Continuous glucose monitors (CGMs) rely on precision electronic components — including specialized connectors and interconnects — to ensure accurate sensing, signal integrity, and reliable data transmission. This article reviews the core functionality of CGMs and highlights the key role of interconnects in these critical medical devices. It also explores how miniaturization drives next-generation CGM design, the need for reliability and resilience in demanding environments, and strategies for ensuring compliance with medical device standards while enabling future functionality.
How CGMs operate and why interconnects matter
As shown in Figure 1, traditional glucometers require a blood sample obtained with a fingerstick. These devices rely on test strips coated with glucose oxidase, an enzyme that reacts with glucose to generate an electrical signal.
Glucometers analyze this signal to determine blood glucose levels. The strength of the electrical current is directly proportional to glucose concentration. Higher glucose levels produce stronger signals, while lower levels result in weaker ones.
Figure 2 shows CGMs measure glucose levels in interstitial fluid using a sensor inserted under the skin.
A typical CGM system comprises three main components: a subcutaneous sensor for glucose detection, a transmitter that wirelessly sends data, and a receiver or smartphone app for real-time monitoring. Many models also integrate with insulin pumps for automated insulin delivery.
There are three primary types of CGMs: real-time, intermittent-scan, and professional-use. Each offers continuous glucose tracking, customizable alerts for hypo- or hyperglycemia, and data-sharing capabilities. For example:
- Dexcom G6 provides glucose readings every five minutes, supported by internal electrical connections and wireless communication protocols that maintain continuous signal flow between the sensor and transmitter.
- FreeStyle Libre delivers blood-free readings through an arm-mounted sensor. Reliable electrical contacts between the sensor and the reader, or NFC, ensure consistent data transfer during repeated scans.
- Eversense uses implantable sensors designed for extended wear. While the 90-day version remains in use, the latest Eversense 365 model lasts up to one year. Both units depend on biocompatible, durable interconnects that maintain signal integrity throughout implantation.
Miniaturization drives next-gen CGM design
Smaller, lighter, and more discreet CGMs empower users with accurate, real-time glucose insights. Product development teams must continuously balance size and functionality to meet user expectations for smaller form factors and expanded feature sets. Miniaturized connectors and interconnects play a crucial role in supporting these design goals.
Ultra-low-profile connectors with high pin density conserve printed circuit board (PCB) space while supporting wireless communication, real-time data processing, and mobile app integration. Custom interconnect solutions — such as compact headers and dual-sided multi-contact terminals — enable stable, space-efficient connections between sensors and PCBs.
Designing for reliability in demanding conditions
As shown in Figure 3, CGMs must operate reliably in dynamic environments, where body motion, sweat, skin oils, and temperature fluctuations can disrupt signal transmission.
Long-term reliability depends on careful material selection, with conductive, corrosion-resistant materials required to maintain electrical performance over time. Biocompatibility is also a critical design factor for implanted components or those in direct contact with skin. Interconnects must resist degradation and prevent adverse biological reactions, adding complexity to both design and regulatory compliance.
Mitigating electromagnetic interference (EMI) from nearby devices presents additional design challenges. Shielded, high-performance interconnects and advanced connectors maintain signal integrity by minimizing electrical noise and EMI, ensuring accurate glucose readings, reliable data analysis, and consistent insulin delivery.
Compact CGMs also require power-efficient architectures to extend battery life while supporting multiple subsystems such as sensors, transmitters, processors, and displays. Interconnects support adaptive power management through low-power designs, efficient distribution modules, and current sensing and overcurrent protection features.
Ensuring compliance and enabling future functionality
CGMs must meet stringent medical device regulations for safety and performance. Compliance typically involves rigorous testing, including environmental stress evaluations and electromagnetic compatibility (EMC) assessments. Selecting interconnects manufactured under ISO 13485–compliant processes for testing, documentation, and quality control helps streamline development and accelerate approval. Close collaboration with experienced suppliers ensures regulatory requirements are addressed early in the design process.
As CGMs evolve, interconnects must support higher data bandwidth, expanded wireless connectivity, and integration with external health platforms. Use cases such as closed-loop insulin delivery and multi-sensor health monitoring require scalable, high-performance interconnect solutions. Designing with future system requirements and technology roadmaps in mind reduces redesign cycles, optimizes system flexibility, and accelerates time to market.
Summary
CGMs rely on specialized connectors and interconnects to enable continuous, accurate glucose sensing, real-time data transmission, and compact, user-friendly designs. These critical components also support wireless connectivity, battery efficiency, and integration with external health platforms. To meet stringent regulatory requirements, they must operate reliably in challenging environments.
References
Miniature Interconnects Scale Down Continuous Glucose Monitors, ConnectorSupplier
Connector Solutions Simplify Design of Wearable Devices, ConnectorSupplier
The Next Generation of Continuous Glucose Monitors, Molex
The 10 Best Glucose Meters and Continuous Glucose Monitors, Healthline
Continuous Glucose Monitoring, NIH
How Do Glucometers Work?, MIT
Regulatory Compliance in the Medical Device Supply Chain, EMT SCM
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