Table 1.

Proposals related to wearable monitoring and sensor networks in a wrist band.

Bibliography	Sensors Included	Advantages and Disadvantages	Novelty of the Proposal
Shin, D. M. et al. (2013).	GPS, ambient light sensor, accelerometer, wireless communications	It stands out for including GPS and implementing location-based positioning.	It is an intelligent surveillance system, for the use and improvement of living conditions of patients with dementia.
Perez, M. N. et al. (2015).	Optical heart rate sensor, accelerometer, a capacitive sensor, and thermistor	It measures activities, such as exercise and sleep quality, that have not been considered in our work.	Monitor the user’s daily activities, including exercise, sleep quality, heartbeat and food types
Shin, D. et al. (2014).	GPS, ambient light sensor, accelerometer, wireless communications	The work is focused on dementia and includes positioning. It also highlights the algorithm for fall detection.	The main purpose of the bracelet is to prevent dementia patients from getting lost and to detect falls.
Sendra, S. et al. (2018).	Accelerometer, microphone, heart rate, and blood oxygen sensor with photoplethysmography, GPS, elastic band to measure breathing and thermometer	It is focused on disease measurement and incorporates sensors not considered in our article.	Control of chronic diseases of children with remote monitoring constantly with the help of remote devices.
Chen, M. et al. (2018).	Electrocardiogram, temperature and the amount of oxygen in the blood	It measures oxygen in the blood, a sensor that has not been considered in our work.	Monitoring the psychological state of the user using Smart Personal Health Advisor (SPHA) systems
Kajornkasirat, S. et al. (2018).	Heart rate sensor, vibrator, audio support, connection via Bluetooth	Aspects of daily life are detected but no accidents or anomalies.	Counts the steps, the calories burned, monitors our sleep, and analyzes the calories we eat at lunch
Maglogiannis, I. et al. (2014).	Accelerometer, gyroscope and contact sensors, vibrator, magnetometer, ambient light sensor and Bluetooth 4.0	Falls are detected with the CUSUM algorithm and we detect the falls through the IMU itself.	Initial evaluation of fall detection using the CUSUM algorithm
Alsulami, M. H. et al. (2016).	Heart rate sensor	Heart rate is monitored with an expert system called KBS. In our case we extend this to other variables.	The use of smart watches to monitor heart rate in older people using expert system called KBS capable of making decisions and taking action.
Karakaya, M. et al. (2017).	Accelerometer and gyroscope	It only uses an IMU with a KNN classifier as a sensor, so our proposal is more complete	Remote monitoring of elderly people’s activities using Smart Watch using a KNN classifier
Reeder, B. et al. (2016).	Gyroscope, microphones, optical heart rate sensor, contact sensor for temperature measurement and light sensor for sun exposure	Very comprehensive review in which several sensors not covered in our work are used.	Systematic review of the uses of intelligent surveillance for health and well-being with different watch models
Nguyen, D. N. et al. (2017).	Shock sensor, microphone, pulse sensor, temperature sensor and GPS	Detection of parameters for anomaly detection using a microphone as an extra to our work.	Smart Watch with automatic voice recording and alarm
Parara, A., & Sekka, S. (2016).	Heart rate sensor, GPS, touch screen and microphone	A system including positioning and a microphone as additional components is presented.	Intelligent user care security surveillance device
Mukhopadhyay, S. C. (2014).	Body temperature sensor, heart rate meter with photoplethysmography (PPG), microphone, camera, accelerometer, and electrocardiogram	It focuses on Human Behavior Activity and is not aimed at alarm detection.	Review of wearable sensors for monitoring human activity
Gope, C. (2015).	Accelerometer, GPS, panic button	It is aimed at the detection of epileptic movements and does not cover other areas of interest in our case.	Smart Watch for surveillance and monitoring of seizures / abnormal movement activities or epileptic seizures.
Wile, D. J. et al. (2014).	Accelerometer	It is aimed at tremor analysis and does not cover other areas of interest in our case.	Smart Watch accelerometry for tremor analysis and diagnosis
Kumari, P. et al. (2017)	Electroencephalogram (EEG), electrooculogram (EOG), electromyography (EMG), electrocardiogram (ECG)	This is similar work that focuses on aspects of monitoring people rather than detecting alarms caused by accidents.	Review of wearables and multimodal interface for human activity monitoring
Manisha, M. et al. (2016)	Heart rate and blood pressure sensor	The application is heart attack detection. So it only uses sensors aimed at detecting heart attacks.	Device targeting heart disease, monitoring heartbeats and blood pressure, to try to reduce the number of deaths due to heart attacks
Dhull, R. et al. (2020)	Failure of respiratory system of human, body temperature, heart rate, and blood pressure.	The smartwatch is used for COVID detection and the sensors it implements and its software are closed to this application.	Discuss the design, principle of operation and features of different smartwatches
Adjiski, V. et al. (2019)	Accelerometer, gyroscope, magnometer, and heart rate sensor	It is dedicated to mining and the smartwatch does not implement fall detection.	Real-time safety situation awareness and predict health and safety incidents before they occur