Although the healthcare industry has been slower to adopt Internet of Things (IoT) technologies than other industries, the industry is primed to transform how we keep people safe and healthy, especially as the demand for solutions to lower healthcare costs increase in the coming years. IoT technologies can help monitor and notify caregivers, and alert healthcare providers with actual real-time data to identify issues before they become critical to allow for earlier intervention.
Increasing Use of Wireless Body Area Networks
Wireless Body Area Networks (WBANs) is new in the medical field, and it has the potential to grow into something very beneficial—ubiquitous healthcare monitoring. Typical examples include the early detection, prevention, monitoring of diseases, elderly assistance at home, and rehabilitation after surgery. Similarly, biofeedback applications which control emotional states and assisted living applications which improve the quality of life for people with disabilities, are getting increasing demands.
WBAN involves sensors that gather and supply physiological data to provide real-time feedback through secure data transmission with very low power consumption. This article discusses several wireless technologies and protocols used for WBAN and the potential challenges to implementation in the medical space.
WBANs use the follow different short-range radio technologies.
The IEEE 802.15.6 standard is the latest international standard for WBAN. It uses different frequency bands for data transmission, including the narrowband (NB), the ultra-wideband (UWB), and the human body communication (HBC). The IEEE 802.15.6 is specifically designed to support a wide range of data rates, to consume less energy, and is exceptionally reliable within the surrounding area of the human body.
The oldest wireless technology used in medical applications is the IEEE 802.11, which is a set of standards for a wireless local area network (WLAN). With high-speed wireless connectivity, it allows large data transfers for video calls and video streaming. The advantage of WLAN is all smartphones, tablets and laptops have Wi-Fi integration. However, the high consumption of energy is a drawback.
ZigBee and 802.15.4
ZigBee targets radio frequency applications that require a low data rate, long battery life, proximity and secure networking. One advantage of the ZigBee protocol is the ability to minimize the time the radio is on and to reduce power consumption. Commercial Zigbee devices operate in the industrial, scientific and medical (ISM) radio bands at 2.4 GHz. A significant disadvantage for ZigBee in WBAN applications is due to the interference with WLAN transmission that uses the same frequency bands.
Bluetooth and Bluetooth Low Energy (BLE)
Bluetooth and Bluetooth Low Energy (BLE) is a short-range communication protocol. BLE is a derived option of Bluetooth that is more suitable for WBAN applications because of its extremely low power idle mode, uncomplicated device discovery and reliable data transfer. BLE uses few channels for pairing devices which makes it ideal for latency-critical applications; one example is an emergency alarm generation in healthcare facilities. However, just like ZigBee, Bluetooth and BLE operate in the 2.4 GHz ISM band, making it susceptible to interference with other devices that use the same frequency bands.
The ability to track physiological signals of patients in a real-time manner enables doctors to monitor patients’ health and to take timely actions. Examples are an electrocardiogram (ECG), heart rate, blood pressure, oxygen saturation, body temperature, and body weight. However, they are not without challenges.
Challenges Implementing WBANs
Transmission Reliability and Data Latency
For medical applications, high-reliability and low-data latency are two critical factors to ensure real-time data transmission is immediately accessible by doctors. System designers must incorporate into their design adaptation features for the nodes when the location, connection and link quality changes.
Consider choosing the network communication infrastructure that has a good quality of service (QoS) for high-risk patients by monitoring parameters like transmission loss rate, delay profile and delay jitter.
Low-power consumption is one of the most challenging requirements for WBAN systems. It is crucial especially for devices like pacemakers, which are expected to operate for many years without replacing the batteries. It is essential to test the WBAN device to ensure that its power consumption level is acceptable before deployment.
Many of the wireless communication protocols for medical devices are operating in the 2.4 GHz ISM band. Coexistence is the ability of the wireless equipment to perform in the presence of other equipment using different operating protocols. System designers need to ensure reliable network performance of the WBAN system in the presence of other smart devices on potentially overcrowded radio bands.
The transmission of health-related information between the sensor nodes and monitoring devices in the WBAN systems and subsequently over the internet is private and confidential. This creates an issue for the system designers as extra power and computation must be used to encrypt transmitted data, hence draining the energy from small batteries.
There is an enormous potential for wireless medical applications to improve the quality of medical care, reduce medical errors, improve the efficiency of caregivers, as well as to enhance the comfort of patients. The use of a WBAN system will inevitably proliferate to many other applications that are non-medical related.
Ensuring the WBAN systems operate securely and reliably makes designing and testing the system important, if not essential.
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