Table 2.
Smartwatch used for each chosen study, including operating system, type of smartwatch used, most important sensors on the smartwatch that were utilized, features used for classification, connectivity type, and application. Note that some studies developed custom-built smartwatches for their applications, and all studies utilized a Bluetooth connection as WiFi was unavailable in the chosen smartwatches
| Article | Operating system | Smartwatch used | Important sensors used | Classification features | Connectivity type | Application |
|---|---|---|---|---|---|---|
| Lockman 2011 [25] | Android Wear, iOS | Smart Monitor SmartWatch | Accelerometer (± 4G) | Duration, frequency, intensity | Bluetooth to PC | Chronic disease self-management |
| Lopez 2014 [26] | N/A—not mentioned | N/A—not mentioned | Accelerometer (range not available) | Intensity, direction | N/A—not mentioned | Chronic disease self-management |
| Sharma 2014 [27] | Android Wear | Pebble | Accelerometer (± 4G) | Mean, energy, high frequency energy content, entropy | Bluetooth to mobile | Chronic disease self-management |
| Chippen-dale 2014 [28] | Android Wear | Sony smartwatch | Microphone, gyroscope (± 8G) | Vertical angular acceleration matched to stepping | WiFi to mobile | Activity monitoring |
| Årsand 2015 [29] | Android Wear | Pebble | LCD screen, accelerometer (± 4G) | Built-in step count | Bluetooth to mobile | Chronic disease self-management |
| Mortaz-avi 2015 [30] | Android Wear | Samsung Gear Live | Accelerometer (± 2G), gyroscope (± 300°/s) | Difference, gyroscope intensity, mean, sum, dominant frequency | Bluetooth to PC | Activity monitoring |
| Boletsis 2015 [31] | Custom | Basis B1 | Heart rate, accelerometer, temperature, skin impedance (recalled, range not available) | Change in heart rate, movement intensity, sweat levels, body temperature, ambient temperature | Bluetooth to PC | Nursing or home-based care |
| Faye 2015 [32] | Android Wear | Samsung Gear Live | Heart rate, pedometer, accelerometer (± 2G) | Average wrist velocity, maximum wrist velocity, heart rate | Bluetooth to mobile | Activity monitoring |
| Haescher 2015 [33] | Android Wear | Simvalley Mobile AW-420 RX | Accelerometer (± 2G), gyroscope (± 256°/s), microphone | Magnitude area, energy, mean crossing rate, dominant frequency, movement intensity | Bluetooth to mobile | Activity monitoring |
| Jeong 2015 [34] | Android Wear | Samsung Gear Live | LCD screen, accelerometer (± 2G) | Positive peak accelerations | Bluetooth to PC | Healthcare education |
| Panagop-oulos 2015 [35] | Android Wear, iOS | N/A—not mentioned | LCD screen, accelerometer (range not available) | N/A—not mentioned | Bluetooth to mobile | Nursing or home-based care |
| Neto 2015 [36] | Android Wear | Samsung Gear Live | Camera, microphone | Face recognition, temporal coherence across video frames | Bluetooth to mobile | Chronic disease self-management |
| Kalantar-ian 2015 [37] | Android Wear | Samsung Gear Live | Microphone | Audio frequency distribution | Bluetooth to mobile | Chronic disease self-management |
| Vilarinho 2015 [38] | Android Wear | LG G Watch R2 | Accelerometer, gyroscope (1G–3G) | Total vectorial acceleration, fall index, absolute vertical acceleration | Bluetooth to mobile | Nursing or home-based care |
| Dubey 2015 [39] | Android Wear | ASUS ZenWatch | Microphone | Kurtosis, negentropy | Bluetooth to PC | Chronic disease self-management |
| Dubey 2015 [40] | Android Wear | ASUS ZenWatch | Microphone | Loudness, fundamental frequency | Bluetooth to PC | Chronic disease self-management |
| Thomaz 2015 [41] | iOS | Pebble | Accelerometer (± 4G) | mean, variance, skewness, kurtosis, root mean square | Bluetooth to mobile | Chronic disease self-management |
| Ali 2016 [42] | Android Wear | Samsung Gear Live | Microphone, LCD screen | None—used as feedback only | N/A—not mentioned | Nursing or home-based care |
| Banos 2016 [43] | N/A—not mentioned | N/A—not mentioned | Accelerometer, gyroscope (range not available) | N/A—not mentioned | Bluetooth to Cloud | Chronic disease self-management |
| Duclos 2016 [44] | Android Wear | Samsung Gear Live | Accelerometer (± 2G) | Acceleration vector variance, relative magnitude | Bluetooth to mobile | Activity monitoring |
| Velez 2016 [45] | Android Wear, iOS | Smart Monitor Smartwatch | Accelerometer (± 4G), microphone | Mean shake frequency and amplitude | Bluetooth to PC | Chronic disease self-management |
| Hosseini 2016 [46] | Android Wear | Samsung Gear Live | Accelerometer (± 2G), heart rate, GPS, LCD screen | Heart rate, total energy expenditure | Bluetooth to Cloud | Chronic disease self-management |
| Dobrican 2016 [47] | Android Wear | Samsung Gear S2 | Heart rate | Change in heart rate | Bluetooth to mobile | Activity monitoring |
| Thorpe 2016 [48] | Android Wear | Sony smartwatch | LCD screen | N/A—not applicable | Bluetooth to mobile | Nursing or home-based care |
| Nair 2016 [49] | Tizen | Samsung Gear S and S2 | Accelerometer (± 2G), heart rate, GPS | Magnitude, standard deviation, signal strength from 0.6–2.5 Hz, dominant frequency | Bluetooth to Cloud | Activity monitoring |
| Micallef 2016 [50] | Android Wear | Samsung Gear S | Microphone, speakers, LCD screen | N/A—not applicable, no classification performed | N/A—no data collection | Chronic disease self-management |
| Ye 2016 [51] | Android Wear | Pebble | Accelerometer (± 4G) | Gravitational field vector, pitch, roll | Bluetooth to mobile | Chronic disease self-management |
N/A not available