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Reduction of mutual coupling in the radiating elements of multiple input multiple output (MIMO) antenna is always an issue and a big challenge for antenna researchers. To address this issue of mutual coupling reduction, an effective method of decoupling has been proposed in this paper. Here, a bandstop filter based isolation technique has been introduced to limit the mutual coupling in each element of the MIMO antenna. A 2 port and a 4 port MIMO antenna have been designed with the proposed decoupling technique, and it is found that the decoupling technique successfully achieves isolation of more than 30 dB for both antennas. In addition to achieving high isolation, the designed MIMO antennas are also made circularly polarized to overcome poor mismatch, lower directive gain, and signal to noise problems in wireless communication. The antenna performance is observed in simulation and verified with measurements. Simulated and measured results show that the 2 port antenna exhibits a 10 dB impedance bandwidth of 5.26 % (2.78–2.93 GHz) and a 3 dB axial ratio bandwidth of 13.08 % (2.65–3.02 GHz), while those for the 4 port antenna are 2.46 % (2.41–2.47 GHz) and 13.10 % (2.36–2.69 GHz). The 2 port antenna supports a peak gain of 3.27 dBi with a maximum efficiency of 85.11 %, while the 4 port antenna successfully increases the gain to 6.49 dBi but decreases the maximum efficiency to 80.54 %. Both the MIMO antennas show excellent diversity performance in terms of envelope correlation coefficient (ECC), Directive Gain (DG), Total active reflection coefficient (TARC), channel capacity loss (CCL), and mean effective gain (MEG) ratio. Both the structures achieve ECC of less than 0.006, DG of more than 9.9 dB, TARC of less than −19.84071 dB, CCL of less than 0.00179 bits/s/Hz, and MEG of less than −0.00577 dB in measurements. The overall dimensions of 2 port and 4 port antennas are limited to 44×22×1.6mm3 and 44×52×1.6mm3, respectively. These characteristics of the proposed antennas make them suitable for use in wireless high-speed communications.

Objective: The study was done to validate the DECAF score for the prediction of prognosis in AECOPD patients. Methodology: 92 AECOPD patients were given scores as per the DECAF system. Patients were monitored during their whole hospital stay. The final results were classified as death and recovery. DECAF score’s importance for the prediction of clinical outcomes was analyzed. Result: Out of 92 patients evaluated, 27 had a DECAF score range between 0-1 (low risks), 5-9 had a DECAF score range between 2-4 (intermediate risks), and 6 had a DECAF score range between 5-6 (high risks). The high-risk group experienced a 100% fatality rate. On the other hand, there was no mortality seen in patients with DECAF scores 0-4 & all the patients recovered successfully. Conclusion: DECAF score uses routine parameters to classify AECOPD Patients into clinically relevant risk groups. Doctors are benefitted from this regarding management purposes.

The ever-growing expectation for high data rates has led to the introduction of multiple-input multiple-output (MIMO) technologies to wireless connectivity. Such a system requires an MIMO antenna with high isolation. At the same time, the MIMO dimension should not be compromised for achieving high isolation. Thus, isolation techniques that do not allow an increase in dimension need to be fostered for MIMO antenna design. In this paper, a novel low-profile, miniaturized MIMO antenna with high isolation was developed considering a split ring resonator (SRR)-based bandstop filter as a decoupling network. The bandstop filter was designed with a unit cell split ring resonator structure and was deployed between two closely spaced monopole MIMO antenna elements to obtain isolation as high as 39.25 dB at 2.61 GHz. Two open-circuit stub lines were attached with the MIMO feeding network to achieve good impedance matching at resonance frequency. The proposed antenna exhibited a peak gain of 3.8 dBi and radiation efficiency of 84%. It had a low envelop correlation coefficient (ECC < 0.12), high diversity gain (DG > 9.95 dB), low mean effective gain ratio (MEG 1/MEG 2 < 0.05 dB), and low channel capacity loss (CCL < 0.042 bits/s/Hz) at resonance frequency. The overall antenna dimension was restricted to 44 mm ×22 mm (0.38 λ0×0.19 λ0) for its easy integration in compact wireless devices.