**2. Electromagnetic interference for implantable medical device**

The electromagnetic interference (EMI) in the implantable medical device can be produced by the external source with the combined electric and magnetic fields [10, 15], as shown in **Figure 4**. EMI is due to radiation that can be through the air from many possible sources (**Table 1**) in our daily life [17–20], including the


### **Table 1.**

*EMI sources from home, outdoor, medical, and industrial environments.*

common consumer device such as mobile phones, radio frequency identification (RFID) based systems, and microwaves. Moreover, the medical procedure-induced EMI is a critical concern. For example, dental equipment and magnetic resonance imaging (MRI) can generate EMI. In particular, the MRI equipment can cause a strong EMI that is very hard to guard against. The MRI machine can produce an intense magnetic field of about two or three teslas that are dangerous to any electronic device. The electromagnetic susceptibility (EMS) is frequently used to define immunity for EMI, which implies the degree of electronic system malfunctions under varying levels of EMI. Therefore, electromagnetic compatibility (EMC) in implantable medical devices such as cardiac pacemakers and vagus nerve stimulators is important to sustain the stable and normal function to treat accidental cardiac issues because humans are always surrounded by electrical equipment [21, 22].
