Device Failure Research Articles

Right-ventricular/pulmonary artery coupling predicts long-term mortality in aortic stenosis patients with different flow types

Abstract Background Right-ventricular (RV) dysfunction in aortic stenosis (AS) patients undergoing transcatheter aortic valve implantation (TAVI) has long been neglected. Right-ventricular to pulmonary artery coupling (RV/PAc), a parameter of RV function, can be determined by echocardiography (tricuspid annular plane systolic excursion over systolic pulmonary artery pressure). Its use for mortality prediction in contemporary AS patients warrants further evaluation, data for different flow types of AS are lacking. Purpose To assess the impact of pathological RV/PAc on long-term mortality in AS patients with different flow types. Methods All 1577 consecutive patients from our registry from 2018 to 2020 were assessed. Patients without tricuspid regurgitation (n=523) or inconclusive echocardiography images (n=111) were excluded. RV/PAc could be analysed in 862 patients. To dichotomize the cohort, a receiver operator curve (ROC) analysis for 2-year mortality was used. Primary endpoint was 2-year mortality. Patients were further analysed according to the Valve Academic Research Consortium (VARC) 3 endpoint definitions. Results By ROC analysis, 0.512 mm/mmHg was defined as a cut-off, dividing the cohort into 428 patients with physiological RV/PAc (above cut-off) and 434 patients with pathological RV/PAc. Patients with pathological RV/PAc were more often male, had more comorbidities, a lower ejection fraction (50% [40-55%] vs. 55% [53-58%], p<0.01) and a higher Society of Thoracic Surgeons (STS) score (4.0 [2.5-6.0] vs. 2.8 [2.0-4.0], p<0.01). Procedural outcomes according to VARC-3 were comparable: the composite endpoints technical failure and device failure at 30 days occurred in 3.9% and 3.5% (p=0.75) and 11.3% and 13.3% (p=0.42) in the pathological and physiological group, respectively. Clinical outcomes in terms of New York Heart Association functional class were comparable at follow-up, with an improvement by at least one class in 76.2% (pathological group) and 79.9% (physiological group, p=0.33). All-cause 2-year mortality was significantly higher in the pathological group (34.9% [30.2-39.2%] vs. 15.4% [11.9-18.8%], p<0.01, hazard ratio, HR, 2.5 [1.9-3.4], Figure 1). The result persisted when adjusted for STS score (HR 2.3 [1.7-3.1]) or in a multivariate Cox regression. Cardiovascular mortality was increased too (pathological, 23.7% [19.3-27.8%], vs. physiological, 8.5% [5.8-11.2%], HR 2.9 [2.0-4.2], p<0.01). The fraction of patients with pathological RV/PAc differed significantly across the AS flow types (high-gradient, 40.3%, classical low-flow low-gradient (LFLG), 73.9%, paradoxical LFLG, 58.9%, and normal-flow low-gradient, 36.6%, p<0.01). Mortality differences persisted in high-gradient and LFLG groups (Figure 2A-D), which was consistent after statistical adjustment. Conclusions RV dysfunction defined as low RV/PAc is a strong predictor for long-term mortality in TAVI patients, with a strong prognostic value also in LFLG AS.

An optimisation-based digital twin for automated operation of rail level crossings

Railway level crossings (LCs), as the intersection of road and rail transport, are the weak points in terms of safety, as they are used by different modes of transport. The safety level at LCs can therefore be affected by the behaviour of the users. However, the level of safety can also be affected by failures and errors in the operation of LC equipment. Apart from safety, errors and failures of the LC devices can lead to longer waiting times for road users. As the volume of traffic on rail and road increases, so does the risk that the level of safety will decrease. The increase in traffic volume via LC leads to higher traffic volume on the road and more frequent trains on the rail, which leads to longer waiting times for road users on the LCs. The longer waiting times can disrupt the traffic flow, especially during peak hours when the growing volume of traffic on road and rail increases road user dissatisfaction. Moreover, in the era of Industry 4.0 and Digital Rail, new digital and automated technologies are being introduced to improve rail performance and competitiveness. These technologies are aligned with the LCs and are intended to ensure the efficient operation of LC and the efficient use of LCs by conventional trains as well. To achieve this, a concept is needed that simultaneously monitors and visualises the operation of LC in real time, identifies potential faults and failures of the LC equipment, and updates and monitors the proper operation of LC based on the historical data and information of the operation of LC according to the road traffic volume and the characteristics of the rail traffic and trains. Therefore, in this study, a digital twin system (DT) for rail LC was initiated and built as a concept that can meet the above requirements for proper LC operation in real time. DT of LC includes all components of LC and communication between them to synchronise the operation of LC according to the real-time requirements. The DT system is able to optimise the operation time of LC by monitoring the operation of LC and collecting data to ensure efficient use of LC and reduce unnecessary waiting time for road users. In this paper, the operation time of LCs on Swedish and Taiwanese railways was compared using the developed level crossing optimisation model (OLC). Since the introduction of new signalling concepts requires an improvement of LC operating characteristics and their design, the operating strategies were modelled using the OLC model. The results of the work show that the optimal values of LC operation time are different for the case studies investigated. The replacement of track circuits as detection devices and the introduction of balises can also positively influence the operation time, as well as increasing the speed of trains via LCs. However, due to the formulation of the OLC model, the impact of a longer train length on the operation of LC is not recognised. The OLC model can be used to estimate the real-time operation time of LC under different traffic conditions as well as the impact of different changes and extensions of LC.

A proactive care pathway that improves medical therapy for patients with heart failure with reduced ejection fraction and implantable cardiac devices

Abstract Background The UK model for follow-up of most patients with implantable cardiac devices is in a device clinic led by cardiac physiologists. This may be their only contact with cardiac services for several years. Many of these patients have heart failure with reduced ejection fraction (HFrEF) but do not have ongoing review in a heart failure clinic if they are clinically stable. ESC guidelines recommend four drug classes for all patients with HFrEF; implementing pathways that increase the prescription of these drugs is a priority as it improves quality of life, reduces hospitalisation and increases lifespan. A new clinical pathway was therefore created to achieve this in patients with cardiac devices at a tertiary cardiac centre in the UK, by combining device and heart failure follow-up in a single clinic. Purpose To evaluate the effectiveness of a new clinical pathway to improve the delivery of medical heart failure therapy to patients with cardiac devices and HFrEF. Methods Education on HFrEF diagnosis was delivered to the cardiac physiology team. This team then screened patients attending device follow-up clinics to identify those with HFrEF, through review of medical records and cardiac imaging. All patients with HFrEF identified by screening, who were not already under the active care of a heart failure team, were referred by the physiology team to a new combined heart failure device clinic. Results From Aug 2022 to Jan 2023, 107 patients were referred to the new heart failure device clinic. 102/107 (95%) patients attended. 72/102 (71%) had HFrEF, 19/102 (19%) had HFmrEF and 16/102 (16%) had HFpEF. Of the 72 patients with HFrEF, mean age was 70 years (range 29 – 90) and 79% were male. At baseline, 4/72 (6%) were in NYHA class I, 41/72 (57%) class II, 27/72 (38%) class III and 0/72 in class IV. At baseline, only 15/72 (21%) patients with HFrEF were prescribed all four drug classes. Following heart failure device clinic review, after an average of 1.9 appointments, 44/72 (61%) patients were prescribed these four drug classes (see Figure 1). Doses of drug classes prescribed at baseline were increased in 18/72 (25%) patients and 6/37 (16%) patients who were taking ACE-I or ARB at baseline were switched to ARNI. Iron status was assessed in 52 patients. 20/52 (38%) were iron deficient and managed with IV iron. Conclusions Many patients with HFrEF and cardiac devices are neither treated with the four key drug classes nor under active follow up by a heart failure team. Proactive screening of patients attending the device clinic by the cardiac physiology team identified patients with HFrEF who were not optimally treated. Subsequent review in a combined heart failure device clinic led to an increase from 21% to 61% of patients taking all four guideline-recommended drugs. Proactive multi-disciplinary working is an effective strategy to improve medical therapy and therefore prognosis for patients with HFrEF and cardiac devices.

Valve-in-valve transcatheter aortic valve implantation for degenerative stentless versus stented surgical bioprostheses

Abstract Introduction Valve-in-valve (ViV) transcatheter aortic valve implantation (TAVI) is a viable and less-invasive alternative to open heart surgery in selected patients with bioprosthetic valve dysfunction. Most ViV-TAVI procedures have been performed in failing stented bioprosthetic valves; stentless bioprostheses lack fluoroscopic markers and could be more challenging for transcatheter therapy. Data on more recent patients applying Valve Academic Research Consortium (VARC)-3 defined outcomes are scarce; thus, we compared patient characteristics, procedural outcomes, and 1-year outcomes of patients with stentless (SL) versus stented (ST) aortic bioprosthetic device failure undergoing ViV-TAVI. Methods Patients undergoing ViV-TAVI between 2007 and 2022 (53% of cases after 2015) at 3 German centres were included in this analysis. The 1-year mortality was the primary outcome measure, secondary outcomes included VARC-3 defined technical and device success and early safety. Results Overall, 43 (11.8%) SL and 313 (88.2%) ST ViV-TAVI were included. Patients were comparable with regard to age (SL: 77 (74; 82) vs. ST: 78 (75; 83), p=0.08), sex (male: SL 70% vs. ST 56%, p=0.08), clinically relevant baseline comorbidities and surgical risk (STS PROM SL 10.0 (4.8; 12.5) % vs. ST 9.4 (4.5; 11.3) %, p=0.62). Aortic regurgitation was the mode of failure in 33% of SL vs. 8% in ST (p<0.01). The rate of self-expanding TAVI prostheses was 86% and 76% in SL and ST, respectively (p=0.15). The rates of technical success (SL: 84% vs ST: 80%, p=0.55), device success (SL: 67% vs ST: 54%, p=0.11), and early safety (SL: 74% vs ST: 62%, p=0.30) were comparable between groups. There were higher rates of mild/moderate residual aortic regurgitation in SL (77.5% vs. 35%, p<0.01), whereas the remaining mean gradient was higher in ST (11.2 (6.0; 15.5) mmHg vs. 17.0 (11.0; 22.0) mmHg, p<0.01). The 30-day mortality rate (SL: 7.0% vs. ST: 2.6%, p=0.14) and Kaplan-Meier estimated 1-year mortality rates (SL: 9.3% vs. ST: 8.2%, p=0.63) were comparable between groups. Conclusion Both SL and ST ViV-TAVI have comparable short-term outcomes according to VARC-3- defined endpoints and similar low rates of 1-year all-cause mortality. However, against the background of a relevant rate of residual aortic regurgitation in SL and increased gradients in ST, long-term studies are of utmost importance to determine the clinical relevance of those factors.

Abstract 11705: Events of Device Failure in Elderly Patients Undergoing Watchman Device Insertion in the United States

Introduction: Watchman device implant reduces various cardio-cerebral events in patients with left atrial appendage. As there is a lack of data on device failure among the elderly undergoing this procedure, we aim to provide a perspective via the 2016-2020 National Inpatient Sample(NIS). Methods: Watchman procedures in patients ages ≥60 years, with a history of atrial fibrillation or flutter, were examined for our study from the NIS. Events of device failure were considered, and variables that may influence such events were studied via logistic regression models. Results: We found 85190 procedures for Watchman device insertion conducted in the United States, and 510 (0.6%) cases reported an event of device failure. Procedures at rural centers reported higher odds of device failure than urban teaching centers (1.3% of rural center procedures vs. 0.6% of urban teaching hospital procedures, aOR 2.970, 95% CI 1.965 -4.488, p<0.01). Meanwhile, patients with a history of CKD (aOR 0.565, p<0.01), hypertension (aOR 0.500, p<0.01), and peripheral vascular diseases (aOR 0.513, p=0.012) showed reduced odds. Several complications were also noted among those with device failure, as 20 cases (3.9% ) had acute kidney injury, 45 patients (8.8%) developed cardiac tamponade, 70 cases (13.7%) had pericardial effusion, and 20 cases (3.9%) necessitated mechanical ventilation. The mean CHA 2 DS 2 -VASc score among patients with device failure was 4.65 (vs. 4.68, p=0.029), and the mean Charlson Comorbidity Index score was 1.42 (vs 1.65, p<0.01). Patients with device failure had a more expensive stay (mean hospital charge $144936 vs. $122504). Conclusions: Device failure was a rare but severe complication involving 0.6% of procedures in our analysis. Many comorbidities influenced events of device failure. As our study found a higher incidence among procedures done in rural centers, further studies to screen and assess the patients and monitor their condition may help improve the outcomes.

Abstract 13319: The Barostim Baroreflex Activation Therapy System: Safety Insights From FDA MAUDE Database

Introduction: BAROSTIM NEO® is a Baroreflex activation therapy (BAT) system which has been approved recently by FDA for patients with refractory heart failure. Post market experience of BAT related complications and performance issues have not been reported. Objective: To analyze the post-approval device failures and patient related adverse events (AE) associated with Barostim NEO® system using Manufacturer and User Facility Device Experience (MAUDE) database. Methods: A MAUDE database search was conducted on December 7, 2022, for reports received between Jan 1, 2019, to November 30, 2022. Manual search of the MAUDE database conducted using the term “Barostim” in the brand name section. The AE were adjudicated to various categories based on the review of the event description for each medical device report (MDR). Results: A total of 22 events were reported which included MDRs reported by physicians or manufacturer or both. Device related malfunction was reported in 45.5% (n=10) whereas patient related AE reported in 77.3% (n=17) cases. Of total device related AE, material split, cut or torn was most commonly reported problem (32%, n=7), followed by high impedance (13.6%, n=3) and low impedance (9.1%, n=2). Of the patient related AE, 32% (n=7) were related to clinical or subclinical infection, 18.2% (n=4) hematoma, 13.6% (n=3) heart failure or myocardial injury, 9.1% (n=2) stroke/CVA, 9.1% and 9.1% (n=2) twiddler’s syndrome. No carotid artery or jugular injury and procedure related death reported in the study period. The report is limited by the lack of information on the total number of BAT devices implanted across the country. Conclusions: This study provides a wide range of device malfunction and patient related post-approval adverse events for Barostim device which have not been reported in any clinical trial/study before. The reported complications seem to be in line with other cardiac implantable electronic devices and no BAT specific complications were noted.

Feasibility and safety study of wearable cyborg Hybrid Assistive Limb for pediatric patients with cerebral palsy and spinal cord disorders.

The wearable cyborg Hybrid Assistive Limb (HAL) is the world's first cyborg-type wearable robotic device, and it assists the user's voluntary movements and facilitates muscle activities. However, since the minimum height required for using the HAL is 150 cm, a smaller HAL (2S size) has been newly developed for pediatric use. This study aimed to (1) examine the feasibility and safety of a protocol for treatments with HAL (2S size) in pediatric patients and (2) explore the optimal method for assessing the efficacy of HAL. This clinical study included seven pediatric patients with postural and motor function disorders, who received 8-12 sessions of smaller HAL (2S size) treatment. The primary outcome was the Gross Motor Function Measure-88 (GMFM-88). The secondary outcomes were GMFM-66, 10-m walk test, 2- and 6-min walking distances, Canadian Occupational Performance Measure (COPM), a post-treatment questionnaire, adverse events, and device failures. Statistical analyses were performed using the paired samples t-test or Wilcoxon signed-rank test. All participants completed the study protocol with no serious adverse events. GMFM-88 improved from 65.51 ± 21.97 to 66.72 ± 22.28 (p = 0.07). The improvements in the secondary outcomes were as follows: GMFM-66, 53.63 ± 11.94 to 54.96 ± 12.31, p = 0.04; step length, 0.32 ± 0.16 to 0.34 ± 0.16, p = 0.25; 2-MWD, 59.1 ± 57.0 to 62.8 ± 63.3, p = 0.54; COPM performance score, 3.7 ± 2.0 to 5.3 ± 1.9, p = 0.06; COPM satisfaction score, 3.3 ± 2.1 to 5.1 ± 2.1, p = 0.04. In this exploratory study, we applied a new size of wearable cyborg HAL (2S size), to children with central nervous system disorders. We evaluated its safety, feasibility, and identified an optimal assessment method for multiple treatments. All participants completed the protocol with no serious adverse events. This study suggested that the GMFM would be an optimal assessment tool for validation trials of HAL (2S size) treatment in pediatric patients with posture and motor function disorders.

Determinants of device success after transcatheter aortic valve replacement in patients with type-0 bicuspid aortic stenosis.

Clinical evidence of transcatheter aortic valve replacement in patients with type-0 bicuspid aortic valve was relatively scarce. Our goal was to explore determinants of device success after transcatheter aortic valve replacement in patients with type-0 bicuspid aortic valve morphology. In this retrospective multicenter analysis, we included 59 patients with symptomatic severe aortic stenosis with type-0 bicuspid aortic valve morphology who underwent transcatheter aortic valve replacement. Type-0 bicuspid aortic valve was identified with multidetector computed tomography scans. The technical success rate was 89.8%, and the device success rate was 81.4%. Patients were divided into a device success group and a device failure group according to Valve Academic Research Consortium- 3 criteria. When we compared the two groups, we found that the ellipticity index of the aortic root and the presence of bulky calcifications at the commissure were statistically different (ellipticity index 35.7 ± 1.7 vs. 29.7 ± 1.1, p = 0.018; bulky calcification at the commissure, 54.5% vs. 4.5%, p < 0.001). Further multivariate logistic analysis showed that bulky calcification at the commissure had a negative correlation with device success (odds ratio 0.030, 95% confidence interval 0.003-0.285, p = 0.002). Yet there was no statistical correlation between the ellipticity index and device success (odds ratio 0.818, 95% confidence interval 0.667-1.003, p = 0.053). The presence of bulky calcifications at the commissure is negatively correlated with device success after transcatheter aortic valve replacement in patients with type-0 bicuspid aortic valve.

Clinical Outcomes of Double Mini-Plating Compared with a Single Superior Plating in Midshaft Clavicular Fractures: A Randomized Clinical Trial Study.

In the current study, we aimed to assess the clinical outcomes of the double-plating method using 2.7 mm compression plates compared with the single superior 3.5 mm compression plating method in displaced midshaft fractures of the clavicle. Thirty patients with midshaft fractures of the clavicle were randomly assigned into two groups. In group A, 15 patients were fixed by a double-plating technique using two 2.7 mm compression plates on the superior and anteroinferior sides of the bone. The fractures in group B were fixed by a superior plating technique using a single 3.5 mm compression plate. Intraoperative bleeding measurement, length of surgical incision, duration of procedure time, and functional scores were assessed post-surgically through one-year follow-ups. There was no significant difference between groups in terms of surgery time. Device failure was not found among all recruited patients. Incision length and device prominence complaint were significantly different between groups (P value = 0.02, P value = 0.03). Mean ± standard deviation intraoperative bleeding rate was 88.67 ± 29.96 milliliter in the double-plating group and 108.67 ± 41.72 milliliter in the other group, which was not different between these two groups (P value = 0.14). There were no signs of non-union either in radiographies or clinically. Double mini-plating of diaphyseal clavicular fractures could result in a smaller surgical incision and a lower rate of prominence without affecting fixation stability and clinical outcomes in comparison with single superior 3.5 mm plates.

A Comparative Analysis of the Early and Late Complication Rates and the Effect of Calcification on the Efficacy of MANTA and ProGlide Vascular Closure Devices.

Introduction The Perclose ProGlide and, more recently, MANTA Large-Bore Closure Device are commonly used vascular closure devices (VCDs) for managing large-bore vascular access haemostasis. The extent of calcification in the common femoral artery (CFA) plays a crucial role in choosing between these devices. ProGlide may face challenges with anterior calcification, while MANTA may have issues with posterior calcification. Our study compared their effectiveness, adjunct usage, calcification impactand early/late complications. Methods A retrospective analysis of procedures involving large-bore CFA access from 2017 to 2022 was conducted. Closure was grouped according to VCD as Group A (ProGlide) and Group B (MANTA). Calcification was designated as anterior and posterior and combined on pre-operative computed tomography angiography along 10 mm segments with 0.625 mm slice thickness. The success of haemostasis was graded as Grade 1 (haemostasis without adjuncts), Grade 2 (haemostasis with adjuncts) and Grade 3 (failed haemostasis needing rescue); Grades 1 and 2 were pooled as successful haemostasis. Statistical analysis was undertaken in Minitab 21 for Windows, particularly analysing calcification and its impact on the success of haemostasis. Results We evaluated 370 large-bore CFA accesses, distributed across two groups: Group A(64.9%, n=243)and Group B(35.1%, n=127), for a total of 205 endovascular procedures (93.1% (191) EVAR and 5.3% (11) TEVAR). The mean age was 74.9±8 years, predominantly males(88.2%, n=181). The average body mass index (BMI) was 28±5.8, with 20.9% (43) individuals having diabetes and 18.5% (37) current smokers. The mean sheath size OD was 16±2.5, with 4.5% (11) re-do groins in Group A and 6.2% (8) in Group B. Successful haemostasis was achieved in 91.8% (n=223) in Group A(44.8%, n=109 Grade 2)and 90.5% (n=115) in Group B(21%, n=27 Grade 2). Rescue operations were needed in 8.2% (20) in Group A and 9.1% (12) in Group B. Pseudoaneurysms developed more commonly in Grade 2 haemostasis with 9.9% (11) in Group A and 1.6% (2) in Group B(p=0.3). Anterior calcification was observed in 14.8% (36) in Group A and 18.8% (24) in Group B. In comparison, posterior calcification was present in 62.5% (152) in Group A and 66.9% (85) in Group B. Notably, calcification did not significantly impact haemostasis (p=0.79). Additional VCD deployment was necessary due to device failure in 4.5% (11) cases in Group A and 1.5% (2) cases in Group B. Conclusion The overall success rate was comparable between the two groups. However, Group A required more adjuncts to achieve successful haemostasis. The site of calcification did not impact the efficacy ofclosure devices.Pseudoaneurysm formation was more frequent when adjuncts were needed.

A Single Centre Long Term Follow Up of the Nellix Endovascular Aneurysm Sealing System

To evaluate the clinical performance at long term follow up of endovascular aneurysm sealing (EVAS, Endologix Inc. Nellix, Irvine, CA, USA) in the treatment of abdominal aortic aneurysm (AAA). Observational, prospective, single centre study of primary AAA interventions with EVAS (n= 117) from November 2013 to November 2016. Endpoints were primary technical success, Nellix device failure, freedom from open surgical conversion (OSC), freedom from secondary intervention, sac rupture, total mortality, and aneurysm related mortality at long term follow up. The median age was 75 years (interquartile range [IQR] 70, 81 years) and 83% were male. The median AAA diameter was 58 mm (IQR 54, 60 mm). The median length of follow up was 6.2 years (IQR 5.6, 6.8 years). Primary technical success was 100%. Median time to Nellix failure was 5.6 years (IQR 3.3, 7.4 years). Freedom from Nellix failure at five and seven years was 54% (95% confidence interval [CI] 54.2 - 63.8%) and 36% (95% CI 22.3 - 49.7%), respectively. Freedom from OSC at five and seven years was 63% (95% CI 53.2 - 72.8%) and 59% (95% CI 47 - 71%), respectively. The secondary intervention rate was 11.4/100 person years. Freedom from secondary intervention at five and seven years was 52% (95% CI 42.2 - 61.8%) and 51% (95% CI 41.2 - 60.8%), respectively. The cumulative mortality rate at five and seven years was 36% and 54%, respectively. Secondary sac rupture occurred in 9.4% (11/117) with a rate of 2/100 person years. Aneurysm related mortality was 12% (14/117) with a rate of 2.5/100 person years. The median survival was four years (IQR 3, 5.6 years). Thirty day mortality for acute OSC was 67% (n= 3) and 17.1% (6/35) for elective OSC. Long term follow up showed an increased failure rate. Diligent surveillance after endovascular AAA treatment is mandatory, especially when promising new devices are put into clinical use.

Advanced Manufacturing Panel at IMAT 2023

Abstract This article presents highlights from a panel session held at International Materials, Applications &amp; Technologies (IMAT) 2023. Experts from ASM affiliate societies shared insights on the impact of new materials and manufacturing technologies in their respective fields. The panel was moderated by David Furrer, Pratt &amp; Whitney. The panelists were Thomas Ackerson, Blue Origin LLC (representing the Failure Analysis Society); Arvind Agarwal, College of Engineering and Computing, Florida International University (Thermal Spray Society); Marvin Barnes, NASA (Heat Treating Society); Jay Demarest, IBM (Electronic Device Failure Analysis Society); and Laura Moyer, Lehigh University (International Metallographic Society).

Comparing the use of midline catheters versus peripherally inserted central catheters for patients requiring peripherally compatible therapies: A pilot randomised controlled trial (the compact trial).

Midline catheter (MC) use has increased in acute-care settings, particularly for patients with difficult venous access or requiring peripherally compatible intravenous therapy for up-to 14 days. Our aim was to assess feasibility and generate clinical data comparing MCs with Peripherally Inserted Central Catheters (PICCs). A two-arm parallel group pilot randomised controlled trial (RCT), comparing MCs with PICCs, was conducted in a large tertiary hospital in Queensland between September 2020 and January 2021. The primary outcome was study feasibility, measured against rates of eligibility (>75%), consent (>90%), attrition (<5%); protocol adherence (>90%) and missing data (<5%). The primary clinical outcome was all-cause device failure. In total, 25 patients were recruited. The median patient age was 59-62 years; most patients were overweight/obese, with ≥2 co-morbidities. The eligibility and protocol adherence criteria were not met; of 159 screened patients, only 25 (16%) were eligible, and three patients did not receive their allocated intervention post-randomisation (88% adherence). All-cause failure occurred in two patients allocated to MC (20%) and one PICC (8.3%). Our study found that a fully powered RCT testing MCs compared with PICCs is not currently feasible in our setting. We recommend a robust process evaluation before the introduction of MCs into clinical practice.

Peripheral intravenous catheter material and design to reduce device failure: A systematic review and meta-analysis.

Patients require vascular access for medical treatments, diagnostic procedures and symptom management. Current failure rates of peripheral intravascular catheters (PIVCs) are unacceptably high (40-50%). This systematic review aimed to determine the effect of different PIVC materials and designs on the incidence of PIVC failure. A systematic search was conducted in November 2022 using CINAHL, PubMed, EMBASE and Cochrane Central Register of Controlled Trials databases. Randomised controlled trials that compared PIVC novel PIVC material/design and standard material/design were included. The primary outcome was all causes of PIVC failure, any reason for device removal due to cessation of device function; and secondary outcomes included individual PIVC complications and infection (local or systemic), and dwell times. Quality appraisal was conducted using the Cochrane risk of bias tool. A meta-analysis was performed using random effects model. Seven randomised controlled trials were eligible for inclusion. In meta-analysis, the impact of material and design on PIVC failure in the studies favoured the intervention arms (RR 0.71, 95% CI 0.57-0.89), however there was substantial heterogeneity (I2=81%, 95% CI 61-91%). Through subgroup analyses, a significant difference on PIVC failure favoured the closed system over the open system (RR 0.85, 95% CI 0.73 to 0.99; I2=23%, 95% CI 0-90%). Catheter material and design can impact PIVC outcome. Conclusive recommendations are limited due to the small number of studies and inconsistent reporting of clinical outcomes. Further rigorous research of PIVC types is necessary to improve clinical practice and device selection pathways should reflect the resulting evidence.

Wireless Human Motion Monitoring by a Wearable 3D Spiral Liquid Metal Sensor with a Spinning Top‐Shaped Structure

AbstractFlexible wireless pressure sensors based on the LC resonance principle have emerged for critical applications in wearable devices. However, the challenge remains to promote the sensing performance while maintaining good wearability of the devices. Herein, a 3D spiral liquid metal sensor (3D‐SLMS) is reported with a spinning top‐shaped structure for wireless human motion detection. The device is composed of only liquid metals embedded in Ecoflex elastomer, thus being highly flexible. The study develops a unique method to fabricate 3D‐SLMS by integration of mask‐assisted spraying of liquid metals and virtual molding tuned by vacuum. Under an external load, the deformation of the spinning top‐shaped structure leads to changes in both inductance and capacitance, offering a detectable shift in the resonant frequency of the sensor. The 3D‐SLMS technology allows for a high sensitivity of −0.502 MHz N−1, a limit of detection as low as 0.71 mN, fast response time of 0.6 s, and stretchability up to 158% without device failure. As a proof‐of‐concept, the wireless pressure detection of various human motions such as arm bending, fisting, boxing, coughing, and flatfoot diagnosis is successfully implemented, thus promising translation of wearable electronics for sport monitoring and medical rehabilitation.

Inhomogeneous oxidation behaviors of FeCoNiTiCu high-entropy alloy nanoparticles confined within graphite shells

The oxidation of magnetic high-entropy alloy nanoparticles (HEA-NPs) is an inevitable process in service environments, which can induce unexpected properties and result in the failure of devices. Graphite shells coating is an effective approach to prevent the oxidation of nanoparticles, and the defects on graphite shells can also have a significant impact on the physical and chemical properties of nanoparticles. Thus, it is significant to uncover the oxidation process and understand the change of magnetic properties of HEA-NPs encapsulated in graphite shells (HEA@C-NPs). Herein, we demonstrate the microstructure evolution of HEA@C-NPs under different annealing temperatures. With the increase of annealing temperatures, the graphite shell is broken gradually and then oxygen atoms enter into the HEA core across the defects in graphite shell. An inhomogeneous partial-empty structure is observed at 300 ℃, which can result from the heterogeneous diffusion of different elements across graphite shell with ununiform defects. Accompanied with the formation of the oxide, the saturation magnetization decreases linearly and the exchange bias effect increases gradually. Our results give some understanding for the oxidation process and thus provide a guidance for designing HEA-NPs on complex service environments.

Twelve-Month Outcomes of Intravascular Lithotripsy for Treatment of Calcified Popliteal and Infrapopliteal Lesions in Patients With Chronic Limb-Threatening Ischemia.

Vessel calcification is estimated to be present in 30% to 50% of patients with peripheral arterial disease (PAD) and is one of the main challenges in endovascular treatment. The popliteal artery is unique compared with other arteries due to its exposure to significant deformation and biomechanical stress during knee motion. Intravascular lithotripsy (IVL) is a novel technique that uses acoustic pressure waves to cause microfractures within the intimal and medial wall calcification. Intravascular lithotripsy is safe in femoropopliteal and infrapopliteal lesions, but follow-up studies are lacking. Therefore, the purpose of this study was to describe the first follow-up outcomes of IVL in popliteal and infrapopliteal arterial disease. This prospective, multicenter cohort study included all patients treated with IVL in the popliteal and infrapopliteal arteries at 4 sites. Standardized follow-up with duplex ultrasonography was scheduled at 6 to 8 weeks and 12 months. The primary safety endpoint was a composite of major adverse events (MAEs) at 30 days. Primary efficacy endpoints were primary patency, limb salvage, and amputation-free survival (AFS) at 12 months. Secondary endpoints were primary-assisted patency and freedom from target lesion revascularization (TLR). Endpoints were distributed for patients with chronic limb-threatening ischemia (CLTI) and intermittent claudication (IC) and estimated using the Kaplan-Meier method. Between April 2021 and March 2023, 29 patients with 30 limbs were treated. Diabetes mellitus (DM) and CLTI were present in 62.1% and 80.0% of patients, respectively. Within the 32 treated lesions, severe calcification was present in 84.4% and bailout stenting was necessary in 12.5% of the lesions. Four MAEs occurred within 30 days: 1 closure device failure, 1 major amputation, and 2 deaths, neither of which was related to the study device. The primary patency, primary-assisted patency, freedom from TLR, limb salvage, and AFS at 12 months were 68.8%, 90.0%, 93.3%, 83.9%, and 57.1% for CLTI patients, respectively. No events occurred in restenosis, re-occlusion, TLR, major amputation, or mortality in patients with IC. This first-ever analysis on follow-up outcomes of IVL in the popliteal and infrapopliteal arteries demonstrated promising safety and efficacy outcomes with a low rate of bailout stenting. Vessel calcification is a common feature in peripheral arterial disease (PAD) and is one of the main challenges in endovascular treatment. The popliteal artery is subjected to biomechanical stress during knee motion, which makes stenting unappealing and often leads to worse clinical outcomes. This study aimed to describe the first follow-up outcomes of IVL in popliteal and infrapopliteal arterial disease. As in line with previous studies, no relevant procedural complications were found and the rate of bail-out stenting was only 12.5%. Moreover, in a complex patient population, this study demonstrated promising safety and efficacy outcomes. The comparison of IVL with angioplasty alone or other vessel preparation devices for popliteal and infrapopliteal arterial disease is warranted.

Investigation of Malpractice Claims Concerning Orthopedic Surgeons in Sari, North of Iran, 2015-2020

Introduction: Treatment failure and claims against physicians may have many negative consequences. Orthopedic surgeons have always been among the most used specialists. Therefore, the investigation of causes and the process of these claims can help reduce the negative effects of medical malpractice on physicians and society. Materials and methods: This retrospective study investigated all medical orthopedic negligence cases in Sari, Iran, from March 2015 to March 2020. Data were collected using a researcher-made checklist and analyzed in SPSS software (V-21). Results: Out of 57 finalized cases investigated in this study, surgeons were found liable in 23 (40%) cases. The mean ± SD age of patients was 41 ± 19.3. Moreover, the level of education had a positive correlation with the surgeon’s liability. The most common cause of complaint was reduced Range of motion (ROM) and the most common type of complained surgery was “open reduction &amp; internal fixation” (ORIF). None of the surgeons were found liable due to surgical site infection or device failure. The mean ± SD time for the file processing was 11.1 ± 10.1 months. The mean indemnity payment was 320 million Iranian Rials (9.7% of indemnity for death in Iran). Conclusion: The most effective way to reduce medical complaint cases is to increase the knowledge and skill levels of physicians. The lack of a blinded arbitration system in both organizations could lead to bias in the case assessment process. Moreover, considering the long processing time of the claims, it is recommended that new technologies should be used to reduce the time and increase the accuracy of the final verdict. The absence of a ‘no-fault’ compensation program is a significant flaw in Iran violating patients’ rights. Also, more studies are needed to evaluate justice and equality in Iranian medical commissions.

Deterioration identification method of key optical devices of fiber optical current transformer based on neural network

AbstractOptical fiber current transformers (FOCTs) are affected by various external factors, resulting in the deterioration or even failure of devices, causing changes in critical state quantities, and reducing the accuracy and reliability of products. To solve this problem, based on the neural network algorithm, this paper starts from the four deterioration characteristics of FOCT SLD junction temperature, SLD output optical power, phase modulator half‐wave voltage, and optical fiber sensing ring temperature, and identifies the deterioration of key optical components of FOCT, which provides a basic model and data support for the online monitoring and early warning to improving the stability and reliability of FOCT in long‐term operation.

Junction temperature prediction method of GaN HEMT power devices based on accurate on-voltage testing

Compared with Si devices, GaN HEMT has lower on-resistance, lower junction capacitance, higher switching frequency, higher switching speed and higher junction temperature capability. It is widely used in automotive, aerospace and other fields. Severe environments may cause the junction temperature of GaN-HEMT to be too high, and excessive temperature is the main reason for power device failure. In order to ensure stable operation of GaN devices under harsh conditions, it is important to extract junction temperature information of semiconductor devices simply and effectively. However, most of the existing junction temperature prediction methods are not applicable to GaN HEMT devices due to its high switching speed and high requirement of prediction accuracy. Thus, we proposed a new method based on an accurate on-voltage clamp circuit to predict the junction temperature of GaN HEMT devices. The interrelation between the on-resistance and the junction temperature is analyzed, and the temperature coefficient is calibrated to obtain the corresponding relationship between the characterization quantity and the junction temperature. The on-resistance testing circuit suitable for GaN device is given and analyzed in detail. Finally, the conduction resistance testing circuit is used to predict the junction temperature of GaN devices, achieving extremely high accuracy. Experiments have verified under 100 ℃, the predicted junction temperature and the actual junction temperature have achieved more than 90% coincidence.