# Applications of Smart Helmet in Applied Sciences: A Systematic Review
## 4 Discussion  
In recent years, smart helmets have rapidly gained popularity among motorcyclists to enhance their safety and comfort. Moreover, safety regulations for workers are being strengthened in many countries; therefore, the growing adoption of advanced wearable technology, including smart helmets, is expected to drive the demand for personal safety. Based on this systematic review, the advantages and limitations of smart helmets can be summarized as follows. **Advantages of smart helmet**  
* Smart helmet is an intelligent and reliable wearable device with low costs of development and operation. * Smart helmets can contribute to improving the safety of motorcyclists and workers by immediately detecting accidents and supporting rescue requests in emergency situations. * Smart helmets are highly expandable and can be used in other applications by adding or removing sensors as needed. * Smart helmets can be combined with wireless communication technology to secure the always-on connectivity of a device. Therefore, data can be acquired in real time from sensors attached to the helmet and transmitted to a cloud server for analysis. **Limitations of smart helmet**  
* Some sensors, such as cameras and global positioning systems attached to smart helmets have potential elements of privacy invasion. To date, there has been insufficient research on the security and privacy of data collected by smart helmets through sensors. * Smart helmets mainly use inexpensive and lightweight sensors. Therefore, there is a possibility that the sensor malfunctions frequently, and a false alarm occurs. * Various sensors can be attached to smart helmets, as needed; however, this can increase the helmet's weight and make it uncomfortable to wear. Moreover, attaching a large battery to power a smart helmet increases the load and can be dangerous to humans. Until now, little research has been conducted on the discomfort and health that people feel when wearing a smart helmet. For future works, some challenges of smart helmets are as follows. 1. Power consumption and battery life: As can be seen from the review results, power consumption is expected to increase as various sensors are being added to the smart helmet. Frequent charging and battery replacement can reduce the utility of the smart  
Figure 11: Number of uses by wireless communication technology and microcontroller types in smart helmet studies. helmet. Therefore, there is a need for a study on how to extend the battery operating time of a smart helmet by using low-power sensors and microcontrollers. 2. Wearability: Smart helmets are relatively heavy compared to traditional helmets because a variety of sensors and microcontrollers are attached. Motorcyclists or field workers wearing heavy smart helmets may feel uncomfortable. In order for a smart helmet to provide its own functions as a wearable device, it is necessary to reduce the weight of the smart helmet by using lightweight materials and parts. Further research is required for this. 3. Human health and safety: Because a smart helmet is worn on a person's head, research on the effect of the electromagnetic field emitted from a sensor or microcontroller on human health is required. In addition, it is necessary to consider the safety of the use of smart helmets in places where combustible gases may exist, such as underground mines and chemical facilities. 4. Durability: Workers wearing smart helmets often work in high humidity and dusty environments. Smart helmets developed to date often have microcontrollers and sensors exposed to the outside of the helmet, and can be vulnerable to high humidity and dust. Research is needed to increase the durability of smart helmets so that smart helmets can provide functions even in harsh working environments. 5. Accuracy: The sensors attached to the smart helmet should be small in size, lightweight, and low power consumption. Sensors that can meet these conditions at the same time may not have high measurement accuracy.