This paper presents the design and implementation of an Internet of Things-based remote health monitoring system for the estimation of Blood Pressure (BP), Heart Rate (HR) and blood oxygen saturation levels (SpO2). Our designed sensor can remotely monitor BP, HR and SpO2. Our device collects, evaluates, predicts and reads health data and then stores it on a remote platform named ‘ThinkSpeak’, which forms an Internet of Things (IoT) platform, with a 0.91 Organic Light-Emitting Diodes (OLED) screen display for viewing numerical health readings locally. We used a biomedical sensor device with an embedded signal condition unit, a single Photoplethysmography (PPG) signal was employed to derive and measure the PPG signal. A computer-based algorithm was generated which factored in selected beneficial parameters measured from a single bio-inspired PPG signal. The measured PPG signal was used to estimate the individual user’s BP (both systolic and diastolic values), HR and SpO2 respectively. An Automatic Multiscale-Based Peak (AMBP) detection algorithm was developed to obtain the maximum peak of the PPG signal. Furthermore, the developed sensor was benchmarked against two standard commercially available measurement devices: a contec ambulatory BP sensor and a Braun pulse oximeter monitor. Our developed sensor is worn as a ring sensor and is interfaced with an Arduino 1010 WIFI MKR for remote health monitoring. Our estimated BP, HR and SpO2 values were remotely monitored and a graphical representation was constructed.

Pulse oximeters are widely used in hospitals and homes for measurement of blood oxygen saturation level (SpO₂) and heart rate (HR). Concern has been raised regarding a possible bias in obtaining pulse oximeter measurements from different fingertips and the potential effect of skin pigmentation (white, brown, and dark). In this study, we obtained 600 SpO₂ measurements from 20 volunteers using three UK NHS-approved commercial pulse oximeters alongside our custom-developed sensor, and used the Munsell colour system (5YR and 7.5YR cards) to classify the participants’ skin pigmentation into three distinct categories (white, brown, and dark). The statistical analysis using ANOVA post hoc tests (Bonferroni correction), a Bland–Altman plot, and a correlation test were then carried out to determine if there was clinical significance in measuring the SpO₂ from different fingertips and to highlight if skin pigmentation affects the accuracy of SpO₂ measurement. The results indicate that although the three commercial pulse oximeters had different means and standard deviations, these differences had no clinical significance.

Stimulated Brillouin scattering (SBS)-based filters can provide high gain, narrow bandwidth, and wideband tunability, which are critical to modern radio frequency (RF) systems. However, it is important to optimize all performance parameters to obtain stable response over wideband along with high gain. We present a novel SBS-based tunable microwave photonic notch filter and amplifier (TMWPNFA) configuration that can perform notch filtering, selective amplification, or both simultaneously by exploiting additional Brillouin gain modes and using both SBS stokes and antistokes in single-mode fiber. The TMWPNFA amplification and notch suppression are shown for maximum of 50 GHz in radio domain, which is the highest reported tunability to our knowledge. The TMWPNFA exhibits high gain of $\simeq 35$ dB by employing RF amplifier (RFA). The TMWPNFA achieves SBS gains from 24 to 4 dB over the range. The suppression achieved by TMWPNFA ranges from 12 to 3 dB. We demonstrated the SBS pump’s RF mixing approach for increasing the −3 dB bandwidth of TMWPNFA to 35 MHz, resulting in greater separation of the amplification and suppression bands. The TMWPNFA phase noise distortion caused by SBS is measured to be less than −8.6 dBc/Hz at 125 kHz spacing. The filter achieved sharp −3 dB bandwidth of 20 MHz and $Q$ factor of 200–2500. The degree of polarization of the SBS pump is shown to be the source of 6 dB gain control. It is shown that additional sound modes produced by SBS, separated by approximately two times bandwidth of SBS, can be used for notch filtering while simultaneously achieving selective amplification. The proposed 50 GHz TMWPNFA would provide unique benefits for satellite, aerospace, and beyond communication technologies.