For years, the “holy grail” of wearable technology has been the ability to monitor blood sugar levels without a single needle prick. While many companies have teased this possibility, a newly revealed patent from Garmin (US 2026/0033750) suggests the company is moving past simple glucose snapshots and targeting something more significant: long-term metabolic health via HbA1c estimation.
A Shift Toward Long-Term Metabolic Insights
Unlike standard Continuous Glucose Monitors (CGMs) that track real-time blood sugar fluctuations, Garmin’s latest research focuses on glycated hemoglobin (HbA1c). This metric provides a three-month average of blood sugar levels, making it a critical tool for identifying pre-diabetes and managing metabolic health.
By focusing on HbA1c rather than instant glucose, Garmin is positioning its future wearables as preventative health companions. This approach could offer athletes and health-conscious users a high-level view of how their lifestyle, diet, and training cycles impact their blood chemistry over weeks and months.
The Science of Light: How Pulse Spectroscopy Works
The core of this innovation lies in advanced photoplethysmography (PPG)—the same light-based technology currently used to measure heart rate and blood oxygen (SpO2). However, Garmin’s proposed system is significantly more complex:
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Multi-Wavelength Precision: The system utilizes at least three distinct wavelengths of light to penetrate the skin.
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Hemoglobin Differentiation: By analyzing how these specific light waves are absorbed and reflected, the device can distinguish between oxygenated, deoxygenated, and glycated hemoglobin.
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Advanced Ratios: The hardware calculates the “AC-to-DC” ratio of these signals to determine the percentage of hemoglobin that has bonded with glucose.
The patent even details two potential sensor designs: one that sits flush against the skin and another that is slightly recessed to minimize light “leakage,” ensuring the highest possible data integrity.
More Than Just Blood Sugar
Interestingly, the patent suggests that this technology could unlock broader blood chemistry data. Because the sensors are designed to differentiate between various forms of hemoglobin, the device may be able to calculate both functional and fractional oxygen saturation. This deeper level of analysis could provide a more comprehensive picture of cardiovascular efficiency than current consumer-grade pulse oximeters.
From Patent to Wrist: What This Means for Users
It is important to note that a patent filing is a declaration of intent, not a product announcement. However, this is the second time in less than a year that Garmin has filed documentation regarding non-invasive blood monitoring.
If this technology makes it into the next generation of Fenix or Forerunner watches, it could revolutionize how we approach fitness. Endurance athletes could monitor how “carb-loading” or high-intensity training affects their long-term glucose trends, while everyday users could receive early warning signs of metabolic drift long before they require a clinical blood test.
Garmin is clearly looking to move beyond the “fitness tracker” label, aiming instead to become a vital tool in the future of non-invasive medical diagnostics.
Also Read: The Best Garmin Watches of 2026: A Beginner’s Guide to the Ultimate Ecosystem
Source: USA Patent Office Via Gadgets and Wearables
