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1.
Ann Card Anaesth ; 27(1): 65-67, 2024 Jan 01.
Article En | MEDLINE | ID: mdl-38722125

ABSTRACT: One-lung ventilation is indicated during thoracic surgery for visualization and exposure of surgical site. It is achieved with bronchial blockers, double-lumen endobronchial tube, single-lumen endotracheal tubes and Univent tube for infants and children. Fibreoptic bronchoscope is required for placing and confirming the correct position of these tubes. We report a perioperative management of safe conduct of one lung ventilation for a 6-year child undergoing left lower lobe lobectomy through C-MAC video laryngoscope guided two single lumen tubes in limited resource settings where paediatric-sized fibreoptic bronchoscope is unavailable.


Intubation, Intratracheal , One-Lung Ventilation , Humans , One-Lung Ventilation/methods , One-Lung Ventilation/instrumentation , Intubation, Intratracheal/methods , Intubation, Intratracheal/instrumentation , Child , Male , Bronchoscopy/methods , Fiber Optic Technology , Female , Laryngoscopy/methods
2.
Sensors (Basel) ; 24(7)2024 Mar 26.
Article En | MEDLINE | ID: mdl-38610339

Antibiotic residues have become a worldwide public safety issue. It is vital to detect multiple antibiotics simultaneously using sensors. A new and efficient method is proposed for the combined detection of two antibiotics (enrofloxacin (Enro) and ciprofloxacin (Cip)) in milk using surface plasmon resonance (SPR) sensors. Based on the principle of immunosuppression, two antibiotic antigens (for Enro and Cip) were immobilized on an optical fiber surface with conjugates of bovine serum albumin using dopamine (DA) polymerization. Each single antigen was bound to its corresponding antibody to derive standard curves for Enro and Cip. The fiber-optic sensor's sensitivity was 2900 nm/RIU. Detection limits were calculated to be 1.20 ng/mL for Enro and 0.81 ng/mL for Cip. The actual system's recovery rate was obtained by testing Enro and Cip in milk samples; enrofloxacin's and ciprofloxacin's mean recoveries from the milk samples were 96.46-120.46% and 96.74-126.9%, respectively. In addition, several different regeneration solutions were tested to analyze the two target analytes' regeneration ability; NaOH and Gly-HCl solutions were found to have the best regeneration ability.


Anti-Bacterial Agents , Surface Plasmon Resonance , Enrofloxacin , Ciprofloxacin , Fiber Optic Technology
3.
ACS Sens ; 9(4): 2110-2121, 2024 Apr 26.
Article En | MEDLINE | ID: mdl-38622791

In this study, we explore the full-spectrum capabilities of fiber-optic surface plasmon resonance (FO-SPR) for analyzing heterogeneous samples with increased comprehensiveness. Our approach involves refining a literature-derived FO-SPR model to more precisely reflect experimental data obtained using a back-reflecting sensor configuration. Key enhancements in our model include adjustments to the thickness and permittivity of the gold SPR-active layer on the FO-SPR sensor as well as improvements to the angular distribution of light within the system. We apply this optimized model to the investigation of the deposition process of a metal-organic framework (MOF), specifically ZIF-8, using FO-SPR. By closely examining the temporal variations in the FO-SPR signal during MOF layer formation, we simultaneously determine the evolving thickness and refractive index (RI) of the MOF layer, offering a dual-parameter analysis. Our results demonstrate that a full-spectrum analysis of the FO-SPR signal can extract critical information from samples exhibiting radial heterogeneity. This advancement significantly enhances the quantitative assessment of various phenomena that alter the refractive index in the sensor's domain, such as adsorption and binding processes. This work thus represents a significant step forward in the field of FO-SPR sensor technology, promising broad applications in areas requiring the precise detection and analysis of complex samples.


Metal-Organic Frameworks , Surface Plasmon Resonance , Surface Plasmon Resonance/methods , Metal-Organic Frameworks/chemistry , Gold/chemistry , Fiber Optic Technology/methods , Fiber Optic Technology/instrumentation
4.
Biomed Phys Eng Express ; 10(3)2024 Apr 26.
Article En | MEDLINE | ID: mdl-38626737

A novel fiber optic biosensor was purposed for a new approach to monitor amyloid beta protein fragment 1-42 (Aß42) for Alzheimer's Disease (AD) early detection. The sensor was fabricated by etching a part of fiber from single mode fiber loop in pure hydrofluoric acid solution and utilized as a Local Optical Refractometer (LOR) to monitor the change Aß42 concentration in Artificial Cerebrospinal Fluid (ACSF). The Fiber Loop Ringdown Spectroscopy (FLRDS) technique is an ultra-sensitive measurement technique with low-cost, high sensitivity, real-time measurement, continuous measurement and portability features that was utilized with a fiber optic sensor for the first time for the detection of a biological signature in an ACSF environment. Here, the measurement is based on the total optical loss detection when specially fabricated sensor heads were immersed into ACSF solutions with and without different concentrations of Aß42 biomarkers since the bulk refractive index change was performed. Baseline stability and the reference ring down times of the sensor head were measured in the air as 0.87% and 441.6µs ± 3.9µs, respectively. Afterward, the total optical loss of the system was measured when the sensor head was immersed in deionized water, ACSF solution, and ACSF solutions with Aß42 in different concentrations. The lowest Aß42 concentration of 2 ppm was detected by LOR. Results showed that LOR fabricated by single-mode fibers for FLRDS system design are promising candidates to be utilized as fiber optic biosensors after sensor head modification and have a high potential for early detection applications of not only AD but possibly also several fatal diseases such as diabetes and cancer.


Alzheimer Disease , Amyloid beta-Peptides , Biosensing Techniques , Early Diagnosis , Fiber Optic Technology , Peptide Fragments , Spectrum Analysis , Alzheimer Disease/diagnosis , Amyloid beta-Peptides/analysis , Humans , Fiber Optic Technology/methods , Peptide Fragments/analysis , Biosensing Techniques/methods , Spectrum Analysis/methods , Optical Fibers , Biomarkers/analysis , Refractometry , Equipment Design
5.
J Clin Anesth ; 95: 111461, 2024 Aug.
Article En | MEDLINE | ID: mdl-38604048

BACKGROUND: There is a search for an ideal agent to facilitate awake fiberoptic intubation (AFOI). Dexmedetomidine is a selective α2 agonist which can be administered through intravenous, intramuscular, buccal, intranasal & inhalational routes. It provides good intubation conditions without oxygen desaturation but may cause hypotension and bradycardia when administered intravenously. Hence, alternative routes of administering dexmedetomidine which may improve its safety profile are worth exploring. METHODS: In this randomised, controlled, double-blind trial, 46 ASA I/II adult participants scheduled for elective ENT surgery were randomly allocated to Group ND (Nebulised Dexmedetomidine) (n = 23) to receive nebulisation with dexmedetomidine 1µg.kg-1 and Group ID (Intravenous Dexmedetomidine) (n = 23) to receive intravenous dexmedetomidine 1µg.kg-1 before AFOI. All the patients received injection midazolam 1 mg i.v. as premedication before anaesthesia was initiated. The primary outcome was the cough score. The secondary outcomes were the RSS, SAYGO boluses, post-intubation score, hemodynamic parameters, recall of the procedure, patient satisfaction score and any side effects. RESULTS: The cough score was significantly lower in nebulized group (2.43 ± 0.992 vs 3.52 ± 1.082) with p = 0.001. RSS(3.30 ± 0.926 vs 4.22 ± 1.126; p = 0.004), number of SAYGO boluses required (2.74 ± 0.864 vs 3.57 ± 1.161; p = 0.009) & the post intubation score (1.48 ± 0.593 vs 2.17 ± 0.778; p = 0.001) were also significantly lower in nebulized group. CONCLUSIONS: Nebulisation with dexmedetomidine results in desirable degree of sedation and better tolerance of the procedure with adequate attenuation of the haemodynamic responses to intubation.


Dexmedetomidine , Fiber Optic Technology , Hypnotics and Sedatives , Intubation, Intratracheal , Nebulizers and Vaporizers , Humans , Dexmedetomidine/administration & dosage , Dexmedetomidine/adverse effects , Intubation, Intratracheal/adverse effects , Intubation, Intratracheal/methods , Double-Blind Method , Male , Female , Adult , Middle Aged , Hypnotics and Sedatives/administration & dosage , Hypnotics and Sedatives/adverse effects , Patient Satisfaction , Administration, Inhalation , Wakefulness/drug effects , Young Adult , Administration, Intravenous
6.
Opt Express ; 32(6): 10033-10045, 2024 Mar 11.
Article En | MEDLINE | ID: mdl-38571224

Fiber optic interferometry combined with recognizing elements has attracted intensive attention for the development of different biosensors due to its superior characteristic features. However, the immobilization of sensing elements alone is not capable of low-concentration detection due to weak interaction with the evanescent field of the sensing transducer. The utilization of different 2D materials with high absorption potential and specific surface area can enhance the intensity of the evanescent field and hence the sensitivity of the sensor. Here, a biosensor has been fabricated using an inline hetero fiber structure of photonic crystal fiber (PCF) and single-mode fiber (SMF) functionalized with a nanocomposite of molybodenum di-sulfide (MoS2) and molecular imprinting polymer (MIP) to detect trace levels of bovine serum albumin (BSA). The sensor showed a wide dynamic detection range with a high sensitivity of 2.34 × 107 pm/µg L-1. It shows working potential over a wide pH range with a subfemtomolar detection limit. The compact size, easy fabrication, stable structure, long detection range, and high sensitivity of this sensor would open a new path for the development of different biosensors for online and remote sensing applications.


Molecular Imprinting , Nanocomposites , Polymers/chemistry , Molybdenum , Fiber Optic Technology
7.
Sci Rep ; 14(1): 9446, 2024 04 24.
Article En | MEDLINE | ID: mdl-38658694

To validate the feasibility of a fiber-optic pressure sensor-based pressure measurement device for monitoring intrarenal pressure and to analyze the effects of ureteral acess sheath (UAS) type, surgical location, perfusion flow rate, and measurement location on intrarenal pressure (IRP). The measurement deviations and response times to transient pressure changes were compared between a fiber-optic pressure sensing device and a urodynamic device IRP in an in vitro porcine kidney and in a water tank. Finally, pressure measurements were performed in anesthetized female pigs using fiber-optic pressure sensing device with different UAS, different perfusion flow rates, and different surgical positions at different renal calyces and ureteropelvic junctions (UPJ). According to our operation, the result is fiber optic pressure sensing devices are highly accurate and sensitive. Under the same conditions, IRP varied among different renal calyces and UPJ (P < 0.05). IRP was lowest at 50 ml/min and highest at 150 ml/min (P < 0.05). Surgical position had a significant effect on IRP (P < 0.05). 12/14 Fr UAS had a lower IRP than 11/13 Fr UAS. Therefore fiber optic pressure sensing devices are more advantageous for IRP measurements. In ureteroscopy, the type of ureteral sheath, the surgical position, the perfusion flow rate, and the location of the measurement all affect the intrarenal pressure value.


Fiber Optic Technology , Kidney , Pressure , Ureteroscopy , Animals , Fiber Optic Technology/instrumentation , Swine , Female , Kidney/physiology , Ureteroscopy/instrumentation , Ureteroscopy/methods , Optical Fibers , Urodynamics
8.
Biosens Bioelectron ; 257: 116312, 2024 Aug 01.
Article En | MEDLINE | ID: mdl-38657380

Pre-eclampsia (PE) is a life-threatening complication that occurs during pregnancy, affecting a large number of pregnant women and newborns worldwide. Rapid, on-site and affordable screening of PE at an early stage is necessary to ensure timely treatment and minimize both maternal and neonatal morbidity and mortality rates. Placental growth factor (PlGF) is an angiogenic blood biomarker used for PE diagnosis. Herein, we report the plasmonic fiber optic absorbance biosensor (P-FAB) strategy for detecting PlGF at femtomolar concentration using polymethyl methacrylate (PMMA) based U-bent polymeric optical fiber (POF) sensor probes. A novel poly(amidoamine) (PAMAM) dendrimer based PMMA surface modification is established to obtain a greater immobilization of the bioreceptors compared to a linear molecule like hexamethylenediamine (HMDA). Plasmonic sandwich immunoassay was realized by immobilizing the mouse anti-PlGF (3H1) on the U-bent POF sensor probe surface and gold nanoparticles (AuNP) labels conjugated with mouse anti-PlGF (6H9). The POF sensor probes could measure PlGF within 30 min using the P-FAB strategy. The limit-of-detection (LoD) was found to be 0.19 pg/mL and 0.57 pg/mL in phosphate-buffered saline and 10× diluted serum, respectively. The clinical sample testing, with eleven positive and eleven negative preeclamptic pregnancy samples, successfully confirmed the accuracy, reliability, specificity, and sensitivity of the P-FAB based POF sensor platform, thereby paving the way for cost-effective technology for PlGF detection and its potential for pre-eclampsia diagnosis.


Biosensing Techniques , Dendrimers , Gold , Metal Nanoparticles , Optical Fibers , Placenta Growth Factor , Pre-Eclampsia , Pre-Eclampsia/diagnosis , Pre-Eclampsia/blood , Pregnancy , Female , Humans , Dendrimers/chemistry , Biosensing Techniques/instrumentation , Biosensing Techniques/methods , Placenta Growth Factor/blood , Gold/chemistry , Metal Nanoparticles/chemistry , Limit of Detection , Immunoassay/methods , Immunoassay/instrumentation , Fiber Optic Technology/instrumentation , Animals , Mice , Polymethyl Methacrylate/chemistry
9.
Sensors (Basel) ; 24(6)2024 Mar 21.
Article En | MEDLINE | ID: mdl-38544254

The accuracy and efficacy of medical treatment would be greatly improved by the continuous and real-time monitoring of protein biomarkers. Identification of cancer biomarkers in patients with solid malignant tumors is receiving increasing attention. Existing techniques for detecting cancer proteins, such as the enzyme-linked immunosorbent assay, require a lot of work, are not multiplexed, and only allow for single-time point observations. In order to get one step closer to clinical usage, a dynamic platform for biosensing the cancer biomarker CD44 using a single-mode optical fiber-based ball resonator biosensor was designed, constructed and evaluated in this work. The main novelty of the work is an in-depth study of the capability of an in-house fabricated optical fiber biosensor for in situ detection of a cancer biomarker (CD44 protein) by conducting several types of experiments. The main results of the work are as follows: (1) Calibration of the fabricated fiber-optic ball resonator sensors in both static and dynamic conditions showed similar sensitivity to the refractive index change demonstrating its usefulness as a biosensing platform for dynamic measurements; (2) The fabricated sensors were shown to be insensitive to pressure changes further confirming their utility as an in situ sensor; (3) The sensor's packaging and placement were optimized to create a better environment for the fabricated ball resonator's performance in blood-mimicking environment; (4) Incubating increasing protein concentrations with antibody-functionalized sensor resulted in nearly instantaneous signal change indicating a femtomolar detection limit in a dynamic range from 7.1 aM to 16.7 nM; (5) The consistency of the obtained signal change was confirmed by repeatability studies; (6) Specificity experiments conducted under dynamic conditions demonstrated that the biosensors are highly selective to the targeted protein; (7) Surface morphology studies by AFM measurements further confirm the biosensor's exceptional sensitivity by revealing a considerable shift in height but no change in surface roughness after detection. The biosensor's ability to analyze clinically relevant proteins in real time with high sensitivity offers an advancement in the detection and monitoring of malignant tumors, hence improving patient diagnosis and health status surveillance.


Biosensing Techniques , Neoplasms , Humans , Biomarkers, Tumor , Biosensing Techniques/methods , Fiber Optic Technology/methods , Optical Fibers , Proteins , Neoplasms/diagnosis , Hyaluronan Receptors
10.
Phys Med Biol ; 69(8)2024 Apr 03.
Article En | MEDLINE | ID: mdl-38478998

Objective. Very high energy electrons (VHEE) in the range of 50-250 MeV are of interest for treating deep-seated tumours with FLASH radiotherapy (RT). This approach offers favourable dose distributions and the ability to deliver ultra-high dose rates (UHDR) efficiently. To make VHEE-based FLASH treatment clinically viable, a novel beam monitoring technology is explored as an alternative to transmission ionisation monitor chambers, which have non-linear responses at UHDR. This study introduces the fibre optic flash monitor (FOFM), which consists of an array of silica optical fibre-based Cherenkov sensors with a photodetector for signal readout.Approach. Experiments were conducted at the CLEAR facility at CERN using 200 MeV and 160 MeV electrons to assess the FOFM's response linearity to UHDR (characterised with radiochromic films) required for FLASH radiotherapy. Beam profile measurements made on the FOFM were compared to those using radiochromic film and scintillating yttrium aluminium garnet (YAG) screens.Main results. A range of photodetectors were evaluated, with a complementary-metal-oxide-semiconductor (CMOS) camera being the most suitable choice for this monitor. The FOFM demonstrated excellent response linearity from 0.9 Gy/pulse to 57.4 Gy/pulse (R2= 0.999). Furthermore, it did not exhibit any significant dependence on the energy between 160 MeV and 200 MeV nor the instantaneous dose rate. Gaussian fits applied to vertical beam profile measurements indicated that the FOFM could accurately provide pulse-by-pulse beam size measurements, agreeing within the error range of radiochromic film and YAG screen measurements, respectively.Significance. The FOFM proves to be a promising solution for real-time beam profile and dose monitoring for UHDR VHEE beams, with a linear response in the UHDR regime. Additionally it can perform pulse-by-pulse beam size measurements, a feature currently lacking in transmission ionisation monitor chambers, which may become crucial for implementing FLASH radiotherapy and its associated quality assurance requirements.


Electrons , Radiotherapy, High-Energy , Radiotherapy Dosage , Fiber Optic Technology , Radiometry/methods
12.
J Biomed Opt ; 29(2): 027004, 2024 Feb.
Article En | MEDLINE | ID: mdl-38419753

Significance: Treatment planning for light-based therapies including photodynamic therapy requires tissue optical property knowledge. This is recoverable with spatially resolved diffuse reflectance spectroscopy (DRS) but requires precise source-detector separation (SDS) determination and time-consuming simulations. Aim: An artificial neural network (ANN) to map from DRS at multiple SDS to optical properties was created. This trained ANN was adapted to fiber-optic probes with varying SDS using transfer learning (TL). Approach: An ANN mapping from measurements to Monte Carlo simulation to optical properties was created with one fiber-optic probe. A second probe with different SDS was used for TL algorithm creation. Data from a third were used to test this algorithm. Results: The initial ANN recovered absorber concentration with RMSE=0.29 µM (7.5% mean error) and µs' at 665 nm (µs,665') with RMSE=0.77 cm-1 (2.5% mean error). For probe 2, TL significantly improved absorber concentration (0.38 versus 1.67 µM RMSE, p=0.0005) and µ's,665 (0.71 versus 1.8 cm-1 RMSE, p=0.0005) recovery. A third probe also showed improved absorber (0.7 versus 4.1 µM RMSE, p<0.0001) and µs,665' (1.68 versus 2.08 cm-1 RMSE, p=0.2) recovery. Conclusions: TL-based probe-to-probe calibration can rapidly adapt an ANN created for one probe to similar target probes, enabling accurate optical property recovery with the target probe.


Fiber Optic Technology , Neural Networks, Computer , Calibration , Computer Simulation , Machine Learning
13.
Nat Commun ; 15(1): 147, 2024 Jan 02.
Article En | MEDLINE | ID: mdl-38167247

Optical tomography has emerged as a non-invasive imaging method, providing three-dimensional insights into subcellular structures and thereby enabling a deeper understanding of cellular functions, interactions, and processes. Conventional optical tomography methods are constrained by a limited illumination scanning range, leading to anisotropic resolution and incomplete imaging of cellular structures. To overcome this problem, we employ a compact multi-core fibre-optic cell rotator system that facilitates precise optical manipulation of cells within a microfluidic chip, achieving full-angle projection tomography with isotropic resolution. Moreover, we demonstrate an AI-driven tomographic reconstruction workflow, which can be a paradigm shift from conventional computational methods, often demanding manual processing, to a fully autonomous process. The performance of the proposed cell rotation tomography approach is validated through the three-dimensional reconstruction of cell phantoms and HL60 human cancer cells. The versatility of this learning-based tomographic reconstruction workflow paves the way for its broad application across diverse tomographic imaging modalities, including but not limited to flow cytometry tomography and acoustic rotation tomography. Therefore, this AI-driven approach can propel advancements in cell biology, aiding in the inception of pioneering therapeutics, and augmenting early-stage cancer diagnostics.


Tomography, Optical , Tomography , Humans , Rotation , Tomography/methods , Tomography, Optical/methods , Fiber Optic Technology , Phantoms, Imaging , Artificial Intelligence , Algorithms , Image Processing, Computer-Assisted/methods
14.
Nanoscale ; 16(6): 3113-3120, 2024 Feb 08.
Article En | MEDLINE | ID: mdl-38258424

As a low-density lipoprotein, tributyrin plays an essential role in food safety and human health. In this study, a novel lipase-conjugated carbon nanotube (CNT) surface plasmon resonance (SPR) fiber-optic sensor is used to specifically detect tributyrin for the first time. In this work, CNTs can be used as an amplifying material to significantly increase the sensitivity of SPR sensors due to their high refractive index and large surface area. CNTs can also be used as an enzyme carrier to provide abundant carboxyl groups for the specific binding of lipases. Covering the surface of the sensor with CNTs can not only enhance the performance of the sensor, but also provide sufficient detection sites for subsequent biomass detection, reduce the functionalization steps, and simplify the sensor preparation process. The experimental results demonstrate that the refractive index sensitivity of the traditional multimode fiber (MMF)-single mode fiber (SMF)-MMF transmissive optical fiber sensor is 1705 nm RIU-1. After covering the sensor with CNTs, the sensitivity is 2077 nm RIU-1, and the sensitivity has been improved very well. In addition, there are abundant functional groups on CNTs, which can provide abundant binding sites. Conjugating lipase on carbon nanotubes helps to achieve linear detection in the range of 0.5 mM to 4 mM tributyrin, with a sensitivity of 4.45 nm mM-1 and a detection limit of 0.34 mM, which is below the 2.26 mM detection standard and meets food safety monitoring requirements. Compared with other sensors, the optical fiber biosensor proposed in this study expands the concentration detection range of tributyrin. Furthermore, the sensor also has good stability, anti-interference performance and specificity. Therefore, the sensor proposed in this paper has good application prospects in the fields of food safety and biomedicine.


Nanotubes, Carbon , Surface Plasmon Resonance , Triglycerides , Humans , Surface Plasmon Resonance/methods , Lipase , Fiber Optic Technology/methods
15.
J Biophotonics ; 17(1): e202300329, 2024 01.
Article En | MEDLINE | ID: mdl-37703422

A single-mode-fiber (SMF)-multimode-fiber (MMF)-tri-core-fiber (TCF) Michelson probe structure is proposed for trace detection of canine distemper virus (CDV). One end of the TCF is cut flat and fused with the multimode fiber, and the other end is coated with a silver film to enhance the reflection, and an optic-fiber sensing probe with SMF-MMF-TCF structure is obtained. The (PDDA/PSS)3 multilayer film is modified on the surface of the fiber by layer-by-layer self-assembly method as a polyelectrolyte binder to immobilize CDV antibodies to form a (PDDA/PSS)3 /CDV antibody composite membrane for specific detection of CDV antigens. The response-recovery test of the sensor is performed to verify its repeatability. The detection limit, the sensitivity, and the linear fitting degree for CDV antigen are 0.1236 pg/mL, 1.1776 dB/(pg/mL), and 0.9899, respectively. At the same time, the stability, selectivity, and clinical samples of the sensors were also verified.


Distemper Virus, Canine , Animals , Fiber Optic Technology
16.
J Radiat Res ; 65(1): 136-143, 2024 Jan 19.
Article En | MEDLINE | ID: mdl-38037422

We demonstrate the application of fluorescence optical fiber coupled to a telecom grade fiber as a sensor for alpha particles using alpha-specific ZnS(Ag) scintillation materials whose wavelength is down-shifted into a low-loss region of the telecom grade fiber transmission band. Telecom-grade fiber optics offer a solution for sensing alpha radiation in deep repositories and cask storage for radioactive materials due to the stability of SiO2 under normal environmental conditions and its relative radiation hardness at low radiation doses. Long-term nuclear waste storage facilities require sensors for the detection of leakage of radioactive materials that are maintenance-free, do not require power and can survive with no 'wear out' mechanisms for decades. By accomplishing the wavelength transformation, we maximize efficiencies in the detection of α-particles and signal transport and can detect alpha scintillation at distances on the order of >1 km with a sensor that is ~3% efficient and can be easily scaled as a sensor array. This paper describes the construction and testing of the sensor including manufacture of the controlled thickness films, verification of the wavelength shift from 450 to 620 nm and optimization of the sensitivity as a function of thickness. We also model the relative sensitivity of the film as a function of film thickness, and we demonstrate a signal-to-noise ratio of 10 at a range of greater than 1 km.


Alpha Particles , Optical Fibers , Silicon Dioxide , Fiber Optic Technology
17.
J Biophotonics ; 17(3): e202300335, 2024 Mar.
Article En | MEDLINE | ID: mdl-38116917

Diffuse optical measurement is an evolving optical modality providing a fast and portable solution for microcirculation assessment. Diffuse optics in static and dynamic modalities are combined here in a system to assess hemodynamics in skin tissues of control and diabetic subjects. The in-house developed system consists of a laser source, fiber optic probe, a low-cost avalanche photodiode, a finite element model (FEM) derived static optical property estimator, and a software correlator for continuous flow monitoring through microvasculature. The studies demonstrated that the system quantifies the changes in blood flow rate in the immediate skin subsurface. The system is calibrated with in vitro flow models and a proof-of-concept was demonstrated on a limited number of subjects in a clinical environment. The flow changes in response to vasoconstrictive and vasodilative stimuli were analyzed and used to classify different stages of diabetes, including diabetic neuropathy.


Diabetes Mellitus , Diabetic Neuropathies , Humans , Diabetic Neuropathies/diagnosis , Microcirculation/physiology , Spectrum Analysis , Skin/blood supply , Fiber Optic Technology
18.
BMJ Case Rep ; 16(12)2023 Dec 01.
Article En | MEDLINE | ID: mdl-38050394

Progressive airway compromise from a neck haematoma is a feared complication of head and neck surgery that can rapidly lead to death if not urgently intervened upon. We report a case of a patient developing a progressively expanding neck haematoma on the first postoperative night after parotidectomy and neck dissection for malignancy. Although he did not have respiratory compromise or stridor, ultrasound examination of his airway revealed marked tracheal deviation, and flexible nasoendoscopy showed significant supraglottic swelling. The decision was made for an awake fibreoptic intubation; however, a complicating factor was a history of lignocaine allergy. This case report describes the unconventional use of atomised ropivacaine in a concentration of 0.5% for topicalisation of the airway. Along with conscious sedation with remifentanil, ropivacaine provided excellent conditions for awake intubation, following which a significant amount of blood was evacuated from the face and neck.


Hypersensitivity , Wakefulness , Male , Humans , Ropivacaine , Intubation, Intratracheal/adverse effects , Lidocaine , Hematoma/etiology , Hematoma/surgery , Fiber Optic Technology
19.
Biosensors (Basel) ; 13(12)2023 Dec 14.
Article En | MEDLINE | ID: mdl-38131789

Timely detection of highly infectious pathogens is essential for preventing and controlling public health risks. However, most traditional testing instruments require multiple tedious steps and ultimately testing in hospitals and third-party laboratories. The sample transfer process significantly prolongs the time to obtain test results. To tackle this aspect, a portable fiber optic surface plasmon resonance (FO-SPR) device was developed for the real-time detection of infectious pathogens. The portable device innovatively integrated a compact FO-SPR sensing component, a signal acquisition and processing system, and an embedded power supply unit. A gold-plated fiber is used as the FO-SPR sensing probe. Compared with traditional SPR sensing systems, the device is smaller size, lighter weight, and higher convenience. To enhance the detection capacity of pathogens, a monolayer graphene was coated on the sensing region of the FO-SPR sensing probe. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was used to evaluate the performance of the portable device. The device can accurately detect the SARS-CoV-2 spike S1 protein in phosphate-buffered saline (PBS) and artificial saliva within just 20 min, and the device successfully detected cultured SARS-CoV-2 virus. Furthermore, the FO-SPR probe has long-term stability, remaining stable for up to 8 days. It could distinguish between the SARS-CoV-2 spike protein and the MERS-CoV spike protein. Hence, this FO-SPR device provides reliable, rapid, and portable access to test results. It provides a promising point-of-care testing (POCT) tool for on-site screening of infectious pathogens.


Biosensing Techniques , Graphite , Humans , Surface Plasmon Resonance/methods , Fiber Optic Technology/methods , Point-of-Care Testing , Biosensing Techniques/methods
20.
J Pak Med Assoc ; 73(11): 2273-2276, 2023 Nov.
Article En | MEDLINE | ID: mdl-38013546

Hunter syndrome (mucopolysaccharidosis type II) has the highest reported prevalence of difficult tracheal intubation among the seven known types of mucopolysaccharidoses. Despite improved difficult airway guidelines and equipment, conventional approaches may fail in some cases. A 10-year-old child with Hunter syndrome, was scheduled for multiple dental extractions. On the first visit, failed intubation was declared as per Difficult Airway Society guidelines in the surgical day-care suite of our institute and the procedure was postponed. The case was then planned to be handled in the main operating room with additional preparation and input from the paediatric otolaryngologist for possible tracheostomy, paediatric intensive care for postoperative need for ventilation, and difficult airway resource faculty for an unconventional approach-videolaryngoscope combined with fibreoptic bronchoscope-which resulted in safe administration of anaesthesia. This case illustrates the importance of meticulous planning in the management of previously failed airway.


Anesthesia , Laryngoscopes , Mucopolysaccharidosis II , Humans , Child , Bronchoscopy , Mucopolysaccharidosis II/complications , Mucopolysaccharidosis II/therapy , Intubation, Intratracheal , Fiber Optic Technology
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