Application of"rotation-correction loop technique"in the retrieval of complex inferior vena cava filters / 介入放射学杂志

Objective To discuss the application of the"rotating guidewire and correcting the filter recovery hook direction technique"("rotation-correction loop technique"for short),a technique invented by the authors in clinical practice,in the retrieval of complex inferior vena cava filter(IVCF),and to discuss its technical skills and advantages.Methods The clinical data of 417 patients carrying an IVCF,who were admitted to the Department of Vascular Surgery of Second Hospital of Shanxi Medical University of China to retrieve IVCF between January 2022 and December 2022,were retrospectively analyzed.Taking the time spent on the retrieval of IVCF and the intraoperative radiation dose as the evaluation indicators,the advantages and disadvantages of the standard filter retrieval technique,the"rotation-correction loop technique"and the other loop-assisted techniques were compared.Results Both the intraoperative radiation dose and the time spent on the retrieval of IVCF using"rotation-correction loop technique"were remarkably lower than those of other loop-assisted techniques(P＜0.000 1).Conclusion For the retrieval of complex IVCF,especially for the IVCF which is heavily tilted and/or its recovered hook is attached to the vascular wall,the use of"rotation-correction loop technique"can shorten the time spent on the the retrieval of IVCF and reduce the intraoperative radiation dose.This technique carries high safety and practicability,the device is simple and it can be manipulated by single physician,which is conducive to clinical application and promotion.(J Intervent Radiol,2024,33:289-294)

Comparative analysis of domestic Octoparms and imported Celect inferior vena cava filter in interventional treatment of venous thromboembolism / 实用放射学杂志

Objective To compare and analyze the application value of domestic Octoparms and imported Celect inferior vena cava filter(IVCF)in the interventional treatment of venous thromboembolism(VTE).Methods Forty patients with VTE were randomly divided into Octoparms group(experimental group)and Celect group(control group)according to the double-blinded method of the central random system.All the patients underwent filter placement,catheter-directed thrombolysis and filter retrieval.The primary end point was the success of filter placement and retrieval,and the secondary end point included indwelling complications such as the occurrence of pulmonary embolism(PE)and filter tilt and migration.Results Forty patients were enrolled in this study,22 patients and 18 patients were divided into the experimental group and the control group,respectively.Among them,11 cases were identified with right lower extremity deep vein thrombosis,29 cases with left lower extremity deep vein thrombosis,17 cases with PE,and 6 cases with inferior vena cava thrombosis.The success rate of IVCF placement was 100%in all participants.Immediately after filter place-ment,the angle of filter tilt was(3.8±2.3)° in the experimental group and(4.9±2.8)° in the control group(t=1.44,P=0.16).Filter retrieval was successful in 21 cases(21/22,95.5%)of the experimental group and 17 cases(17/18,95.5%)of the control group.There was no significant difference between the two groups(t=0.14,P=0.89).The mean indwelling time of filter was(8.0±2.1)days in the experimental group and(9.7±3.1)days in the control group(t=0.73,P=0.47).The angle of filter tilt was(5.3±3.4)° in the experimental group and(5.7±7.7)° in the control group(t=0.19,P=0.85).There was no significant difference for filter placement and retrieval between the two groups(t=0.48 and 2.00,P=0.06 and 0.64,respectively).There were no complications of filter migration,strut penetration or new PE in both groups.Conclusion The application value of domestic Octoparms and impor-ted Celect IVCF is similar in interventional treatment of VTE.

Study on the calibration for the outputs of photon and electron beams of dual-mode of linear accelerator based on IAEA 277 and 381 reports / 中国医学装备

Objective:To calibrate the absorbed doses of the configured ray water with different gears of energies in accelerator based on<The use of plane-parallel ionization chambers in high-energy electron and photon beams>of International Atomic Energy Agency(IAEA)277 and 381 reports,so as to ensure the accuracy of the output dose of the linear accelerator during clinical radiotherapy.Methods:Elekta Infinity linear accelerator was used in this study,and the photon beam energies were respectively 6MV flattening filter(FF)mode and 6MV flattening filter free(FFF)mode.The electron beam energies were respectively 4,6,8,10,12 and 15MeV.According to the IAEA TRS277 and TRS381 reports,the calibrations of output doses in photon and electron beam waters were performed respectively by using the PTW dosimeter,PTW30013 finger type of ionization chamber and PTW34001 parallel plate ionization chamber.The error of each step was analyzed,and the accuracies of the calibrations of using different standards for the output waters of linear accelerator were compared.Results:The output amounts of photon beams of FF mode and FFF mode of 6MV at the maximum dose point in water were respectively 1.003 and 1.008cGy/MU.The output amounts of the energy of each gear of electron beams of 4,6,8,10,12 and 15MeV at the maximum dose point in water were respectively 1.003,1.002,0.998,0.999,1.000 and 1.003 cGy/MU.The calibration of the output of each gear of energy rays at the maximum dose point in water was 1cCy corresponded to 1MU,which error was less than 1%.Conclusion:The calibration for the output dose amount of accelerator in water on the basis of IAEA TRS277 and trs381 can ensure the accuracy of the output dose of the accelerator.

Value of flattening filter-free mode in deep inspiration breath-hold intensity-modulated radiotherapy after modified radical surgery for left breast cancer / 肿瘤研究与临床

Objective:To investigate the value of flattening filter-free (FFF) mode in postoperative deep inspiration breath-hold (DIBH) intensigy-modulated radiotherapy for left breast cancer.Methods:A retrospective case series study was conducted. Clinical data of 21 patients with left breast cancer who underwent DIBH intensity-modulated radiotherapy after modified radical surgery in Meizhou People's Hospital from January 2021 to December 2022 were retrospectively analyzed. On the DIBH-mode CT of each patient, the 7-field intensity-modulation plan was designed using the plan developed in the 6 MV FFF-mode (FFF group) or the plan developed in the 6 MV flattening filter (FF)-mode (FF group). The target areas and organs at risk, dosimetric and biological parameters, and dose validation results were compared between the two plans.Results:Twenty-one patients were female with the age [ M ( Q1, Q3)] of 47 years old (32 years old, 61 years old). The percentage of target areas receiving 95% of the prescribed dose (V 95%) was (95.9±0.8)% and (95.7±1.9)% in the FF and FFF groups ( t = 2.98, P = 0.089), and the maximum dose was (5 401±251) cGy and (5 424±201) cGy ( t = 2.85, P = 0.181), the fitness indices were 0.88±0.05 and 0.87±0.06 ( t = 0.32, P = 0.562), the homogeneity indices were 1.06±0.01 and 1.07±0.02 ( t = 2.91, P = 0.009), the equivalent uniform doses (EUD) were (51.81±0.21) Gy and (51.97±0.20) Gy ( t = 0.51, P = 0.309), and the tumor control probability (TCP) was (99.68±0.01)% and (99.61±0.02)% ( t = 0.81, P = 0.560). The plans of the FFF group and the FF group were compliant, and the doses of all organs at risk to be irradiated were within the clinically acceptable range, and the radiation doses in the FFF group in the left lung [5 Gy irradiated volume (V 5 Gy), mean dose (D mean), EUD and normal tissue complication rate (NTCP)], right lung (V 5 Gy and D mean), heart (V 10 Gy, D mean, EUD and NTCP), and right breast (V 5 Gy, D mean and EUD) were differently lower than those in the FF group, and the differences were statistically significant (all P < 0.05). The monitor units in the FFF and FF groups were (984±132) MU and (751±145) MU ( t = -1.25, P < 0.001), and the total beam-on time was (1.4±0.3) min and (2.2±0.4) min ( t = 0.68, P < 0.001); individual field beam-on time was (12±7) s and (16±10) s ( t = 2.68, P = 0.001), and the beam-on time for each field in patients of the FFF group was less than 25 s; γ pass rates were (97.1±2.8)% and (97.6±2.1)% ( t = 0.59, P = 0.484). Conclusions:In the intensity-modulated radiotherapy of left breast cancer, the radiation dose of the energy to the critical organs in FFF mode is lower and has higher dose rate and shorter treatment time. FFF combined with DIBH technique has positive clinical significance in the intensity-modulated radiotherapy of breast cancer.

Application of filter membrane method and smear method in the evaluation of disinfection effect of flexible endoscope / 中国内镜杂志

Objective To compare the application value of filter membrane method and smear method on the evaluation of disinfection effect of flexible endoscope.Methods 242 flexible endoscopes after cleaning and disinfection from January 2022 to November 2022 were collected as the study subjects,and the disinfection effect of all endoscopes was tested by filter membrane method and smear method.The qualified rate,pathogen detection rate,colony detection and use cost of the two detection methods were compared.Results Among the 242 flexible endoscopes,the total qualified rate of filter membrane method was lower than that of smear method while the total detection rate of pathogenic bacteria and the number of bacterial colony were significantly higher than those of smear method(P<0.05).In the two evaluation methods,the colony count detected by gastroscopy was mainly≤100 cfu/n,and the colony count detected by enteroscopy was mainly≥100 cfu/n(P>0.05).The economic cost and time cost of filter membrane method were higher than those of smear method(P<0.05),and filter membrane method increased the annual depreciation cost of the suction filtration system of 976 yuan.Conclusion Compared with smear method,filter membrane method is more effective in evaluating the disinfection of flexible endoscope,but its economic cost and time cost are also higher.However,in order to build a green environment-friendly hospital,it is necessary to increase the investment of endoscopy center,thus it is recommended to apply filter membrane method.

Design of Filtration System for Aerated Sewage Water

The study investigated the potential of sand and activated charcoal filtration systems to enhance water quality for irrigation by treating aerated sewage effluent from. Setup involved a 60 cm deep sand filter connected as the inlet to another 30 cm deep sand filter and this filter linked as the inlet to a 30 cm deep charcoal filter. These filters were operated in series at hydraulic loading rates (HLR) of 60 m/h and 10 m/h. Notably, operating the filters in series at an HLR of 10 m/h yielded superior effluent water quality compared to an HLR of 60 m/h. System achieved significant removal efficiencies for turbidity, BOD5, COD, Total Nitrogen (Total-N), Total Phosphorous (Total-P) with 71.9%, 54.4%, 71.9%, 44.4%, 39.1%, and 42.9% with a 90 cm deep sand filter at an HLR of 10 m/h, and also with a combination of sand and charcoal filters at an HLR of 25 m/h system achieved 81.6%, 80.3%, 63.5%, 47.5%, and 64.3% respectively. We also examined the chemical characteristics of both untreated and treated sewage water samples, revealing a hierarchy of cation and anion prevalence as follows: Na+ > Ca2+ > Mg2+ > K+ for cations, and Cl- > HCO3- > SO42- > CO32- for anions. Our study demonstrates that the combination of aeration and sand filtration effectively ensures safety by preventing water body pollution and unpleasant odours with high-quality treated wastewater suitable for sustainable agricultural use.

Corrección del artefacto producido en imágenes tomográficas en equipos odontológicos / Correction of the artifact produced in tomographic images in dental equipment

Objetivo: disminuir el efecto de artefacto que generan objetos de alta densidad mediante la utilización de filtros de distintos materiales y espesores, ubicados en lugares estratégicos del tomógrafo. Material y métodos: se utilizaron filtros de aluminio y de cobre ubicados en lugares estratégicos en el equipo tomográfico. Se realizaron cortes oblicuos en piezas dentarias con restauraciones metálicas y en implantes; se midió la extensión del artefacto en ancho y alto en cada adquisición tomográfica. Resultados: se hallaron diferencias significativas respecto a la disminución de la dispersión de acuerdo con cada filtro con respecto a la no utilización de estos elementos. Conclusión: la utilización de filtros logró disminuir el efecto de artefacto en estructuras de alta densidad, obteniendo una mejor calidad de imagen para el diagnóstico, permitiendo que el software pueda reconstruir una imagen real (AU)

Objective: to diminish the artifact effect generated by high density objects by using filters of different materials and thickness, located in strategic places of the tomograph. Material and methods: aluminum and copper filters located in strategic places in the tomographic equipment were used. Oblique cuts were made on dental pieces with metal restorations and implants; the extension of the artifact in width and height was measured in each tomographic acquisition. Results: significant differences were found regarding the decrease of the dispersion according to each filter with respect to the non-use of these elements. Conclusion: the use of filters achieves to diminish the artifact effect in structures of high density, obtaining a better image quality for the diagnosis, allowing the software to reconstruct a real image (AU)

Photostability of avobenzone in a commercial sunscreen SPF 50 with the addition of quencher upon sun exposure

Background: Sunscreen can prevent acute and chronic skin damage, acute skin damage includes the burning effect that is felt on the skin, chronic skin damage due to exposure to UV A and UV B rays, namely skin cancer. Avobenzone is a UV filter that is often used but is unstable when exposed to sunlight, for this reason a quencher is added as an avobenzone photostabilizer in commercial sunscreen SPF 50.Methods: Photostability of avobenzone sunscreen formula SPF 50 before and after adding the quencher was tested in the sun using a quartz plate, then analyzed using UV vis spectrophotometer and high-performance liquid chromatography (HPLC).Results: Testing using a UV vis spectrophotometer, SPF 50 sunscreen with the addition of solastay S1® is the best quencher because it can reduce the photodegradation of avobenzone compared to octocrylene, polycrylene (Polyester-8) and Sinoxyl HSS® (trimethoxybenzylidene pentanedione). FSOL2 is the best formula than FSOL1 and FSOL3 because it is more photostable in reducing avobenzone photodegradation. Follow-up testing with HPLC, FSOL2 can retain 50.56% avobenzone after 120 min of sun exposure.Conclusions: The addition of solastay as a quencher is proven to reduce the photodegradation of avobenzone under sunlight.

Improvement of bovine pestiviral diagnosis by the development of a cost-effective method for detecting viral RNA in fresh specimens and samples spotted in filter papers / Optimización del diagnóstico de Pestivirus bovinos mediante el desarrollo de una metodología económica para detectar ARN viral en muestras frescas y fijadas en papeles de filtro

Abstract Bovine pestiviruses are the causative agents of bovine viral diarrhea, a disease thatcauses severe economic losses in cattle. The aim of this study was to improve their diagnosisby developing a RT-qPCR to detect bovine pestiviruses A, B and H; and to set up a protocolfor collecting, shipping and preserving bovine pestiviral RNA on filter papers. The developedRT-qPCR showed high sensitivity in detecting these viruses in different matrices: viral stocks,semen and serum samples. With regard to the possibility of using the technique to test serumpools, it was possible to identify a positive serum sample within a pool containing 30 sera.In addition to evaluating the qPCR from fresh samples, the use of filter papers to sow bovinesamples was analyzed. The sampling method on two different filter papers using bovine blooddrops was a useful alternative for diagnostic purposes and allowed to preserve pestiviral RNAfor up to 12 months under refrigeration.

Resumen Los Pestivirus bovinos son los agentes causales de la diarrea viral bovina, una enfermedad que genera importantes pérdidas económicas en el ganado vacuno. El objetivo de este trabajo fue mejorar su diagnóstico mediante el desarrollo de una RT-qPCR para detectar los Pestivirus bovinos A, B y H y disenar un protocolo de recolección, envío y conservación de ARN viral en papeles de filtro. La RT-qPCR desarrollada demostró alta sensibilidad en la detección de estos virus en diferentes matrices: stock viral, suero y semen. Respecto de la posibilidad de usar la técnica para testear pools de suero, fue posible identificar un suero positivo dentro de un pool compuesto por 30 sueros. Además de evaluar la qPCR en muestras frescas, se analizó el uso de papeles de filtro para sembrar muestras de bovinos. La metodología de toma de muestras en dos tipos de papeles de filtro usando gotas de sangre fue una alternativa útil para el diagnóstico y permitió conservar ARN viral por hasta 12 meses a temperaturas de refrigeración.

Biocompatibility of the Oxygenator on Pulsatile Flow by Electron Microscope

ABSTRACT Introduction: Extracorporeal perfusion flow type requires further investigation. The aim of this study is to compare the effects of pulsatile and nonpulsatile flow on oxygenator fibers that were analyzed by scanning electron microscope (SEM) and to extensively study patients' coagulation profiles, inflammatory markers, and functional blood tests. Methods: Twelve patients who had open heart surgery were randomly divided into two groups; the nonpulsatile flow (group NP, six patients) and pulsatile flow (group P, six patients) groups. Both superficial view and axial sections of the oxygenator fiber samples were examined under SEM to compare the thickness of absorbed blood proteins and amount of blood cells on the surface of oxygenators. Platelet count, coagulation profile, and inflammatory predictors were also studied from the blood samples. Results: Fibrinogen levels after cardiopulmonary bypass were significantly lower in group NP (group P, 2.57±2.78 g/L; group NP; 2.39±0.70 g/L, P=0.03). Inflammatory biomarkers such as C-reactive protein, interleukin (IL)-6, IL-12, apelin, S100β, and tumor necrosis factor alpha were comparable in both groups. Axial sections of the oxygenator fiber samples had a mean thickness of 45.2 µm and 46.5 µm in groups P and NP, respectively, and this difference is statistically significant (P=0.006). Superficial view of the fiber samples showed obviously lower platelet, leukocyte, and erythrocyte levels in group P. Conclusion: Our study demonstrated that both cellular elements and protein adsorption on oxygenator fibers are lower in the group P than in the group NP. Pulsatile perfusion has better biocompatibility on extracorporeal circulation when analyzed by SEM technique.

Smartphone co-aided cobalt blue anterior segment with intraocular lens photography

In this report, we have utilized a smartphone-based innovative tool named anterior segment photography with an intraocular lens (ASPI) with a cobalt blue filter on the smartphone flash for photographing fluorescein-stained corneas. An intraocular lens along with a cobalt blue filter was attached to the smartphone camera to achieve this purpose. The filter could block out all wavelengths of light except the blue wavelength (450–490 nm) emerging from the smartphone camera. A pilot study was conducted on 27 eyes of 25 patients where images of various corneal pathologies were obtained using ASPI blue light imaging. The images were clear and highly magnified and could be used for documentation, teleconsultation for expert opinion, education, and monitoring of disease progression. ASPI-aided blue light imaging could be easily fabricated and is a frugal inexpensive device, which is used by different ophthalmic personnel to obtain fluorescein-stained corneal images.

Comparison of visual function before and after wearing amber filter in low vision patients with primary retinitis pigmentosa / 国际眼科杂志(Guoji Yanke Zazhi)

AIM: To compare the visual function of low-vision patients with primary retinal pigmentosa(RP)before and after wearing amber filter.METHODS: Self-control before and after study. A total of 30 patients(60 eyes)with low vision who were diagnosed with primary RP in the ophthalmology clinic of Xi'an No.1 Hospital from August 2021 to March 2022 were collected. The uncorrected distance visual acuity(UCDVA), best-corrected distance visual acuity(BCDVA), uncorrected near visual acuity(UCNVA), best-corrected near visual acuity(BCNVA), visual field and Farnsworth-Munsell(FM)-100 color visions were recorded before and after wearing amber filter. The contrast sensitivity(CS)in three visual environments including bright room, darkroom and darkroom with glare was measured and recorded respectively, and the changes of those parameters were analyzed before and after wearing filter.RESULTS: UCDVA and BCDVA after wearing the filter were better than those before wearing(t=-2.32, P&#x0026;#x003C;0.001; t=-6.77, P&#x0026;#x003C;0.001), while there was no statistically significant difference in UCNVA and BCNVA before and after wearing filter. The visual field index(VFI)after wearing filter was lower than that before wearing(t=8.62, P&#x0026;#x003C;0.001), and the mean defect(MD)of visual field was greater than that before wearing(t=7.73, P&#x0026;#x003C;0.001). FM100 color chess test showed that both total error score(TES)and partial error score(PES)in multiple regions were higher than those before wearing filter(P&#x0026;#x003C;0.001). After wearing, the CS of each frequency band in the environment of bright room and darkroom with glare was higher than that before wearing(P&#x0026;#x003C;0.001), and there was no statistically significant difference in each frequency band before and after wearing amber filter under the environment of darkroom without glare.CONCLUSION: Patients with low vision of primary RP showed improved UCDVA and BCDVA, but unchanged UCNVA and BCNVA after wearing amber filter, while the visual field and color discrimination were worse than those before wearing filter. The CS of the bright room and darkroom with glare environment was improved than before wearing filter, while there were no significant changes in CS under darkroom without glare.

Simultaneous determination of six aniline compounds in workplace air by high performance liquid chromatography / 中国职业医学

Objective To establish a high performance liquid chromatography (HPLC) method for simultaneous determination of six aniline compounds (ADs) in workplace air. Methods GDH-1 air sampling tube was used to collect six co-existing ADs such as aniline, o-toluidine, N-methylaniline, m-methylaniline, p-methylaniline and N,N-dimethylaniline in the vapor and aerosol of workplace air. The samples were desorbed and eluted using a methanol solution containing 1.00% ammonia water, followed by separation on a C18 chromatographic column and detection using a diode array detector. Results The quantification range of the method was 0.19 -253.50 mg/L, with the correlation coefficient of 0.999 9 for all six ADs. The minimum detection range was 0.02-0.06 mg/m3, and the minimum quantitation range was 0.04-0.19 mg/m3 [both calculated for a 15.0 L sample with a desorption (elution) solution volume of 3.00 mL]. The average desorption and elution efficiencies were 92.15%-104.41% (silica gel) and 94.29%-104.29% (filter membrane). The intra-assay relative standard deviation (RSD) ranged from 0.90%-9.72% (silica gel) and 0.57%-6.96% (filter membrane). The inter-assay RSD ranged from 2.03%-9.78% (silica gel) and 2.50%-8.62% (filter membrane). The samples were stable at room temperature for seven days. Conclusion This method can be used for the simultaneous determination of six ADs in workplace air.

Selection of sterilizing-grade filter for preparation of human coagulation factor Ⅷ/ von Willebrand factor complex / 中国输血杂志

【Objective】 To screen the sterilizing-grade filters applicable for production of human coagulation factor Ⅷ/von Willebrand factor complex(FⅧ/VWF)and study the sterilization filtration process. 【Methods】 Four sterilizing-grade filters for FⅧ/VWF were evaluated through indicators such as filtration capacity, filtration flux, recovery rate of FⅧ activity, recovery rate of VWF activity, recovery rate of VWF antigen, recovery rate of protein and VWF molecular distribution. The sterilizing-grade filter with the best filtration performance was selected for further study. The study was designed by general full-factor design to determine the appropriate filitered protein concentration and filitered speed range through evaluating the total filtered protein amount, recovery rate of protein and filtration efficiency, and then the process operation parameters was determined. 【Results】 The filtration flux of Sartobran P, Sartopore 2 XLG, Sartopore Platinum and Sartopore 2 XLI were 1.71±0.01, 1.80±0.01, 1.34±0.01, and 1.81±0.04 L·(m2)-1·min-1, respectively; the recovery rates (%) of FⅧ activity were 97.09±2.82, 99.22±0.99, 96.87±1.85 and 93.76±1.21, respectively; the recovery rates (%) of VWF activity were 98.12±1.42, 99.95±1.85, 94.80±1.62 and 92.09±1.67, respectively. Between Sartopore 2 XLG and Sartobran P, the difference of filtration flux (P<0.001) was statistically significant; between Sartopore 2 XLG and Sartopore Platinum, the differences of the filtration flux (P<0.001) and VWF potency recovery rate (P<0.05) were statistically significant; between Sartopore 2 XLG and Sartopore 2 XLI, the differences of FⅧ potency recovery rate (P<0.01) and VWF potency recovery rate (P<0.01) were statistically significant. The optimal process operating space of Sartopore 2 XLG was protein concentration of 0.45-0.58 mg/mL, and filtration rate of 1.48-2.95 L·(m2)-1·min-1. 【Conclusion】 Sartopore 2 XLG is the most suitable filter for the production of FⅧ/VWF and the DoE test proves that it has good process operation space.

Effect of respiratory filter on pulmonary function in occupational health examination / 中华劳动卫生职业病杂志

Objective: To explore the influence and significance of respiratory filter on the judgment of pulmonary function and the conclusion of occupational health examination in occupational health examination. Methods: From August to November 2020, 252 occupational health examinees were randomly selected as the research objects, and the lung function was examined with the respiratory filter bite and the straight cylinder bite without filter, respectively. The lung function examination indexes and the qualification rate of lung function examination were analyzed and compared between the two groups, and the diagnostic criteria of lung function examination was corrected. Results: 252 subjects were 36 (30, 42) years old. The qualified rate of lung function examination with respiratory filter bite (28.17%, 71/252) was lower than that with straight cylinder bite (34.92%, 88/252) , the difference was statistically significant (P<0.05) . The percentage of forced vital capacity in normal predicted value (FVC%) , percentage of forced expiratory volume in the first second in normal predicted value (FEV(1)%) , and percentage of forced expiratory volume in the first second in forced vital capacity (FEV(1)/FVC%) of subjects using respiratory filter bite were lower than those using the straight cylinder bite (P<0.05) . The corrected diagnostic criteria of pulmonary function were FVC%>78%, FEV(1)%>77%, FEV(1)/FVC%>68%. There was no significant difference between the qualified rate of the respiratory filter bite lung function test calculated according to the corrected diagnostic criteria (35.71%, 90/252) and the qualified rate of the straight cylinder bite lung function test calculated according to the original diagnostic criteria (34.92%, 88/252) (P>0.05) . Conclusion: In occupational health examination, the use of respiratory filter may affect the results of pulmonary function examination. The diagnostic criteria of pulmonary function can be corrected according to different filtering effects to ensure the accuracy of the conclusions of occupational health examination.

A Ventricular Fibrillation Recognition Method Based on Random Forest and BP Neural Network / 中国医疗器械杂志

Ventricular fibrillation is the most common pathophysiological mechanism leading to cardiac arrest. If cardiac arrest can be rescued in time, the survival rate of patients can be greatly improved. Therefore, rapid and accurate identification of ventricular fibrillation is extremely important. This paper proposes an automatic detection algorithm for ventricular fibrillation based on random forest and BP (back propagation) neural network. Pass the ECG signal through a 6 s moving window, calculate 6 kinds of characteristic parameters according to the time-frequency domain information of the signal, use these 6 kinds of characteristic parameters as the input of the classifier, carry out classification and test, and give the authoritative experts in the database. A total of 44 cases of related data were used to evaluate the method. The results show that using the ten-fold cross-validation method, the accuracy of classification of ventricular fibrillation in the CU database (Creighton University Ventricular Tachyarrhythmia Database) and the AHA database (the American Heart Association Database) has reached 96.38% and 99.45%, which has certain applicability.

Clinical application of the convertible vena cava filter / 中华普通外科杂志

Objective:To evaluate the short-term efficacy, safety and complications of convertible vena cava filter.Methods:The clinical and follow-up data of 103 patients who were placed with the convertible vena cava filter from May 2017 to May 2018 were retrospectively analyzed.Results:The convertible vena cava filters were successfully implanted in all cases. Twenty-seven cases underwent filter conversion, and 26 cases were successfully converted (5-145 days after implantation). None of them had complications such as thrombus formation, displacement, tilt, fracture or vein wall penetration. The reasons for no conversion included age (18.4%, 19/103), high-risk patients (12.6%, 13/103), limited organ function (9.7%, 10/103), etc. Ninety-four patients (91.3%) were followed up for 6 months. One developed thrombus in the filter, 3 developed lower limb venous thrombosis without inferior vena cava occlusion, and no patients were found with symptomatic pulmonary embolism.Conclusions:The convertible vena cava filter can safely and effectively reduce the incidence of perioperative pulmonary embolism.Age, limited organ function and high-risk of thrombosis are the main reasons for the low conversion rate.

Uncalibrated Positioning Method for Puncture Robots Based on Optical Navigation / 中国医疗器械杂志

Robotic puncture system has been widely used in modern minimally invasive surgery, which usually uses hand-eye calibration to calculate the spatial relationship between the robot and the optical tracking system. However, the hand-eye calibration process is time-consuming and sensitive to environmental changes, which makes it difficult to guarantee the puncture accuracy of the robot. This study proposes an uncalibrated positioning method for puncture robot based on optical navigation. The method divides the target path positioning into two stages, angle positioning and position positioning, and designs angle image features and position image features respectively. The corresponding image Jacobian matrix is constructed based on the image features and updated by online estimation with a cubature Kalman filter to drive the robot to perform target path localization. The target path positioning results show that the method is more accurate than the traditional hand-eye calibration method and saves significant preoperative preparation time by eliminating the need for calibration.

Platelet Removal Efficiency by Leukocyte Filter in Red Blood Cell Units at Different Storage Periods / 中山大学学报(医学科学版)

ObjectiveThe aim of this study is to investigate change of platelet count in red blood cell （RBC） units at different storage periods and explore the efficiency of platelet removal by leukocyte filter. MethodsA total of 58 RBC units were divided into four groups according to different storage periods： 1 week Group （16）， 2 weeks Group （16）， 3 weeks Group （14） and 4 weeks Group （12）. RBC units in the four groups were filtered through leukocyte filter. The RBC samples before and after filtration were obtained. The platelet count was detected by automatic blood cell counter and the efficiency of platelet removal was calculated. RBC samples before filtration were made into blood cell smears. The blood cell smears were dyed with Wright-Giemsa stain， and the morphology of platelets was observed through a microscope. ResultsThe platelet count in RBC units stored for 1， 2， 3 and 4 weeks was （286.5±62.34）×109/L， （238.0±57.37）×109/L， （193.6±56.21）×109/L and （167.8±24.76）×109/L， respectively. Platelet count in blood stored for 3 weeks （P<0.01） and 4 weeks （P <0.000 1） were significantly lower than those stored for 1 weeks. When observed in the blood smears of RBC units at different storage periods， platelets with normal morphology were distributed in clump and scattered style. The platelet removal rates of the four groups were （80.13±9.06） %， （76.41±10.13） %， （77.78±9.30） % and （70.63±9.39） %， respectively， with no significant difference （P >0.05）. ConclusionsPlatelet count in RBC units decreases gradually as the storage period increases， but most platelets still remain in RBC units of late storage periods （3 weeks and 4 weeks）. The leukocyte filter is able to remove most of the platelets， and the removal efficiency is similar among the groups.

Comparison of patient satisfaction with red-free (green) versus yellow light using binocular indirect ophthalmoscope for retinal examination

Purpose: Comparison of patient satisfaction with red?free (green) versus yellow light using binocular indirect ophthalmoscope for retinal examination. Methods: This is an observational questionnaire?based study of 100 myopes in the age group of 18–40 years coming for a routine check?up or for refractive surgery workup. The examination was done using an indirect ophthalmoscope and a 20D lens with green or yellow light and was assigned in two groups randomly using the coin toss method, following which, a questionnaire was used to assess the following parameters: a) level of comfort, b) any complaints of discomfort during examination, d) preference of the used light source in future, e) grading of discomfort on a linear scale, and f) patient cooperation and duration of examination. Results: Patients were randomized for observation with IDO using either green light (n = 55) or yellow light (n = 45) filter. In the study, 46 patients (83.6%) were very comfortable and only 9 patients (16.4%) experienced mild discomfort when using red?free (green) light, while only 3 patients (6.7%) were very comfortable and 31 (68.9%) had mild discomfort when using yellow light. The complaints of watering with yellow and green light were noted in 36 patients (80.0%) and 15 patients (27.3%), pain in 13 patients (28.9%) and 3 patients (5.5%), light sensitivity in 29 patients (64.4%) and 4 patients (7.3%), respectively, all being significantly more in yellow light category (P < 0.001). The time of examination was significantly more in yellow light category with 83 ± 10.75 seconds (P < 0.001). Conclusion: Retinal examination using the green filter of indirect ophthalmoscope is more comfortable in examining the patients as compared to routine yellow light with decreased number of complaints, lesser examination time, and better patient cooperation.