Safety and performance of MR-conditional pacing systems with automated MRI mode at 1.5 and 3 Tesla.

OBJECTIVES: To evaluate at 1.5 and 3 T MRI the safety and performance of trademarked ENO®, TEO®, or OTO® pacing systems with automated MRI Mode and the image quality of non-enhanced MR examinations. METHODS: A total of 267 implanted patients underwent MRI examination (brain, cardiac, shoulder, cervical spine) at 1.5 (n = 126) or 3 T (n = 141). MRI-related device complications, lead electrical performances stability at 1-month post-MRI, proper functioning of the automated MRI mode and image quality were evaluated. RESULTS: Freedom from MRI-related complications at 1 month post-MRI was 100% in both 1.5 and 3 T arms (both p < 0.0001). The stability of pacing capture threshold was respectively at 1.5 and 3 T (atrial:: 98.9% (p = 0.001) and 100% (p < 0.0001); ventricular: both 100% (p < 0001)). The stability of sensing was respectively at 1.5 and 3 T (atrial: 100% (p = 0.0001) and 96.9% (p = 0.01); ventricular: 100% (p < 0.0001) and 99.1% (p = 0.0001)). All devices switched automatically to the programmed asynchronous mode in the MRI environment and to initially programmed mode after the MRI exam. While all MR examinations were assessed as interpretable, artifacts deteriorated a subset of examinations including mostly cardiac and shoulder ones. CONCLUSION: This study demonstrates the safety and electrical stability of ENO®, TEO®, or OTO® pacing systems at 1 month post-MRI at 1.5 and 3 T. Even if artifacts were noticed in a subset of examinations, overall interpretability was preserved. CLINICAL RELEVANCE STATEMENT: ENO®, TEO®, and OTO® pacing systems switch to MR-mode when detecting magnetic field and switch back on conventional mode after MRI. Their safety and electrical stability at 1 month post MRI were shown at 1.5 and 3 T. Overall interpretability was preserved. KEY POINTS: • Patients implanted with an MRI conditional cardiac pacemaker can be safely scanned under 1.5 or 3 Tesla MRI with preserved interpretability. • Electrical parameters of the MRI conditional pacing system remain stable after a 1.5 or 3 Tesla MRI scan. • The automated MRI mode enabled the automatic switch to asynchronous mode in the MRI environment and to initial settings after the MRI scan in all patients.

Warning and active steering rollover prevention control for agricultural wheeled tractor.

Tractor rollover is regarded as the most fatal incident in agricultural production, but some of which can be avoided by timely anti-rollover warning and active control. There have been a lot of researches on the tractor rollover model building and rollover protective structure designing but few on the anti-rollover control. The purpose of this study is to develop a cheaper and practical anti-rollover control system based on active steering technique and to prove the efficiency of the proposed scheme for the wheeled tractors. A three-degree-of-freedom rollover dynamics model including automatic steering system is established. A control scheme by adjusting the roll angle to keep the stability based on the adaptive sliding mode control is proposed with the estimated lateral velocity according to the feedback correction principle. Front wheel angle tracking controller is designed adopting internal model control (IMC) theory. Simulation results exhibit that the active anti-rollover control can calculate the stability index in real time and can keep it within the stable range by adjusting the front steering wheel angle. It is prospective for the proposed scheme to provide a valuable reference to reduce tractor rollover accidents.

Secondary Medication Administration and IV Smart Pump Setup.

ABSTRACT: Secondary infusion by large-volume IV smart pump is used extensively in the acute care setting for one-time or intermittent administration of medications such as antibiotics, electrolyte replacements, and some oncology drugs. Consistent and accurate delivery of secondary medications requires a full understanding of the system and setup requirements. Unfortunately, it is not uncommon for nurses to find a secondary medication only partially administered when their programming should have resulted in a complete infusion. This article discusses the technical requirements that every nurse should know when administering secondary medications using an IV smart pump.

Microscopic and chemical characterization of PVC tube used for dialysis lines: A new approach.

Polyvinylchloride is universally agreed upon to be the material of choice for tubings and for containers for medical application. Many alterations of the chemical/physical surface conditions, mainly due to an altered extrusion process, could influence its biocompatibility by promoting platelet aggregation. Biocompatibility and safety of the medical device must be preserved, also monitoring the migration of additives within polyvinylchloride during the diffusion process. A large variety of methods are used to verify the correct composition and extrusion of polyvinylchloride but, generally, they need long experimental time and are expensive. The aim of the study is to propose a simple, economic and rapid approach based on Fourier transform-infrared spectroscopy and Coomassie Blue staining. The method has been used to detect chemical and morphological defects caused by an altered extrusion process on 20/75 polyvinylchloride tubings in a blind test. This approach positively identified altered samples in 80% of the cases. The suggested approach represents a reliable and versatile method to detect and monitor surface defects by an easy, inexpensive and reproducible method.

Evaluation method and platform of vibrational disturbance test for ventricular assist devices.

OBJECTIVE: For ventricular assist devices utilizing levitation bearing technology, collision and wear of the rotor would occur if the bearing cannot resist disturbances from patient activities and vibration/shock impacts. The reliability of ventricular assist devices can be seriously affected, potentially impairing blood compatibility (e.g. thrombus generation) and threatening patient safety. In this article, we proposed a vibrational disturbance test protocol for ventricular assist devices. METHODS: Two kinds of vibrational disturbances-translational and rotational-were defined and the disturbance levels determined as 6G and 10 rad/s per possible patient activity impact. A test platform was built according to the disturbance level requirements. RESULTS: The test platform successfully generated the required disturbance. The vibration test evaluation criteria for ventricular assist device assistance (characterized by the pressure head, flow rate, and driving current waveform) were well verified. CONCLUSION: Compared with translational vibration, rotational vibration had a greater impact on the rotor. Accurate control of high-speed rotor is difficult because of the gyroscopic effect. As conventional random vibration tests cannot cover all risk situations, it is recommended that translational and rotational disturbance tests are carried out for levitation ventricular assist devices. We recommend that researchers and manufacturers pay attention to the vibrational impact of rotor-levitated ventricular assist devices.

[How did the private labs fit onto COVID-19 crisis?] / Comment les laboratoires de biologie médicale privés français se sont adaptés à la crise de la COVID-19 ?

Confronted with the COVID-19 crisis, healthcare professionals have had to tackle an epidemic crisis of a huge magnitude for which they were not prepared. Medical laboratories have been on the front line, from collecting samples to performing the analysis required to diagnose this new pathology. Responding to the needs and to the urgency of the situation, the authorities relied on the network of private laboratories. In France, private laboratory medicine represents 70% of overall activity, and with a network of more than 4,000 local laboratories, private laboratory medicine has been the cornerstone of the « screen-trace-isolate ¼ strategy. This article gives feedback from private laboratory medicine professionals, directly involved in the reorganization carried out at the pre-analytical, analytical and post-analytical stages, during the crisis from March to October 2020.

Measurement of filtration efficiencies of healthcare and consumer materials using modified respirator fit tester setup.

During the current SARS-CoV-2 pandemic there is unprecedented demand for personal protective equipment (PPE), especially N95 respirators and surgical masks. The ability of SARS-CoV-2 to be transmitted via respiratory droplets from asymptomatic individuals has necessitated increased usage of both N95 respirators in the healthcare setting and masks (both surgical and homemade) in public spaces. These precautions rely on two fundamental principles of transmission prevention: particle filtration and droplet containment. The former is the focus of NIOSH N95 testing guidelines, and the latter is an FDA guideline for respirators and surgical masks. While studies have investigated droplet containment to provide guidance for homemade mask production, limited work has been done to characterize the filtration efficiency (FE) of materials used in home mask making. In this work, we demonstrate the low-cost (<$300) conversion of standard equipment used to fit-test respirators in hospital and industrial settings into a setup that measures quantitative FEs of materials based on NIOSH N95 guidelines, and subsequently measure FEs of materials found in healthcare and consumer spaces. These materials demonstrate significant variability in filtration characteristics, even for visually similar materials. We demonstrate a FE of 96.49% and pressure drop of 25.4 mmH20 for a double-layer of sterilization wrap used in surgical suites and a FE of 90.37% for a combination of consumer-grade materials. The excellent filtration characteristics of the former demonstrate potential utility for emergent situations when N95 respirators are not available, while those of the latter demonstrate that a high FE can be achieved using publicly available materials.

New Directions in Ensuring Catheter Safety.

Tunneled dialysis catheters remain the most common vascular access used to initiate hemodialysis. Unfortunately, their use is associated with higher morbidity and mortality when compared with arteriovenous fistulae or grafts. Different types of catheters with different designs and material properties function differently. Additional devices and medications can be used to decrease the rates of infection and thrombosis. The current available tunneled dialysis catheters remain far from the desired goal and innovation in the field of dialysis vascular access remains in dire need.

The Utility of Color Doppler to Confirm Endotracheal Tube Placement: A Pilot Study.

INTRODUCTION: Grayscale ultrasound (US) imaging has been used as an adjunct for confirming endotracheal tube (ETT) placement in recent years. The addition of color Doppler imaging (CDI) has been proposed to improve identification but has not been well studied. The aim of this study was to assess whether CDI improves correct localization of ETT placement. METHODS: A convenience sample of emergency and critical care physicians at various levels of training and experience participated in an online assessment. Participants viewed US video clips of patients, which included either tracheal or esophageal intubations captured in grayscale or with CDI; there were five videos of each for a total of 20 videos. Participants were asked to watch each clip and then assess the location of the ETT. RESULTS: Thirty-eight subjects participated in the online assessment. Levels of training included medical students (13%), emergency medicine (EM) residents (50%), EM attendings (32%), and critical care attendings (5%). The odds ratio of properly assessing tracheal placement using color relative to a grayscale imaging technique was 1.5 (p = 0.21). Regarding the correct assessment of esophageal placement, CDI had 1.4 times the odds of being correctly assessed relative to grayscale (p = 0.26). The relationship between training level and correct assessments was not significant for either tracheal or esophageal placements. CONCLUSION: In this pilot study we found no significant improvement in correct identification of ETT placement using color Doppler compared to grayscale ultrasound; however, there was a trend toward improvement that might be better elucidated in a larger study.

Multi-Level-Phase Deep Learning Using Divide-and-Conquer for Scaffolding Safety.

A traditional structural analysis of scaffolding structures requires loading conditions that are only possible during design, but not in operation. Thus, this study proposes a method that can be used during operation to make an automated safety prediction for scaffolds. It implements a divide-and-conquer technique with deep learning. As a test scaffolding, a four-bay, three-story scaffold model was used. Analysis of the model led to 1411 unique safety cases for the model. To apply deep learning, a test simulation generated 1,540,000 datasets for pre-training, and an additional 141,100 datasets for testing purposes. The cases were then sub-divided into 18 categories based on failure modes at both global and local levels, along with a combination of member failures. Accordingly, the divide-and-conquer technique was applied to the 18 categories, each of which were pre-trained by a neural network. For the test datasets, the overall accuracy was 99%. The prediction model showed that 82.78% of the 1411 safety cases showed 100% accuracy for the test datasets, which contributed to the high accuracy. In addition, the higher values of precision, recall, and F1 score for the majority of the safety cases indicate good performance of the model, and a significant improvement compared with past research conducted on simpler cases. Specifically, the method demonstrated improved performance with respect to accuracy and the number of classifications. Thus, the results suggest that the methodology could be reliably applied for the safety assessment of scaffolding systems that are more complex than systems tested in past studies. Furthermore, the implemented methodology can easily be replicated for other classification problems.

Implantation Time Has No Effect on the Morphology and Extent of Previously Reported "Degradation" of Prolene Pelvic Mesh.

OBJECTIVES: Prolene polypropylene ("Prolene") meshes demonstrate no in vivo degradation, yet some claim degradation continues until no more Prolene polypropylene can be oxidized. We studied whether implantation time affects the morphology/extent of previously reported as cracking/degradation of completely cleaned Prolene explants. METHODS: Urogynecological explants (248 patients) were collected. After excluding non-Prolene/unknown meshes and those without known implantation times, completely cleaned explants (n = 205; 0.2-14.4 years implantation) were analyzed with light microscopy, scanning electron microscopy, and Fourier transform infrared spectroscopy. Based on implant times and storage (fixative or dry), representative specimens were randomly selected for comparison. Controls were unused ("exemplar") TVT specimens with and without intentional oxidation via ultraviolet light exposure. RESULTS: Prolene explants included 31 dry (18 TVT; 7 Prolift; 4 Gynemesh; 2 others) and 174 wet (87 TVT; 47 Prolift; 10 Gynemesh; 30 others) specimens. Specimens had similar morphologies before cleaning. Progressive cleaning removed tissue and cracked tissue-related material exposing smooth, unoxidized, and nondegraded fibers, with no visible gradient-type/ductile damage. Fourier transform infrared spectroscopy of the explants confirmed progressive loss of proteins. Cleaning intentionally oxidized exemplars did not remove oxidized carbonyl frequencies and showed deep cracks and gross fiber rupture/embrittlement, unlike the explants and nonoxidized exemplars. CONCLUSIONS: If in vivo Prolene degradation exists, there should be wide-ranging crack morphology and nonuniform crack penetration, as well as more cracking, degradation, and physical breakage for implants of longer implantation times, but this was not the case. There is no morphologic or spectral/chemical evidence of Prolene mesh degradation after up to 14.4 years in vivo.

Heuristic evaluation and simulated use testing of infusion pumps to inform pump selection.

BACKGROUND: Poorly designed infusion pumps can lead to user errors and adverse incidents. Therefore, assessments of their usability and performance that can inform managerial decisions about the selection of appropriate medical devices are essential. OBJECTIVE: This study aimed to identify design deficiencies and evaluate the usability and performance of four infusion pump models and thus inform decisions about infusion pump selection. METHODS: Four evaluators evaluated the interface designs of the pumps according to a series of design principles in a heuristic evaluation in order to identify pump design deficiencies. Additionally, 60 registered nurses participated in simulated use testing to perform a series of tasks using the pumps in order to examine the pump performances. Outcome measures included task completion time, frequency of deviations, frequency of requests for assistance, and nurses' perceptions. RESULTS: Design issues identified included system status visibility, information access, and error prevention. The results of simulated use testing favored some pumps over others, depending on which outcome measures were considered. CONCLUSIONS: Heuristic evaluations and simulated use testing can provide information about the basic usability of medical devices and related operational issues. However, practitioners should select appropriate evaluation principles, testing tasks, and outcome measures based on the tested medical devices and contexts.

[Establishment of Sampling Inspection Scheme Paradigm for Medical Device Sampling Inspection].

This paper introduces the sampling scheme and the inspection scheme paradigm followed in organizing the sampling inspection of medical devices. The sampling scheme paradigm includes the definition and operation guidelines for sampling products, the regulations for individual sampling batches and related model specifications, accessory data, validity period, storage conditions, etc., the requirements for sampling areas, places and quantities, and the requirements for samples to be sent to inspection institutions. The inspection scheme paradigm includes the provisions for inspection basis, inspection items and determination principles.

Safety Considerations of 7-T MRI in Clinical Practice.

Although 7-T MRI has recently received approval for use in clinical patient care, there are distinct safety issues associated with this relatively high magnetic field. Forces on metallic implants and radiofrequency power deposition and heating are safety considerations at 7 T. Patient bioeffects such as vertigo, dizziness, false feelings of motion, nausea, nystagmus, magnetophosphenes, and electrogustatory effects are more common and potentially more pronounced at 7 T than at lower field strengths. Herein the authors review safety issues associated with 7-T MRI. The rationale for safety concerns at this field strength are discussed as well as potential approaches to mitigate risk to patients and health care professionals.

Incidence of appropriate implantable cardioverter-defibrillator therapy and mortality after implantable cardioverter-defibrillator generator replacement: results from a real-world nationwide cohort.

AIMS: The safety of omitting implantable cardioverter-defibrillator (ICD) generator replacement in patients with no prior appropriate therapy, comorbid conditions, and advanced age is unclear. The aim was to investigate incidence of appropriate ICD therapy after generator replacement. METHODS AND RESULTS: We identified patients implanted with a primary prevention ICD (n = 4630) from 2007 to 2016, who subsequently underwent an elective ICD generator replacement (n = 670) from the Danish Pacemaker and ICD Register. The data were linked to other databases and evaluated the outcomes of appropriate therapy and death. Predictors of ICD therapy were identified using multivariate Cox regression analyses. A total of 670 patients underwent elective ICD generator replacement. Of these, 197 (29.4%) patients had experienced appropriate therapy in their 1st generator period. During follow-up of 2.0 ± 1.6 years, 95 (14.2%) patients experienced appropriate therapy. Predictors of appropriate therapy in 2nd generator period was low initial left ventricular ejection fraction (≤25%) [hazard ratio (HR) 1.87, confidence interval (CI) 1.13-1.95] and appropriate therapy in 1st generator period (HR 3.95, CI 2.57-6.06). For patients with appropriate therapy in 1st generator period, 4-year incidence of appropriate therapy was 50.6% vs. 16.4% in those without (P < 0.001). Among patients >80 years with no prior appropriate therapy 8.8% of patients experienced appropriate therapy after replacement. Comorbidity burden and advanced age were associated with reduced device utilization after replacement and a high competing risk of death without preceding appropriate therapy. CONCLUSION: A significant residual risk of appropriate therapy in the 2nd generator was present even among patients with advanced age and with a full prior generator period without any appropriate ICD events.

Cardiovascular magnetic resonance imaging in patients with cardiac implantable electronic devices: best practice and real-world experience.

AIMS: Cardiovascular magnetic resonance (CMR) imaging has long been a contraindication for patients with a cardiac implantable electronic device (CIED). Recent studies support the feasibility and safety for non-thoracic magnetic resonance imaging, but data for CMR are sparse. The aim of the current study was to determine the safety in patients with magnetic resonance (MR)-conditional or non-MR-conditional CIED and to develop a best practice approach. METHODS AND RESULTS: All patients with a CIED undergoing CMR imaging (1.5 T) between April 2014 and April 2017 were included in the study. Devices were programmed according to the standardized protocol directly before and after the CMR examination. Follow-up interrogation was performed 6 months after CMR examination. Results were compared with a large, reference cohort of CIED patients not undergoing any MR examination. A total of 200 consecutive patients with a CIED (non-MR-conditional, n = 103) were included in the study. Directly after CMR imaging, one device failure (0.5%, battery status = end of service) was noted necessitating premature generator replacement. In three patients (2%) of pacemaker/implantable cardioverter-defibrillator (ICD) carriers a sustained ventricular tachycardia (VT) occurred during CMR imaging. Ten ICD showed a decrease in battery capacity immediately after CMR. Overall, the reference cohort showed comparable changes of CIED function during follow-up. CONCLUSION: With adherence to a standardized protocol and established exclusion criteria CMR imaging could safely be performed in patients with a CIED. The potential risks of device malfunction necessitate the presence of a device trained individual during the entire CMR examination. If there is a history of VT storm the attendance of an experienced cardiologist, should be mandatory.