A respiration rate (RR) monitoring system was created by integrating a Fibre Bragg Grating (FBG) optical fibre sensor into a respirator mask. The system exploits the sensitivity of an FBG to temperature to identify an individual's RR by measuring airflow temperature variation near the nostrils and mouth. To monitor the FBG response, a portable, battery-powered, wireless miniature interrogator system was developed to replace a relatively bulky benchtop interrogator used in previous studies.
View Article and Find Full Text PDFObjective: Establish whether pregnancies complicated by gestational diabetes mellitus (GDM) are associated with a fetal cardiac phenotype that predisposes to arrhythmia; utilising measurements derived from non-invasive abdominal fetal ECG.
Design: Prospective observational study.
Setting: Three tertiary obstetric units, United Kingdom.
Significance: Our goal is to understand the root cause of reported oxygen saturation ( ) overestimation in heavily pigmented skin types to devise solutions toward enabling equity in pulse oximeter designs.
Aim: We aim to gain theoretical insights into the effect of skin tone on curves using a three-dimensional, four-layer tissue model representing a finger.
Approach: A finger tissue model, comprising the epidermis, dermis, two arteries, and a bone, was developed using a Monte Carlo-based approach in the MCmatlab software.
Introduction: Leakage of orogastric secretions past the cuff of a tracheal tube is a contributory factor in ventilator-associated pneumonia. Current bench test methods specified in the International Standard for Anaesthetic and Respiratory Equipment (EN ISO 5361:2023) to test cuff leakage involve using a glass or plastic rigid cylinder model of the trachea. There is a need for more realistic models to inform cuff leakage.
View Article and Find Full Text PDFPulse oximeters' (POs) varying performance based on skin tones has been highly publicised. Compared to arterial blood gas analysis, POs tend to overestimate oxygen saturation (SpO) values for people with darker skin (occult hypoxemia). The objective is to develop a test bench for assessing commercial home and hospital-based POs in controlled laboratory conditions.
View Article and Find Full Text PDFCompression therapy is widely used as the gold standard for management of chronic venous insufficiency and venous leg ulcers, and the amount of pressure applied during the compression therapy is crucial in supporting healing. A fibre optic pressure sensor using Fibre Bragg Gratings (FBGs) is developed in this paper to measure sub-bandage pressure whilst removing cross-sensitivity due to strain in the fibre and temperature. The interface pressure is measured by an FBG encapsulated in a polymer and housed in a textile to minimise discomfort for the patient.
View Article and Find Full Text PDFSens Actuators B Chem
February 2022
This work reports an optical fibre probe functionalised with 'cotton-shaped' gold-silica nanostructures for relative humidity (RH) monitoring. The sensor response utilises the localised surface plasmon resonance (LSPR) of self-assembled nanostructures: gold nanospheres (40 nm) surrounded by one layer of poly (allylamine hydrochloride) and hydrophilic silica nanoparticles (10-20 nm) on the end-facet of an optical fibre via a wavelength shift of the reflected light. Sensor optimisation is investigated by varying the density of gold nanoparticles on the end-facet of an optical fibre.
View Article and Find Full Text PDFBiomed Opt Express
January 2022
Incorrect endotracheal tube (ETT) cuff inflation pressure causes significant problems for intubated patients. The technical development and first use of a smart ETT for measurements at the cuff-trachea interface during mechanical ventilation are described. The intra-tracheal multiplexed sensing (iTraXS) ETT contains integrated optical fibre sensors to measure contact pressure and blood perfusion.
View Article and Find Full Text PDFBackground: International newborn resuscitation guidelines recommend electrocardiogram (ECG) heart rate (HR) monitoring at birth. We evaluated the application time of pre-set ECG electrodes fixed to a polyethene patch allowing adhesive-free attachment to the wet skin of the newborn chest.
Objectives: Using a three-electrode pre-set ECG patch configuration, application success was calculated using video analysis and measured at three time points, the time to (1) apply electrodes; (2) detect recognizable QRS complexes after application; and (3) display a HR after application.
Capillary refill time (CRT) refers to the time taken for body tissue to regain its colour after an applied blanching pressure is released. Usually, pressure is manually applied and not measured. Upon release of pressure, simple mental counting is typically used to estimate how long it takes for the skin to regain its colour.
View Article and Find Full Text PDFHealthc Technol Lett
February 2021
The desire of many engineers is to see their work end up as a final product offering a real benefit to society-for a lecturer/professor at a university, this is a dream often out of reach of the majority. However, the university academic is a changed species from the early days of the binary line between Universities and Polytechnics and when a lecturer meant just that-teaching to future engineers. This article describes the process and experience gained by a university engineer to spin out their research from the university sector and achieve the goal of a product reaching a global audience.
View Article and Find Full Text PDFBackground & Aims: Intrahepatic cholestasis of pregnancy (ICP) is associated with an increased risk of stillbirth. This study aimed to assess the relationship between bile acid concentrations and fetal cardiac dysfunction in patients with ICP who were or were not treated with ursodeoxycholic acid (UDCA).
Methods: Bile acid profiles and NT-proBNP, a marker of ventricular dysfunction, were assayed in umbilical venous serum from 15 controls and 76 ICP cases (36 untreated, 40 UDCA-treated).
Textile-based systems are an attractive prospect for wearable technology as they can provide monitoring of key physiological parameters in a comfortable and unobtrusive form. A novel system based on multichannel optical fibre sensor probes integrated into a textile sleeve is described. The system measures the photoplethysmogram (PPG) at two wavelengths (660 and 830 nm), which is then used to calculate oxygen saturation (SpO).
View Article and Find Full Text PDFAdvancements in availability and specificity of light-emitting diodes (LEDs) have facilitated trait modification of high-value edible herbs and vegetables through the fine manipulation of spectra. Coriander ( L.) is a culinary herb, known for its fresh, citrusy aroma, and high economic value.
View Article and Find Full Text PDFAim: A device for newborn heart rate (HR) monitoring at birth that is compatible with delayed cord clamping and minimises hypothermia risk could have advantages over current approaches. We evaluated a wireless, cap mounted device (fhPPG) for monitoring neonatal HR.
Methods: A total of 52 infants on the neonatal intensive care unit (NICU) and immediately following birth by elective caesarean section (ECS) were recruited.
An optical fibre sensor for monitoring relative humidity (RH) changes during exercise is demonstrated. The humidity sensor comprises a tip coating of poly (allylamine hydrochloride) (PAH)/silica nanoparticles (SiO NPs) deposited using the layer-by-layer technique. An uncoated fibre is employed to compensate for bending losses that are likely to occur during movement.
View Article and Find Full Text PDFThe widely applied capillary refill time (CRT) measurement is currently performed by manually applying pressure and using a stopwatch to record the time taken for the skin to recover its normal colour after a blanching pressure is applied. This method is highly subjective and observer-dependent. This paper presents a new, integrated optical sensor probe, combining monitoring of the capillary refilling process with the blanching pressure applied.
View Article and Find Full Text PDFIntroduction: Noninvasive fetal heart rate monitoring using transabdominal fetal electrocardiographic detection is now commercially available and has been demonstrated to be an effective alternative to traditional Doppler ultrasonographic techniques. Our objective in this study was to compare the results of computerized identification of fetal heart rate patterns generated by ultrasound-based and transabdominal fetal electrocardiogram-based techniques with simultaneously obtained fetal scalp electrode-derived heart rate information.
Material And Methods: We applied an objective computer-based analysis for recognition of fetal heart rate patterns (Monica Decision Support) to data obtained simultaneously from a direct fetal scalp electrode, Doppler ultrasound, and the abdominal-fetal electrocardiogram techniques.
Background: A novel medical device has been developed to address an unmet need of standardizing and facilitating heart rate recording during neonatal resuscitation. In a time-critical emergency resuscitation, where failure can mean death of an infant, it is vital that clinicians are provided with information in a timely, precise, and clear manner to capacitate appropriate decision making. This new technology provides a hands-free, wireless heart rate monitoring solution that easily fits the clinical pathway and procedure for neonatal resuscitation.
View Article and Find Full Text PDFA novel optical sensor probe combining monitoring of blood oxygen saturation (SO₂) with contact pressure is presented. This is beneficial as contact pressure is known to affect SO₂ measurement. The sensor consists of three plastic optical fibres (POF) used to deliver and collect light for pulse oximetry, and a fibre Bragg grating (FBG) sensor to measure contact pressure.
View Article and Find Full Text PDFMatern Health Neonatol Perinatol
September 2016
Background: Previous researchers have studied circadian changes in the fetal heart rate (FHR) on small sample sizes and in a strictly controlled environment. This study was undertaken to investigate these changes during the late second and third trimesters, using a portable fetal electrocardiogram recording device (Monica AN24) in pregnant women in home and hospital environments with unrestricted mobility.
Methods: This was a prospective cohort study of 54 pregnant women with uncomplicated singleton pregnancies between 25 and 40 weeks gestation.
Objective: To develop a compact probe that can be used to monitor humidity in ventilator care equipment. A mesoporous film of alternate layers of Poly(allylamine hydrochloride) (PAH) and silica (SiO2) nanoparticles (bilayers), deposited onto an optical fibre was used. The sensing film behaves as a Fabry-Perot cavity of low-finesse where the absorption of water vapour changes the optical thickness and produces a change in reflection proportional to humidity.
View Article and Find Full Text PDFA system has been developed in which multi-exposure laser speckle contrast imaging (LSCI) is implemented using a high frame rate CMOS imaging sensor chip. Processing is performed using a field programmable gate array (FPGA). The system allows different exposure times to be simulated by accumulating a number of short exposures.
View Article and Find Full Text PDFPulse oximetry is a noninvasive and continuous method for monitoring the blood oxygen saturation level. This paper presents the design and testing of a single-chip pulse oximeter fabricated in a 0.35 µm CMOS process.
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