Continuously Operating Biosensor and Its Integration into a Hermetically Sealed Medical Implant

Area of Science:

• Biomedical Engineering
• Implantable Biosensors
• Microelectromechanical Systems (MEMS)

Background:

• Continuous glucose monitoring is crucial for diabetes management.
• Existing implantable systems face challenges in regulatory approval and long-term stability.
• Cardiovascular implant technology offers a foundation for robust medical device design.

Purpose of the Study:

• To present an integration concept for an implantable biosensor for continuous blood sugar monitoring.
• To utilize established cardiovascular implant modules to streamline regulatory certification.
• To demonstrate the feasibility of using affinity viscometry for metabolite sensing in interstitial tissue.

Main Methods:

• System architecture based on cardiovascular implant modules.
• Biomedical microelectromechanical systems (BioMEMS) sensor chip using 0.25-µm CMOS/BiCMOS technology.
• Affinity viscometry principle for sensing.
• Medical Implant Communication Service (MICS) band (402–405 MHz) for communication.
• Titanium housing for hermetical sealing; epoxy header for sensor and antenna.

Main Results:

• A system architecture leveraging existing cardiovascular implant technology was conceptualized.
• The biosensor design incorporates BioMEMS and established CMOS/BiCMOS processes.
• Communication protocols utilize the MICS band for secure data transmission.
• Hermetical sealing with titanium housing ensures biocompatibility and device longevity.

Conclusions:

• The proposed integration concept facilitates the development of implantable biosensors for continuous metabolite monitoring.
• Repurposing cardiovascular implant components can significantly reduce legal certification hurdles.
• This approach demonstrates the potential for reliable sensing of low-molecular-weight metabolites in interstitial tissue.