Standardized home blood pressure monitoring: Rationale behind the 722 protocol.

Home blood pressure (HBP) has been recognized as a prognostic predictor for cardiovascular events, and integrated into the diagnosis and management of hypertension. With increasing accessibility of oscillometric blood pressure devices, HBP monitoring is easy to perform, more likely to obtain reliable estimation of blood pressures, and feasible to document long-term blood pressure variations, compared to office and ambulatory blood pressures. To obtain reliable HBP estimates, a standardized HBP monitoring protocol is essential. A consensus regarding the optimal duration and frequency of HBP monitoring is yet to be established. Based on the current evidence, the "722" protocol, which stands for two measurements on one occasion, two occasions a day (morning and evening), and over a consecutive of 7 days, is most commonly used in clinical studies and recommended in relevant guidelines and consensus documents. HBP monitoring based on the "722" protocol fulfills the minimal requirement of blood pressure measurements to achieve agreement of blood pressure classifications defined by office blood pressures and to predict cardiovascular risks. In the Taiwan HBP consensus, the frequency of repeating the "722" protocol of HBP monitoring according to different scenarios of hypertension management, from every 2 weeks to 3 months, is recommended. It is reasonable to conclude that the "722" protocol for HBP monitoring is clinically justified and can serve as a basis for standardized HBP monitoring.

BACKGROUND

Home blood pressure (HBP) is defined as a form of out‐of‐office blood pressures self‐measured at home, in contrast to office blood pressure (OBP) measured in the clinical setting. Blood pressure fluctuates in response to environmental and pathophysiological stimuli, leading to diurnal, day‐to‐day and seasonal variations. The variations of blood pressures can be reliably assessed by HBP monitoring. It has been demonstrated that HBP was more closely associated with cardiovascular risks than OBP, and offered prognostic information independent of OBP. There is evidence suggesting that morning HBP was more related to the risk of stroke than evening HBP. Contemporary guidelines and consensus recommend that both standardized office and out‐of‐office blood pressures should be assessed to confirm the diagnosis of hypertension. Incorrect diagnosis of hypertension often occurs if only OBP is assessed, particularly in a non‐standardized manner.

Given the increasing affordability of oscillometric sphygmomanometers, HBP measurement is readily accessible, quite affordable; and is able to monitor daily, weekly, and even monthly and yearly variations of blood pressures, as compared to ambulatory blood pressure (ABP) monitoring. ABP monitoring is another form of out‐of‐office blood pressures measured regularly in a period of minutes for 1 or 2 days. Cumulative evidence has shown that HBP monitoring could be used to guide and improve hypertension management, with or without co‐interventions, such as team‐based care or telemonitoring. However, the standardized HBP measurement protocol and follow‐up schedule are yet to be established. Factors like how to reliably evaluate HBP and assess HBP variations, how to define a reliable HBP estimate, and the tedious burden with long‐term HBP measurement should all be taken into consideration while constructing a protocol for standardized HBP measurement. We herein reviewed the methods of HBP monitoring used and its relations with cardiovascular outcomes in clinical studies to determine how to obtain optimal estimation of HBP. Recommendations from current guidelines and consensus regarding HBP protocols were also summarized. Finally, a practical approach to standardize HBP measurement for the diagnosis and management of hypertension is suggested.

Clinical studies exploring the effectiveness of home blood pressure monitoring

Prior studies have shown that HBP is an independent and better predictor of cardiovascular events than office BP, and is able to guide antihypertensive treatment to achieve better control of hypertension than usual care. As shown in Table 1, the 7‐day measurement of HBP was most commonly used to estimate HBP in clinical studies designed to assess the effectiveness of HBP monitoring. In the PAMELA (Pressioni Arteriose Monitorate E Loro Associazioni) study, only two HBP measurements obtained over 2 days were not associated with better predictability of mortality compared to OBP. HBP measured for at least 3 days appeared to be the minimal requirement to obtain reliable HBP estimation for cardiovascular outcome prediction (Table 1). Most of the studies required HBP measured both in the morning and evening, except the HOMED‐BP (Hypertension Objective Treatment Based on Measurement by Electrical Devices of Blood Pressure) study and the Ohasama study, where only morning HBP was obtained. To reduce the bias of blood pressure measurement on each occasion, duplicate or triplicate measurements with an interval of 1–2 min were required. Furthermore, it was generally recommended that more than half of total HBP readings supposed to be measured over a week should be obtained to achieve reliable HBP estimation. In the Didima study, duplicate HBP readings in the morning and evening for 3 days were required. At least 6, out of 12 expected HBP measurements, were asked to estimate HBP, by averaging all available measurements. The SHEAF (Self‐Measurement of Blood Pressure at Home in the Elderly: Assessment and Follow‐up) study required the elderly hypertensive participants to take triplicate blood pressure readings in the morning and evening for 4 days. The minimal requirement of blood pressure readings to estimate HBP was at least 15 of 24 expected measurements and at least six readings obtained in the morning and at least 6 readings obtained in the evening. Taken together, given that blood pressure measurements on the first day are generally discarded as recommended in most guidelines/consensus, a minimum of 4 consecutive days of HBP measurements, with duplicate measurements on 2 occasions a day, is required to obtain HBP estimation with a sufficient prognostic value.

TABLE 1

Clinical studies investigating the effectiveness of HBP monitoring in the control and prognosis of hypertension, ranked by the number of days of HBP monitoring required to obtain HBP estimation

		Timing					HBP estimation
Study	Days of measurement required	Morning	Evening	Number of readings per measurement occasion	Intervals between each measurement (minute)	Rest time before HBP measurement (minute)	First day discarded	Estimate
Studies requiring only morning readings for HBP estimation
<7 days of HBP measurements
HOMED‐BP study 8 , 27	5 days before clinic visit (though HBP was measured every day)	Within 1 h of awakening, before breakfast, before taking antihypertensives	(One evening BP reading at bedtime)	1	–	2	–	Mean of all morning readings
≥7 days of HBP measurements
TASMINH2 study 28	7 days (the first week of each month)	V	–	2	5	–	–	Mean of all the second morning readings
TASMIN‐SR study 29	7 days (the first week of each month)	V	–	2	5	–	–	Mean of all the second morning readings
HOMED‐BP study with digital intervention 30	7 days/month	V	–	2	5	–	–	Mean of all the second readings morning
Ohasama study 9 , 31	28 days	Within 1 h of awakening, before taking antihypertensives	(One evening BP reading at bedtime)	1	–	≥2	–	Mean of all morning readings
Studies requiring morning and evening readings for HBP estimation
<7 days of HBP measurements
PAMELA study 7	2 days	7 a.m. next morning after clinic visit	7 p.m. at the same day of clinic visit	2	1	–	–	Mean of all measurements
HONEST study 32	2 days	Within 1 h of awakening, before breakfast, before taking antihypertensives	Just before bedtime	2	–	1‐2	–	Mean of all measurements
Didima study 11	3 days	6:30 a.m. ‐ 10 a.m.	5 p.m. ‐ 11 p.m.	2	1	5	–	Mean of all measurements
SHEAF study 3	4 days	8 a.m.	8 p.m.	3	–	5	–	Mean of all measurements (at least ≥15 readings, including ≥6 morning, ≥6 evening readings)
Okumiya K and colleagues 33	5 days	6 a.m. ‐ 7 a.m.	8 p.m. ‐ 9 p.m.	2	–	5	–	Mean of all the readings
≥7 days of HBP measurements
Niiranen TJ and colleagues 34	7 days	6 a.m. ‐ 9 a.m.	6 p.m. ‐ 9 p.m.	2	–	2	–	Mean of all measurements
THOP trial 35	7 days just before clinic visit	6 a.m. ‐ 10 a.m.	6 p.m. ‐ 10 p.m.	3	–	5	–	Mean of all measurements
Finn‐Home study 2	7 days	6 a.m. ‐ 9 a.m.	6 p.m. ‐ 9 p.m.	2	2	10	–	Mean of all measurements
HOMERUS study 36	7 days just before clinic visit	V	V	3	–	≥5	–	–
TASMINH4 trial 6	7 days (the first week of each month)	V	V	2	–	–	–	Mean of all measurements
J‐HOME study 37	2 weeks	Within 1 h of awakening, before breakfast, before taking antihypertensives	Just before bedtime	1	–	2	–	Mean of all measurements
Shimbo D and colleagues 38	6 days/week for 10 weeks	4 days: morning; 2 days: mid‐morning	4 days: evening; 2 days: mid‐afternoon	3	‐	‐	–	Mean of all measurements

Abbreviations: ABP, ambulatory blood pressure; BP, blood pressure; CV, cardiovascular; Finn‐Home, Finnish home BP monitoring; HBP, home blood pressure; HOMED‐BP: Hypertension Objective Treatment Based on Measurement by Electrical Devices of Blood Pressure; HOMERUS: Home versus Office Measurement, Reduction, of Unnecessary treatment Study; J‐HOME, Japan Home versus Office Blood Pressure Measurement Evaluation; OBP, office blood pressure; PAMELA, Pressioni Arteriose Monitorate E Loro Associazioni; SHEAF: Self‐Measurement of Blood Pressure at Home in the Elderly: Assessment and Follow‐up; TASMINH2, Telemonitoring and Self‐Management of Hypertension Trial; TASMINH4, Telemonitoring and/or self‐monitoring of blood pressure in hypertension; TASMIN‐SR, Targets and Self‐Management for the Control of Blood Pressure in Stroke and at Risk Groups; THOP: Treatment of Hypertension Based on Home or Office Blood Pressure.

‐: indicated “not available” or “none.”.

Clinical studies exploring the optimal protocol for home blood pressure monitoring

The optimal duration of HBP measurement is influenced by how many times BP readings are taken each day. In general, both morning and evening HBP measurements taken on a consecutive of at least 3 days, if first‐day readings are not discarded, are required to derive reliable HBP estimates for the diagnosis of hypertension and cardiovascular risk prediction. , , While blood pressure measurements taken over a consecutive of 7 to 14 days are needed if HBP is taken only in the morning (Table 2). , In the IDH (Improving the Detection of Hypertension) study, a community cohort of 316 adults not treated with antihypertensive medications were asked to measure morning and evening HBP for 14 days to determine the optimal number of measurements needed for reliable HBP estimations. The results revealed that, for diagnosis of hypertension, HBP estimates derived from ≥3‐day consecutive measurements were enough if one to two morning and one to two evening readings were obtained daily, while 4 or ≥5 days were needed if only morning readings or evening ones were obtained, respectively. The IDHOCO (International Database of HOme blood pressure in relation to Cardiovascular Outcome) study combined individual participant data from the Ohasama, Finn‐Home, and Tsurugaya cohorts, and used the first morning HBP readings to assess the optimal number of HBP measurements to obtain reliable HBP estimation. It was found that a minimum of 7‐day HBP measurements was required to achieve an optimal agreement of blood pressure classifications by OBP with the κ coefficient of ≥.9. Similarly, the Ohasama study showed that ≥14‐day single morning HBP measurement was needed to reliably predict the stroke risk.

TABLE 2

Clinical studies exploring the optimal HBP protocol for diagnosis of hypertension and cardiovascular risk prediction, ranked by the number of days of HBP monitoring required to obtain HBP estimation

		HBP measurement protocol
		Each day					Estimation
Study	Study objective	Morning	Evening	Measurements per occasion	Time interval between each measurement (minute)	Rest time before HBP measurement (minute)	First day discarded	Estimate	Study results
HBP estimation based on only morning readings
IDHOCO study 15	To determine optimal number of days for HBP measurement in 4802 adults from two Japanese (Ohasama and Tsurugaya studies) and one Finnish (Finn‐Home study) cohorts taking HBP readings for 7 days	Only the first morning HBP reading of 7 days used for analysis (Ohasama study: one morning and one evening readings for 28 days; Tsurugaya study: one morning reading, within 1 h of awakening and before breakfast and taking antihypertensives, for 28 days; Finn‐Home study: two morning and two evening readings for 7 days)			–	≥2 in Ohasama and Tsurugaya studies; 10 in Finn‐Home study	–	Mean of all morning readings	Agreement between HBP and OBP in BP classification is optimal using ≥7 days of morning BP measurements.
Ohasama study 16	To investigate the optimal number of HBP measurements in association with stroke risk in 1491 Japanese Adults having 14–28 days of HBP measurements	V (within 1 h of awakening, before taking antihypertensives)	(One evening BP reading at bedtime)	1	–	–	–	Mean of all morning HBP readings	The predictive ability of HBP for stroke risk increased with more HBP readings, which should be derived from at least 3‐day but preferably ≥14‐day measurements.
HBP estimation based on morning and evening readings
Finn‐Home study 12	To explore optimal schedule for assessment of HBP variability in 1706 Finnish adults measuring HBP for 7 days	6 a.m. ‐ 9 a.m., before breakfast, before taking antihypertensives	6 p.m. ‐ 9 p.m.	2	2	10	V	Means of (1) all remaining morning readings, and (2) all remaining (morning and evening) HBP readings	HBP variability derived from ≥3‐day systolic morning HBP was significantly associated with future CV events.
SMART study 39	To determine number of HBP measurements for accurate BP estimates in 1710 French hypertensive patients measuring HBP for 4 days	8 a.m.	8 p.m.	3	–	5	V	Mean of all remaining measurements	≥6 HBP readings is needed to improve measurement precision.
Stergiou GS and colleagues 13	To determine minimum number of HBP for reliable BP estimate in 189 Greek hypertensive patients having HBP measured in 3 work days for 2 weeks	7 a.m. ‐ 10 a.m.	6 p.m. ‐ 9 p.m.	2	1	5	V	Mean of all remaining measurements	≥3 days of HBP measurements is needed to provide reliable HBP estimates.
J‐HOP study 4	To determine the optimal schedule for HBP monitoring in prognostic risk of stroke and CAD in 4310 Japanese adults measuring HBP for 14 days	V (within 1 h after awakening, before breakfast, before taking antihypertensives)	V (before going to bed)	3	1/4	≥2	V	Mean of all remaining measurements	Both morning and evening systolic HBP were independent predictors for stroke, rather than CAD.
IDH study 14	To determine number of measurements needed for HBP estimates in a community cohort of 316 American adults undertaking 21‐day HBP measurements	V (immediately after awakening)	V	2	1	5	‐	Mean of all measurements over the first 2 weeks	Using the average of morning and evening readings, 3 days of HBP are needed to reliably diagnose hypertension

Abbreviations: BP, blood pressure; CAD, coronary artery disease; CV, cardiovascular; Finn‐Home, Finnish home BP monitoring; HBP, home blood pressure; IDH: Improving the Detection of Hypertension; IDHOCO, International Database of HOme blood pressure in relation to Cardiovascular Outcome; J‐HOP: Japan Morning Surge‐Home Blood Pressure; NA, not available; OBP, office blood pressure; SMART: Self‐Measurement for the Assessment of the Response to Trandolapril.

‐: indicated “not available” or “not recommended.”.

Guidelines and consensus recommendations: the “722” protocol for standardized home blood pressure monitoring

As outlined in Tables 3 and 4, most current guidelines and consensus suggest the 7‐day HBP measurement schedule, consisting of 2 morning and 2 evening readings each day—i.e., the “722” protocol, is optimal for the diagnosis and management of hypertension, although 3 to 5‐day measurements were at a minimum. Morning HBP is recommended to be measured within 1 h after awakening, and before taking medications, breakfast, and vigorous physical activity. The timing of evening HBP measurement is subject to the time interval between taking supper and going to bed. Evening HBP is recommended to be measured before going to bed if the time interval is more than 2 h; otherwise, is measured before taking supper. To mitigate the measurement bias which occurs with higher probability at the beginning of a measurement stint, it is recommended that duplicate or triplicate HBP readings should be taken per measurement occasion, and that the first‐day measurements could be excluded from HBP estimation. Although the accuracy of oscillometric blood pressure devices remain doubtful in the presence of atrial fibrillation, it has been reported that the accuracy of systolic blood pressure could be acceptable, rather than that of diastolic blood pressure, especially if the mean of triplicate measurements is used. Given that systolic blood pressure is more prognostically predictive than diastolic blood pressure, and that the auscultatory method of blood pressure measurement could fail owing to muffled Korotkoff sounds, the Taiwan consensus for HBP measurement recommends that ≥3 repeated measurements could be plausible in the presence of atrial fibrillation. Given the prognostic impact of morning HBP surge has been recognized, averages of morning and evening HBP measurements should be separately considered. ,

TABLE 3

Details of the HBP protocol recommended by different guidelines for the diagnosis and management of hypertension, ranked by year of publication

	HBP protocol
	Timing			Schedule						Estimation
Guidelines & consensus (year of publication)	As the basis of hypertension diagnosis	Assessment of treatment	Before each visit	Duration	Morning	Evening	No. of measurements on each occasion	Time interval between repeated measurements (minute)	Rest time before HBP measurement (minute)	Minimal requirement	First day discarded	HBP estimate	HBP threshold for high blood pressure	Long‐term follow‐up
ACC/AHA guideline (2018) 40	–	V (Weekly, 2 weeks after regimen change)	V	7 days	V (before medication)	V (before dinner)	≥2	1	≥5	≥2 measurement occasions	–	Mean of all measurements	130/80	–
ESC guideline (2018) 41	–	V	V	6‐7 days	V	V	2	1‐2	3‐5	≥3 days	–	Mean of all measurements	135/85	–
Chinese guideline (2019) 42	–	V	–	7 days	V (before medication and breakfast)	V (before dinner)	2‐3	1‐2	≥5	≥6 days	V	Mean of all remaining measurements	135/85	1‐2 days per week (once in the morning, once in the evening)
Korean guideline (2019) 43	‐	–	V	7 days	V (within 1 h after awakening, prior to medication and breakfast)	V (before going to bed)	1‐3	NA	1‐2	≥7 days for hypertension diagnosis; ≥ 5‐7 days before clinic visit	V	Mean of all remaining measurements	135/85	–
NICE guideline (2019) 44	–	–	–	7 days	V	V	2	1	–	≥3 days	V	Mean of all remaining measurements	135/85	–
JSH guideline (2019) 21	–	V	–	7 days	V (within 1 h after awakening, prior to medication and breakfast)	V (before going to bed)	2	NA	1‐2	≥5 days	–	Mean of all measurements, and separate means of morning & evening readings	135/85	–
Indonesian guideline (2019) 45	–	V	–	≥3 days (within 1 h after awakening, before medication and breakfast)	V (within 1 h after awakening, before medication, before breakfast)	V (before going to bed)	2‐3	1	–	≥3 days	V	Mean of all remaining measurements	135/85‐	–
Canada guideline (2020) 46	–	–	–	7 days	V (before breakfast and medication)	V (2 h after dinner, before medication)	2	NA	5	–	V	Mean of all remaining measurements	135/85	–
ISH guideline (2020) 47	–	V	–	3‐7 days	V (before medication)	V	2	1	5	–	V	Mean of all remaining measurements	135/85	1‐2 measurements per week or per month
Taiwan guideline (2022) 48	V	V	V	7 days (within 1 h after awakening, before medication and breakfast)	V (within 1 h before bedtime)	≥2 (≥€3 in presence of atrial fibrillation)	2	1	≥5	≥4 days	V	Separate means of the remaining morning & evening readings	130/80	7‐day (“722”) cycle every 2 weeks to 3 months based on hypertension control status

Abbreviations: ACC, American College of Cardiology; AHA, American Heart Association; AMA, American Medical Association; ESC, European Society of Cardiology; ESH, European Society of Hypertension; HBP, home blood pressure; HBPM, home blood pressure monitoring; HOPE Asia, Outcome Prevention and Evidence in Asia; ISH, International Society of Hypertension; JSH. Japanese Society of Hypertension; NICE, National Institute for Health and Care Excellence.

‐: indicated “not available” or “not recommended.”.

TABLE 4

Details of the HBP protocol recommended by different guidelines and consensus for HBP monitoring, ranked by year of publication

	HBP protocol
	Timing			Schedule						Estimation
Guidelines & consensus (year of publication)	Confirmation of hypertension diagnosis	Assessment of treatment	Before each visit	Duration	Morning	Evening	No. of measurements on each occasion	Time interval between repeated measurements (minute)	Rest time before HBP measurement (minute)	Minimal requirement	First day discarded	HBP estimate	HBP threshold for high blood pressure	Long‐term follow‐up
ESH guideline (2010) 49	V	V	V	7 days	V (before medication)	V (before dinner)	2	1‐2	≥5	≥3 days	V	Mean of all remaining measurements	135/85	1‐2 measurements per week
JSH guideline (2012) 50	V	V	–	2 to 4 weeks	V (within 1 h after awakening, prior to medication and breakfast)	V (before going to bed)	1‐3	1‐2	1‐2	≥5 days	–	Mean of all measurements	135/85	≥3 days/week if BP is under control; ≥5 days/week for drug titration
HOPE Asia Network consensus (2018) 5	V	V	–	7 days	V (within 1 h after awakening, prior to medication and breakfast)	V (before going to bed)	≥2	1	2	≥3 days of both morning and evening measurements	–	Mean of all measurements, and separate means of morning & evening readings	135/85	–
Chinese guideline (2020) 51	V	V	–	5‐7 days	V (before breakfast and medication)	V (after dinner, before going to bed)	2‐3	1	5	–	–	Mean of all measurements	135/85	≥1 day per week
Taiwan HBP consensus (2020) 19	V	V	V	7 days	V (within 1 h after awakening, prior to medication and breakfast)	V (within 1 hbefore bedtime)	≥2 (≥€3 if atrial fibrillation)	1	5	≥4 days	V	Separate means of the remaining morning & evening readings	135/85	7‐day (“722”) cycle every 2 weeks to 3 months based on hypertension control status, or ≥€€1 occasion (with two measurements) per week
AHA & AMA joint statement (2020) 52	V	V	–	7 days (8 days, if first day is discarded)	V	V	2	1	5	≥3 days (≥€4 days if first day is discarded)	V	Mean of all remaining measurements	130/80	1‐3 days per week
ESH practice guideline (2021) 53	V	V	–	7 days	V (before breakfast and medication)	V (before medication and dinner)	2	1	3‐5	≥3 days	V	Mean of all remaining measurements	135/85	1‐2 occasions (with two measurements per occasion) per week or per month

Abbreviations: ACC, American College of Cardiology; AHA, American Heart Association; AMA, American Medical Association; ESC, European Society of Cardiology; ESH, European Society of Hypertension; HBP, home blood pressure; HBPM, home blood pressure monitoring; HOPE Asia, Outcome Prevention and Evidence in Asia; ISH, International Society of Hypertension; JSH, Japanese Society of Hypertension; NICE, National Institute for Health and Care Excellence.

‐: indicated “not available” or “not recommended.”.

Prior studies showed that inadequate rest before BP measurement could lead to biased BP estimation. Because it has been shown that roughly 50% of individuals with their systolic BP stabilized within 5 min after a sitting rest in the clinical setting, , most current guidelines recommend at least 5‐min rest before each BP measurement occasion (Tables 3 and 4). However, recent studies showed that less than 5‐min rest, even without rest, might be acceptable if OBP was estimated using triplicate BP readings obtained at a 1‐min interval. , It has been concerned that too much rest could make HBP like automated OBP, probably leading to underestimation of usual BP. Provided that home setting is less stressful than clinical setting, shorter than 5‐min rest might be plausible if HBP estimates are derived using repetitive BP readings on each measurement occasion.

The follow‐up schedule for home blood pressure monitoring

For patients with well‐controlled hypertension, 1 to 2‐day measurements with duplicate readings per occasion on a weekly or monthly basis are generally recommended. Given the evidence of above‐mentioned clinical studies and clinical guidelines and consensus recommendations, a comprehensive HBP follow‐up schedule, based on blood pressure classifications and status of hypertension management was provided in the 2022 Taiwan Hypertension Guidelines (Figure 1). In general, if blood pressure is not under control, the “722” protocol should be conducted more frequently. For well‐controlled hypertensive patients, the 7‐day consecutive HBP measurement is recommended to be conducted every 3 months.

FIGURE 1

Frequency of follow‐up of the “722” protocol for standardized home blood pressure monitoring according to different clinical scenarios

CONCLUSIONS

While the reliability of HBP estimation is weighed against the long‐term burden of repetitive HBP measurements, it is reasonable to conclude that the “722” protocol for HBP measurement is clinically justified. Along with well‐designed patient training and education programs, together with experienced healthcare coworkers and consultants, HBP measurement based on the “722” protocol can serve as the foundation for standardized HBP monitoring.

CONFLICT OF INTEREST

YCC has received unrestricted educational grants from Viatris and Omron and from Medtronic for activities of the Malaysian Society for World Action on Salt, Sugar and Health (MyWASSH); and also has received speaker honoraria from Medtronic, Astra‐Zeneca, Omron and Xepa‐Sol. KK reports research grant and consulting fees from A&D, Omron Healthcare, Fukuda Denshi; honoraria from Omron Healthcare; Participation in Advisory board of Fukuda Denshi, outside the submitted work.

AUTHOR CONTRIBUTIONS

Hung‐Ju Lin wrote the manuscript. Heng‐Yu Pan, Chen‐Huan Chen, Hao‐Min Cheng, Yook‐Chin Chia, Guru Prasad Sogunuru, Jam Chin Tay, Yuda Turana, Narsingh Verma, Kazuomi Kario, and Tzung‐Dau Wang reviewed and edited the manuscript. T.D.W. is the guarantor responsible for the integrity of this work.