Developing a Needle Free Continuous Glucose Monitoring System


Most people using a continuous glucose monitoring system (CGMs) love the increased  blood sugar control they get from the device. Studies* have confirmed that the added control isn’t just a feeling, but a reality . So, if people using CGMs have better blood sugar management then why don’t all people with diabetes use them? The two main reasons are the high cost, which makes them unaffordable for many people with diabetes, and the invasiveness of the device– the pain of the insertion and the discomfort of having a sensor attached to the body.

But now is seems like a small company from the Boston area is about to change this.

Echo Therapeutics, a transdermal medical device company with expertise in advanced skin permeation technology, is developing a noninvasive continuous glucose monitoring system. The new system, called the Symphony tCGM System, is a needle free, wireless, transdermal continuous glucose monitoring system designed to provide accurate, real-time continuous blood glucose data.

We had the opportunity to talk to Mr. Pat Mooney, CEO, President and Chairman of the Board of Echo Therapeutics, about this exciting product in development, and the first thing we wanted to understand was how the needle free continuous glucose monitoring system works.

The Symphony tCGM System is unique in that it pairs the glucose-oxidase sensing technology used in current sensors like the Dexcom with Echo’s proprietary breakthrough technology, the Prelude  SkinPrep system.

First, the Prelude® SkinPrep device is used to permeate the skin before placing the sensor. The Prelude abrades the skin, removing 0.1 mm of skin using an electrical current. This process takes 3 -8 seconds, and removal of the small layer of skin allows the measuring of a number of physiological properties, including interstitial glucose levels. The abrasion is so shallow it is not even visible.

Following skin permeation with Prelude, a 1-3 day biosensor is placed on the permeated site. Because the skin has been prepared, the sensors are only microns away from the blood vessels, and are able to measure interstitial glucose—not blood glucose directly, as is the case with existing CGMs like the Dexcom—as it flows from the blood into surrounding tissues.

 How the Symphony tCGM Works

The Symphony wirelessly provides the patient’s glucose level every minute to a remote monitor. The monitor then tracks the glucose levels and rate of glucose changes and provides visual and audible alarms if the patient’s glucose levels move outside the target range, which can be personalized for each patient.

The Symphony’s sensors have a much shorter life span (1-3 days) than current CGMs sensors (3-7 days) but the painlessness of the process makes it less of a nuisance. The noninvasiveness doesn’t only mean less pain while applying the sensor; it also means you’re not creating wounds as you do with the current sensors. The dead skin removed in the abrasion process grows back within four days, leaving no visible scarring. The shorter-term sensor also minimizes adhesive use, which helps to limit skin irritation.

How The Symphony tCGM Continuous Glucose Monitoring System Works

The noninvasiveness of the Symphony definitely gives it great appeal: no needle means no pain.  But that’s only part of what we’re looking for in a continuous glucose monitor. We also want to know about its accuracy, which is no less important. Mooney told us that the Symphony will be more accurate than current continuous glucose monitoring systems because the Symphony sensor is much closer to the blood vessels than existing products. The skin, where the Symphony is situated, is highly vascularized, whereas fat and subcutaneous tissue, into which all the current sensors are inserted, is avascular in comparison.  The Symphony also measures blood sugar levels once every minute compared to once every five minutes in current models. The Symphony will require only one hour to initialize, compared to two hours in current models and needs to be calibrated less often.

The last, but not at all the least, advantage of the system will be its price. Although we were not given a target price for the system, the company claims it will be much cheaper than the currently available CGMs models, making the Symphony tCGM system an affordable solution for many people with diabetes.

What makes the system more affordable is that most of the system is reusable. The Prelude, which removes the layer of skin before applying the sensor, is rechargeable with only the tips being changed per use. The tips Mooney says “ cost pennies to make.”

The Symphony tCGM sensors are reusable with only the biosensing strips needing to be changed per use. The tCGM comes with two sensors per kit so one can be recharged while the other is being used. The sensors cost $10 – $15 to make (no consumer price yet). The bio sensing strips, on the other hand, will cost under a dollar each to make, and thus can be sold at a high margin while still being cheaper than the currently available alternatives. This will make the Symphony very cost competitive, says Mooney. “We will be in the strips business,” he notes, making the comparison to the business model used for blood glucose monitoring kits.  It promises to be a “high margin, cheaper business” than than the current continuous glucose monitoring systems.

With a product in development that seems to hold tremendous promise, our next question to Mooney was, “How long until the Symphony comes to market?”  That will depend on FDA approval.  To date, the product has been tested on patients with type 1 and type 2 diabetes in hospitals (critical care) and at home. Following a third critical care study conducted in 2012 the company hopes to begin meetings with the FDA to plan pivotal program. They also hope to file for EU approval at the end of this year, and aim to receive EU approval early next year.  Once on the market in Europe, there will be pressure on the FDA to approve the device for use in the U.S.

In the U.S., Echo intends to first seek approval for the hospital version of the device, which they hope will be available by the second half of 2013. The consumer version, which will require separate FDA approval, they hope to make available during 2014, assuming the approval process will be easier once prior approval has been granted for the hospital version.

*Continuous Glucose Monitoring and Intensive Treatment of Type 1 Diabetes

*Glycaemic control in type 1 diabetes during real time continuous glucose monitoring compared with self monitoring of blood glucose: meta-analysis of randomised controlled trials using individual patient data

Michael Aviad contributed to this article.

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Tamara P Wolfe
Tamara P Wolfe
5 years ago

Is this still not available for purchase?

Kathy White
11 years ago

This product seems to have it all.  Accuracy, cost, reusability; the fact that its needle free is just a bonus.  The size looks about the same as the dexcom transmitter?  The biggest reason that I like this is that it contains a biological step forward instead of an electronic one.  I’ll be watching the progress of this product.

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