ECMOve:A Mobilization Device for Extracorporeal Membrane Oxygenation Patients

Extracorporeal membrane oxygenation (ECMO) is a temporary lifesaving treatment for critically ill patients with severe respiratory or cardiac failure. Studies demonstrated the feasibility of in-hospital mobilizing during and after ECMO treatment preventing neuromuscular weakness and impaired physical functioning. Despite more compact mobile ECMO devices, implementation of ambulatory ECMO remains labor-intensive, complex, and challenging. It requires a large multidisciplinary team to carry equipment, monitor and physically support the patient, and to provide a back-up wheelchair in case of fatigue. Moreover, there is no adequate solution to ensure the stability of the patient’s cannula and circuit management during ambulation. We developed a system contributing to improvement and innovation of current ambulatory ECMO patient programs. Our modular cart-in-cart system carries necessary ECMO equipment, features an extendable walking frame, and contains a folding seat for patient transport. An adjustable shoulder brace with lockable tubing-connectors enables safe fixation of the blood tubing. ECMOve provides safety, support, and accessibility while performing ambulatory ECMO for both patient and caregiver. Prototype evaluation in a simulated intensive care unit showed feasibility of our design, but needs to be evaluated in clinical care

CARD8:A Gas-Exchange-Area-Adjustable Oxygenator for Extremely Preterm Infants

Purpose: Worldwide, 600,000 infants are born extremely premature (EP) each year. Supporting the immature lungs of these smallest patients today using mechanical ventilation can cause severe lung damage. Extracorporeal gas exchange (ECMO) used as an “artificial placenta” is expected to provide an alternative treatment to allow full maturation of the lungs. The long-term application for patients doubling their weight every six weeks, requires a new type of “growing” oxygenator.Materials & Methods: We developed a gas-exchange-area-adjustable oxygenator that allows to operate at two different size stages without changing the device nor increasing the flow resistance. Our prototype houses two concentric oxygenator-chambers of equal gas exchange area. When the outer chamber is in operation, the oxygenator provides the required gas exchange area for a 24-week infant. Single-chamber operation allows adaequate gas exchange of volume flows from 50 - 125 ml/min while double-chamber operation then covers flow-demands from 125 - 200 ml/min. Both operational modes in combination can cover the needs of infants from 24 to 28 weeks postmenstrual age. We performed gas-transfer measurements of the prototype in accordance with ISO 7199 and FDA guideline.Results: Gas transport performance for the outer cylinder operating at Vblood = 50 mL/min (24 week premature infant) is VO2 = 1.8 mL/min (= 36 mLO2/Lblood flow). At a flow of Vblood = 125 mL/min the second chamber was switched on and the gas transfer performance increased by 50.1 %. Both chambers have a gas transport performance of VO2 = 4.19 ml/min at Vblood = 150 ml/min (= 28 mLO2/Lblood flow)Conclusion: It could be demonstrated that the gas-transfer of the newly proposed volume-adjustable oxygenator design is sufficient to increase the gas transfer performance while increasing the blood volume flow. We consider this a first milestone for oxygenation of growing EP infants without the need to replace the extracorporeal circuit, avoiding the associated risks

Influence of utilizing hemodialysis membranes outside-in on solute clearance and filtration efficiency – One step towards a novel combined lung and kidney support device

Many membrane oxygenator patients suffer from renal disfunction. For these patients, a novel device integrating artificial lung and kidney support is being developed. Although outside-in blood flow is standard for membrane oxygenators, this is not typical for hemodialysis systems. The effect of outside-in blood flow on the efficiency of hemodialysis fibers for continuous hemodialysis and hemofiltration is yet unclear. This study evaluates the efficiency of commercial hemodialyzer membranes utilized outside-in compared to traditional inside-out mode regarding clearance of urea and creatinine, and ultrafiltration coefficient during in-vitro tests with porcine blood. Our results showed that dialyzers (1.2 m2, asymmetric hollow fibers) utilized outside-in had similar clearances of urea and creatinine compared to dialyzers used in the traditional mode (p &gt; 0.7). However, outside-in dialyzers had an ultrafiltration coefficient four times lower than dialyzers applied in a conventional way, but adequate fluid removal could be achieved by controlling pressures in the system. This in-vitro study indicates that outside-in fibers could be sufficiently effective to maintain typical continuous renal replacement therapy doses. We regard this as one step towards a novel device with a mixed membrane fiber bundle utilizing blood flow outside both hemodialysis fibers and gas exchange fibers to provide simultaneous lung and kidney support.</p

TPMS-based membrane lung with locally-modified permeabilities for optimal flow distribution

Membrane lungs consist of thousands of hollow fiber membranes packed together as a bundle. The devices often suffer from complications because of non-uniform flow through the membrane bundle, including regions of both excessively high flow and stagnant flow. Here, we present a proof-of-concept design for a membrane lung containing a membrane module based on triply periodic minimal surfaces (TPMS). By warping the original TPMS geometries, the local permeability within any region of the module could be raised or lowered, allowing for the tailoring of the blood flow distribution through the device. By creating an iterative optimization scheme for determining the distribution of streamwise permeability inside a computational porous domain, the desired form of a lattice of TPMS elements was determined via simulation. This desired form was translated into a computer-aided design (CAD) model for a prototype device. The device was then produced via additive manufacturing in order to test the novel design against an industry-standard predicate device. Flow distribution was verifiably homogenized and residence time reduced, promising a more efficient performance and increased resistance to thrombosis. This work shows the promising extent to which TPMS can serve as a new building block for exchange processes in medical devices

Совершенствование управления техническим состоянием магистрального нефтепровода при оптимизации работы станции катодной защиты

В процессе исследования проводились расчеты параметров катодной защиты магистрального нефтепровода, применение метода оптимизации работы станции катодной защиты. Приведены мероприятия по охране труда и безопасности проведения работ по обслуживанию станций катод-ной защиты, охране окружающей среды, технико-экономическая часть.In today’s world, a stronger demand for corrosion knowledge arises due to several reasons. Among them, the application of new materials requires extensive information concerning corrosion behavior of these particular mate-rials. Also the corro-sivity of water and atmosphere have increased due to pol-lution and acidification caused by industrial production. The trend in technolo-gy to produce stronger materials with decreasing size makes it relatively more expensive to add a corrosion allowance to thickness. Particularly in applica-tions where accurate dimensions are required, widespread use of welding due to developing construction sector has increased the number of corrosion prob-lems. Developments in other sectors such as offshore oil and gas extraction, nuclear power production and me