This paper presents a planar microwave sensor for the noninvasive detection of glucose concentration in diabetic patients. The designed sensor operates from the 3.8 to 6.2 GHz frequency band, which covers the 5.8 GHz Industrial Scientific and Medical (ISM) band. The designed sensor shows a percentage bandwidth of 23.8% with a reflection coefficient (S11) of −50 dB at the resonance frequency of 5.7 GHz. The detection was carried out by varying the relative permittivity of the blood in accordance with the glucose concentration based on the Cole–Cole model. The measured result is calculated in terms of varying resonance frequency with variation in the reflection coefficient |S11| of the designed sensor. The observed frequency shift and corresponding sensitivity of the sensor are found at 1.7 GHz and 0.089 MHz/mg dL−1, respectively. An experimental validation has also been performed, and the frequency shift is analyzed by interacting the human thumb with the sensor. The simulated and experimental results of the designed sensor suggest that it can be useful for detecting glucose concentration noninvasively for diabetic patients.

Background: Painful diabetic neuropathy (PDN) is a frequent complication of diabetes mellitus. Current treatment recommendations are based on short-term trials, generally of ≤3 months’ duration. Limited data are available on the long-term outcomes of this chronic disease. The objective of this study was to determine the long-term clinical effectiveness of the management of chronic PDN at tertiary pain centres. Methods: From a prospective observational cohort study of patients with chronic neuropathic non-cancer pain recruited from seven Canadian tertiary pain centres, 60 patients diagnosed with PDN were identified for analysis. Data were collected according to Initiative on Methods, Measurement, and Pain Assessment in Clinical Trials guidelines including the Brief Pain Inventory. Results: At 12-month follow-up, 37.2% (95% confidence interval [CI], 23.0-53.3) of 43 patients with complete data achieved pain reduction of ≥30%, 51.2% (95% CI, 35.5-66.7) achieved functional improvement with a reduction of ≥1 on the Pain Interference Scale (0-10, Brief Pain Inventory) and 30.2% (95% CI, 17.2-46.1) had achieved both these measures. Symptom management included at least two medication classes in 55.3% and three medication classes in 25.5% (opioids, antidepressants, anticonvulsants). Conclusions: Almost one-third of patients being managed for PDN in a tertiary care setting achieve meaningful improvements in pain and function in the long term. Polypharmacy including analgesic antidepressants and anticonvulsants were the mainstays of effective symptom management.