How Novel Technology can Overcome the Limitations of CGM Systems
Author: Luca Vita
Continuous glucose monitoring (CGM) devices are small implants worn under the skin, with the primary focus of allowing patients to check glucose levels in real time. To allow such, sensors measure glucose levels 24/7 which enables the individual to check trends and be alerted to periods of highs and lows. The information is sent digitally to a display device, such as a smart phone, and can be shared with a healthcare team; so they can review, and make adjustments for the appropriate treatment plan (1). The CGM however, does not measure the blood glucose directly, instead it measures the glucose present in the interstitial fluid that surrounds the body’s cells. As a result, there is a small time delay compared to a blood measurement, especially after eating or exercise. A finger-prick test is necessary if an individual is contemplating changing their treatment, for example to treat a hypoglycaemia, to ensure an informed decision is made with the most accurate result.
The anatomical breakdown of a CGM
CGM devices can be broken down into three main components: sensor, transmitter, and receiver (2)
The sensor is typically a glucose oxidase (GOD) based sensor, which is inserted into the subcutaneous fatty layer just under the skin. Glucose concentration is estimated, based on the production of hydrogen peroxide by GOD and the associated release of electric current, which is directly proportional to the concentration of glucose in the interstitial fluid. The sensor is usually a 5mm long metallic filament and is typically applied to the abdomen or back of the upper arm.
The transmitter attaches to the top of where the sensor was inserted. The transmitter receives electrical signals from the sensor and sends the information wirelessly to the receiver, via radio waves. The transmitter either comes with a battery that is chargeable/replaceable or with a set battery that requires a full replacement of transmitter every few months.
The receiver is a battery powered handheld device, often a smart phone, however, specific receiver devices are available. Its job is to receive the signals produced by the sensor and display it to the user. It allows users to observe past and current trends; and can produce alarms when specific blood glucose thresholds are breached. Furthermore, modern CGM receivers allow users to share results with family or healthcare.
The limitations of the components of current CGMs
One of the greatest limitations that comes with using a CGM is the cost. CGMs are more expensive than using a standard glucose meter, via the finger-prick method. This is largely due to the components of the CGM. First, the use of precious metals in the sensor, to enable electrical signal conduction to the transmitter, means that the costs of raw materials and production of such devices are higher than that of novel devices using innovative materials. Second, due to the use of particular enzymes, current CGM sensors must be replaced every seven to fourteen days. The use of expensive material results in increasing the issue of high cost two-fold. Finally, considering the price tag that comes with a CGM, The devices accuracy and performance still fall short on the standard current healthcare demands.
How do novel materials overcome these issues?
The development and incorporation of novel materials in CGM devices has allowed movement from the inclusion of expensive raw materials, such as the precious metals. Gii-Sens is world’s first 3D graphene foam sensor that allows enhanced performance, of that from precious metal electrodes, at the cost of carbon. Our product is a flexible, thin film substrate that is fully customisable, allowing easy integration into any bioassay. It is scalable for reel-to-reel manufacturing, with a simple one-step process; helping to provide the low-cost innovation that CGM devices are looking for. Additionally, Gii-Sens operates via a three-electrode system without the need for labels. This increases the life of CGM devices, eliminating the requirement for as many frequent replacements; to maintain low costs. Finally, Gii-Sens can offer a higher assay performance under the same operating conditions compared to other electrochemical sensors. This ability, coupled with lower manufacturing costs and prolonged product life enables us to meet healthcare standards of the future at an affordable price.
If you would like to develop the future of sensing into your devices today, then please contact us for further discussion.
Reference
Facchinetti, A. (2016). Continuous Glucose Monitoring Sensors: Past, Present and Future Algorithmic Challenges. 16(12).
Freckmann, G. (2020). Basics and use of continuous glucose monitoring (CGM) in diabetes therapy. 44(2).