Bringing Smile to Diabetic Patients with
Non-invasive Glucose Monitoring
True 3rd generation CGMS
The first-generation blood glucose meter (BGM) measures blood glucose level (BGL) through an electrochemical reaction of an enzyme with blood collected using finger pricking with a needle, 4 or 5 times a day. This technique has the limitation for continuous blood glucose measurement required for continuous insulin management in type-1 diabetic patients caused by abnormal insulin secretion.
The second-generation blood glucose meter does not draw blood every time, but inserts needle of an enzyme-based sensor into the interstitial fluid about 5 mm below the skin, and continuously measures blood glucose level at every 5-minute for a week. Weekly replacement causes a large cost burden (about $100) on patients, also causes skin troubles due to adhesion tapes required to hold the sensor. A time delay is also inherent in the measurement of BGL from the interstitial fluid. This may cause a risk of hypoglycemia shock.
SB Solution’s third-generation real-time CGMS, unlike enzyme or fluorescence-based sensors, does not degrade over time. So, it is possible to use electromagnetic (EM) sensor under the skin for a long-term and the cost burden is dramatically reduced. There is no contact dermatitis problem, and it is a product that solves the risk of hypoglycemia through real-time BGL measurement.
Uniqueness of SB Solution’s CGMS
Senseonics, USA introduced subcutaneous CGMS to the market after receiving European CE approval in 2016 and US FDA approval in 2018. Senseonics succeeded in commercializing subcutaneous implantable CGMS by extending the sensor lifespan to 3 months based on fluorescent material, but the cost burden is high. The sensor costs over $1,000 and has to be replaced every 3 months which is inconvenient due to frequent replacements. The risk factors such as hypoglycemic shock have not been resolved due to the time delay caused by glucose measurement in the interstitial fluid. So, it is generally evaluated as 2.5 generation CGMS.
The 3rd generation CGMS developed by SB Solutions is EM-based sensor that can be used for several years without the need of a battery under the skin in a manner similar to Senseonics. The power required for sensor operation is delivered from an external device using WPT technology.
BGL information is measured from the interstitial fluid and transmitted to the external device in every 5 minutes. The accumulated blood glucose data can be viewed by linking with the patient’s smartphone via Bluetooth. It has a built-in function to pre-alert the patient using on-body vibration before a possible event of hypoglycemic shock. In short, our CGMS consists of an embedded sensor, an external device, and an app on a smartphone.
The existing 2/2.5 generation CGMS has a problem of delay due to measurement from only interstitial fluid. Our CGMS can save the golden time to prevent hypoglycemic shock by measuring large BGL changes in blood vessels in real-time with external EM sensors. It is a true 3rd generation CGMS that can solve the risk factors caused by time delay.
Core technology overview
Unlike enzyme or fluorescent based blood glucose sensors, EM-based sensor does not degrade over time. It is an implant and external sensors that operate in invasive mode (Mode-1) and single mode (Mode-2) to continuously measure blood glucose. In addition, to overcome the time delay problem of 2 ~ 2.5 generation CGMS, we developed an external EM sensor that operates in the array mode (Mode-3) that can directly monitor large blood glucose changes in blood vessels in real time.
|This mode has the key role of precise blood glucose measurement. It
measures change in blood glucose diffused in the interstitial fluid
at every 5-minute through an ultra-small EM sensor. With a diameter
less than 3 mm, it can be inserted with an injector under the skin.
The invasive mode sensor scans the vicinity of the sensor with a fine frequency resolution over a wide band. It can precisely measure changes in frequency due to the changes of permittivity (changes in blood glucose) based on the strength of reflection.
Compared to the external EM-based non-invasive blood sugar sensor proposed by several other research institutes, our sensor excludes the effect of pressure, temperature, humidity, and movement during measurement. This EM-based continuous blood glucose sensing technology is developed by SB solutions.
|The mode is responsible for measuring blood glucose from outside
of the body with a little lower precision than mode-1. In the single mode,
the EM sensor attached on skin measures changes in blood glucose
in the interstitial fluid at every 5-minute similar to invasive mode.
The single-mode is a non-invasive blood glucose sensing mode. It measures blood glucose by analyzing changes in coupling strength of EM-waves penetrating through the interstitial fluid.
This single mode functions as coarse scanning of blood glucose level. The invasive mode precisely detects (fine scanning) within the determined range. The fusion of redundant information from mode-1 and mode-2 sensors can estimate accurate blood glucose over a wide range of 40 - 600 mg/dl.
|This mode detects the danger in real time when there is a large change
In blood glucose from outside of the body. The EM-wave from sensor
passes through the interstitial fluid and monitors the blood glucose
change in the blood vessel located deeper in real time.
The blood glucose level in the interstitial fluid has a time delay of 5 ~ 20 minutes compared to the actual blood glucose level in the blood vessels. The array mode sensor uses multiple sensors in parallel to increase the penetration depth of EM-waves for sensing blood vessels.
Overcoming the time delay problem with a continuous blood glucose measurement system and a smartphone application
Mode 1 (invasive mode) sensor advancement based on near-field technology
Figure 1. Simulation result of Mode-1 sensor and electromagnetic wave distribution
Mode1 Sensor: SoC with embedded wireless power reception and external device with wireless power transmission
MCU-based wireless power transfer algorithm for SWIPT implementation (refer to Figure 2)
Figure 2. SWIPT SoC of simultaneously transmitting power and data communication for driving Model1 sensor
SoC circuit design for ultra-small size and ultra-low power Mode-1 sensor
Determination of required performance for each circuit and design with system-level analysis
Figure 3. Interface configuration diagram of Mode 1 SoC Sensor
Mode-2 (single-mode) sensor development based on resonance moment analysis
Figure 4. resonance moment analysis for Mode-2 sensor
Mode-3 (array mode) sensor to improve coupling strength and penetration depth
Figure 5. Antenna Analysis for Mode-3 sensor
In vitro biocompatibility evaluation according to ISO standards
Figure 5. Sensor interface SoC configuration diagram for driving Model-1 sensor
Analysis of biocompatible packaging materials for subcutaneous insertion
Figure 6. Sensor implant condition inside body
Comparison with other products
|Company M||Company D||Company E||SB solutions|
|Measurement type||minimally invasive||minimally invasive||Subcutaneous Implant||Subcutaneous Implant|
|price/year||USD 5,199||USD 6,600||USD 4,200||USD 900|
|Measuring Technique||Finger prick with microneedle||Finger prick with microneedle||Sensor implanted just under the skin||Implantable sensor under the skin and an external sensor*|
|sensor life||6 days||7 days||90 days||2-5 years (semi-permanent)|
|Calibration cycle||Every 12 hour||Every 12 hour||Every 12 hour||Once-a-day then automatic correction function|
|transmitter position||above the sensor||above the sensor||above the sensor||around the sensor|
|Power supply method||battery||battery||IPT wireless power transfer||MR wireless power transmission|
CGMS for pets
As the demand for quality medical services increases for companion animals, it is expanding to treat diseases and early diagnosis of diseases for companion animals.
Reference : https://www.banfield.com/Banfield/media/PDF/Downloads/soph/Banfield-State-of-Pet-Health-Report-2016.pdf