Design of Inductive Coils for Wireless Power Transfer to Pediatric Implants

The advent of technology has completely revolutionized the healthcare industry and made it possible to treat rare and incurable diseases using engineering. Digitalization is making it much easier to monitor, medicate and treat patients using assistive technology. In the past decade, several breakthroughs have been made in terms of treating heart failure. Heart failure is a critical condition in which the ability of a patient’s heart muscle is reduced therefore the heart cannot pump blood on its own. Early diagnosis and treatment of some of the early symptoms such as coronary heart disease, congenital defects, hypertension can prevent the progression of this condition however if the patient is in the final stages of heart failure, the treatment options are limited. Apart from transplantation, one of the best methods is using an implanted device called as ventricular assist device (VAD). VAD’s are mechanical pumps used to assist in the continuous flow of blood when the heart muscles begin to fail. They are used to bridge the gap while a patient is waiting for transplantation or in some instances considered as destination therapy. Living with a VAD is overwhelming on its own. A transcutaneous driveline is present to connect the pump to an external power source and controller to make sure it is charged and working efficiently. It is critical that the device is never in contact with water and the site of the driveline requires special dressing to prevent infection and sepsis. It can drastically change the quality of life for the patient. Wireless power transfer technology and inductive resonance coupling can help eliminate the drive-line and any drive-line related issues and infection. This project is focused on analyzing, designing and testing inductive coils to help wirelessly power implantable devices. Wireless power transfer via inductive coils occurs when a current carrying transmitter coil induces a voltage in the receiver coil through electromagnetic induction. The coils are theoretically solved based on the constraints and limitation for implantable devices and modelled using a designing editor called EAGLE. By evaluating important parameters like inductance, mutual inductance, coupling coefficient etc., of the two coils, the efficiency of power transfer can be determined. COMSOL, a Multiphysics platform is used to simulate and verify the parameters before experimental testing. The coils are etched on copper films and tested for efficiency. Using chemicals, a phantom human tissue environment is created to simulate wireless power transfer between the coils. When it comes to medical implants, safety and regulations are very essential. In order to prevent a potential hazard and life-threatening risks, all the necessary standards need to be followed. Therefore, through the appropriate selection, design and implementation, inductive coils can be used to wirelessly power implants and help improve the quality of life.