Device Selection Research Articles

Clinical Outcomes and Left Ventricular Functional Remodeling after Extracorporeal Membrane Oxygenation Assisted Percutaneous Coronary Intervention in Patients with Ischemic Cardiomyopathy: A Single-Center Retrospective Observational Study of 76 Cases.

Ischemic cardiomyopathy (ICM) is a common condition that leads to left ventricular (LV) functional remodeling and poor prognosis. Extracorporeal membrane oxygenation (ECMO) can provide temporary circulatory support and facilitate percutaneous coronary intervention (PCI) in patients with ICM and hemodynamic instability. However, the impact of ECMO-assisted PCI on LV functional remodeling and clinical outcomes in ICM patients is unclear. We retrospectively analyzed 76 patients with ICM who underwent ECMO-assisted PCI at our institution between January 2013 and December 2022. We assessed the changes in LV functional remodeling using echocardiography at baseline and 12 months after the procedure. We also evaluated the incidence of major adverse cardiac and cerebrovascular events (MACCEs) and ECMO-related complications during hospitalization and at one-year follow-up. The mean baseline left ventricular ejection fraction (LVEF) was 29.98 ± 2.65%. The rate of complete revascularization was 58%. The median duration of ECMO support was 38.99 hours. The most common ECMO-related complications were bleeding (8%) and lower extremity ischemia (5%). The one-year mortality rate was 30%. The overall freedom from MACCEs at 12 months was 59% (95% confidence interval (CI): 49-71%). LVEF increased significantly after the procedure from baseline to 6 months, yet decreased slightly at 12 months, although it was still higher than the baseline value. Wall motion score index (WMSI), end-diastolic volume index (EDVI), and end-systolic volume index (ESVI) decreased significantly from baseline to 12 months, indicating an improvement in LV function and a reduction in LV size. In a high-volume tertiary center with extensive experience in advanced heart failure therapies and a dedicated ECMO team, ECMO-assisted PCI demonstrated feasibility and safety in patients with ischemic cardiomyopathy. However, the rate of complete revascularization was modest at 58%. Despite the high-risk profile of the patients, ECMO-assisted PCI was associated with a significant improvement in LV functional remodeling and a favorable 12-month survival rate. Further prospective studies are needed to confirm these findings and to identify the optimal patient and device selection criteria for ECMO-assisted PCI.

Design and Development of a Side Spray Device for UAVs to Improve Spray Coverage in Obstacle Neighborhoods

Electric multirotor plant protection unmanned aerial vehicles (UAVs) are widely used in China for efficient and precise plant protection at low altitude for low volumes. Unstructured farmland in China has various types of obstacles, and UAVs usually use a detour path to avoid obstacles due to flight altitude limitations. However, existing UAV spray systems do not spray when in obstacle neighborhoods during obstacle avoidance, resulting in insufficient droplet coverage and reduced plant protection quality in the area. To improve the droplet coverage in obstacle neighborhoods, this article carries out a study of side spray technology with an electric quadrotor UAV, and proposes the design and development of a side spray device. The relationship between the obstacle avoidance path of the UAV and the spray pattern of the side spray device and their effect on droplet coverage in obstacle neighborhoods was explored. An accurate measurement method of the relative position between the UAV and obstacles was proposed. Spray angle calculations and nozzle selection for the side spray device were carried out in conjunction with the relative position. A rotor wind field simulation model was designed based on the lattice Boltzmann method (LBM), and the spatial layout of the side spray device on the UAV was designed based on the simulation results. To explore suitable spray patterns for the side spray device, comparative experiments of droplet coverage in obstacle neighborhoods were carried out under different environments, spray patterns, and flight parameter combinations. The relationship between the flight parameter combinations and the distribution uniformity of droplets and the effective swath width of the side spray device was explored. The experimental results were analyzed by an analysis of variance (ANOVA) and a relationship model was obtained. The results showed that the side spray device can effectively improve droplet coverage in obstacle neighborhoods compared to a device without side spray using the same flight parameter combinations. The effective swath width in obstacle neighborhoods can be increased by a minimum of 6.35%, maximum of 35.32%, and average of 15.25% using the side spray device. The error between the predicted values of the relational model and the field experiment results was less than 15%. The results verify the effectiveness and rationality of the method proposed in this article. This study can provide technical and theoretical references for improving the plant protection quality of UAVs in obstacle environments.

Comparison of the Accuracy and Reliability of Instrumental Shade Selection Devices and Visual Shade Selection: An in Vitro Study.

New shade-matching devices are available for clinical use, but their accuracy and reliability have not been investigated. This in vitro study compared the accuracy and reliability of a shade-matching colorimeter (Optishade), a spectrophotometer (VITA Easyshade V), and visual shade matching in simulated clinical conditions. Shade matching was conducted with two digital devices; (Optishade and Vita Easyshade) and the visual shade selection method, with a new 16-tab Vita Classical shade guide. Shade tabs were placed within a gingival matrix and measurements were taken from the central area of each shade tab enclosed in a black box to simulate the oral cavity. Visual assessments were conducted independently by two examiners. For the reliability assessment, each shade tab was measured 20 times by each examiner. Accuracy was calculated as a percentage of the matching readings with the actual shade per each tab. Data were analyzed with the one-way ANOVA test (α = 0.05) and Pairwise Comparison (Bonferroni Post hoc Test) to assess accuracy. The reliability evaluation was conducted by comparison between both examiners using mean and standard deviation; by a two-tailed t-test for the independent samples for all the three groups included in the study. The shade matching accuracy of Optishade was 97.50%, Vita Easyshade 89.38%, and visual method 62.19%. Statistically, high significant difference in accuracy (p < 0.001) was found when comparing both Optishade and VITA Easyshade with the visual method. Additionally, there was statistically significant difference in accuracy (p < 0.05) when Optishade was compared to Vita Easyshade. The reliability of the Optishade was 99.6% and Vita Easy shade was 99.38%. Statistically, showed no statistically significant difference in the reliability of shade match obtained within the same group when comparing the readings of Examiner 1 and Examiner 2 (p > 0.05). The colorimeter demonstrated the highest accuracy, followed by the spectrophotometer, and the visual shade selection method. Both digital methods investigated in this study showed comparable reliability. The results of this study emphasize the clinical advantage of digital shade-matching devices over visual shade-matching. The colorimeter offers high accuracy for shade matching and should be considered to use for shade matching especially with restorations in the esthetic zone.

Short and Long-Term Outcomes of Transcatheter Aortic Valve Implantation in the Small Aortic Annulus: A Systematic Literature Review.

Transcatheter aortic valve implantation has revolutionized the treatment of aortic stenosis. The small aortic annulus is one of the most challenging aspects of aortic stenosis treatment and since the beginning, TAVI has shown promising results in this subgroup of patients. This systematic literature review aims to investigate the short and long-term outcomes of TAVI in the small aortic annulus. The literature was meticulously screened for this topic until April 2024 using the PRISMA guidelines. Technical aspects, characteristics of this subgroup of patients, hemodynamic performances, and outcomes are discussed. The importance of device selection has shown up, with insight into the differences between self-expandable and the balloon-expandable valves. Two special populations were also taken into account: outcomes of TAVI in the small aortic annulus with bicuspid aortic valve and extra-small aortic annulus. The last 10 years have been paramount in technological advancements, bringing TAVI to broader use in this population. While several important trials underscored the usefulness of TAVI in the small aortic annulus population, the clinical practice still lacks consensus on the ideal device, and the outcomes are debated. The pivotal role of TAVI in this context needs to be addressed with a patient-tailored approach to optimize patient care.

Vascular access device selection: Optimizing patient outcomes - Part 1.

A systematic evaluation of vascular access device (VAD) selection incorporates patient, device, and infusate characteristics to ensure optimal device placement. This article explores VAD selection from the perspective of vessel health and preservation and describes VAD selection options and indications, VAD-related complications, and strategies to reduce those complications.

Abstract ID: 60 Magnetic Sphincter Augmentation for Gastroesophageal Reflux Disease: Implications of sizing technique and device selection on safety outcomes using the LINX Reflux Management System

Abstract ID: 60 Magnetic Sphincter Augmentation for Gastroesophageal Reflux Disease: Implications of sizing technique and device selection on safety outcomes using the LINX Reflux Management System

Femoral Large Bore Sheath Management: How to Prevent Vascular Complications From Vessel Puncture to Sheath Removal.

Transfemoral access is nowadays required for an increasing number of percutaneous procedures, such as structural heart interventions, mechanical circulatory support, and interventional electrophysiology/pacing. Despite technological advancements and improved techniques, these devices necessitate large-bore (≥12 French) arterial/venous sheaths, posing a significant risk of bleeding and vascular complications, whose occurrence has been related to an increase in morbidity and mortality. Therefore, optimizing large-bore vascular access management is crucial in endovascular interventions. Technical options, including optimized preprocedural planning and proper selection and utilization of vascular closure devices, have been developed to increase safety. This review explores the comprehensive management of large-bore accesses, from optimal vascular puncture to sheath removal. It also discusses strategies for managing closure device failure, with the goal of minimizing vascular complications.

Placement of the feline V-gel Advanced supraglottic airway device and tracheal selectivity during controlled mechanical ventilation: a clinical and tomodensitometric evaluation.

The aims of the study was to assess the placement of the V-gel Advanced (V-gel-A) and to evaluate tracheal selectivity during controlled mechanical ventilation, using CT. In this prospective clinical study, 20 healthy cats undergoing general anaesthesia for an elective procedure underwent four successive CT scans from the nose to the mid-abdomen: at baseline (no device); after the placement of the V-gel-A, after a controlled mechanical ventilation (CMV) period of 5 mins; and after the placement of an endotracheal tube (ETT). Using both a purpose designed position score and a gas score estimating the quantity of gas in different digestive regions, the position of the V-gel-A and presence of gas in the digestive tract at each step were evaluated. Number of attempts and times required to place the V-gel-A and ETT were recorded and compared. The V-gel-A was found to be correctly placed, with position scores of 3/5 in six cats, 4/5 in 13 cats and 5/5 in one cat. Imperfect positioning was due to minor axial rotation or incomplete occlusion of the oesophagus by the tip of the device. The gas scores significantly increased after placement of the V-gel-A compared with baseline and after CMV was initiated. Correct positioning of the device was mostly achieved at the first attempt; no significant difference was found in the time required to place V-gel-A vs ETT, nor in the number of attempts (P >0.05). The V-gel-A was clinically easy to place and use in both spontaneous and controlled ventilation. The device properly fitted the larynx and was never observed to occlude the airway. However, incomplete occlusion of the oesophagus was frequently observed and may lead to a lack of complete tracheal selectivity.

Optimal patient and mechanical circulatory support device selection in acute myocardial infarction cardiogenic shock

Optimal patient and mechanical circulatory support device selection in acute myocardial infarction cardiogenic shock

Joint IoT Device Selection and Health-Aware Beamforming Design for MIMO-WPT

Joint IoT Device Selection and Health-Aware Beamforming Design for MIMO-WPT

Live Motile Sperm Sorting Device Improves Embryo Aneuploidy: A Retrospective Cohort Study

Background: Conventional sperm selection methods, involving centrifugation, exert a detrimental effect on sperm DNA integrity due to mechanical stress. The recent noninvasive sperm selection device, CA0, based on live sperm sorting technology, facilitates the retrieval of highly motile sperm and minimizes sperm DNA fragmentation (SDF). This study was to investigate the impact of various sperm separation methods, with and without centrifugation, on embryo ploidy status. Methods: The retrospective study comprised 82 intracytoplasmic sperm injection (ICSI) cycles involving preimplantation genetic testing for aneuploidy (PGT-A) cases, with a focus on recruiting egg donation cycles to thoroughly investigate the impact of male factors. Two populations are classified based on semen quality: normozoospermic ([Formula: see text] = 33) and non-normozoospermic ([Formula: see text] = 49). Subjects were allocated to either swim-up (SU) or CA0. Preimplantation genetic testing results were recorded. Results: When comparing male characteristics between subgroups, no significant differences were observed except for a lower normal morphology rate in the CA0 group compared to SU (SU: 3 [3–4] vs. CA0: 2 [2–2.8], [Formula: see text] &lt; 0.0001) in the non-normozoospermic cohort. There were no differences in female factors such as age and mature oocyte count (MII) number between subgroups, indicating that this model is ideal for assessing the impact of male factors on clinical outcomes. In the normozoospermic cohort, euploidy rates were similar between SU and CA0 (SU: 71.9% vs. CA0: 64.2%). However, in the non-normozoospermic cohort, CA0 showed a significantly higher euploidy rate compared to SU (SU: 53.6% vs. CA0: 74.2%) and a lower aneuploidy rate (SU: 37.1% vs. CA0: 25.8%). Additionally, CA0 minimized the incidence of mosaic embryos, whereas a mosaicism rate of 9.3% was observed with SU. This trend highlights CA0’s distinct advantage in optimizing outcomes for non-normozoospermic cases. Conclusions: CA0 is a reliable intervention to optimize paternal genetic quality before assisted insemination, thereafter effectively reducing the incidence of embryo aneuploidy associated with male factors.

The fragile urethra: what to do next?-a narrative review.

Although the artificial urinary sphincter (AUS) has demonstrated successful outcomes in treating male stress urinary incontinence (SUI) for the past five decades, this procedure also carries inherent risks, including recurrent SUI, device malfunction, local tissue compromise, and infection/erosion, all of which may require revision surgery with or without device replacement. Patients that are at the highest risk for such untoward events often possess unhealthy urethral tissue (termed a "fragile urethra") that is compromised and unable to provide optimal cuff coaptation and continence. Accordingly, there are several techniques to address recalcitrant SUI in the setting of a fragile urethra to afford an improved chance of return to continence. Here, we review characteristics of patients that are at higher risk for an untoward outcome following AUS implantation and further define strategies to promote optimal success with device implantation. The aim of this paper is to review the available literature and describe surgical options for male SUI in patients with known or anticipated urethral tissue compromise. A thorough literature review was completed by querying PubMed for relevant articles. Search terms included artificial urinary sphincter, failure, recalcitrant, urethral atrophy, fragile urethra, revision, radiation, cystectomy, incontinence, and/or urethroplasty published between 1975 and 2022. Options for management of the fragile urethra include cuff relocation, cuff downsizing, tandem cuff placement, transcorporal cuff placement, pressure regulating balloon exchange with increased or decreased pressure, bulbospongiosus preservation, sub-cuff ventral capsulotomy, urethral wrapping with graft, and in select cases, urinary diversion, or complete device removal with a return to SUI. Proper patient selection is paramount to optimize outcomes. Advantages and disadvantages of each strategy are reviewed. Numerous techniques are viable options for patients with recalcitrant SUI in the setting of a fragile urethra, but high-quality evidence with reproducible outcomes for many of these strategies remain limited. Proper patient selection as well as adequate counseling by experienced implant surgeons may help optimize outcomes. Further multi-institutional investigations with longer term outcomes are needed to improve patient selection and counseling with shared decision-making prior to any intervention.

Prospective Comparison of Nine Different Handheld Ultrasound (HHUS) Devices by Ultrasound Experts with Regard to B-Scan Quality, Device Handling and Software in Abdominal Sonography.

The HHUS market is very complex due to a multitude of equipment variants and several different device manufacturers. Only a few studies have compared different HHUS devices under clinical conditions. We conducted a comprehensive prospective observer study with a direct comparison of nine different HHUS devices in terms of B-scan quality, device handling, and software features under abdominal imaging conditions. Nine different HHUS devices (Butterfly iQ+, Clarius C3HD3, D5CL Microvue, Philips Lumify, SonoEye Chison, SonoSite iViz, Mindray TE Air, GE Vscan Air, and Youkey Q7) were used in a prospective setting by a total of 12 experienced examiners on the same subjects in each case and then assessed using a detailed questionnaire regarding B-scan quality, handling, and usability of the software. The evaluation was carried out using a point scale (5 points: very good; 1 point: insufficient). In the overall evaluation, Vscan Air and SonoEye Chison achieved the best ratings. They achieved nominal ratings between "good" (4 points) and "very good" (5 points). Both devices differed significantly (p < 0.01) from the other seven devices tested. Among the HHUS devices, Clarius C3HD3 and Vscan Air achieved the best results for B-mode quality, D5CL Microvue achieved the best results for device handling, and SonoEye Chison and Vscan Air achieved the best results for software. This is the first comprehensive study to directly compare different HHUS devices in a head-to-head manner. While the majority of the tested devices demonstrated satisfactory performance, notable discrepancies were observed between them. In particular, the B-scan quality exhibited considerable variation, which may have implications for the clinical application of HHUS. The findings of this study can assist in the selection of an appropriate HHUS device for specific applications, considering the clinical objectives and acknowledging the inherent limitations.

Aspects of renal function and renal artery anatomy as indications for renal denervation.

Renal denervation (RDN) is a minimally invasive, endovascular catheter-based procedure using radiofrequency, ultrasound, or alcohol-mediated ablation to treat resistant hypertension. As more attention is focused on the renal sympathetic nerve as a cause and treatment target of hypertension, understanding the anatomy of the renal artery may have important implications for determining endovascular treatment strategies as well as for future selection of devices and appropriate candidates for RDN treatment. However, the anatomical structure of the renal artery (RA) is complex, and standardized morphological evaluations of the RA structure are lacking. Computed tomography angiography or magnetic resonance angiography imaging is useful for assessing RA anatomy before conducting RDN. RA echocardiography is an established noninvasive screening method for significant stenosis. Major randomized controlled trials have limited enrollment to patients with preserved renal function, usually defined as an estimated glomerular filtration rate (eGFR) ≥ 45 mL/min/1.73 m2. Therefore, the level of renal function at which RDN is indicated has not yet been determined. This mini-review summarizes the characteristics of renal artery anatomy and renal function that constitute indications for renal denervation. (Role of Clinical Trials: K. Kario is an Executive Committee Principal Investigator for the Spyral OFF MED, the Spyral ON MED, the DUO and the REQUIRE; a Coordinating investigator for the TCD-16164 study; a Site Principal Investigator for the HTN-J, the Spyral OFF MED, the Spyral ON MED, the DUO, the REQUIRE and the TCD-16164 study). Evaluation of renal arteries for radiofrequency renal denervation. A Simultaneous quadrantal ablations at four sites in the main renal artery or the equivalent renal artery to the main renal artery. B If there is a renal artery branch with a diameter >3 mm in the middle of the main renal artery, this branch is the distal end of the main renal artery. In this case, four simultaneous and quadrantal ablations can be performed on the equivalent renal arteries. C Four simultaneous and quadrantal ablations can be performed in the branch renal artery. D Sonication should be spaced at least 5 mm (one transducer*) apart. Perform 2 to 3 mm proximal to the arterial bifurcation. Perform 2 to 3 mm distal to the abdominal aortic inlet.

Predictors of residual tricuspid regurgitation after interventional therapy: an automated deep-learning CT analysis

Computed tomography (CT) is used as a valuable tool for device selection for interventional therapy in tricuspid regurgitation (TR). We aimed to evaluate predictors of TR reduction using CT and automated deep learning algorithms. Patients with severe to torrential TR and CTs prior to either percutaneous annuloplasty (PA) or tricuspid transcatheter edge-to-edge repair (T-TEER) were enrolled. CTs were analyzed using automated deep learning algorithms to assess tricuspid valve anatomy, right heart morphology, and function. Outcome parameters comprised post-interventional TR ≤ 1 and all-cause mortality. 84 patients with T-TEER (n = 32) or PA treatment (n = 52) were enrolled. Patients with a post-interventional TR ≤ 1 presented lower tenting heights and smaller tenting angles compared to patients with a TR > 1. Tenting height showed the best accuracy for post-interventional TR > 1 with an AUC of 0.756 (95% CI 0.560–0.951) in the T-TEER and 0.658 (95% CI 0.501–0.815) in the PA group, consistent with a suggested threshold of 6.8 mm and 9.2 mm, respectively. Patients with a post-interventional TR ≤ 1 exhibited a mortality of 4% and those with a TR > 1 of 12% during a follow-up of 331 ± 300 and 370 ± 265 days, respectively (p = 0.124). To conclude, tenting is associated with procedural outcomes and should be considered during screening for interventional TR therapy.

Imaging in acute percutaneous mechanical circulatory support in adults: a clinical consensus statement of the Association for Acute CardioVascular Care (ACVC) of the ESC, the European Association of Cardiovascular Imaging (EACVI) of the ESC and the European branch of the Extracorporeal Life Support Organization (EuroELSO).

The use of temporary mechanical circulatory support (tMCS) in cardiogenic shock patients has increased during the last decades with most management strategies relying on observational studies and expert opinion, including hemodynamic monitoring, device selection, and timing of support institution/duration. In this context, imaging has a pivotal role throughout the patient pathway, from identification to initiation, monitoring, and weaning. This manuscript summarizes the consensus of an expert panel from the European Society of Cardiology Association for Acute CardioVascular Care, the European Association of CardioVascular Imaging, and the European Extracorporeal Life Support Organization, providing the rationale for and practical guidance of imaging to tMCS based on existing evidence and consensus on best current practice.

Vascular access device selection: Optimizing patient outcomes - Part 1.

Vascular access device selection: Optimizing patient outcomes - Part 1.

Study of leachable compounds in hospital pharmacy-compounded prefilled syringes, infusion bags and vials

Hospital pharmacy compoundings are crucial for maintaining patient care. They are time- and cost-effective in hospital pharmacy settings because they prevent waste, preparation errors, dosage errors, microbial contamination and breakage due to handling. Unfortunately, the drawbacks of hospital pharmacy compounding include the selection of inappropriate medical devices (MDs) for long-term storage, which could directly impact patients.In this study, three important hospital pharmaceutical compoundings, vancomycin in prefilled syringes (PFSs) made of polypropylene (PP) material, paediatric parenteral nutrition (PN) in ethylene vinyl acetate (EVA) bags and diluted insulin in cyclic olefin copolymer (COC) vials, were selected for leachate study and risk assessment. These compounds were studied via a semiquantitative screening approach by means of an ultrahigh-performance liquid chromatography coupled to high-resolution mass spectrometry (UHPLC-HRMS) with postcolumn infusion and an in-house built database. 17 leachable compounds for the PFS, 25 for the PN, and 10 for the vial were identified, and their concentrations were estimated for toxicological assessments.In conclusion, all MDs used in hospital pharmacy compoundings were observed suitable thanks to risk assessments. However, suitable MDs recommended for long-term storage would remain with polymers like COC, for higher safety when exposed to frail and vulnerable patients like neonates and infants.

Study of SiGeAsTe and SiGeAsSe chalcogenide thin films by Raman spectroscopy and understanding of their OTS properties

In this paper, a range of sputtered ternary and quaternary (Si)(Ge)AsxTe3 layers (x: 2 or 5) and (Si)(Ge)As2Se3 layers are examined using Raman spectroscopy. The results are linked to the Ovonic Threshold Switching properties of these materials when incorporated in selector devices, as observed in separate studies. In case of both the As-rich and As-poor tellurides, a large amount of homopolar bonds are present as the spectra are dominated by peaks associated with As–As and Te–Te bonds. Such homopolar bonds are commonly linked with drift in OTS properties. In the case of the selenides the spectra are dominated by modes associated with heteropolar As–Se bond vibrations. Adding Ge as an alloying element has a significant impact on the bond structure for both material systems. In contrast, Si has a much less pronounced impact and will mostly bond with itself. Time-resolved Raman measurements were also performed to determine the stability of the layers under micro-Raman laser excitation. At the regular exposure settings, no significant changes in the spectra were observed during the measurement. At elevated exposure settings, however, persistent changes in the bond structure can be induced for certain compositions.

Measurement and evaluation of personal attenuation rating before and after the training of the noise-exposed workers wearing foam earplugs

Objective: To measure and compare the difference of personal attenuation rating (PAR) of the workers wearing foam earplugs before and after the training, and to evaluate the effect of ear protector wearing training on the noise protection. Methods: In February 2023, 94 workers exposed to noise in a machinery manufacturing factory were selected as subjects. The production noise in the workplace was measured and subjects were trained to wear earplugs. The PAR values of wearing 3M 1110 foam test earplugs were measured and recorded before and after the training by using the fit testing of hearing protection device. The differences between the actual PAR values with nominal values and the noise attenuation values in related standards were compared, and the protective effect of hearing protection device before and after training was evaluated. Results: The average age of the subjects was (36.76±11.48) years old, the average length of service was (16.34±11.64) years, and the average exposure time to noise was (15.67±11.64) years. The noise detection results of the subjects' posts were ranged from 80.1 to 94.3 dB (A). The results of subjects wore 3M 1110 foam test earplugs for fit testing showed that the binaural PAR value after training was (19.3±6.4) dB (A), which was significantly higher than that before training (11.1±7.4) dB (A) (t=13.31, P<0.001). After training, 11 people (11.70%) could reach the corrected noise reduction value (NRR value), 26 people (27.66%) could reach the standard of single noise reduction value (SNR value) ×0.6, and 84 people (89.36%) could reach the standard of (NRR-7) /2. The under protection rate of hearing protectors after training (7.45%) was significantly lower than that before training (45.74%), and the difference of different protection levels before and after training was statistically significant (χ(2)=40.83, P<0.001) . Conclusion: It is suggested that enterprises should use the fit testing instead of nominal value estimation to evaluate the noise reduction effect of hearing protection device. Special training on the selection and use of hearing protection device should be strengthened, so as to ensure that workers wear them correctly and improve the protective effect of hearing protection device.