# Wearables for Industrial Work Safety: A Survey
## 3 State-of-the-Art Techniques in the Field of Industrial Wearables
### Data Collection and Wearable Metrics
\begin{table}
\begin{tabular}{c c c} \hline \hline
**Metric** & **Description** & **Example Accuracy** & **Examples** \\ \hline Blood pressure & The pressure that blood puts on the walls of blood vessels. There are systolic or upper (normal value: less than 120 mmHg) and diastolic or lower (normal value: less than 80 mmHg) blood pressure [45]. The average working range of blood pressure sensors is 0-320 mmHg [46; 47]. & 86\% [48] & Arm cuffs with attached sensors [49], cuff-less blood pressure sensors [50] \\ \hline Calorie & A unit equal to the amount of heat needed to increase one gram of water temperature by one degree Celsius. There are several ways how to calculate the number of calories (e.g., based on the number of steps or heart rate [51]), resulting in a wide range of wearables providing this function. & \(>\)91\% (walking); \(>\)90\% (running) [52] & Accelerometers, pressure sensors in fitness bracelets, smart shoes [51], etc. \\ \hline Electrocardiogram (ECG) & The electrical activity of the heart [49]. The unit of measurement is Volts. ECG is the main diagnostic method for detecting cardiovascular diseases such as hypertrophy, heart attack, arrhythmia [53]. & \(>\)90\% [54] & Skin electrodes [49] in clothes [55], chest straps [56], etc. \\ \hline Electroencephalogram (EEG) & The electrical activity of the brain [57]. The unit of measurement is Volts. EEG is used to identify and predict brain-related diseases (e.g., Alzheimer’s disease, epilepsy, dementia) [58]. In addition, it also used for the emotion detection [59; 60]. Until now, ECG, EEG, and EMG are performed mainly in medical institutions. However, there are already some wearable devices on the market for such measurements. & \(>\)86\% [59; 60] & Headset [57; 61] \\ \hline Electro-myography (EMG) & The electrical activity of the muscles [49]. The unit of measurement is Volts. When measuring EMG, the critical point is the exact position of the electrodes on the muscles. EMG is used to identify the muscle traumas and monitor the recovery tendency after such traumas [62]. & \(>\)90\% [63] & Skin electrodes [49] embedded in bracelets, waist straps [64], clothes [65]. \\ \hline Glucose & The level of sugar in the blood. It is measured in grams per liter or moles per liter. High glucose level identifies diabetes, the symptoms of which are quite wide, ranging from visual impairment to increased fatigue and depressive episodes [66; 67] & \(>\)95\% [68] & Strip-base [69], implantable [70] glucose sensors, smart tattoos [71] \\ \hline Heart rate and pulse & Heart rate is the number of heartbeats per minute. Pulse is the number of vibrations of the aortic walls. Pulse may be a less accurate characteristic in pathologies (for example, extrasystole) since not all heartbeats lead to the formation of a pulse wave [72]. Critical boundaries usually range between 40-200 beats per minute and depend on current activity, gender, age, health, type of activity, etc. & \(>\)76\% [73] & Pulse oximeter [74], chest [75] and wrist straps [69], fitness bracelets \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Human body-related metrics.