Cloud Enabled Body Area Network
Indian Institute of Information Technology Guwahati Subhasish Dhal
Indian Institute of Information Technology Guwahati
There is a proverb that says prevention is better than cure. Doctors usually suggest several measures such as regular medical check up, clinical tests, physical exercises, healthy diet, etc., to prevent diseases. However, with the enormous advancements in computing and healthcare technologies, it is of natural demand that a person, facing any sudden medical emergency, be reported instantly and automatically to all the concerned parties such as the patient herself/himself, medical service provider (MSP), doctors, etc. This is made possible by use of a newly emerged technology called Body Area Network (BAN). This technology consists of different sensor nodes implanted in the human body to read physiological health information (PHI) parameters such as blood sugar, blood pressures, body temperature, etc. If any PHI reading is beyond the normal range of the corresponding PHI, the medical event is reported instantly. However, the minute monitoring and detail analysis of PHI data 24 x 7 requires huge computational resources, which is beyond the reach of BAN. An appropriate Cloud environment can be an aid to overcome this computational limitation. In this mechanism, a medical user (MU) empowered with BAN is connected with a Cloud (also can be termed as health Cloud) environment. BAN attached to the medical user continuously sends the physiological readings to the Cloud, which in turn does all the tasks of data analysis and reports to all the concerned parties, whenever there is any medical abnormality found by the analysis. The MSPs are, on the other hand, registered with the same Cloud to provide services to the MU remotely such as monitoring the MU's physiological status when hospitalization is not necessary for continuing the treatment. MSPs also can use Cloud aided BAN technology for the MUs admitted in their own healthcare facility. In case of any medical abnormality, the selection of appropriate MSP, depending on the nature of ailment, is also done by Cloud automatically. However, one of the essential requirements in this technology is both MU and MSP have to share several sensitive information such as real identity, physical location, physiological parameters, infrastructural status, etc., with the Cloud. These can become threats in several forms for the users of this nice and useful technology. In this chapter, the several kinds of threats against the security and privacy of the users of Cloud aided BAN are discussed. Also, it briefly enlightens the research attempts that tried to thwart these threats and enable this very useful technology for use in a smart society.
The term Computer Network (or simply, Network) is a common word in the field of Computer Science and Electronics. Network is the wired or wireless interconnection among the computing devices and switching elements that enables communication among the devices. It is also the backbone of today's revolution in information and communication technology. Wireless Sensor Network (WSN) is a kind of network, where sensors are the communicating devices. Sensors are the tiny electronic devices that can sense some physical characteristics such as temperature, air moisture, wind speed, wind direction, physical movements, etc. A block diagram of a sensor node is shown in Figure 5.1.
Different types of sensors used in medical fields can be classified into three categories: physiological sensors, bio-kinetic sensors, and ambient sensors. Physiological sensors measure blood pressure, blood glucose, body temperature,
Figure 5.1: Block Diagram of a typical Sensor Node
blood oxygen, etc. Bio-kinetic sensors measure human movement in terms of acceleration and angular rate of rotation while in motion or movement. Ambient sensors are those which can measure environmental parameters such as temperature, humidity, light, and sound pressure level. Over the past decades, several bio-sensors (or body sensors) have been developed that can read different physiological parameters such as body temperature, blood glucose, blood pressures, etc. These bio-sensors in a human body form a special kind of network, known as body area network (BAN) or wireless body area network (WBAN). A sink node or gateway node is placed in the human body to accumulate the physiological readings. A hand-held device such as smart phone, or a smart wrist watch, connected to the Internet forwards these physiological data to servers in hospitals or such service providers for analysis. However, all the hospitals may not be well equipped for this continuous data analysis because it involves investment in computing resources, infrastructure, and skilled personnel. Therefore, Cloud is an alternative for this continuous physiological condition monitoring without fail. This health Cloud can be public Cloud or private Cloud. To restrict the scope of our discussion, we assume the health Cloud as public Cloud. If there is any abnormality in the physiological reading of a user, then that is reported instantly to all concerned parties so that medical treatment can be started as early as possible.
As society is evolving towards smart society, several countries are taking up projects to make some of its cities smart cities. Hospitals are also using more and more smart technology-enabled services to cater to its patients. This can be better explained with some examples.
I. Suppose a patient is hospitalized in a critical care unit with severe medical problems, and has been stabilized after few days of medical treatment. Therefore, the same critical care unit can be vacated and allocated to another severe patient, and the patient in stable condition can be shifted to general bed for further observation and treatment. However, patients in the general beds need to be monitored with proper care as the patient is still not fully recovered. Since the general beds do not have facilities like critical care units, BAN can help to monitor this patient continuously. Thus the critical care unit can be utilized for multiple patients without any lack of care to any patient.
II. The aged population is increasing day by day. There are many aged persons, who are otherwise medically fit, but can suffer a lot if they fall on the floor by losing physical balance. This sudden fall, if not detected early, can delay the proper treatment and can become very fatal. If the elderly people are powered with BAN, then medical care to them can be much more effective.
III. Many people usually suffer cardiac problem or cerebral attack during their sleep, where they succumb to death most of the times without any medical treatment. This can be prevented at large if a person is equipped with BAN.
IV. Similarly, parents feel helpless and become worried because their children cannot express the nature of their physical uneasiness. The anxiety of parents and sufferings of children can be reduced if the reason for their physical uneasiness can be instantly detected by cloud enabled BAN.
V. Next, consider a situation where a person is met with a severe road accident with nobody around to notify the family members or the doctors. And the physical condition of the person is so critical that, if the person does not get quick medical treatment, the result may be catastrophic. If the person is equipped with BAN, and the BAN is connected to a Cloud, the medical emergency of the person can be immediately analysed and detected by the Cloud, which in turn can notify the nearest trauma care service provider for sending ambulance to the accident spot without any delay. This can largely speed up the treatment of the patient and thus life of the patient can become out of danger.
VI. In another example, consider the case that many road accidents occur in the late night or early morning due to the fact that the driver falls asleep at the wheel. As a result, the car may collide with some other vehicle or objects like a tree. Even if the driver closes his eyes for a fractions of a second, there may be a catastrophic mishap. This type of accident can be reduced if the driver is equipped with BAN having a sensor for monitoring sleep or awake status.
Thus there are several examples where BAN can immensely help in proper and efficient treatment. These examples can serve as the motivation for a smart society to adopt cloud-enabled BAN for detecting most of the medical problems instantly. So far, we have discussed only the application of BAN for continuous monitoring of health data. However, BAN can also be used in so many other applications. These include sports training, military applications, medical automation system, human computer interaction systems such as gesture detection system and emotion recognition system, information security and forensic systems such as deception detection system and authentication system, and education systems such as smart tutoring system and teaching assistant system .
Although Cloud based BAN is of great help in a medical emergency, the involvement of a third party, i.e., Cloud, can become a security and privacy risk for the users. The medical behaviour of a user can be easily eavesdropped and exploited. The research community considered this as a very important aspect to deploy Cloud based BAN in healthcare. In the next few sections, we will gradually highlight these issues and their countermeasures available in the literature.
Figure 5.2: A human body with some sensor nodes