAMI/ESH/ISO Universal Standard (ISO 81060-2: 2018) and can be recommended for BP measurement. As shown in Fig. 2a, scatter points of SBP distributed balanced in the mean difference level line, and the 87% limits of agreement of test device and reference sphygmomanometer were (−10 to 10) mmHg, 13% Scatter points were outside the 87% limits. As to DBP, the number change to 14% scatter points were outside the 86% as shown in Fig. 2b. The differences of SBP, DBP between the test device and reference sphygmomanometer were acceptable clinically, which can be considered having good agreement.

The clinical mean value of the differences and SD for each subject of F1701T is considered reasonably small, F1701T is as reliable and accurate as the reference sphygmomanometer, and no safety problem or accident is affecting the subjects. The safety and efficacy of the Sphygmomanometer under test can meet the requirements of ISO 81060-2:2018 Noninvasive sphygmomanometers – Part 2: Clinical validation of automated measurement type.

Conclusion

The BP monitor JAMR F1701T (arm type) met the requirements of the AAMI/ESH/ISO Universal Standard (ISO 81060-2:2018) with excellent performance, and hence can be useful for BP measurement at homes and clinics.

Acknowledgements

The devices were provided by Shenzhen Jamr Technology Co., Ltd., (Danyang, Jiangsu Province, China) and they also provided funding for this study.

Conflicts of interest

Our hospital received funding from Shenzhen Jamr Technology Co., Ltd. according to the contract of the research, and the researchers were paid for their efforts after the completion of the research, we have fully disclosed these interests to the editor and magazine. We carried out the research in strict accordance with the regulations of GCP and gave each researcher a clear division of labor and responsibilities to ensure the independence and accuracy of the data, by which we manage any potential conflicts that may arise from the research.