For millions of people worldwide who need external force to regulate their heart rhythm, pacemakers and implantable cardioverter defibrillators (ICDs) are life changing technologies they rely on. Although both devices are implantable medical devices aimed at improving the quality of life for patients with arrhythmia (a disease of irregular heartbeat), they each have different uses.

A pacemaker is an implantable medical device designed to help patients maintain normal heartbeat and rhythm. This device comes with a small computer that is implanted under the skin above the patient's chest. When the heart beats at an abnormal speed or loses rhythm, the computer can immediately sense it. At this time, it will emit low energy electrical pulses, causing the heart to return to a stable rhythm and rate.

Not to help maintain a normal heartbeat, but to prevent or prevent potentially dangerous arrhythmias that may lead to cardiac arrest by using low-energy or high-energy shocks  Like a pacemaker, ICD is implanted under the patient's skin and includes a computer that tracks heart rate and rhythm. The key difference between these two devices is that for ICD, if the patient's heartbeat is too fast or abnormal, the ICD will emit an electric shock, causing it to return to normal. Some ICDs can also act like pacemakers, signaling when a patient's heart rate is too slow.

Although pacemakers and ICDs have different functions, these two implantable medical devices also have many similarities. Due to the crucial importance of these two devices for patients who need them, the small circuit boards inside these devices (including very small electronic components such as capacitors) must use high reliability (Hi Rel) electrical components.

The challenges faced in designing electrical components for life support technology


Due to the fact that both pacemakers and ICDs are implanted in the human body, these devices must be kept as small as possible. Nowadays, medical device designers are constantly innovating device designs to further reduce size. The new lead-free pacemaker currently under development is only about one tenth the size of a traditional cardiac pacemaker. Therefore, the continuous miniaturization of electrical components such as capacitors used in these devices is a daunting challenge.

A wise choice to help reduce the size of capacitors is to use multilayer ceramic capacitors (MLCC). Due to the MLCC design being able to establish multiple layers within the same capacitor, it can provide a capacitance level equivalent to using multiple parallel single-layer capacitors (SLCs). Although this multi-layer design is slightly thicker (higher) than SLC, it reduces the overall volume of the capacitor and can meet the high capacitance values required for cardiac pacemakers and ICDs.


In addition to requiring smaller and smaller capacitors, the capacitors used in these devices must also be highly reliable. Although high reliability may sound like a subjective term, in the healthcare industry, it has a very specific meaning - the design of components must maintain consistently excellent quality and safety performance for a long period of time.

This is not an easy task as these components must undergo rigorous testing and extensive screening, referencing established military specifications (MIL-SPECs) to demonstrate reliability. For medical components, MIL-PRF-55681 and MIL-PRF-123 are the most commonly used screening specifications. Overall, MIL-PRF-55681 defines medium K stable dielectrics designated as BX, while MIL-PRF-123 covers general requirements for high reliability, universal (BX and BR), and temperature stable (BP and BG) ceramic dielectric constant value capacitors (via and SMD). The screening criteria for MIL-PRF-123 are more stringent, thus providing a higher level of reliability compared to MIL-PRF-55681.

KPD provides you with capacitors that meet various application requirements

Lou's Capacitor (KPD) can assist equipment manufacturers in selecting suitable MLCC and can jointly complete the required testing and screening of equipment at our factory in the United States. Lou's capacitors (KPD) have decades of rich experience in manufacturing highly reliable MLCCs suitable for implantable medical devices such as ICDs and pacemakers. This means that you can be confident that our components can meet both high reliability and safety requirements, and can be used on circuit boards of critical implantable medical devices.

At the same time, we are also well aware that in addition to meeting the miniaturization and high reliability requirements of capacitors described in this article, there are many other factors that guide the selection of capacitors, such as materials, leakage resistance, stability, and price. Therefore, KPD offers a variety of Hi-Rel capacitor series products that can meet your precise specifications for medical implant devices. From elementary charge storage to anti electromagnetic interference (EMI) and high-frequency noise filtering, to signal absorption and smoothing, our products are ideal for your high reliability.