Non-Invasive Technologies For Continuous Glucose Monitoring

Numerous researchers have worked to develop non-invasive technologies for continuous glucose monitoring. Different methodologies and approaches have been proposed in this field. Potassium is the most abundant intracellular cation in the human body. Various studies undergone related to the potassium variation in plasma in accordance with the diabetes. It is proved that there is a very clear alteration in the blood potassium level in diabetes patients. This section explains some of the related works which include different approaches made by the researchers to measure blood glucose level and the potassium level in human body without taking the blood sample.

Non-invasive glucose monitoring devices (NGM) and continuous glucose monitoring systems (CGM) have become a major area of research. Most of the technologies where comprehensively studied by S.Vashist. According to Vashist the research efforts in this field is continuously increasing. Even though the researches are happening at higher rate, the most widely used device for measuring glucose level is still the glucometer which is incorporated with a fingerstick. His study says that the majority of NGM technologies are based on spectroscopy. The main challenge in the design of next generation NCGM is the cost effectiveness and accuracy aspects. He concludes his work by stating that there should be tremendous improvement in the field of NCGM to meet this challenge. M D Shawkat Ali, N J Shoumy, S Khatun, L M Kamarudin and V Vijayeswari proposed a paper on NGM and performance analysis by ultra-wide band (UWB) imaging technique. They have introduced a patient friendly method of measuring glucose level by using UWB microwave imaging and artificial intelligence.

The scattered signal obtained from the receiver was analyzed and characteristic features were extracted for pattern recognition through artificial neural network. The authors are giving guarantee of 80-85 % accuracy in the detection of glucose in plasma.

In 2016 Volkan Turgul and Izzet Kale proposed a sensor technology which deals with the RF/microwave sensor to measure the glucose level non-invasively. In this work they have fabricated a compact radio frequency sensor based on a microwave resonator and a pressure sensing circuit. The pressure sensing circuit is meant for monitoring the pressure applied on to the sensor by the fingertip since the sensor’s frequency response depends on the pressure applied on it. The sensor response is studied, and the results obtained accurately. One of the drawbacks of this work is that a big variation in the blood sugar level will provide only a minute shift in the frequency.

P Sampath Reddy and K Jyosna from VNR Vignana Jyothi institute have come with a portable device for monitoring of blood glucose level non-intrusively. They have used near infra-red sensors (transmitter & receiver) and a microcontroller. This device is capable of detect the blood glucose level as well as to predict the required amount of insulin based on the sugar level. Microcontroller is used to calculate the sugar level according to the body mass index of the person. The resultant voltage obtained from the receiver is taken as a parameter to find out the glucose concentration. The reliability of the device is 80% as per the author and the accuracy in result can be increased by increasing the wavelength of the infrared light. Nikolay Kascheev, Oleg Kozyrev, Maxim Leykin, Alexey Vanyagin from Russia have done a study on the non-invasive blood glucose monitoring and developed a wearable sensor device in 2017. The spectroscopy based glucometer uses near infrared LED s and photodiode as the sensing part and the resulted information from the signals are studied and processed using artificial neural network algorithm and it returns the users glucose level.

Absorption of light in a solution is highly affected by the water content in that solution. Since the 50% percent of blood is water, the result may be affected. This complication is overcome by utilizing the optical and near infrared range.