Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 621
Filtrar
1.
Life Sci Space Res (Amst) ; 25: 42-52, 2020 May.
Artículo en Inglés | MEDLINE | ID: mdl-32414492

RESUMEN

The feasibility and design of the CultCube 12U CubeSat hosting a small Environmental Control and Life Support Systems (ECLSS) for the autonomous cultivation of a small plant in orbit is described. The satellite is aimed at running experiments in fruit plants growing for applications in crewed vehicles for long-term missions in space. CultCube is mainly composed of a pressurized vessel, constituting the outer shell of the ECLSS, and by various environmental controls (water, nutrients, air composition and pressure, light, etc.) aimed at maintaining a survivable habitat for the fruit plants to grow. The plant health status and growth performances is monitored using hyperspectral cameras installed within the vessel, able to sense leaves' chlorophyll content and temperature, and allowing the estimation of plant volume in all its life cycle phases. The paper study case is addressed to the in-orbit experimental cultivation of a dwarf tomato plant (MicroTom), which was modified for enhancing the anti-oxidants production and for growing in stressful environments. While simulated microgravity tests have been passed by the MicroTom plant, the organism behaviour in a real microgravity environment for a full seed-to-seed cycle needs to be tested. The CultCube 12U CubeSat mission presents no particular requirements on the kind of orbit, whereas its minimum significative duration corresponds to one seed-to-seed cycle for the plant, which is 90 days for the paper study case. In the paper, after an introduction on the importance of an autonomous testbed for plant cultivation, in the perspective of the implementation of bioregenerative systems on-board future manned long-term missions, the satellite design and the MicroTom engineered plant for in-orbit growth are described. In addition to the description of the whole set of subsystems, with focus on the payload and its controllers and instrumentation, the system budgets are presented. Finally, the first tests conducted by the authors are briefly reported.


Asunto(s)
Sistemas Ecológicos Cerrados , Sistemas de Manutención de la Vida/instrumentación , Solanum lycopersicum/crecimiento & desarrollo , Producción de Cultivos/instrumentación , Sistemas de Manutención de la Vida/economía , Vuelo Espacial/economía , Vuelo Espacial/instrumentación , Nave Espacial , Ingravidez
2.
Life Sci Space Res (Amst) ; 25: 53-65, 2020 May.
Artículo en Inglés | MEDLINE | ID: mdl-32414493

RESUMEN

The Arthrospira-B experiment is the first experiment in space ever allowing the online measurements of both oxygen production rate and growth rate of Limnospira indica PCC8005 in batch photobioreactors running on-board ISS. Four bioreactors were integrated in the ISS Biolab facility. Each reactor was composed of two chambers (gas and liquid) separated by a PTFE membrane and was run in batch conditions. Oxygen production was monitored by online measurement of the total pressure increase in the gas chamber. The experiments are composed of several successive batch cultures for each reactor, performed in parallel on ISS and on ground. In this work, a model for the growth of the cyanobacterium Limnospira indica PCC8005 (also known as Arthrospira or spirulina) in these space membrane photobioreactors was proposed and the simulation results obtained are compared to the experimental results gathered in space and on ground. The photobioreactor model was based on a light transfer limitation model, already used to describe and predict the growth and oxygen production in small to large scale ground photobioreactors. It was completed by a model for pH prediction in the liquid phase allowing assessment of the pH increase associated to the bicarbonate consumption for the biomass growth. A membrane gas-liquid transfer model is used to predict the gas pressure increase in the gas chamber. Substrate limitation is considered in the biological model. A quite satisfactory fit was achieved between experimental and simulation results when a suitable mixing of the liquid phase was maintained. The data showed that microgravity has no first order effect on the oxygen production rate of Limnospira indica PCC8005 in a photobioreactor operating in space in zero gravity conditions.


Asunto(s)
Cianobacterias/crecimiento & desarrollo , Oxígeno/metabolismo , Fotobiorreactores , Cianobacterias/metabolismo , Concentración de Iones de Hidrógeno , Sistemas de Manutención de la Vida/instrumentación , Luz , Modelos Teóricos , Nave Espacial , Ingravidez
3.
Metas enferm ; 22(7): 56-64, sept. 2019. ilus, tab
Artículo en Español | IBECS | ID: ibc-184100

RESUMEN

En los pacientes postoperados de cirugía cardiaca, la mayoría de las paradas cardiorrespiratorias (PCR) requieren una reapertura esternal emergente. Cuando esta situación no revierte, la colocación de un dispositivo de membrana de oxigenación extracorpórea (ECMO) se ha definido como una terapia eficaz para mejorar la supervivencia y disminuir los daños neurológicos. La canulación de ECMO central en estos pacientes supone una opción rápida y segura, aunque es necesaria la formación continua y la realización de guías de procedimiento para que todo el personal pueda actuar de manera rápida y eficaz. El desarrollo de este protocolo tiene como objetivos: a) Estandarizar la secuencia de intervenciones en la colocación de ECMO central en PCR. b) Establecer y definir los roles de cada uno de los profesionales implicados durante el proceso. c) Describir las posibles complicaciones que pueden aparecer para poder prevenir su aparición o minimizar sus consecuencias. d) Identificar los diagnósticos de Enfermería y planificar los cuidados adecuados


In patients who have undergone cardiac surgery, most cardiorespiratory arrests (CRAs) require emergent sternal reopening. When this situation is not reversed, the use of extracorporeal membrane oxygenation (ECMO) has been defined as an effective therapy in order to improve survival and reduce neurological damage. Central ECMO cannulation in these patients represents a fast and safe option, though continuous training is required, as well as preparing procedure guidelines so that all the staff can act in a fast and effective manner. The objectives for developing this protocol are: a) To standardize the sequence of interventions in the placement of central ECMO at CRA; b) To determine and define the roles of each professional involved during the process; c) To describe any potential complications that might appear, in order to prevent them or minimize their consequences; d) To identify nursing diagnoses and determine the adequate plan of care


Asunto(s)
Humanos , Atención de Enfermería , Enfermería Práctica , Cateterismo , Circulación Extracorporea/enfermería , Paro Cardíaco/enfermería , Cirugía Torácica , Periodo Posoperatorio , Sistemas de Manutención de la Vida/instrumentación , Diagnóstico de Enfermería , Evaluación en Enfermería
4.
Trends Biotechnol ; 37(11): 1164-1174, 2019 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-31303341

RESUMEN

Human space exploration and settlement will require leaps forward in life support for environmental management and healthcare. Life support systems must efficiently use nonrenewable resources packed from Earth while increasingly relying on resources available locally in space. On-demand production of components and materials (e.g., 3D printing and synthetic biology) holds promise to satisfy the evolving set of supplies necessary to outfit human missions to space. We consider here life support systems for missions planned in the 2020s, and discuss how the maker and 'do-it-yourself' (DIY) biology communities can develop rapid, on-demand manufacturing techniques and platforms to address these needs. This Opinion invites the diverse maker community into building the next generation of flight hardware for near-term space exploration.


Asunto(s)
Sistemas de Manutención de la Vida/instrumentación , Vuelo Espacial/instrumentación , Humanos , Biología Sintética/instrumentación , Biología Sintética/métodos , Ingravidez
6.
Life Sci Space Res (Amst) ; 20: 35-52, 2019 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-30797433

RESUMEN

Bioregenerative technologies, in particular algae photobioreactors, have the potential to provide closed-loop environmental control and life support for human space flight, if robust enough for long-duration deep space missions. This paper reviews the failure modes, causes, and effects of an algal photobioreactor system for use in space flight environmental control and life support applications. The likelihood and severity for each failure is estimated, and associated mitigation or contingency plans are described. Failure modes can stem from either the algae cellular physiology or the engineered system needed for the application and are grouped in this paper accordingly.


Asunto(s)
Sistemas Ecológicos Cerrados , Sistemas de Manutención de la Vida/instrumentación , Microalgas/fisiología , Fotobiorreactores , Nave Espacial/instrumentación , Humanos , Hidrodinámica
7.
Sci Total Environ ; 651(Pt 2): 2080-2086, 2019 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-30321729

RESUMEN

Water management subsystem (WMS) is a major component of the controlled ecological life support system (CELSS). For guaranteeing the water requirement of crop growth and crewmember's daily life, a WMS was established in a 4 person 180-day integrated experiment (carried out in Shenzhen, China, 2016) to maintain a closed cycle with a total water amount of ~23 m3. The design and operation of the WMS was summarized as follows: (1) Collection and allocation of condensate water. About 917 L/d condensate water (>98% was from plants' evapotranspiration) was collected, and ~866 L/d of which was reused as plant nutrient solution after ultraviolet (UV) disinfection, and 50.6 L/d was used as the raw water for the domestic water supply module (DWS). (2) Domestic water supply. The condensate water from the plant cabin was purified through the DWS, a modified membrane bioreactor (MBR) system, and then provided hygiene and potable water to 4 crewmembers with different water quality standards. (3) Wastewater recovery. 51.4 L/d wastewater from urination and personal hygiene were treated together via a biological wastewater treatment process to complete the conversion of nitrogen and organic matters, and then recycled to plant nutrient solution. (4) Nutrient solution recycling. In the overall water cycle process, the plant nutrient solution was continuously self-circulated and the water quality of which was maintained at a relatively stable level with total organic carbon of 20-30 mg/L and NH4+-N < 1.0 mg/L. The 180-day continuous operation demonstrated that a 100% water closure was achieved. Based on the results of this study, an upgraded water cycle system for larger-scale and longer-term CELSS has been proposed.


Asunto(s)
Sistemas de Manutención de la Vida/instrumentación , Eliminación de Residuos Líquidos/métodos , Purificación del Agua/métodos , Abastecimiento de Agua/métodos , China , Eliminación de Residuos Líquidos/instrumentación , Purificación del Agua/instrumentación
8.
Pediatr Phys Ther ; 30(3): E1-E6, 2018 07.
Artículo en Inglés | MEDLINE | ID: mdl-29924078

RESUMEN

PURPOSE: To examine the feasibility of a new open-area body weight support system (BWSS) to act as both an "assistive" and a "rehabilitative" device within the home. INTERVENTION: A 5-year-old boy with spina bifida used the BWSS during self-selected activities for 10 weeks. Feasibility, behavioral, and clinical assessments provided a quantification of his activity in and out of the BWSS. OUTCOMES: On average, the child used the device on 2.7 days/week and for 67 minutes/day during intervention. When in the BWSS (assistive role), the child's locomotor activity and engagement in adapted sports activities increased. When not in the BWSS (rehabilitative role), the child's functional mobility and ambulatory ability increased. WHAT THIS CASE ADDS: The use of the open-area in-home BWSS was feasible for regular home use and associated with an increase in functional mobility for a child with spina bifida.


Asunto(s)
Peso Corporal/fisiología , Servicios de Atención de Salud a Domicilio , Sistemas de Manutención de la Vida/instrumentación , Limitación de la Movilidad , Rehabilitación/instrumentación , Rehabilitación/métodos , Disrafia Espinal/rehabilitación , Preescolar , Humanos , Masculino , Resultado del Tratamiento , Estados Unidos
9.
Life Sci Space Res (Amst) ; 17: 1-14, 2018 May.
Artículo en Inglés | MEDLINE | ID: mdl-29753408

RESUMEN

A soil-based cropping unit fuelled with human urine for long-term manned space missions was investigated with the aim to analyze whether a closed-loop nutrient cycle from human liquid wastes was achievable. Its ecohydrology and biogeochemistry were analysed in microgravity with the use of an advanced computational tool. Urine from the crew was used to supply primary (N, P, and K) and secondary (S, Ca and Mg) nutrients to wheat and soybean plants in the controlled cropping unit. Breakdown of urine compounds into primary and secondary nutrients as well as byproduct gases, adsorbed, and uptake fractions were tracked over a period of 20 years. Results suggested that human urine could satisfy the demand of at least 3 to 4 out of 6 nutrients with an offset in pH and salinity tolerable by plants. It was therefore inferred that a urine-fuelled life support system can introduce a number of advantages including: (1) recycling of liquids wastes and production of food; (2) forgiveness of neglect as compared to engineered electro-mechanical systems that may fail under unexpected or unplanned conditions; and (3) reduction of supply and waste loads during space missions.


Asunto(s)
Glycine max/crecimiento & desarrollo , Sistemas de Manutención de la Vida/instrumentación , Suelo/química , Vuelo Espacial , Triticum/crecimiento & desarrollo , Orina/química , Humanos , Vuelo Espacial/instrumentación , Administración de Residuos/métodos , Recursos Humanos
10.
Artif Organs ; 42(4): 354-364, 2018 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-29323409

RESUMEN

The objective of this study was to compare three different hemoconcentrators (Hemocor HPH 400, Mini, and Junior) with two different neonatal ECMO circuits using a roller or a centrifugal pump at different pseudo-patient pressures and flow rates in terms of hemodynamic properties. This evidence-based research is necessary to optimize the ECMO circuitry for neonates. The circuits used a 300-mL soft-shell reservoir as a pseudo-patient approximating the blood volume of a 3 kg neonate, two blood pumps, and a Quadrox-iD Pediatric oxygenator with three different in-line hemoconcentrators (Hemocor HPH 400, Mini, and Junior). One circuit used a Maquet H20 roller pump and another circuit used a Maquet RotaFlow centrifugal pump. The circuit was primed with lactated Ringer's solution followed by heparinized packed red blood cells with a hematocrit of 40%. The pseudo-patient's pressure was manually maintained at 40, 60, or 80 mm Hg and the flow rate was maintained at 200, 400, or 600 mL/min with a circuit temperature of 36°C. Pressure and flow data was recorded using a custom-made data acquisition device. Mean pressures, diverted blood flow, pressure drops, and total hemodynamic energy (THE) were calculated for each experimental condition. The roller pump and centrifugal pump performed similarly for all hemodynamic properties with all experimental conditions. The Hemocor HPH Junior hemoconcentrator added the highest resistance to the circuit. The Hemocor HPH Junior provided the highest circuit pressures, lowest diverted blood flow, highest pressure drop across the circuit, and highest THE generated by the pump. The Hemocor HPH 400 added the least resistance to the circuit, providing the lowest circuit pressures, more diverted flow, lowest pressure drop, and the lowest THE generated by the pump. However, the THE delivered to the patient was the same for the three hemoconcentrators. While the three hemoconcentrators performed differently in terms of hemodynamic properties throughout the circuit, the THE transmitted to the patient was similar for all three hemoconcentrators due to the consistent pseudo-patient's pressure that was manually maintained for each trial. While the THE delivered to the patient indicates similar perfusion for these patients with any of the three hemoconcentrators, the differences in added resistance to the circuit may impact the decision of which hemoconcentrator is used. There was no clinically significant difference between the two circuits with the roller versus centrifugal pump in terms of hemodynamic properties in this study. Further in vivo research is warranted to confirm our findings.


Asunto(s)
Oxigenación por Membrana Extracorpórea/instrumentación , Sistemas de Manutención de la Vida/instrumentación , Modelos Cardiovasculares , Oxigenación por Membrana Extracorpórea/métodos , Filtración , Hemorreología , Humanos , Recién Nacido , Oxigenadores de Membrana , Presión
11.
Artif Organs ; 42(4): 365-376, 2018 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-28940550

RESUMEN

The objective of this study was to evaluate the hemodynamic performance and gaseous microemboli (GME) handling ability of a simulated neonatal extracorporeal life support (ECLS) circuit with an in-line continuous renal replacement therapy (CRRT) device. The circuit consisted of a Maquet RotaFlow centrifugal pump or HL20 roller pump, Quadrox-iD Pediatric diffusion membrane oxygenator, 8-Fr arterial cannula, 10-Fr venous cannula, and Better-Bladder (BB) with "Y" connector. A second Quadrox-I Adult oxygenator was added postarterial cannula for GME experiments. The circuit and pseudo-patient were primed with lactated Ringer's solution and packed human red blood cells (hematocrit 40%). All hemodynamic trials were conducted at ECLS flow rates ranging from 200 to 600 mL/min and CRRT flow rate of 75 mL/min at 36°C. Real-time pressure and flow data were recorded with a data acquisition system and GME were detected and characterized using the Emboli Detection and Classification Quantifier System. CRRT was added at distinct locations such that blood entered CRRT between the pump and oxygenator (A), recirculated through the pump (B), or bypassed the pump (C). With the centrifugal pump, all CRRT positions had similar flow rates, mean arterial pressure (MAP), and total hemodynamic energy (THE) loss. With the roller pump, C demonstrated increased flow rates (293.2-686.4 mL/min) and increased MAP (59.4-75.5 mm Hg) (P < 0.01); B had decreased flow rates (129.7-529.7 mL/min), and MAP (34.2-45.0 mm Hg) (P < 0.01); A maintained the same when compared to without CRRT. At 600 mL/min C lost more THE (81.4%) (P < 0.01) with a larger pressure drop across the oxygenator (95.6 mm Hg) (P < 0.01) than without CRRT (78.3%; 49.1 mm Hg) (P < 0.01). C also demonstrated a poorer GME handling ability using the roller pump, with 87.1% volume and 17.8% count reduction across the circuit, compared to A and B with 99.9% volume and 65.8-72.3% count reduction. These findings suggest that, in contrast to A and B, adding CRRT at position C is unsafe and not advised for clinical use.


Asunto(s)
Embolia Aérea/prevención & control , Oxigenación por Membrana Extracorpórea/métodos , Sistemas de Manutención de la Vida/instrumentación , Modelos Cardiovasculares , Diálisis Renal/métodos , Terapia de Reemplazo Renal/métodos , Oxigenación por Membrana Extracorpórea/efectos adversos , Oxigenación por Membrana Extracorpórea/instrumentación , Gases , Hemofiltración/efectos adversos , Hemofiltración/instrumentación , Hemofiltración/métodos , Hemorreología , Humanos , Recién Nacido , Oxigenadores de Membrana , Diálisis Renal/efectos adversos , Diálisis Renal/instrumentación , Terapia de Reemplazo Renal/efectos adversos , Terapia de Reemplazo Renal/instrumentación
12.
Artif Organs ; 42(4): 377-385, 2018 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-29193160

RESUMEN

Technological innovations in pediatric extracorporeal life support circuits can reduce system-related complications and may improve patients' outcome. The Deltastream DP3 (Medos Medizintechnik AG, Stolberg, Germany) is a novel rotational pump with a diagonally streamed impeller that can be used over a broad range of flows. We collected patient data from seven pediatric centers to conduct a retrospective cohort study. We examined 233 patients whose median age was 1.9 (0-201) months. The DP3 system was used for cardiopulmonary support as veno-arterial extracorporeal membrane oxygenation (ECMO) in 162 patients. Respiratory support via veno-venous ECMO was provided in 63 patients. The pump was used as a ventricular assist device in eight patients. Median supporting time was 5.5 (0.2-69) days and the weaning rate was 72.5%. The discharge home rate was 62% in the pulmonary group versus 55% in the cardiac group. Extracorporeal cardiopulmonary resuscitation was carried out in 24 patients (10%) with a survival to discharge of rate of 37.5%. About 106 (47%) children experienced no complications, while 33% suffered bleeding requiring blood transfusion or surgical intervention. Three patients suffered a fatal cerebral event. Renal replacement therapy was performed in 28% and pump or oxygenator exchange in 26%. Multivariable analysis identified system exchange (OR 1.94), kidney failure (OR 3.43), and complications on support (OR 2.56) as risk factors for dismal outcome. This novel diagonal pump has demonstrated its efficacy in all kinds of mechanical circulatory and respiratory support, revealing good survival rates.


Asunto(s)
Reanimación Cardiopulmonar/instrumentación , Oxigenación por Membrana Extracorpórea/instrumentación , Hemorragia/epidemiología , Sistemas de Manutención de la Vida/instrumentación , Insuficiencia Renal/epidemiología , Adolescente , Reanimación Cardiopulmonar/efectos adversos , Reanimación Cardiopulmonar/métodos , Reanimación Cardiopulmonar/mortalidad , Niño , Preescolar , Europa (Continente) , Oxigenación por Membrana Extracorpórea/efectos adversos , Oxigenación por Membrana Extracorpórea/métodos , Femenino , Corazón Auxiliar/efectos adversos , Hemorragia/etiología , Humanos , Lactante , Recién Nacido , Unidades de Cuidados Intensivos/estadística & datos numéricos , Masculino , Oxigenadores , Flujo Pulsátil , Insuficiencia Renal/etiología , Estudios Retrospectivos , Tasa de Supervivencia , Resultado del Tratamiento
13.
Artif Organs ; 41(8): 717-726, 2017 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-28782157

RESUMEN

Extracorporeal life support (ECLS) provides mechanical support following cardiac surgery when respiratory or cardiac failure occurs. The aim of this study was to analyze the safety and feasibility of the Medos Deltastream diagonal pump (DP3) ECLS system in pediatric cardiac patients. We described the technical considerations and risk factors related to the survival outcomes in 102 pediatric cardiac patients who received ECLS support between March 2011 and April 2016. We switched from the DP2 system, which was used for the initial 25 patients, to the DP3 system after November 2012. The DP3 was then used in a consecutive series of 77 patients (4.5% of all pediatric patients who underwent congenital heart surgery during the same time period). The patients' median age was 90 days (range: 2 days-12 years), while their median weight was 4 kg (range: 2.1-40 kg). Fifty four patients (70%) were weaned off ECLS, while 28 patients (36.3%) were successfully discharged from the hospital by means of the DP3 system. The median ECLS duration for survivors was 8.2 days (range: 4-14.5 days). The ECLS indications, durations, and initiation times had no statistical significance in terms of survival. Renal, hemorrhagic, and neurologic complications were all associated with decreased hospital discharge rates (P = 0.003, P = 0.045, and P < 0.001 respectively). Higher lactate levels (P = 0.009) and longer duration for normalization (P < 0.001) were both associated to failure to wean off ECLS support and, hence, to hospital deaths. The weaning rate was 36% prior to November 2012. It increased to 70.3% after that time (P = 0.009). The mechanical complication rate was 9% with the DP3 system and 32% with the DP2, which was statistically significant (P = 0.009). Additionally, the lactate levels were higher and decreased more slowly in the patients supported by the DP2. As a result of the shift to the DP3 system, a revised ECLS protocol, and increased ECLS experience, a significant improvement was observed in our clinical outcomes. The results of this study suggested that the combination of a DP3 pump and a Hilite oxygenator in pediatric ECLS circuits may improve durability and reduce circuit-induced complications.


Asunto(s)
Oxigenación por Membrana Extracorpórea/efectos adversos , Oxigenación por Membrana Extracorpórea/instrumentación , Cardiopatías Congénitas/cirugía , Procedimientos Quirúrgicos Cardíacos/efectos adversos , Procedimientos Quirúrgicos Cardíacos/instrumentación , Procedimientos Quirúrgicos Cardíacos/métodos , Niño , Preescolar , Diseño de Equipo , Oxigenación por Membrana Extracorpórea/métodos , Femenino , Humanos , Lactante , Recién Nacido , Sistemas de Manutención de la Vida/instrumentación , Masculino , Resultado del Tratamiento
14.
Transfusion ; 57(6): 1391-1395, 2017 06.
Artículo en Inglés | MEDLINE | ID: mdl-28301052

RESUMEN

BACKGROUND: Activation and consumption of platelets (PLT) and clotting factors along with hemolysis occurs when blood contacts the extracorporeal life support (ECLS) circuit and its components. STUDY DESIGN AND METHODS: The objective was to examine the effects of reducing ECLS circuit volume by decreasing tubing length and changing components on blood product usage in neonatal and pediatric patients. Blood product administration was analyzed in 40 consecutive patients who required ECLS for respiratory or cardiac failure before (PRE) and after (POST) changes in circuit design and components. RESULTS: The total circuit volume was reduced from 500 mL (PRE) to 275 mL (POST). In the POST group, total blood product volume usage was 58% lower compared to the PRE group (81 mL/kg/day vs. 191 mL/kg/day, p = 0.003), 65% lower for fresh-frozen plasma (FFP; 15 mL/kg/day vs. 43 mL/kg/day, p = 0.001), and PLT volumes trended lower. In the subgroup of infants with respiratory or cardiac failure, there was a 55% reduction of a total blood product replacement (61 mL/kg/day vs. 136 mL/kg/day, p = 0.008), red blood cell (RBC) use was 61% lower (28 mL/kg/day vs. 71 mL/kg/day, p < 0.049), and there was a 73% reduction in FFP use (11 mL/kg/day vs. 41 mL/kg/day, p < 0.001). In the subgroup of postoperative infants, there was a 25% decrease in RBC use (86 mL/kg/day vs. 115 mL/kg/day, p = 0.03). CONCLUSION: Decreasing the ECLS circuit volume by reducing the tubing length and changing the components was associated with a significant reduction in blood product usage.


Asunto(s)
Eritrocitos/fisiología , Oxigenación por Membrana Extracorpórea/instrumentación , Humanos , Sistemas de Manutención de la Vida/instrumentación , Plasma
15.
Artif Organs ; 41(1): 55-65, 2017 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-28093803

RESUMEN

The objective of this study is to evaluate electrocardiography (ECG)-synchronized pulsatile flow under varying heart rates and different atrial and ventricular arrhythmias in a simulated extracorporeal life support (ECLS) system. The ECLS circuit consisted of an i-cor diagonal pump and console, an iLA membrane ventilator, and an 18 Fr arterial cannula. The circuit was primed with lactated Ringer's solution and packed red blood cells (hematocrit 35%). An ECG simulator was used to trigger pulsatile flow and to generate selected cardiac rhythms. All trials were conducted at a flow rate of 2.5 L/min at room temperature for normal sinus rhythm at 45-180 bpm under non-pulsatile and pulsatile modes. Various atrial and ventricular arrhythmias were also tested. Real-time pressure and flow data were recorded using a custom-based data acquisition system. The energy equivalent pressure (EEP) generated by pulsatile flow was always higher than the mean pressure. No surplus hemodynamic energy (SHE) was recorded under non-pulsatile mode. Under pulsatile mode, SHE levels increased with increasing heart rates (45-120 bpm). SHE levels under a 1:2 assist ratio were higher than the 1:1 and 1:3 assist ratios with a heart rate of 180 bpm. A similar trend was recorded for total hemodynamic energy levels. There was no statistical difference between the two perfusion modes with regards to pressure drops across the ECLS circuit. The main resistance and energy loss came from the arterial cannula. The i-cor console successfully tracked electrocardiographic signals of 12 atrial and ventricular arrhythmias. Our results demonstrated that the i-cor pulsatile ECLS system can be synchronized with a normal heart rate or with various atrial/ventricular arrhythmias. Further in vivo studies are warranted to confirm our findings.


Asunto(s)
Arritmias Cardíacas/fisiopatología , Oxigenación por Membrana Extracorpórea/instrumentación , Frecuencia Cardíaca , Flujo Pulsátil , Electrocardiografía/instrumentación , Diseño de Equipo , Hemodinámica , Humanos , Sistemas de Manutención de la Vida/instrumentación
16.
Biomed Tech (Berl) ; 62(2): 111-121, 2017 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-28121614

RESUMEN

Computational models of biophysical systems generally constitute an essential component in the realization of smart biomedical technological applications. Typically, the development process of such models is characterized by a great extent of collaboration between different interdisciplinary parties. Furthermore, due to the fact that many underlying mechanisms and the necessary degree of abstraction of biophysical system models are unknown beforehand, the steps of the development process of the application are iteratively repeated when the model is refined. This paper presents some methods and tools to facilitate the development process. First, the principle of object-oriented (OO) modeling is presented and the advantages over classical signal-oriented modeling are emphasized. Second, our self-developed simulation tool ModeliChart is presented. ModeliChart was designed specifically for clinical users and allows independently performing in silico studies in real time including intuitive interaction with the model. Furthermore, ModeliChart is capable of interacting with hardware such as sensors and actuators. Finally, it is presented how optimal control methods in combination with OO models can be used to realize clinically motivated control applications. All methods presented are illustrated on an exemplary clinically oriented use case of the artificial perfusion of the systemic circulation.


Asunto(s)
Gráficos por Computador , Diagnóstico por Computador/métodos , Estudios Interdisciplinarios , Sistemas de Manutención de la Vida/instrumentación , Modelos Biológicos , Terapia Asistida por Computador/métodos , Algoritmos , Investigación Biomédica/instrumentación , Investigación Biomédica/métodos , Simulación por Computador , Diagnóstico por Computador/instrumentación , Lenguajes de Programación , Terapia Asistida por Computador/instrumentación
17.
J Card Fail ; 23(2): 181-196, 2017 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-27989868

RESUMEN

Extracorporeal life support (ECLS) describes a system that involves drainage from the venous circulation and return via an oxygenator into the arterial circulation (veno-arterial extracorporeal membrane oxygenation). ECLS provides effective cardiopulmonary support, but the parallel circulation has complex effects on the systemic and pulmonary circulatory physiology. An understanding of the physiological changes is fundamental to the management of ECLS. In this review, the key physiological concepts and the implications on the clinical management of ECLS are discussed. In addition, the clinical outcomes associated with ECLS in cardiogenic shock are systematically reviewed. The paucity of clinical trials on ECLS highlights the need for randomized trials to guide the selection of patients.


Asunto(s)
Oxigenación por Membrana Extracorpórea/métodos , Insuficiencia Cardíaca/terapia , Fenómenos Fisiológicos , Choque Cardiogénico/terapia , Enfermedad Crítica/terapia , Circulación Extracorporea/métodos , Femenino , Insuficiencia Cardíaca/diagnóstico , Insuficiencia Cardíaca/mortalidad , Humanos , Sistemas de Manutención de la Vida/instrumentación , Masculino , Monitoreo Fisiológico/métodos , Medición de Riesgo , Choque Cardiogénico/diagnóstico , Choque Cardiogénico/mortalidad , Tasa de Supervivencia , Factores de Tiempo , Resultado del Tratamiento
18.
Artif Organs ; 41(1): 70-75, 2017 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-27862035

RESUMEN

The objective of this study is to evaluate the impact of an open or closed recirculation line on flow rate, circuit pressure, and hemodynamic energy transmission in simulated neonatal extracorporeal life support (ECLS) systems. The two neonatal ECLS circuits consisted of a Maquet HL20 roller pump (RP group) or a RotaFlow centrifugal pump (CP group), Quadrox-iD Pediatric oxygenator, and Biomedicus arterial and venous cannulae (8 Fr and 10 Fr) primed with lactated Ringer's solution and packed red blood cells (hematocrit 35%). Trials were conducted at flow rates ranging from 200 to 600 mL/min (200 mL/min increments) with a closed or open recirculation line at 36°C. Real-time pressure and flow data were recorded using a custom-based data acquisition system. In the RP group, the preoxygenator flow did not change when the recirculation line was open while the prearterial cannula flow decreased by 15.7-20.0% (P < 0.01). Circuit pressure, total circuit pressure drop, and hemodynamic energy delivered to patients also decreased (P < 0.01). In the CP group, the prearterial cannula flow did not change while preoxygenator flow increased by 13.6-18.8% (P < 0.01). Circuit pressure drop and hemodynamic energy transmission remained the same. The results showed that the shunt of an open recirculation line could decrease perfusion flow in patients in the ECLS circuit using a roller pump, but did not change perfusion flow in the circuit using a centrifugal pump. An additional flow sensor is needed to monitor perfusion flow in patients if any shunts exist in the ECLS circuit.


Asunto(s)
Oxigenación por Membrana Extracorpórea/instrumentación , Velocidad del Flujo Sanguíneo , Centrifugación/instrumentación , Simulación por Computador , Diseño de Equipo , Eritrocitos/citología , Hemodinámica , Humanos , Recién Nacido , Sistemas de Manutención de la Vida/instrumentación , Modelos Cardiovasculares , Presión
20.
Acta Biomed ; 87(1): 28-37, 2016 05 06.
Artículo en Inglés | MEDLINE | ID: mdl-27163893

RESUMEN

UNLABELLED: Abstract PURPOSE: several therapeutic options are used in emergency situations, when heart and/or lung functions acutely fail. Because of the poor results of conventional treatments, the use of an extra-corporeal life support (ECLS) systems able to completely assume the heart and lung functions in emergency situations is becoming a viable alternative. We have developed a unique ECLS system for patients needing extended respiratory and/or circulatory support and controlled hypothermia. METHODS: the ECLS apparatus is portable and easy to handle by incorporating a disposable centrifugal blood pump, a membrane oxygenator, a waterless heating/cooling device. A sensor's system is integrated in the equipment for continuous monitoring/displaying of several parameters. RESULTS: the system was tested in bench laboratory studies and in large experimental animals to check feasibility, functionality, durability, consistency and safety. Adult sheep were used, after cannulation of large vessels in the neck, either to test the apparatus in normal physiologic conditions, or under controlled mild hypothermia (33 to 34° C). Two modes of vascular access were tested:  veno-arterial (V-A) and veno-venous (V-V). Vital parameters and systolic blood pressures were continuously monitored up to 48 hours. DISCUSSION: initial laboratory experiment of the He-Art apparatus indicated that the system was safe and able to control and stabilize the hemodynamic conditions. The device represented a second generation ECLS system, by adding the protective effect of moderate to mild hypothermia against ischemic cardiac and brain injuries.


Asunto(s)
Insuficiencia Cardíaca/terapia , Hipotermia Inducida , Sistemas de Manutención de la Vida/instrumentación , Insuficiencia Respiratoria/terapia , Animales , Oxigenación por Membrana Extracorpórea , Insuficiencia Cardíaca/fisiopatología , Hemodinámica , Insuficiencia Respiratoria/fisiopatología , Ovinos
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...