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1.
Article in English | MEDLINE | ID: mdl-38745381

ABSTRACT

Tricuspid regurgitation is a common valve disease with high incidence and poor prognosis. For elderly patients and those with a history of open heart surgery, second thoracotomy and valve replacement carry a high risk. Transcatheter tricuspid valve replacement (TTVR) has become an alternative treatment for patients with high surgical risk. LuX-Valve is a novel self-expandable valve that does not rely on radial force to anchor the valve annulus. The preliminary results have been satisfactory, and this technology is gradually being adopted in China and around the world. Successful implementation of this technique depends on echocardiographic preoperative screening, intraoperative guidance, and postoperative follow-up. The purpose of this article is to provide a state-of-the-art review of the key points and technical considerations for preoperative screening, intraoperative guidance, and postoperative follow-up for TTVR.

2.
Eur Heart J Digit Health ; 5(3): 219-228, 2024 May.
Article in English | MEDLINE | ID: mdl-38774374

ABSTRACT

Aims: Permanent pacemaker implantation and left bundle branch block are common complications after transcatheter aortic valve replacement (TAVR) and are associated with impaired prognosis. This study aimed to develop an artificial intelligence (AI) model for predicting conduction disturbances after TAVR using pre-procedural 12-lead electrocardiogram (ECG) images. Methods and results: We collected pre-procedural 12-lead ECGs of patients who underwent TAVR at West China Hospital between March 2016 and March 2022. A hold-out testing set comprising 20% of the sample was randomly selected. We developed an AI model using a convolutional neural network, trained it using five-fold cross-validation and tested it on the hold-out testing cohort. We also developed and validated an enhanced model that included additional clinical features. After applying exclusion criteria, we included 1354 ECGs of 718 patients in the study. The AI model predicted conduction disturbances in the hold-out testing cohort with an area under the curve (AUC) of 0.764, accuracy of 0.743, F1 score of 0.752, sensitivity of 0.876, and specificity of 0.624, based solely on pre-procedural ECG images. The performance was better than the Emory score (AUC = 0.704), as well as the logistic (AUC = 0.574) and XGBoost (AUC = 0.520) models built with previously identified high-risk ECG patterns. After adding clinical features, there was an increase in the overall performance with an AUC of 0.779, accuracy of 0.774, F1 score of 0.776, sensitivity of 0.794, and specificity of 0.752. Conclusion: Artificial intelligence-enhanced ECGs may offer better predictive value than traditionally defined high-risk ECG patterns.

3.
Sensors (Basel) ; 24(8)2024 Apr 18.
Article in English | MEDLINE | ID: mdl-38676208

ABSTRACT

The era of Industry 4.0 is gradually transforming our society into a data-driven one, which can help us uncover valuable information from accumulated data, thereby improving the level of social governance. The detection of anomalies, is crucial for maintaining societal trust and fairness, yet it poses significant challenges due to the ubiquity of anomalies and the difficulty in identifying them accurately. This paper aims to enhance the performance of the current Graph Convolutional Network (GCN)-based Graph Anomaly Detection (GAD) algorithm on datasets with extremely low proportions of anomalous labels. This goal is achieved through modifying the GCN network structure and conducting feature extraction, thus fully utilizing three types of information in the graph: node label information, node feature information, and edge information. Firstly, we theoretically demonstrate the relationship between label propagation and feature convolution, indicating that the Label Propagation Algorithm (LPA) can serve as a regularization penalty term for GCN, aiding in training and enabling learnable edge weights, providing a basis for incorporating node label information into GCN networks. Secondly, we introduce a method to aggregate node and edge features, thereby incorporating edge information into GCN networks. Finally, we design different GCN trainable weights for node features and co-embedding features. This design allows different features to be projected into different spaces, greatly enhancing model expressiveness. Experimental results on the DGraph dataset demonstrate superior AUC performance compared to baseline models, highlighting the feasibility and efficacy of the proposed approach in addressing GAD tasks in the scene with extremely low proportions of anomalous data.

4.
Food Funct ; 15(9): 4785-4804, 2024 May 07.
Article in English | MEDLINE | ID: mdl-38511466

ABSTRACT

A diet containing natural active compounds that can inhibit the hydrolytic activity of α-glucosidase on carbohydrates and intestinal glucose absorption is an effective means of controlling postprandial hyperglycemia. Phlorizin and polydatin as phenolic glycosides have a high affinity for the catalytic site of α-glucosidase, but exhibited unsatisfactory competitive inhibitory capacity, with an IC50 of 0.97 and >2 mM, respectively. However, dodecyl-acylated derivatives of phlorizin and polydatin exerted α-glucosidase inhibitory capacity, with an IC50 of 55.10 and 70.95 µM, respectively, which were greatly enhanced and much stronger than that of acarbose with an IC50 of 2.46 mM. The SPR assay suggested the high affinity of dodecyl phlorizin and dodecyl polydatin to α-glucosidase with equilibrium dissociation constant (KD) values of 12.0 and 7.9 µM, respectively. Both dodecyl phlorizin and dodecyl polydatin reduced the catalytic ability of α-glucosidase by reversible noncompetitive and uncompetitive mixed inhibition, which bind noncovalently to the allosteric site 2 through hydrogen bonds and hydrophobic interactions, thereby inducing the secondary structure unfolding and intrinsic fluorescence quenching of α-glucosidase. Confocal microscopy detection visually showed significant inhibitory effects on FITC-labeled glucose uptake in intestinal Caco-2 cells by phlorizin, polydatin, dodecyl phlorizin and dodecyl polydatin. In addition, based on the differentiated Caco-2 cell monolayer model, dodecyl phlorizin and dodecyl polydatin suppressed intestinal glucose transport more effectively than phlorizin and polydatin, suggesting that they were promising in vivo hypoglycemic active compounds.


Subject(s)
Glucose , Glucosides , Glycoside Hydrolase Inhibitors , Hypoglycemic Agents , Phlorhizin , Stilbenes , alpha-Glucosidases , Phlorhizin/pharmacology , Phlorhizin/chemistry , Glycoside Hydrolase Inhibitors/pharmacology , Glycoside Hydrolase Inhibitors/chemistry , Stilbenes/pharmacology , Stilbenes/chemistry , Glucosides/pharmacology , Glucosides/chemistry , alpha-Glucosidases/metabolism , alpha-Glucosidases/chemistry , Humans , Hypoglycemic Agents/pharmacology , Hypoglycemic Agents/chemistry , Caco-2 Cells , Glucose/metabolism , Animals , Intestinal Absorption/drug effects
5.
Asian J Surg ; 2024 Mar 05.
Article in English | MEDLINE | ID: mdl-38448293

ABSTRACT

Surgery after neoadjuvant chemoradiotherapy remains the gold standard for the treatment of resectable esophageal cancer (EC); however, chemoradiotherapy without surgery has been recommended in specific cases. The aim of this meta-analysis is to analyse the survival between surgeries after neoadjuvant chemoradiotherapy compared with definitive chemoradiotherapy in order to provide a theoretical basis for clinically individualised differential treatment. We conducted an initial search of MEDLINE (PubMed), the Cochrane Library, and Embase for English-only articles that compared treatment regimens and provided survival data. According to the final I2 value of the two survival indicators, the random effect model or fixed effect model was used to calculate the overall hazard ratio (HR) and 95% confidence intervals (CI). Cochrane's Q test was used to judge the heterogeneity of the studies, and a funnel plot was used to evaluate for publication bias. A sensitivity analysis was performed to verify the stability of the included studies. A total of 38 studies involving 29161 patients (neoadjuvant therapy: 15401, definitive chemoradiotherapy: 13760) were included in the analysis. The final pooled results (HR = 0.74, 95% CI: 0.67-0.82) showed a statistically significant increase in overall survival with neoadjuvant chemoradiotherapy plus surgery compared with definitive chemoradiotherapy. Subgroup analyses were performed to determine the effects of heterogeneity, additional treatment regimens, study types, and geographic regions, as well as histologic differences, complications, and recurrence, on the overall results. For people with esophageal cancer that can be removed, neoadjuvant chemoradiotherapy combined with surgery improves survival compared to definitive chemoradiotherapy. However, more research is needed to confirm these results and help doctors make decisions about treatment.

6.
Rev Sci Instrum ; 95(1)2024 Jan 01.
Article in English | MEDLINE | ID: mdl-38284813

ABSTRACT

A double spherical shell (DSS) electric field sensor based on charge sensing has characteristics of small size and simple fabrication, which are appropriate for measuring complex electric field environments, but the sensitivity is low. To improve the sensitivity of the DSS electric field sensor, we theoretically analyze the effect of the diameter of the outer spherical shell opening on the sensitivity of the sensor. The sensors with outer spherical shell apertures of 2, 4, and 6 mm are designed and manufactured, and the sensor's sensitivity, linearity, hysteresis, and repeatability are tested. The relative error of the sensor is evaluated by measuring the rotational characteristics of the sensor. The experimental results show that the sensor sensitivity increases with the increase in hole diameter, while the sensor has good linearity, hysteresis, and repeatability after opening the hole. The rotational characteristics experiments' results show that the sensors' relative errors with different apertures are 18, 23, and 31%, respectively. The DSS open-hole structure is more suitable for electric field measurements than the conventional flat plate structure.

7.
World J Clin Oncol ; 15(1): 130-144, 2024 Jan 24.
Article in English | MEDLINE | ID: mdl-38292656

ABSTRACT

BACKGROUND: Hepatocellular carcinoma (HCC) is an aggressive subtype of liver cancer and is one of the most common cancers with high mortality worldwide. Reprogrammed lipid metabolism plays crucial roles in HCC cancer cell survival, growth, and evolution. Emerging evidence suggests the importance of fatty acid binding proteins (FABPs) in contribution to cancer progression and metastasis; however, how these FABPs are dysregulated in cancer cells, especially in HCC, and the roles of FABPs in cancer progression have not been well defined. AIM: To understand the genetic alterations and expression of FABPs and their associated cancer hallmarks and oncogenes in contributing to cancer malignancies. METHODS: We used The Cancer Genome Atlas datasets of pan cancer and liver hepatocellular carcinoma (LIHC) as well as patient cohorts with other cancer types in this study. We investigated genetic alterations of FABPs in various cancer types. mRNA expression was used to determine if FABPs are abnormally expressed in tumor tissues compared to non-tumor controls and to investigate whether their expression correlates with patient clinical outcome, enriched cancer hallmarks and oncogenes previously reported for patients with HCC. We determined the protein levels of FABP5 and its correlated genes in two HCC cell lines and assessed the potential of FABP5 inhibition in treating HCC cells. RESULTS: We discovered that a gene cluster including five FABP family members (FABP4, FABP5, FABP8, FABP9 and FABP12) is frequently co-amplified in cancer. Amplification, in fact, is the most common genetic alteration for FABPs, leading to overexpression of FABPs. FABP5 showed the greatest differential mRNA expression comparing tumor with non-tumor tissues. High FABP5 expression correlates well with worse patient outcomes (P < 0.05). FABP5 expression highly correlates with enrichment of G2M checkpoint (r = 0.33, P = 1.1e-10), TP53 signaling pathway (r = 0.22, P = 1.7e-5) and many genes in the gene sets such as CDK1 (r = 0.56, P = 0), CDK4 (r = 0.49, P = 0), and TP53 (r = 0.22, P = 1.6e-5). Furthermore, FABP5 also correlates well with two co-expressed oncogenes PLK1 and BIRC5 in pan cancer especially in LIHC patients (r = 0.58, P = 0; r = 0.58, P = 0; respectively). FABP5high Huh7 cells also expressed higher protein levels of p53, BIRC5, CDK1, CDK2, and CDK4 than FABP5low HepG2 cells. FABP5 inhibition more potently inhibited the tumor cell growth in Huh7 cells than in HepG2 cells. CONCLUSION: We discovered that FABP5 gene is frequently amplified in cancer, especially in HCC, leading to its significant elevated expression in HCC. Its high expression correlates well with worse patient outcome, enriched cancer hallmarks and oncogenes in HCC. FABP5 inhibition impaired the cell viability of FABP5high Huh7 cells. All these support that FABP5 is a novel therapeutic target for treating FABP5high HCC.

8.
Int J Biol Macromol ; 254(Pt 3): 128001, 2024 Jan.
Article in English | MEDLINE | ID: mdl-37949274

ABSTRACT

Betanin, a water-soluble pigment known for its high bioactivity, is hindered by pH and temperature sensitivity, weak ionic strength, and low bioavailability. In this study, nanoliposome (NPS), chitosan-coated NPS (CNPS), and chondroitin sulfate-chitosan bilayer-modified nanoliposomes (SCNPS) were prepared based on a layer-by-layer electrostatic interaction method for betanin encapsulation. The increase of polymer layers from NPS to SCNPS led to a monotonic increment from 223.57 to 522.33 nm in size, from -27.73 to 16.70 mV in negative charge and from 0.22 to 0.35 in polydispersity index. The chemical stability against pH (ranging from 2 to 10), ionic type (KCl, CaCl2, ALCl3) and ionic strength (100, 500 mM) significantly impacted the appearance and particle size of the double-layered nanoliposome. In vitro digestion experiment showed that SCNPS displayed higher stability and slower betanin release compared to NPS and CNPS. This study demonstrates that betanin can be efficiently encapsulated by SCNPS with improved stability and bioavailability.


Subject(s)
Chitosan , Nanoparticles , Liposomes/chemistry , Chitosan/chemistry , Chondroitin Sulfates , Betacyanins/chemistry , Particle Size , Digestion , Nanoparticles/chemistry
9.
BMJ Open ; 13(12): e078061, 2023 12 18.
Article in English | MEDLINE | ID: mdl-38110378

ABSTRACT

INTRODUCTION: Decisions regarding the optimal timing of intervention for asymptomatic aortic stenosis (AS) are controversial. The study aims to identify potential risk factors for asymptomatic patients with severe AS that are associated with worse prognosis and to evaluate the benefits of early interventions for asymptomatic patients presenting with one or more additional risk factors. METHODS AND ANALYSIS: This is a non-interventional, prospective, open-label, multicentre registry study across China. A total of 1000 patients will be enrolled and categorised as symptomatic or asymptomatic. The primary endpoint is the occurrence of all-cause mortality, stroke, acute myocardial infarction and heart failure-related hospitalisation at 1-year follow-up. In asymptomatic severe AS patients presenting with one or more risk factors, the occurrence rate of the primary endpoint between those who undergo transcatheter aortic valve replacement (TAVR) and those who do not will be compared. We will also compare the occurrence rate of the primary endpoint for asymptomatic severe AS patients with additional risk factors who undergo TAVR with those presenting with symptoms. This study is believed to provide additional evidence to help clinicians identify and refer severe AS patients who are asymptomatic but present with additional risk factors for early intervention of TAVR. ETHICS AND DISSEMINATION: The study protocol has been approved by the local ethics committee of each participating site: West China Hospital, Sichuan University; Sir Run Run Shaw Hospital, Zhejiang University School of Medicine; Second Hospital of Hebei Medical University; Tianjin Chest Hospital; and First Affiliated Hospital of Nanchang University. All participants will provide written informed consent. Study results will be published through academic conferences and peer-reviewed journals. TRIAL REGISTRATION: This study was registered at the Chinese Clinical Trial Registry (https:// www.chictr.org.cn), with the registration number ChiCTR2200064853.


Subject(s)
Aortic Valve Stenosis , Transcatheter Aortic Valve Replacement , Humans , Aortic Valve Stenosis/surgery , Multicenter Studies as Topic , Prospective Studies , Registries , Risk Factors , Transcatheter Aortic Valve Replacement/adverse effects , Treatment Outcome
11.
Circ Cardiovasc Interv ; 16(12): e013083, 2023 12.
Article in English | MEDLINE | ID: mdl-37846559

ABSTRACT

BACKGROUND: Data concerning the outcomes of transcatheter aortic valve replacement in type 0 bicuspid aortic stenosis (AS) are scarce. The study aims to compare the outcomes of transcatheter aortic valve replacement for AS in patients with type 0 bicuspid, type 1 bicuspid, and tricuspid aortic valve anatomy. METHODS: We enrolled consecutive patients undergoing transcatheter aortic valve replacement for severe AS between 2012 and 2022 in this single-center retrospective cohort study. The primary outcome was mortality, while secondary outcomes included in-hospital complications such as stroke and pacemaker implantation and transcatheter heart valve hemodynamic performance. RESULTS: The number of patients with AS with type 0 bicuspid, type 1 bicuspid, and tricuspid aortic valve anatomy was 328, 302, and 642, respectively. Self-expanding transcatheter heart valves were used in the majority of patients (n=1160; 91.4%). In the matched population, differences in mortality (30 days: 4.2% versus 1.7% versus 1.7%, Poverall=0.522; 1 year: 10% versus 2.3% versus 6.2%, Poverall=0.099) and all stroke (30 days: 1.0% versus 0.9% versus 0.0%, Poverall=0.765; 1 year: 1.4% versus 1.6% versus 1.3%, Poverall=NS) were nonsignificant, and the incidence of overall in-hospital complications was comparable among groups. Ascending aortic diameter was the single predictor of 1-year mortality in type 0 bicuspid patients (hazard ratio, 1.59 [95% CI, 1.03-2.44]; P=0.035). The proportion of patients with a mean residual gradient ≥20 mm Hg was the highest in those with type 0 bicuspid anatomy, although the need for permanent pacemaker implantation was the lowest in this group. CONCLUSIONS: Major clinical outcomes of transcatheter aortic valve replacement for AS in patients with type 0 bicuspid, type 1 bicuspid, and tricuspid aortic valve anatomy are equivalent at short- and mid-term follow-up. These observations merit further exploration in prospective international registries and randomized controlled trials.


Subject(s)
Aortic Valve Stenosis , Heart Valve Diseases , Stroke , Transcatheter Aortic Valve Replacement , Humans , Aortic Valve/diagnostic imaging , Aortic Valve/surgery , Transcatheter Aortic Valve Replacement/adverse effects , Prospective Studies , Retrospective Studies , Heart Valve Diseases/diagnostic imaging , Heart Valve Diseases/surgery , Treatment Outcome , Aortic Valve Stenosis/diagnostic imaging , Aortic Valve Stenosis/surgery , Aortic Valve Stenosis/etiology , Stroke/etiology , Stroke/surgery
12.
BMC Public Health ; 23(1): 1771, 2023 09 11.
Article in English | MEDLINE | ID: mdl-37697364

ABSTRACT

BACKGROUND: The correlation between stable geomagnetic fields and unstable geomagnetic activities with mortality, incidence, and prevalence of cardiovascular diseases (CVDs) remains ambiguous. METHOD: To investigate the correlations between geomagnetic field (GMF) intensity and geomagnetic disturbance (GMD) and CVDs events in global, long-period scale, global and 204 countries and territories were included on the base of 2019 Global Burden of Disease study (GBD 2019). Data of GMF intensity, GMD frequency, CVDs events, weather and health economic indicators from 1996 to 2019 of included locations were collected. Linear regression and panel data modelling were conducted to identify the correlations between GMF intensity and CVDs events, multi-factor panel data analysis was also generated to adjust the effect of confounding factors. RESULTS: For the average data during 1996-2019, linear regression model revealed consistent positive correlations between total GMF (tGMF) intensity and mortality of total CVDs [coef = 0.009, (0.006,0.011 95%CI)], whereas negative correlations were found between horizonal GMF (hGMF) intensity and total CVD mortality [coef = -0.010 (-0.013, -0.007 95%CI)]. When considering the time trend, panel data analysis still demonstrated positive correlation between tGMF and total CVDs mortality [coef = 0.009, (0.008,0.009 95%CI)]. Concurrently, the hGMF negatively correlated with total CVDs mortality [coef = -0.008, (-0.009, -0.007 95%CI)]. When the panel models were adjusted for confounding factors, no reverse of correlation tendency was found between tGMF, hGMF and CVDs events. In high-income territories, positive correlation was found between geomagnetic storm (GMS) frequency and mortality of total CVDs [coef = 14.007,(2.785, 25.229 95%CI)], however, this positive trend faded away gradually with the latitude decreasing from polar to equator. CONCLUSIONS: Stable and long-term horizontal component of GMF may be beneficial to cardiac health. Unstable and short-term GMF called GMD could be a hazard to cardiac health. Our results suggest the importance of regular GMF in maintaining cardio-health state and the adverse impacts of GMD on cardiac health.


Subject(s)
Cardiovascular Diseases , Humans , Cardiovascular Diseases/epidemiology , Glia Maturation Factor , Data Analysis , Economics, Medical , Factor Analysis, Statistical
15.
FASEB J ; 37(10): e23142, 2023 10.
Article in English | MEDLINE | ID: mdl-37650634

ABSTRACT

Despite encouraging advances in early diagnosis and treatment, cardiovascular diseases (CVDs) remained a leading cause of morbidity and mortality worldwide. Increasing evidence has shown that the electromagnetic field (EMF) influences many biological processes, which has attracted much attention for its potential therapeutic and diagnostic modalities in multiple diseases, such as musculoskeletal disorders and neurodegenerative diseases. Nonionizing EMF has been studied as a therapeutic or diagnostic tool in CVDs. In this review, we summarize the current literature ranging from in vitro to clinical studies focusing on the therapeutic potential (external EMF) and diagnostic potential (internal EMF generated from the heart) of EMF in CVDs. First, we provided an overview of the therapeutic potential of EMF and associated mechanisms in the context of CVDs, including cardiac arrhythmia, myocardial ischemia, atherosclerosis, and hypertension. Furthermore, we investigated the diagnostic and predictive value of magnetocardiography in CVDs. Finally, we discussed the critical steps necessary to translate this promising approach into clinical practice.


Subject(s)
Cardiovascular Diseases , Coronary Artery Disease , Hypertension , Myocardial Ischemia , Humans , Cardiovascular Diseases/diagnosis , Cardiovascular Diseases/therapy , Electromagnetic Fields
16.
J Clin Med ; 12(15)2023 Aug 01.
Article in English | MEDLINE | ID: mdl-37568469

ABSTRACT

The snare-assisted technique has been described to facilitate transcatheter aortic valve replacement (TAVR) delivery system advancement in complex aortic anatomies. However, the evidence is limited to case reports. To evaluate the safety profile of the snare-facilitated approach and its impact on self-expanding (SE) TAVR outcomes, we collected consecutive patients who underwent transfemoral SE-TAVR for aortic stenosis, using propensity score matching (PSM) separately in tricuspid and type-0 and type-1 bicuspid aortic valve morphology between the snare and non-snare groups. In 766 patients, despite the snare group having significantly larger annulus angulation and maximal ascending aortic diameter, both groups achieved comparable 30-day device success rates, regardless of first-generation or new-generation valve use. After PSM, the snare group had a significantly lower new permanent pacemaker implantation rate among 193 type-0 patients (3.3% vs. 18.3%, p = 0.01). The ipsilateral group used new-generation valves less frequently (23.0% vs. 75.4%, p < 0.001), but there were no significant inter-group differences in procedure-related events, except for a lower incidence of PVL ≥ mild in the ipsilateral group (14.9% vs. 32.3%, p = 0.01). In conclusion, the snare-assisted technique appears useful in SE-TAVR with angulated aortic root anatomy, and the benefits were comparable between ipsilateral and contralateral snare techniques.

18.
J Agric Food Chem ; 71(20): 7689-7702, 2023 May 24.
Article in English | MEDLINE | ID: mdl-37167604

ABSTRACT

Arbutin, salidroside, polydatin, and phlorizin are typically natural bioactive phenolic glycosides. To improve the liposolubility and bioavailability, highly liposoluble derivatives including 6'-O-lauryl arbutin, 6'-O-lauryl salidroside, 6″-O-lauryl polydatin, and 6″-O-lauryl phlorizin were efficiently synthesized by enzymatic acylation in a green solvent 2-MeTHF. Their reaction conversions reached 84.4, 99.5, 99.8, and 89.1%, respectively, when catalyzed by Lipozyme 435 at 20 mg/mL at 50 °C. As expected, the derivatives had high log P (1.66-2.37) and retained good antioxidant activity, making them potential alternatives to butylated hydroxytoluene (BHT) and tert-butyl-hydroquinone (TBHQ) in lipid systems. Then, the intestinal permeability characteristics and metabolism of phenolic glycosides and their derivatives were investigated based on Caco-2 monolayers. The permeability of polydatin and phlorizin was mainly through active transport, but that of arbutin and salidroside involved both passive diffusion and active uptake. The acylated derivatives suffered from severe CES-mediated hydrolysis but exhibited a larger transported amount than phenolic glycosides.


Subject(s)
Arbutin , Glycosides , Humans , Phlorhizin , Caco-2 Cells , Permeability
19.
Rev Sci Instrum ; 94(3): 035105, 2023 Mar 01.
Article in English | MEDLINE | ID: mdl-37012824

ABSTRACT

The collimator is an essential part of the fiber optic rotary joint design. This study proposes the Large-Beam Fiber Collimator (LBFC) with a double collimating lens and a Thermally Expanded Core (TEC) fiber structure. The transmission model is constructed based on the defocusing telescope structure. The effects of TEC fiber's mode field diameter (MFD) on the coupling loss are investigated by deriving the loss function for the influence of collimator mismatch error and implementing it on a fiber Bragg grating temperature sensing system. The experimental results show that the coupling loss decreases with the increase of the MFD of TEC fiber, while the coupling loss is less than 1 dB when the mode field diameter is greater than 14 µm. TEC fibers can reduce the effect of angular deviation. Considering the coupling efficiency and deviation, the preferred mode field diameter for the collimator is 20 µm. The proposed LBFC enables bidirectional transmission of optical signals for temperature measurement.

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