Medical-Equipment-Technology

This paper presents a compact multi-band rectifier with an improved impedance matching bandwidth. It uses a combination of-matching network (MN) at Port-1, with a parallel connection of three cell branch MN at Port-2. The proposed impedance matching network (IMN) is adopted to reduce circuit complexity, to improve circuit performance, and power conversion efficiency (PCE) of the rectifier at low input power. The fabricated rectifier prototype operates at 0.92, 1.82, 2.1, 2.46 and 2.65 GHz covering GSM/900, GSM/1800, UMTS2100, and Wi-Fi/2.45-LTE2600. The size of the compact rectifier on the PCB board is 0.13λ g × 0.1λ g. The fabricated rectifier achieved an RF-to DC (radio frequency direct current) PCE of 31.8%, 24%, 22.7%, and 15%, and 14.1% for −20 dBm at the five respective measured operating frequencies. The circuit attains a peak RF-to-DC PCE of 82.3% for an input power of 3 dBm at 0.92 GHz. The proposed rectifier realizes an ambient output dc voltage of 454 mV for multi-tone in...

This work presents a compact quad-band rectifier implemented using a multi-stub impedance matching network (IMN). The IMN comprises three blocks of multiple stub tuning connected via a meandered line (MDL) to achieve multiple frequency susceptance blocks. The proposed rectifier is designed to operate at (1.82 GHz, 2.1 GHz, 2.4 GHz, and 2.67 GHz) for GSM/1800, UMTS/2100, Wi-Fi, and LTE/2600 frequency bands. The rectifier occupies a total area of 0.45 λ g × 0.25 λ g on the RT/Duroid 5880 PCB board using full ground architecture. The fabricated rectifier achieved RF-to-dc (radio frequency direct current) power conversion efficiency (PCE) of (31.7%, 23.5%, 25.4%, 15.5%) across the four operating frequencies for an input power of −20 dBm, respectively. The proposed quad-band rectifier realized a peak RF-to-dc PCE of 86.8% from the four-tones RF input power at 3 dBm. The rectifier can also attain over 55% RF-to-dc PCE along 1.7 GHz to 2.4 GHz frequency range, and at 2.67 GHz for 0 dBm inp...

Aim of this paper is to study the effect of Gastric Myoelectric Activity (GMA) in finger PPG signal. To this end, Pulse Rate Variability (PRV) analysis in combination with Poincare plots was selected. In PRV, the power of High Frequency (HF) component significantly changes ...

Abstract In this article we investigate the presence of gastric motility (GM) oscillation in the lower frequency range of photoplethysmography (PPG) signal. The objective of this article is to analyze the lower frequency oscillations of PPG signal using the novel autoregressive ( ...

This paper is an experimental study to examine the possibility of extracting gastric myoelectric activity (GMA) from photoplethysmographic (PPG) signals. Diagnosing GMA is a clinically challenging task because of its invasive/cumbersome methods. It is known that the PPG consists of information related to heart rate, respiratory rate and phenomena. Here we take this thread further and see whether GMA can

Understanding the hemodynamic interactions of a non-cardiac system with the main circulatory system is a challenging task in modern medicine. In this study the effect of gastric myoelectric activity (GMA) on peripheral blood volume pulse, acquired by photoplethysmographic (PPG) technique during fasting and postprandial states are analyzed using wavelets. PPG and Electrogastrogram (EGG) signals were acquired simultaneously from 8 healthy