# Resilience in the Internet of Medical Things: A Review and Case Study
## 1 Introduction  
To minimize human involvement in the healthcare domain, the necessity of the Internet of Medical Things (IoMT) has emerged. It encompasses vital applications ranging from remote patient monitoring (RPM) to remote surgery. Through RPM, a patient with a complex health condition can receive 24-h medical care by the clinician remotely. An emergency medical care unit works proactively and can arrive at their location if the patient requires the urgent attention of medical staff. During the COVID-19 pandemic, numerous new IoMT applications such as Telehealth, Telemedicine, and smart wearable devices have emerged and gained widespreadacceptance in the medical community [1]. Through its operational capabilities, IoMT provides continuous monitoring services for patients with various chronic diseases and significantly reduces the life risks from heart attacks, brain hemorrhages, and low insulin levels. It also proves beneficial to patients by preventing unnecessary hospital admissions for observation, thereby mitigating substantial medical expenses. A survey conducted among patients availing of RPM services from various IoMT vendors indicates that 90 percent of them are satisfied with the services of the IoMT ([[https://www.fiereehealthcare.com/tech/patients-board-health-tracking-devices-but-don-t-trust-consumer-wearables-survey-finds](https://www.fiereehealthcare.com/tech/patients-board-health-tracking-devices-but-don-t-trust-consumer-wearables-survey-finds)]([https://www.fiereehealthcare.com/tech/patients-board-health-tracking-devices-but-don-t-trust-consumer-wearables-survey-finds](https://www.fiereehealthcare.com/tech/patients-board-health-tracking-devices-but-don-t-trust-consumer-wearables-survey-finds)) accessed on 18 September 2024). Although rapid advancement is occurring in the IoMT networks, issues such as security and privacy breaches are still unresolved. Moreover, faults such as connection breaks and packet loss are also major concerns that cause failure in IoMT networks. To better understand the problem, consider a scenario (shown in Figure 1) where a person has a cardiac history and has been in continuous observation through RPM. Through those wearable sensors that can measure and transfer the heart rate, respiratory rate, and pulse rate, the patient's health status should continuously be transferred to the clinician at the hospital. Patients should be connected through these sensors consistently for continuous monitoring, and the data about their health status should be transferred in real-time. However, due to multiple causes, such as natural disasters, floods, or any security breach, the patients can lose their internet connection. Meanwhile, if the patient experiences a severe heart attack, how can the information about the patient's critical health status be shared with the clinician at this moment, so that an emergency medical care unit can arrive at the patient's location and their survival is ensured. The American Heart Association (AHA) recommends that if medical personnel can administer appropriate interventions to a cardiac arrest patient within 4-6 min, the likelihood of surviving the attack increases [2]. So, the system can afford a downtime of only 4-6 min and the data transmission must be re-established from the failure within this duration. Otherwise, the information will lose its usefulness if it is received at the receiver's end after this duration, and the patient might lose his life. This paper focuses on how to make the IoMT network more resilient to these kinds of faults and failures. Errors and faults can appear in IoMT networks during unforeseen events, such as cyber-attacks and war situations, or during any natural disasters, such as floods, earthquakes, etc. It might be sensor failure, gateway device faults, or end-to-end communication errors. Different solutions in the literature use several different technologies to make the  
Figure 1: Possible issues of remote patient monitoring. IoMT networks more resilient to these failures.