Medical Devices Having MRI Compatible Metal Alloys

An MRI compatible medical device includes a non-magnetic metal alloy portion including a first and at least a second metal. A surface of the metal alloy portion includes an integral MRI heating resistant surface structure having a thickness greater than or equal to 3 nanometers. The MRI heating resistant surface structure includes one or more of (i) a matrix phase including the first and second metal having a plurality of nanometer or micron scale particles, precipitates and/or inclusions constituting a volume fraction greater than or equal to 3%, wherein the particles, precipitates or inclusions differ in chemical composition and physical characteristics of the matrix phase and are discontinuously distributed therein; (ii) a level of crystalinity at least 5% less as compared to a level of crystalinity in the bulk of the metal alloy portion; (iii) one or more metal atoms different from the first and second metal having a concentration profile evidencing diffusion into the metal alloy portion

Shape memory thermal conduction switch

A thermal conduction switch includes a thermally-conductive first member having a first thermal contacting structure for securing the first member as a stationary member to a thermally regulated body or a body requiring thermal regulation. A movable thermally-conductive second member has a second thermal contacting surface. A thermally conductive coupler is interposed between the first member and the second member for thermally coupling the first member to the second member. At least one control spring is coupled between the first member and the second member. The control spring includes a NiTiFe comprising shape memory (SM) material that provides a phase change temperature <273 K, a transformation range <40 K, and a hysteresis of <10 K. A bias spring is between the first member and the second member. At the phase change the switch provides a distance change (displacement) between first and second member by at least 1 mm, such as 2 to 4 mm

Mechanical properties of superelastic and shape-memory NiTi and NiTi-TiC composites investigated by neutron diffraction

Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 1999.Includes bibliographical references (leaves 149-152).by Rajan Vaidyanathan.Ph.D

Atrial myxoma invading right ventricular cavity and pulmonary artery

Study report a 42-years-old female came with complaints of dyspnoea on exertion, and recurrent cough for past one year. She gives history of significant weight loss for the past 6 months. Trans thoracic echocardiogram showed large pedunculated myxoma measuring 28*18 mm attached to posterior wall of right atrium extending into right ventricle and outflow tract. Computed tomography pulmonary angiogram showed acute bilateral pulmonary thromboembolism with left upper lobe infarct. She underwent complete removal of the tumour along with patch of atrial wall with pulmonary embolectomy using Fogarty baloon catheter through median sternotomy. Her postoperative course was uneventful. This case is reported for its rarity of presentation of right atrial myxoma with pulmonary embolism

Shape memory-based actuators and release mechanisms therefrom

SM-based actuators (110) and release mechanisms (100) therefrom and systems (500) including one or more release mechanisms (100). The actuators (110) comprise a SM member (118) and a deformable member (140) mechanically coupled to the SM member (118) which deforms upon a shape change of the SM member triggered by a phase transition of the SM member. A retaining element (160) is mechanically coupled to the deformable member (140), wherein the retaining element (160) moves upon the shape change. Release mechanism (100) include an actuator, a rotatable mechanism (120) including at least one restraining feature (178) for restraining rotational movement of the retaining element (160) before the shape change, and at least one spring (315) that provides at least one locked spring-loaded position when the retaining element is in the restraining feature and at least one released position that is reached when the retaining element is in a position beyond the restraining feature (178). The rotatable mechanism (120) includes at least one load-bearing protrusion (310). A hitch (400) is for mechanically coupling to the load, wherein the hitch is supported on the load bearing protrusion (310) when the rotatable mechanism is in the locked spring-loaded position

International Consensus Statement on Rhinology and Allergy: Rhinosinusitis

Background: The 5 years since the publication of the first International Consensus Statement on Allergy and Rhinology: Rhinosinusitis (ICAR‐RS) has witnessed foundational progress in our understanding and treatment of rhinologic disease. These advances are reflected within the more than 40 new topics covered within the ICAR‐RS‐2021 as well as updates to the original 140 topics. This executive summary consolidates the evidence‐based findings of the document. Methods: ICAR‐RS presents over 180 topics in the forms of evidence‐based reviews with recommendations (EBRRs), evidence‐based reviews, and literature reviews. The highest grade structured recommendations of the EBRR sections are summarized in this executive summary. Results: ICAR‐RS‐2021 covers 22 topics regarding the medical management of RS, which are grade A/B and are presented in the executive summary. Additionally, 4 topics regarding the surgical management of RS are grade A/B and are presented in the executive summary. Finally, a comprehensive evidence‐based management algorithm is provided. Conclusion: This ICAR‐RS‐2021 executive summary provides a compilation of the evidence‐based recommendations for medical and surgical treatment of the most common forms of RS

Spray generation from free and half-free jets

This is an experimental investigation of the ligament and drop formation at the free surface of wall jets, flowing over sand-roughened plates, and on unbounded two-dimensional jets, discharging into atmosphere. Experiments were conducted with both fresh and simulated sea water. Measurements were made with several high-speed imagers and a pulsating laser system and analyzed through the use of appropriate software. The wall-jet Reynolds number ranged from 3.5x10(exp 4) to 8.5x10(exp 4), the Froude number from 15 to 30, and the Weber number from 3,000 to 7,500. The positions of the transition and primary breakup as well as the characteristics of the ligament forest and droplets were determined from the digitized images and interpreted in terms of the characteristics of the turbulent boundary layer and a phenomenological model based on our observations and measurements. The emphasis has been on the physics of the phenomenon rather than on the development of empirical relationshipshttp://www.archive.org/details/spraygenerationf00vaidLieutenant, United States NavyApproved for public release; distribution is unlimited

Temperature Profile In Thin Wires During Laser Heating

The temperature distribution in a moving thin wire heated by a rectangular profile laser beam is studied. The output Gaussian profile beam of a laser system is transformed to a rectangular profile beam and the corresponding laser irradiance is integrated in the transverse direction to obtain the one-dimensional heat flux in the wire. The typical radius of the wire is in the range of hundreds of micrometers and the length of the wire can be infinitely long. The local temperature can vary from a few hundred to several thousand Kelvin depending on the laser intensity and, therefore, temperature-dependent thermophysical properties need to be considered. The resulting non-linear heat conduction equation is solved analytically to express the temperature distribution as an integral equation. The integral was determined numerically and the solution adopted is computationally robust. The results are presented in terms of two dimensionless numbers Bi and Pe so that a graphical representation of the solution can be easily applied to determine the laser processing parameters for other wires

Dynamics of hydrogen in sodium in LMFBR secondary circuit

391-396Steam generator (SG) of a liquid metal cooled fast breeder reactor (LMFBR) comprises sodium on the shell side transferring heat to water in the tubes. Any crack in the tube will result in the water reacting with sodium producing hydrogen and other corrosive reaction products. This may lead to the damage of the neighbouring tubes. Monitoring of hydrogen concentration in sodium can indicate the initiation of a sodium water reaction (SWR). The hydrogen detectors are based on the diffusion of hydrogen in the sodium through a nickel membrane and measurement of the hydrogen concentration by a mass spectrometer. A numerical model has been developed to estimate the amount of hydrogen concentration in the secondary loop during water/steam leak in SG. The model has been validated based on experiments with hydrogen injection in one loop and actual sodium water reaction in another loop. It has been found that the increase in hydrogen concentration was very well predicted by the code

The Maritime Preposition Force Ship 2010

The views expressed in this report are those of the authors and do not reflect the offical policy or position of the Department of Defense or the U.S. Government.A systems engineering approach to the design of a ship which will satisfy the requirements for a Maritime Prepositioning Force (MPF) for the year 2010 and beyond is presented. This ship, the MPF 2010, will provide the means by which the United States Marine Corps will be able to successfully employ the tenets of Operational Maneuver From the Sea (OMFTS) and the Ship-to-Objective Maneuver (STOM) against an objective. The current Maritime Prepositioning Ship (MPS) squadrons are used to preposition supplies, vehicles, and equipment throughout the world for use by a Marine Air-Ground Task Force (MAGTF) of Marine Expeditionary Force - Forward, MEF (FWD) size, in times of crisis. However, these squadrons presently require that a secure airfield and port (or beachhead) be available so that the prepositioned MPS assets can be offloaded and married with arriving MAGTF personnel ashore. As such, the current MPS squadrons do not support the concepts of OMFTS and STOM. The MPF 2010 will provide the capability to embark a MEF (FWD), marry the MEF (FWD) with its prepositioned equipment while en route to the objective, and then act as sea base from which it will be able to employ air, ground, and amphibious assets to project power ashore.Total Ship Systems Engineering educational processFund number(s): N6523607WR00390.Approved for public release; distribution is unlimited