A Fully-Integrated 0.068-mm³ Implantable Pressure Sensing Device With Wireless Energy Harvesting and Data Telemetry

Area of Science:

• Biomedical Engineering
• Microsystems and Nanosystems
• Wireless Sensor Networks

Background:

• Implantable medical devices require miniaturized sensors for minimally invasive procedures.
• Existing wireless sensors often face challenges with power supply, size, and integration.

Purpose of the Study:

• To report a fully-integrated, sub-0.1 mm³ wireless pressure sensing device for implantable applications.
• To demonstrate a novel system-on-a-chip (SoC) design for miniature wireless sensing.

Main Methods:

• Integration of a customized SoC with a piezoresistive pressure transducer, eliminating off-chip components.
• Development of a resistance-to-time converter, 915 MHz energy harvester, and backscatter telemetry.
• Utilizing chopper stabilization and supply noise cancellation for advanced noise management.

Main Results:

• Achieved a total sensor volume of 0.068 mm³, enabling delivery via a 0.5 mm needle.
• Demonstrated wireless power harvesting and data transmission with low power consumption (9.75 μW).
• Reported pressure sensing resolution of 3.1 mmHg and temperature sensing resolution of 0.18°C.

Conclusions:

• The developed device represents a significant advancement in miniaturized implantable wireless sensing technology.
• The sensor's small size, wireless power, and high precision are suitable for various implantable applications.
• Successful in-vitro testing demonstrates robustness and potential for in-vivo use.