Table 2 Summary of parameters derived from the TUM:W smart-watch
Abbreviation | Sensor (dimension) | Assessment | Operationalization | Outcome | (thought) Target |
|---|---|---|---|---|---|
CADENCE95 | Pedometer (PA) | 60s every 60s | Steps/min | 95th perc | Continuous walking capacity (to cover distance) |
CADENCE | Pedometer (PA) | 60s every 60s | Steps/min if > 5 recognized steps | Mean | Walking fragmentation |
MEANG | Accelerometer (PA) | 5s every 5s | Mean acceleration | 90th perc | Energy expenditure |
MAD | Accelerometer (PA) | 5s every 5s | Average deviation from mean of signal | 90th perc | Energy expenditure |
STEPFREQ | Pedometer (PA) | 5s every 5s | Steps/s | 90th perc | Short distance walking (e.g., indoors) |
ACTI | Gyroscope (beyond PA) | 5s every 5s | Mean angular vel | 90th perc | Intensity of upper-limb use (e.g., during ADL) |
AUTOCOR | Gyroscope (beyond PA) | 5s every 2.5s | Highest coefficient of autocorrelation | 90th perc | Continuity of cyclic movements |
AUTOCORFREQ | Gyroscope (beyond PA) | 5s every 2.5s | Frequency of highest autocorrelation (1.0–3.0Hz) | 90th perc | Speed of cyclic movements |
MAX5 | Gyroscope (beyond PA) | 60s every 30s | 5 highest vel. peaks | 90th perc | Intensity of upper-limb use |
STD | Gyroscope (beyond PA) | 60s every 30s | Standard deviation of signal | 90th perc | Intensity of upper-limb use (by the variance of its movement) |
STDMEAN | Gyroscope (beyond PA) | 60s every 30s | Standard deviation of signal divided by the mean of the signal | 90th perc | Intensity of upper-limb use in relation to maximum capacity (within the 60s scenario) |
PEAKRATIO | Gyroscope (beyond PA) | 60s every 30s | Ratio of delimited (min. distance to last minimum) and all vel. peaks | 90th perc | Movement smoothness (signal-to-noise) |
PEAKSPER360 | Gyroscope (beyond PA) | 60s every 30s | Number of vel. peaks per 360° summed rotation | 90th perc | Movement smoothness |
MEANPEAK | Gyroscope (beyond PA) | 60s every 30s | Average height of vel. peaks | 90th perc | Intensity of upper-limb use |
PEAKSTD | Gyroscope (beyond PA) | 60s every 30s | Standard deviation of the height of vel. peaks | 90th perc | Intensity of upper-limb use |
PEAKSTDMEAN | Gyroscope (beyond PA) | 60s every 30s | Standard deviation of the height of vel. peaks divided by the mean of vel. peaks | 90th perc | Intensity of upper-limb use in relation to maximum capacity (within the 60s scenario) |
FATREV | Accelerometer (PA) | n.a | Ratio of ≥ 30s and ≥ 5s activity bouts (> 100 milli-g) | Complete dataset | Activity fragmentation (e.g., by fatigability) |
RELPA | Accelerometer (PA) | 5s every 5s | Relative time with > 100 milli-g | Complete dataset | Physical activity |
LOW | Gyroscope (beyond PA) | 5s every 2.5s | If > 5 steps/min, ratio of coeff. of autocor. < 0.30 and all > 5 steps/min data points | Complete dataset | Amount of gait with low autocorrelation (e.g., by changes of movement direction) |