Hyun-Sung An

How accurate are the wrist-based heart rate monitors during walking and running activities? Are they accurate enough?

Background Heart rate (HR) monitors are valuable devices for fitness-orientated individuals. There has been a vast influx of optical sensing blood flow monitors claiming to provide accurate HR during physical activities. These monitors are worn on the arm and wrist to detect HR with photoplethysmography (PPG) techniques. Little is known about the validity of these wearable activity trackers. Aim Validate the Scosche Rhythm (SR), Mio Alpha (MA), Fitbit Charge HR (FH), Basis Peak (BP), Microsoft Band (MB), and TomTom Runner Cardio (TT) wireless HR monitors. Methods 50 volunteers (males: n=32, age 19–43 years; females: n=18, age 19–38 years) participated. All monitors were worn simultaneously in a randomised configuration. The Polar RS400 HR chest strap was the criterion measure. A treadmill protocol of one 30 min bout of continuous walking and running at 3.2, 4.8, 6.4, 8.0, and 9.6 km/h (5 min at each protocol speed) with HR manually recorded every minute was completed. Results For group comparisons, the mean absolute percentage error values were: 3.3%, 3.6%, 4.0%, 4.6%, 4.8% and 6.2% for TT, BP, RH, MA, MB and FH, respectively. Pearson product-moment correlation coefficient (r) was observed: r=0.959 (TT), r=0.956 (MB), r=0.954 (BP), r=0.933 (FH), r=0.930 (RH) and r=0.929 (MA). Results from 95% equivalency testing showed monitors were found to be equivalent to those of the criterion HR (±10% equivalence zone: 98.15–119.96). Conclusions The results demonstrate that the wearable activity trackers provide an accurate measurement of HR during walking and running activities.

How valid are wearable physical activity trackers for measuring steps

Abstract Wearable activity trackers have become popular for tracking individual’s daily physical activity, but little information is available to substantiate the validity of these devices in step counts. Thirty-five healthy individuals completed three conditions of activity tracker measurement: walking/jogging on a treadmill, walking over-ground on an indoor track, and a 24-hour free-living condition. Participants wore 10 activity trackers at the same time for both treadmill and over-ground protocol. Of these 10 activity trackers three were randomly given for 24-hour free-living condition. Correlations of steps measured to steps observed were r = 0.84 and r = 0.67 on a treadmill and over-ground protocol, respectively. The mean MAPE (mean absolute percentage error) score for all devices and speeds on a treadmill was 8.2% against manually counted steps. The MAPE value was higher for over-ground walking (9.9%) and even higher for the 24-hour free-living period (18.48%) on step counts. Equivalence testing for step count measurement resulted in a significant level within ±5% for the Fitbit Zip, Withings Pulse, and Jawbone UP24 and within ±10% for the Basis B1 band, Garmin VivoFit, and SenseWear Armband Mini. The results show that the Fitbit Zip and Withings Pulse provided the most accurate measures of step count under all three different conditions (i.e. treadmill, over-ground, and 24-hour condition), and considerable variability in accuracy across monitors and also by speeds and conditions.

Accuracy of inclinometer functions of the activPAL and ActiGraph GT3X+: A focus on physical activity

PURPOSE The purpose of the study was to examine the accuracy of inclinometer functions of the ActiGraph GT3X+ (AG) (worn on the waist and wrist) and the activPAL (AP) in assessing time spent sitting, standing, and stepping. METHODS A total of 62 adults (age: 18-40 yrs; male:37; female:25) wore three activity monitors (AG waist, and AG wrist, and AP) while completing 15 different types of activities. The 15 activities were classified into 3 different postures (sitting, standing, and stepping) based on the directly observed behaviors. Minutes estimated from the inclinometers of the three monitors were directly compared to those from direct observation (criterion method) using mean absolute percent error (MAPE) values, effect sizes (Cohens D), and equivalence testing. RESULTS The AP was more accurate than the both waist- and wrist-worn AG in both sitting and standing activities, but the AG was more accurate than the AP in stepping activity when the stepping activity was determined with 0.7 step/s threshold. Equivalence testing indicated that the time measured by the waist-, wrist-worn AG, and AP showed significant equivalence to the time in the equivalence zone (90% confidence interval: 2.7 to 3.3min) for 6, 5, and 7 activities, respectively. CONCLUSIONS The AP was reasonably accurate for detecting sitting, standing, and stepping, and the AG was very accurate for classifying stepping when the stepping activity was determined by the formula created by 0.7 step/s threshold. It is expected that the result of the study would contribute to performing movement pattern analyses and health promotion research for classifying activities.

Validity Of Optical Blood Flow Heart Rate Monitors: 1010 May 27, 3

CONCLUSIONS METHODS INTRODUCTION RESULTS Physical Activity in Health Promotion • Heart rate (HR) monitors are a valuable device for individuals who are interested in improving and/or tracking fitness. • These devices can be worn on the wrist or forearm and detects HR by use of an optical blood flow sensor without a chest strap. However, little is known about the validity of these commercially available HR monitors. • The purpose of this study was to validate the Schoche (SC) (RhythmTM), Basis B1 Band (BB) (BASIS Science, Inc.), and Mio Alpha (MA) (Physical Enterprises, Inc.) wireless heart rate monitors. Instruments • All participants simultaneously wore the SC on left forearm, the BB on the right wrist, the MA on the left wrist, and Polar heart rate strap on their chest. • The Schoche (SC) (RhythmTM) measures HR, calories burned, distance, speed, pace, and controls your music. • The Basis B1 Band (BB) (BASIS Science, Inc.) contains a 3D accelerometer to measure movement and is able to measure skin temperature, the ambient temperature, and the galvanic skin response when engaged in activity. • The Mio Alpha (MA) (Physical Enterprises, Inc.) is accurate at high speeds, has 3 user-settable heart rate zones, shows time, and has an exercise timer. • All of these devices use optical sensors to measure blood flow, are waterproof, and use Bluetooth technology to connect to a smartphone or tablet to display results. Procedures • The exercise protocol consisted of one 30-minute bout of continuous walking and running in which the treadmill speed increased every 5 minutes. • HR was recorded every minute from each monitor including the Polar HR monitor as a criterion measure. • The results demonstrate that the wireless wrist-oriented heart rate monitors provide an accurate measurement of HR during exercise. • However, further research is needed to validate these monitors with a larger sample in different environments RESULTS • Fifteen college students participated in this study. METHODS Female (N=4) Range Male (N=11) Range Age (y) 26.5 ± 5.7 23 35 27.3 ± 5.1 22 37 Height (cm) 164.3 ± 6.7 158.5 174 181.3 ± 4.0 175 186.5 Weight (kg) 60.7 ± 7.1 52.5 69.7 84.8 ± 14.5 67.63 109.2 BMI (kg · m2) 22.4 ± 1.1 20.9 23.4 25.7 ± 4.0 21.3 33.9 6.1 % 11.7 % 18.2 %

Validity Of The Ihealth-bp7 And Withings-bp800 Self-measurement Blood Pressure Monitors: 985 Board #6 May 27, 3

CONCLUSIONS INTRODUCTION RESULTS Physical Activity in Health Promotion • Blood pressure (BP) control among treated people with hypertension remains poor. • Home BP monitoring devices have led to their widespread adoption, and are now consistently utilized for the evaluation and management of hypertension. • The purpose of this study is to validate the wireless iHealth-BP7 and WithingsBP800 monitors according to the European Society of Hypertension (ESH) International Protocol revision Instruments • iHealth-BP7 (iHealth Lab, Inc., Mountain View, CA) is a wireless, noninvasive blood pressure measurement system connected by Bluetooth technology to smartphones or tablet PCs. It is designed to measure the systolic, diastolic blood pressure and pulse rate by inflatable cuff wrapped around the wrist. • Withings-BP800 (Withings, Inc., Lewes, DE) measures blood pressure by the cuff oscillometric method. It is directly connected to smartphones or tablet PCs, monitoring blood pressure and pulse. • The iHealth-BP7 monitor is recommended as a valid home BP monitoring device, however the Withings-BP800 fails to meet the ESH criteria in this study potentially due to the small sample size. • Since the ESH protocol requires 33 subjects, further study with additional participants is warranted to determine validation of both devices METHODS (Cont.) Participants • 11 participants (31.2 ± 9.4 years) participated in this study Protocol • Participants were asked to sit and relax for 10-15 min with legs uncrossed, and back supported prior to the test. In all participants, sequential left arm measurements were performed by two trained observers using a mercury sphygmomanometer and one supervisor using the devices (iHealth-BP7 and Withings-BP800). Part 1 ≤5mmHg ≤10mmHg ≤15mmHg Grade 1 Mean SD Pass Requirement Two of 24.3 29 32 All of 21.6 27 31 Achieved SBP 28 33 33 Pass -0.55 3.75 DBP 26 33 33 Pass 0.54 3.62 Part 2 2/3 ≤ 5mmHg 0/3 ≤ 5mmHg Grade 2 Grade 3 Pass Requirement ≥ 8 ≤ 1 Achieved SBP 10 0 Pass Pass DBP 9 0 Pass Pass Part 3 Result Pass Table 2.1. Validation Results of iHealth-BP7 Part 1 ≤5mmHg ≤10mmHg ≤15mmHg Grade 1 Mean SD Pass Requirement Two of 24.3 29 32 All of 21.6 27 31 Achieved SBP 21 33 34 Pass 3.18 4.37 DBP 25 30 33 Pass -0.35 5.42 Part 2 2/3 ≤ 5mmHg 0/3 ≤ 5mmHg Grade 2 Grade 3 Pass Requirement ≥ 8 ≤ 1 Achieved SBP 8 2 Fail Fail DBP 9 1 Pass Pass Part 3 Result Fail Table 2.2. Validation Results of Withings-BP800 Sex Male : female 6 : 5 Age Range (low : high) 25 : 56 Mean (SD) 31.2 (9.4) Arm Circumference (cm) Range (low : high) 23.4 : 34.8 Mean (SD) 30.0 (3.8) Cuff for test device (cm) Standard 33 (22-42) Wrist Circumference Range (low : high) 13.4 : 18.5 Mean (SD) 15.6 (1.5) Recruitment BP (mmHg) SBP Range (low : high) 87.5 : 117.5 Mean (SD) 103.5 (11.1) DBP Range (low : high) 54 : 76 Mean (SD) 63.7 (6.6) METHODS Table 1. Participants details UNIVERSITY OF NEBRASKA AT OMAHA, SCHOOL OF HEALTH, PHYSICAL EDUCATION AND RECREATION | PHYSICAL ACTIVITY IN HEALTH PROMOTION • The mean differences between the iHealth-BP7 and sphygmomanometer readings were -0.55 ± 3.75 (SBP) and 0.54 ± 3.62 (DBP). · iHealth-BP7 ·Whithings-BP800 ·Stethoscope & Sphygmomanometer • The mean differences between the Withings-BP800 and sphygmomanometer readings were 3.18 ± 4.37 (SBP) and -0.35 ± 5.42 (DBP).