OBJECTIVE: To enhance the reliability of medical equipment, this study aims to develop a failure cause diagnosis model and provide rational suggestions for efficient equipment use. METHODS: Combine fault tree analysis (FTA) to identify basic events causing equipment failure and calculate their prior probabilities. Obtain conditional probability tables for each node through expert assessment. Integrate triangular fuzzy number theory with Bayesian network (BN) to construct a fuzzy Bayesian network (FBN) for posterior probability inference and sensitivity analysis. RESULTS: Using endoscopes as the subject, the analysis shows that the model accurately calculates the endoscope failure probability at 0.385%, and identifies the key causes: improper cleaning ( X5, posterior probability 0.36064), untimely fault detection ( X8, posterior probability 0.23571), irregular transportation ( X6, posterior probability 0.11344), and natural aging ( X10, posterior probability 0.11377). Sensitivity analysis also confirms their influence weights (mutual information values are 0.00749, 0.00591, 0.00202, 0.00174). CONCLUSION The model can accurately perform quantitative analysis and rapid fault location of medical equipment failures, enabling effective preventive measures.
Bayes Theorem ; Fuzzy Logic ; Equipment Failure Analysis/methods* ; Equipment Failure ; Algorithms

OBJECTIVE: The aim of the current study was to evaluate the effect of ultraviolet (UV) photofunctionalization of dental titanium implants with exposure to the oral cavity on osseointegration in an animal model. METHODS: Forty-eight titanium implants (Camlog Conelog 4.3 mmx9.0 mm) were placed epicrestally into the edentulous jaws of three minipigs and implant stability was assessed by measuring the implant stability quotient (ISQ). Prior to implantation half of the implants were photofunctionalized with intense UV-light. After three months, the implants were exposed and ISQ was measured again. After six months of implant exposure, the minipigs were sacrificed and the harvested specimens were analyzed using histomorphometric, light, and fluorescence microscopy. MAIN RESULTS: Forty-two of 48 implants osseointegrated. The overall mean bone-implant contact area (BIC) was (64±22)%. No significant differences were found in BIC or ISQ value (multivariate analysis of variance (MANOVA), P>0.05) between implants with and without exposure to UV photofunctionalization. CONCLUSIONS No significant effects were observed on osseointegration of dental titanium implants nine months after exposure of UV photofunctionalization.
Animals ; Dental Implantation, Endosseous ; methods ; Dental Implants ; Equipment Failure Analysis ; Female ; Hydrophobic and Hydrophilic Interactions ; Male ; Models, Animal ; Osseointegration ; Surface Properties ; Swine ; Swine, Miniature ; Titanium ; Ultraviolet Rays

PURPOSE: The purpose of this study was to evaluate the repeatability and matching accuracy between two identical intraoral spectrophotometers. MATERIALS AND METHODS: The maxillary right central incisor, canine, and mandibular left central incisor of each of 30 patients were measured using 2 identical intraoral spectrophotometers with different serial numbers (EasyShade V). The color of each shade tab from 3 shade guides (VITA 3D-Master) was also determined with both devices. All measurements were performed by a single operator. Statistical analyses were performed to verify the repeatability, accuracy, and the differences between the devices with paired t-tests, one-way ANOVA, and intra-class correlation coefficients (ICCs) (α=.05). RESULTS: A high level of measurement repeatability (ICC>0.90) among L *, a *, and b * color components was observed within and between devices (P < .001). Intra-device matching agreement rates were 80.00% and 81.11%, respectively, while inter-device matching agreement rate was 51.85%. ANOVA revealed no significant different color values within each device, while paired t-test provided significant different color values between both devices. The CIEDE2000 color differences between both devices were 2.28±1.61 ΔE 00 for in-vivo readings. Regarding the clinical matching accuracy of both devices, ΔE 00 values between teeth and matching shade tabs were 3.05±1.19 and 2.86±1.02, respectively. CONCLUSION: Although two EasyShade V devices with different serial numbers show high repeatability of CIE L*, a*, and b* measurements, they could provide different color values and shade for the same tooth.
Dimensional Measurement Accuracy ; Equipment Failure Analysis ; Humans ; In Vitro Techniques ; Incisor ; Reading ; Spectrophotometry ; Tooth

In this paper, the common errors in medical devices test reports are classified and analyzed. And then the main 11 influence factors for these inspection report errors are summarized. The hierarchy model was also developed and verified by presentation data using MATLAB. The feasibility of comprehensive weights quantitative comparison has been analyzed by using the analytic hierarchy process. In the end, this paper porspects the further research direction.
Equipment Failure Analysis ; Equipment and Supplies ; standards ; Models, Theoretical

This study aimed to investigate the causes and managements of the fractures and migrations of the implantable venous access port catheter (IVAPC). The fracture or migration of IVAPC occurred in 4 patients who were treated between May 2012 and January 2014 in Union Hospital, Wuhan, China. The port catheter leakage was found in 2 cases during drug infusion. Catheters that dislodged to the superior vena cava and right atrium were confirmed by port angiogram. The two dislodged catheters were successfully retrieved by interventional procedures. Catheter fracture occurred in two cases during port removal. One catheter was eventually removed from the subclavian vein through right clavicle osteotomy and subclavian venotomy, and the other removed by external jugular venotomy. Flushing the port in high pressure and injury of the totally implantable venous access port (TIVP) during implantation are usually responsible for catheter displacement. Interventional retrieval procedure can be used if the catheter dislodges to the vena cava and right atrium. Catheter fracture may occur during removal if clipping syndrome occurs or the catheter is sutured very tight during implantation.
Angiography ; Catheters, Indwelling ; Central Venous Catheters ; Child ; Child, Preschool ; Device Removal ; methods ; Equipment Failure ; Equipment Failure Analysis ; Female ; Heart Atria ; diagnostic imaging ; surgery ; Humans ; Male ; Middle Aged ; Osteotomy ; methods ; Suture Techniques ; Vena Cava, Superior ; diagnostic imaging ; surgery ; Young Adult

To evaluate the fatigue behavior of nitinol stents, we used the finite element method to simulate the manufacture processes of nitinol stents, including expanding, annealing, crimping, and releasing procedure in applications of the clinical treatments. Meanwhile, we also studied the effect of the crown area dimension of stent on strain distribution. We then applied a fatigue diagram to investigate the fatigue characteristics of nitinol stents. The results showed that the maximum strain of all three stent structures, which had different crown area dimensions under vessel loads, located at the transition area between the crown and the strut, but comparable deformation appeared at the inner side of the crown area center. The cause, of these results was that the difference of the area moment of inertia determined by the crown dimension induced the difference of strain distribution in stent structure. Moreover, it can be drawn from the fatigue diagrams that the fatigue performance got the best result when the crown area dimension equaled to the intermediate value. The above results proved that the fatigue property of nitinol stent had a close relationship with the dimension of stent crown area, but there was no positive correlation.
Alloys ; Computer Simulation ; Equipment Failure Analysis ; Finite Element Analysis ; Stents

OBJECTIVETo evaluate the shaping ability of Reciproc, WaveOne,Mtwo and ProTaper instruments in simulated S-shaped root canals.

METHODSA total of 40 simulated S-shaped resin blocks were divided randomly into four groups, each group was prepared with Reciproc (group A), WaveOne (group B), Mtwo (group C) and ProTaper (group D), respectively. The preparation time and reduction of working length after preparation were measured. Pre- and postoperative images were obtained by a scanner and superimposed using Photoshop. Changes of coronal curve and apical curve curvature, as well as material removal from the inner and outer canal wall at 10 points beginning 1 mm from the end point of the canal, were measured using ImageJ. Centering ability was determined, accordingly. The data were analyzed using the one-way ANOVA and Student-Newman-Keuls.

RESULTSThe preparation time of group A and group B were (42.1 ± 2.7) and (41.5 ± 3.2) s respectively, significantly less than that of group C and group D [(62.7 ± 2.8), (62.8 ± 5.2) s] (P < 0.05).Reductions of working length after preparation were not significantly different among the four groups (P > 0.05). Coronal curve curvature changes of group A, group B and group D were (4.69 ± 0.63)°, (4.15 ± 0.89)° and (4.13 ± 0.59)° respectively, significantly less than that of group C[(5.26 ± 0.70)°], P < 0.05. Apical curve curvature changes were not significantly different among the four groups (P > 0.05). At the 2 mm point, the centering ability of group A[ (-0.242 ± 0.042) mm], group B[(-0.191 ± 0.077) mm], and group D[(-0.272 ± 0.046) mm] was better than group C[(-0.343 ± 0.057 mm] significantly (P < 0.05). At the 3 mm and 4 mm point, the centering ability of group A and group B was better than group C and group D significantly (P < 0.05). Whilst at the 5 mm point, the centering ability of group D was better than group A and group B (P < 0.05).

CONCLUSIONSReciproc and WaveOne could complete preparation faster and could maintain the original S-shaped canal curvature better than Mtwo and ProTaper, especially in the apical part.

Endovascular salvage of the hypogastric artery using iliac branch device (IBD) during endovascular aortic aneurysm repair (EVAR), offers less invasive alternative solution to surgery to prevent pelvic ischemia. We have performed the first Korean surgeon custom-made IBD for this purpose to overcome the limitation of unavailability of the devices in Korea. Four patients with abdominal aortic aneurysm with bilateral common iliac artery aneurysm (CIAA) were treated using custom-made IBDs from October 2013 to December 2013. IBD was created in back table before EVAR operation using TFLE Zenith iliac limb stent graft (Cook Inc.). Three V12 (Atrium, Inc.) one Viabahn (Gore, Inc.) were used for bridging between IBD and target hypogastric artery. With this modification of IBD procedure, exteriorize the guide wire without snare device is possible which offers another benefit in terms of reducing medical costs comparing to commercial IBD. All operations were successful without any device related complications or postoperative endoleaks. During the mean follow up of 3 months, all IBD were patent without clinical complications. Surgeon custom made IBD is feasible and useful to preserve pelvic perfusion especially in the situation of limited commercial IBD availability in many countries. Long-term follow-up is needed to evaluate stent graft patency and IBD-related complications.
Aged ; Aortic Aneurysm, Abdominal/*surgery ; *Blood Vessel Prosthesis ; Endovascular Procedures/*instrumentation ; Equipment Design ; Equipment Failure Analysis ; Female ; Humans ; Iliac Aneurysm/*surgery ; Iliac Artery/*surgery ; Male ; Salvage Therapy/*instrumentation/methods ; *Stents

A rubber tip disconnection of Arrow-Trerotola percutaneous thrombolytic device (PTD) may occur occasionally. We experienced 5 cases of a rubber tip disconnection among 453 mechanical thrombectomy sessions with the use of PTD. We present a report about these five cases and suggest possible causes for the occurrences.
Aged ; Catheter Obstruction/*etiology ; Equipment Failure Analysis/*methods ; Female ; Humans ; Male ; Middle Aged ; Renal Dialysis/*instrumentation ; Rubber ; Thrombectomy/*instrumentation ; Treatment Outcome

In an effort to overcome the drawbacks of distraction osteogenesis using the Ilizarov external fixator, intramedullary lengthening devices have been developed and applied for long bone distraction osteogenesis. Several successful cases have been reported, leading to the next generation of distraction osteogenesis. However, intramedullary lengthening devices have their own problems, such as device failure, difficulty of control of the lengthening degree. The authors report on a case of device failure during distraction osteogenesis using ISKD(R) (Orthofix Inc.) in the distraction phase, and the strategy that involved switching to a lengthening over nail system, which uses the Ilizarov external fixator, in order to obtain the target length.
Equipment Failure ; Equipment Failure Analysis ; External Fixators ; Osteogenesis, Distraction*