Dual-band biomedical rectenna system for wireless data and power transfer

2022 ELE Engineering Design Project (MA01)

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Faculty Lab Coordinator

Marco Antoniades

Topic Category

Signal Processing / Communication

Preamble

Existing designs of implantable biomedical devices such as pacemakers, heart pumps, and cardiac defibrillators employ either limited-lifespan internal batteries or cumbersome external batteries that require a subcutaneous wire connection. Both of these approaches have significant limitations that can be eliminated by implementing a wireless charging scheme. Such a scheme would involve a transmitter outside of the body and a rectenna (rectifier + antenna & power management unit) residing on the implanted device inside the body. In this project, a dual-band implantable biomedical rectenna system will be developed, in order to enable wireless data transfer as well as wireless power transfer to an implanted device.

Objective

The objective of this research project is to design and build a compact dual-band rectenna system for implantable biomedical devices, that consists of an external transmitter, and an implanted rectenna with a power management unit.

Partial Specifications

1. The overall size of the implanted system will be defined based on a standard device such as a pacemaker, heart pump, or cardiac defibrillator.
2. The frequency of operation will be limited to medical ISM bands.
3. The system should be able to charge a standard-size battery by providing a constant DC current from a wireless AC source placed directly outside of the body, and up to 30 cm away.
4. The system must also be able to simultaneously support a data transmission at a separate frequency.
5. The system has to conform to standard specific absorption rate (SAR) levels defined for the safe operation of wireless devices.
6. The design should maximize the overall efficiency of the unit by maximizing the radiation efficiency of the antenna and the efficiency of the rectifier.

Suggested Approach

The students should become familiar with state-of-the-art compact rectenna designs, which have been designed specifically for operation within a human body by studying relevant research papers and books. They should also become familiar with standard AC-DC rectifier designs and should be able to adapt these for an implantable scenario. The rectennas could employ transmission-line metamaterials in order to reduce their size and improve their performance. Features such as their size, radiation efficiency, transmitted power and matching performance will be evaluated within realistic human body environments, emulated in industry-standard electromagnetic simulation software.

Group Responsibilities

The group should work collaboratively as a team to define the specifications for each component of the system in order to achieve the overall objective of the project, which is to wirelessly charge an implanted device from an external transmitter outside of the body at one frequency, while providing wireless telemetry functionality at another frequency. Each component will be designed separately, which will then be integrated to form a final working prototype of the dual-band implantable rectenna system.

Student A Responsibilities

Implantable antenna design and fabrication

Student B Responsibilities

AC-DC rectifier design and fabrication

Student C Responsibilities

Power management unit design and fabrication

Student D Responsibilities

3D printing of implantable devices and integration of rectenna

Course Co-requisites

ELE 861 – Microwave Engineering

To ALL EDP Students

Due to COVID-19 pandemic, in the event University is not open for in-class/in-lab activities during the Winter term, your EDP topic specifications, requirements, implementations, and assessment methods will be adjusted by your FLCs at their discretion.