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. 2021 Dec 24;12(1):11. doi: 10.3390/jpm12010011

Table 3.

Previous studies assessing daily behavioral patterns in patients with MCI and AD using nonwearable sensor-based in-home assessment.

References Participants and Study Protocol
(1. Study Design; 2. Participants; 3. Sensor Type; 4. Duration; 5. Machine Learning Technique)
Main Findings
Hayes et al. [26]
  1. Observational cross-sectional study

  2. Healthy (n = 7; mean age: 90.0 y; F:M = 5:2); MCI (n = 7; mean age: 88.4 y; F:M = 4:3)

  3. Passive infrared motion sensors and magnetic contact door sensors

  4. Six months

- Walking speed was more variable in patients with MCI.
- Day-to-day pattern of activities was more variable in patients with MCI.
Dodge et al. [27]
  1. Observational longitudinal study

  2. Healthy (n = 54; mean age: 84.9 y; %F: 91%); amnestic MCI (n = 8; mean age: 84.5 y; %F: 88%); non-amnestic MCI (n = 31; mean age: 83.8 y; %F: 84%)

  3. Passive infrared sensors

  4. Three years

- Daily walking speeds and their variability were associated with non-amnestic MCI.
Hayes et al. [28]
  1. Observational cross-sectional study

  2. Healthy (n = 29; mean age: 87.5 y; F:M = 26:3); amnestic MCI (n = 6; mean age: 84.8 y; F:M = 5:1); non-amnestic MCI (n = 10; mean age: 86.5 y; F:M = 9:1)

  3. Wireless passive infrared motion sensors and magnetic contact door sensors

  4. Six months

- Patients with amnestic MCI showed less sleep disturbance than both those with non-amnestic MCI and healthy elderly.
Petersen et al. [29]
  1. Observational study

  2. Healthy (n = 75; mean age: not clear; F:M = not clear); MCI (n = 10; mean age: not clear; F:M = not clear)

  3. Pyroelectric infrared motion sensors and contact sensors

  4. One year

- Patients with MCI spent an average 1.67 h more inside the home than healthy elderly.
Urwyler et al. [30]
  1. Observational study

  2. Healthy (n = 10; mean age: 73.9 y; F:M = 7:3); dementia (n = 10; mean age: 76.7 y; F:M = 7:3)

  3. A wireless-unobtrusive sensors (temperature, humidity, luminescence, presence [passive infrared radiation], and acceleration)

  4. Twenty consecutive days

- Patients with dementia showed unorganized behavior patterns.
Rawtaer et al. [31]
  1. Observational cross-sectional study

  2. Healthy (n = 21; mean age: 73.0 y; F:M = 14:7); MCI (n = 28; mean age: 75.1 y; F:M = 19:9)

  3. Multiple sensor system (passive infrared motion sensors, proximity beacon tags, a sensor equipped medication box, a bed sensor, and a wearable sensor)

  4. Two months

- Patients with MCI were less active than healthy subjects and had more sleep interruptions per night.
- Patients with MCI had forgotten their medications more times per month than healthy subjects.
Akl et al. [34]
  1. Observational longitudinal study

  2. Healthy (n = 79; mean age: not clear; F:M = not clear); MCI (n = 18; mean age: not clear; F:M = not clear)

  3. Passive infrared motion sensors and wireless contact switches

  4. Three years

  5. Support vector machine, random forest

- Variabilities in weekly walking speed, morning and evening walking speeds, and subjects’ age and gender were the most important for the process of detecting MCI.
- This study autonomously detected MCI with receiver operating characteristic curve (0.97) and precision–recall curve (0.93) using a time windows of 24 weeks.
Akl et al. [35]
  1. Observational longitudinal study

  2. Healthy (n = 59; mean age: not clear; F:M = not clear); amnestic MCI (n = 11; mean age: not clear; F:M = not clear); non-amnestic MCI (n = 15; mean age: not clear; F:M = not clear)

  3. Passive infrared motion sensors and wireless contact switches

  4. Three years

  5. Clustering (affinity propagation)

- This study automatically detected MCI (F0.5 score, 0.856) and non-amnestic MCI (F0.5 score, 0.958).
Alberdi et al. [36]
  1. Observational longitudinal study

  2. Healthy (n = 13; mean age: 82.85 y; F:M = 9:4); at risk (n = 10; mean age: 86.20 y; F:M = 10:3); MCI (n = 6; mean age: 84.50 y; F:M = 5:1)

  3. Passive infrared motion sensors

  4. Two years

  5. Regression: support vector regression, linear regression, K nearest neighbors; Classification: support vector machine, adaboost, multilayer perceptron, random forest

- Sleep and overnight patterns along with daily routine features contributed to the prediction of several health assessments.
- All algorithms could build statistically significant prediction models.
Nakaoku et al. [37]
  1. Observational study

  2. Normal cognition (n = 55; mean age: 75.0 y; F:M = 18:37); cognitive impairment (n = 23; mean age: 78.0 y; F:M = 6:17)

  3. Unobtrusive in-house power monitoring system (air conditioner, microwave oven, washing machine, rice cooker, television, and induction heater)

  4. One year

  5. Generalized linear model

- Three independent power monitoring parameters (air conditioner, microwave oven, and induction heater) representing activity behavior were associated with cognitive impairment.
- The prediction model with power monitoring data had better predictive ability (accuracy, 0.82; sensitivity, 0.48; and specificity, 0.96).

ADL activities of daily living, MCI mild cognitive impairment, AD Alzheimer’s disease.