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ABSTRACT: Computational fluid dynamics (CFD) is a useful tool in characterizing artificial lung designs by providing predictions of device performance through analyses of pressure distribution, perfusion dynamics, and gas transport properties. Validation of numerical results in membrane oxygenators has been predominantly based on experimental pressure measurements with little emphasis placed on confirmation of the velocity fields due to opacity of the fiber membrane and limitations of optical velocimetric methods. Biplane X-ray digital subtraction angiography was used to visualize flow of a blood analogue through a commercial membrane oxygenator at 1-4.5 L/min. Permeability and inertial coefficients of the Ergun equation were experimentally determined to be 180 and 2.4, respectively. Numerical simulations treating the fiber bundle as a single momentum sink according to the Ergun equation accurately predicted pressure losses across the fiber membrane, but significantly underestimated velocity magnitudes in the fiber bundle. A scaling constant was incorporated into the numerical porosity and reduced the average difference between experimental and numerical values in the porous media regions from 44 ± 4% to 6 ± 5%.
Annals of biomedical engineering 05/2013; · 2.41 Impact Factor
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ABSTRACT: Venovenous extracorporeal membrane oxygenation (ECMO) can support gas exchange in patients with primary respiratory failure. Venovenous ECMO can be initiated through a single-site, dual-lumen cannula designed for insertion in the right internal jugular vein. We describe four cases of hypercapnic or hypoxemic respiratory failure, in which we performed single-site cannulation of the left internal jugular vein with 23 Fr or 27 Fr bicaval dual-lumen catheters when the right internal jugular vein was inaccessible because of either stenosis or thrombosis. The surgical approach for left-sided access is similar to the approach used for the right internal jugular vein. The left-sided approach resulted in equivalent blood flow and gas exchange compared with our previous experience with right-sided cannulation. This case series demonstrates the feasibility of placing a bicaval dual-lumen catheter in the left internal jugular vein for the initiation of venovenous ECMO when the right internal jugular vein is inaccessible.
ASAIO journal (American Society for Artificial Internal Organs: 1992) 10/2012; · 1.39 Impact Factor
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ABSTRACT: Our original venovenous perfusion-induced systemic hyperthermia (vv-PISH) system appeared to significantly improve the survival of patients with lung cancer, but was too complex with numerous dialysis problems. We tested a simplified vv-PISH circuit that includes the Avalon Elite (Avalon Laboratories, LLC, Rancho Dominguez, CA) double lumen cannula, a modified heat exchanger, a water heater/cooler, and a centrifugal pump. The purpose of this study was to evaluate this simplified vv-PISH system (without hemodialyzer) and to investigate the physiologic response to whole-body hyperthermia in pigs. We tested our vv-PISH circuit in healthy adult female swine (n = 7, 55-68 kg). The therapeutic core temperature (42°C), calculated as mean of rectal, bladder, and esophageal temperatures, was achieved in six swine. A maximum difference of 0.5°C was observed between the individual temperature sensor readings, indicating homogeneous heat distribution. Heart rate and mean arterial pressure were transiently altered, but were safely managed. A significant elevation in pulmonary artery pressure occurred during the heating phase, resulting in death of one pig. In all other pigs, pulmonary artery pressure returned to physiologic values during the therapeutic phase. Arterial blood electrolytes were maintained without the need of a dialyzer. Major organ function was within normal parameters. The simplified vv-PISH circuit reliably delivered the hyperthermic dose with no need of dialysis.
ASAIO journal (American Society for Artificial Internal Organs: 1992) 10/2012; · 1.39 Impact Factor
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ABSTRACT: Conventional extracorporeal membrane oxygenation is bulky and non-ambulatory and requires multiple blood transfusions. We hypothesized that a percutaneous, paracorporeal artificial lung (PAL) could be established through a single venous cannulation to provide long-term ambulatory respiratory support.
Our PAL system was tested in 11 healthy sheep. An Avalon Elite dual-lumen cannula (DLC), inserted through the right jugular vein into the superior vena cava, right atrium, and inferior vena cava, was connected to a CentriMag pump and compact hollow-fiber gas exchanger, forming a short-circuit PAL system. All sheep were moved to intensive care unit and were ambulatory after anesthesia recovery. Hemodynamics and device performance were measured daily.
The ambulatory PALs were successfully established in all sheep. The sheep were awake, ate, and moved freely in the metabolic cage, with no need of artificial nutrition or blood transfusion. All sheep had stable hemodynamics, with 2 liters/min of average circuit flow and hemoglobin levels exceeding 9.2 g/dl throughout the experiment. A progressive decrease of oxygen transfer and carbon dioxide removal capacity was observed. Sheep were euthanized between 10 and 24 days for bleeding (n = 2), gas exchanger failure (n = 6), and DLC issues (n = 3).
We successfully established long-term ambulatory PAL for up to 24 days in 11 animals using our patented DLC through a single-site percutaneous venous cannulation. Critical bleeding/thrombosis formation and gas exchanger durability remain two major challenges for long-term-ambulatory PAL.
The Journal of heart and lung transplantation: the official publication of the International Society for Heart Transplantation 03/2012; 31(6):648-54. · 3.54 Impact Factor
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ABSTRACT: The altered respiratory mechanics in patients with chronic obstructive pulmonary disease (COPD) present unique challenges with regard to treatment during an acute exacerbation that often leads to respiratory support with mechanical ventilation. Alternative therapies are badly needed to reduce morbidity and mortality associated with mechanical ventilator use. We hypothesized that arteriovenous carbon dioxide removal (AVCO2R) coupled with continuous positive airway pressure (CPAP) would achieve total gas exchange eliminating the need for intubation/mechanical ventilation, thus reducing baro/volutrauma. This hypothesis was tested in six adult sedated apneic sheep with AVCO2R administered through a simple arteriovenous (AV) shunt for CO2 removal. Because it is impractical to apply a CPAP mask to conscious sheep, the CPAP was mimicked in intubated/sedated sheep by positive end-expiratory pressure (PEEP) of 5–10 mmH2O with negligible ventilation. The AVCO2R and CPAP-mimic maintained Pao2 and Paco2 in the normal physiological ranges. The CO2 removal was 120–150 ml/min through AVCO2R with AV blood flow of 1.1–1.5 L/min. A high fraction of inspired oxygen percentage (Fio2) level (89 ± 3%) was required to achieve 40 ± 7% O2 in the small bronchus. Thus, AVCO2R and CPAP-mimic achieved total gas exchange in anesthetized sheep and may be a potential option for acute COPD exacerbation in humans.
ASAIO Journal 02/2012; 58(2):155–159. · 1.39 Impact Factor
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ABSTRACT: Acute respiratory distress syndrome (ARDS) is characterized by an acute inflammatory response that compromises alveolar-capillary membrane integrity. Clinical symptoms include refractory hypoxemia, noncardiogenic edema, and decreased lung compliance. The purpose of this review is to summarize the different ARDS large-animal models in terms of similarity to the clinical disease and underlying pathophysiology. The repeated lavage, oleic acid, endotoxin, and smoke/burn ARDS models will be discussed in this review. While each model has significant benefits, none is without weaknesses. Thus, the choice of large-animal ARDS model must be carefully considered based upon the study focus and investigative team experience.
The Annals of thoracic surgery 01/2012; 93(4):1331-9. · 3.74 Impact Factor
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ABSTRACT: We are developing a total cavopulmonary support system for failing Fontan physiology using the percutaneous Wang-Zwische double-lumen cannula (DLC).
We developed a sheep model of failing Fontan physiology through a right thoracotomy in 5 sheep. An extracardiac conduit was anastomosed to the inferior vena cava and superior vena cava, and a graft was applied to connect the conduit and the right pulmonary artery (PA) to create total vena cava-to-PA diversion, excluding the right heart. The DLC (commercialized as AvalonElite, Avalon Laboratories LLC, Rancho Dominguez, CA) was coupled with a CentriMag pump (Levitronix Waltham, MA) to form a cavopulmonary support system. The DLC was inserted through the right jugular vein and the superior vena cava into the extracardiac conduit with the infusion lumen opening aligned with the right PA bridge. Blood was withdrawn from the superior vena cava and the inferior vena cava through the drainage lumen and pumped into the right PA through the infusion lumen, with flow adjusted to 4.0±0.5 L/min.
A successful Fontan model was created without cardiopulmonary bypass. After total venous blood diversion from the vena cava to the right PA artery, failing Fontan physiology developed, evidenced by elevated central venous pressure and dropping mean PA pressure and systolic arterial pressure. The DLC was successfully inserted, and hemodynamics were normalized in all 5 sheep for the duration of the 2-hour study.
We created a model of failing Fontan circulation in sheep without cardiopulmonary bypass. The DLC system achieved total cavopulmonary support for 2 hours in our failing Fontan sheep model.
The Annals of thoracic surgery 06/2011; 91(6):1956-60. · 3.74 Impact Factor
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ABSTRACT: Extracorporeal membrane oxygenation (ECMO) provides supplementary oxygenation and carbon dioxide removal for selected patients on mechanical ventilatory support. Venovenous ECMO is traditionally established by dual cannulation of the internal jugular and femoral veins. We report our institutional experience using single-site, dual-lumen cannula for venovenous ECMO as an alternative to the 2-catheter approach. This approach minimizes recirculation and avoids use of the femoral site, which confers potential advantages.
This is a retrospective review of a single institution's experience with a new bicaval dual lumen ECMO cannula. During a 19-month period, 27 consecutive patients were placed on ECMO using this catheter inserted through the right internal jugular vein.
Single-site venovenous ECMO support was uneventfully initiated in 26 of the 27 patients (median age, 42 years; interquartile range, 31 to 58 years) and achieved full flows and adequate gas exchange. Median ventilator days before ECMO was 1 day (interquartile range, 0.25 to 3.5 days). The median duration of ECMO support was 9 days (interquartile range, 5.5 to 11.5 days). Decannulation was achieved in 70% of the patients and extubation in 59%. Two were bridged to lung transplantation and are still alive. The overall survival and hospital discharge rate was 56%. There was no device failure or in-cannula thrombosis. One superior vena cava injury occurred, and one cannula required repositioning.
Single-site venovenous ECMO has advantages compared with traditional venovenous ECMO. Using image guidance, the cannula can reliably be used in prolonged venovenous ECMO cases.
The Annals of thoracic surgery 06/2011; 91(6):1763-8; discussion 1769. · 3.74 Impact Factor
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ABSTRACT: Our goal was to create a clinically relevant large animal model of pulmonary hypertension to serve as a platform allowing preclinical risk/benefit assessment of innovative therapies including artificial lung prototypes.
Small amounts of filtered air were continuously infused into the pulmonary circulation of sheep (n = 4) for 8 wk. Hemodynamics and blood gases were measured daily. After termination of air embolization, the sheep were observed for 1 additional wk to assess the constancy of the pulmonary artery pressure changes. At the end of wk 9, all sheep were sacrificed and necropsy was performed.
All animals survived the study and developed pulmonary hypertension by wk 5. Mean pulmonary artery pressures were elevated from 14 ± 1 at baseline to 35 ± 1 mmHg at wk 8 (P < 0.01) and remained unchanged throughout wk 9. A similar increase in pulmonary vascular resistance was observed. Systemic arterial pressure and PaO(2) dropped slightly compared with baselines but remained in safe ranges. Histologic evidence of severe pulmonary arterial remodeling and significant right ventricle hypertrophy was observed.
We conclude that our 8-wk model of continuous air embolization produces reliable, chronic pulmonary hypertension in sheep with sustained hemodynamic changes, significant pulmonary vascular remodeling, and right ventricle hypertrophy.
Journal of Surgical Research 05/2011; 170(1):e11-6. · 2.25 Impact Factor
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ABSTRACT: There exists a growing demand for new technology that can take over the function of the human lung, from assisting an injured or recently transplanted lung to completely replacing the native organ. Many obstacles must be overcome to achieve the lofty goals and expectations of such a device. An artificial lung must be able to sustain the gas exchange requirements of a normal functioning lung. Pursuant to this purpose, the device must maintain appropriate blood pressure, decrease injury to blood cells and minimize clotting and immunologic response. Attachment methods vary, and ideally researchers want to find a way that minimizes bodily trauma, maximizes gas exchange and utilizes the inherent properties of the native lung. The currently proposed methods include the parallel, in-series and venous double-lumen cannula configurations. For the time being, current research focuses on the extracorporeal (i.e., outside the body) placement, but ultimate long-term goals look toward total implantation.
Organogenesis 01/2011; 7(1):23-7. · 2.17 Impact Factor
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ABSTRACT: Our current ovine smoke/burn acute respiratory distress syndrome (ARDS) model utilizes a manual bee smoker. This smoke delivery system lacks standardization and reproducibility, with 20% of sheep failing to meet ARDS criteria. Time to reach ARDS criteria and survival time are also variable. The mild volutrauma (15 mL/kg) applied after smoke/burn injury may also fail to induce ARDS within 24 h. We hypothesized that these inconsistencies were associated with the bee smoker and the mild volutrauma. In the current study, we addressed these problems to improve the consistency of the smoke/burn ARDS model.
Adult female sheep (n = 10) were given a 40% total body surface area third degree cutaneous burn and 48 breaths (4 × 12) of cotton smoke under general anesthesia. A modified ventilator was then used to deliver a precise and consistent smoke volume (tidal volume) to the sheep. Additional barotrauma was induced by pressure control ventilation (40 cm H(2)0). When ARDS criteria (PaO(2)/FiO(2) < 200) were met, the ARDS Network low tidal volume ventilation protocol (6-8 mL/kg ideal body weight) was used.
Carboxyhemoglobin levels were 81.4% ± 5.6% immediately following smoke injury. All sheep met ARDS criteria within 24 h (12.5 ± 4.9 h). Mean survival time post-injury was 62.1 ± 26.4 h. White blood cells and granulocytes were significantly elevated at 24 h post-smoke/burn injury. Lung tissue at necropsy was consistent with ARDS.
The refinements made to the original ovine smoke/burn ARDS model produce a more reliable time to ARDS onset, injury severity, and time of death.
Journal of Surgical Research 11/2010; 164(1):e155-62. · 2.25 Impact Factor
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ABSTRACT: Acute respiratory distress syndrome (ARDS) mortality remains high with no effective pharmacotherapy available. A chemically modified tetracycline (COL-3) is a potent inhibitor of matrix metalloproteinases. Prophylactic COL-3 administration has been shown to be effective in ARDS treatment. In the present study, the therapeutic effect of COL-3, given shortly after injury, was investigated in an ovine ARDS model.
The ovine ARDS model was induced by combined 40% body area third-degree burn, smoke inhalation, and barotrauma injuries. The sheep were randomly assigned into two groups: control (10% Solutol, n = 5) or COL-3 (200 mg/m(2), n = 5). Intravenous administration of COL-3 or vehicle was performed 1 hour after the smoke and burn injury. When ARDS criteria were met (arterial partial pressure of oxygen to fraction of inspired oxygen ratio < 200) or no later than 24 hours after injury (if criteria not met), animals underwent the ARDS Network ventilation protocol. At 96 hours after injury or at animal death, lung pathologic processes were assessed.
Administration of COL-3 improved hemodynamics and reduced carbon dioxide levels. Administration of COL-3 also significantly delayed ARDS development and prolonged survival time compared with the control group (20.4 + or - 3.8 hours versus 12.9 + or - 3.3 hours; 94.2 + or - 4.0 hours versus 58.6 + or - 26.4 hours; p < 0.05, respectively). Survival analysis showed a higher 96-hour survival from ARDS with COL-3 administration as compared with control (80% versus 20%; p < 0.05). Lung pathologic processes were also improved by COL-3. Plasma matrix metalloproteinase-2 level increased in control but not in COL-3-treated animals.
Our present study suggests that COL-3 may be an effective pharmacotherapy for ARDS treatment.
The Annals of thoracic surgery 08/2010; 90(2):419-26. · 3.74 Impact Factor
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ABSTRACT: Our goal is ambulatory total respiratory and right heart assistance allowing a bridge to lung transplant. To that end, we have coupled a compact paracorporeal gas exchange device with a right ventricular assist device (RVAD) to create an "OxyRVAD."
Through a limited left thoracotomy, the main pulmonary artery (PA) and right atrium (RA) were exposed in 5 anesthetized sheep. After a systemic heparin bolus, a 12-mm outer diameter crimped graft glued to tubing was anastomosed (end to side) to the main PA and a VAD atrial cannula was placed through the RA appendage. The chest was drained and closed, then the PA graft flowed at 1 to 2 L/min as a shunt to the RA overnight. The next day, the animal was reanticoagulated, and the shunt cannulae clamped and divided. The OxyRVAD unit, consisting of commercially available components including an axial flow pump and low-resistance cardiopulmonary bypass gas exchange device, was interposed. Pumping from RA to PA was maintained at 3 L/min.
Five consecutive sheep survived the implant, and stood and ate normally after initiation of the OxyRVAD. Three survived the full 2-week study, and a fourth was sacrificed on day 13 owing to a storm-related power failure. For these 4 sheep, pump flow was stable at 3 L/min. Carbon dioxide removal was constant and total during the experiment at 200 +/- 19 mL/min. Oxygen transfer was 144 +/- 44 mL/min. One sheep had progressive thrombocytopenia and was sacrificed on day 5 after implant.
Our ambulatory OxyRVAD can provide total assistance for the right heart and lungs in normal awake sheep for 14 days.
The Annals of thoracic surgery 12/2007; 84(5):1699-703. · 3.74 Impact Factor
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ABSTRACT: To develop ambulatory total respiratory and right heart assistance for up to 4 weeks as a bridge to lung transplantation, we coupled a compact gas exchange device with a right ventricular assist device (RVAD), a compact rotary blood pump, to create an "OxyRVAD."
Our ambulatory OxyRVAD includes a portable (4 x 4 x 7-cm) centrifugal pump with heparin saline-purged needle roller bearings and an ultra-low-resistant gas exchange device (BioLung, MC3, Ann Arbor, MI). In 6 anesthetized sheep, the main pulmonary artery (PA) and right atrium (RA) were exposed through a left fourth intercostal thoracotomy. A 12-mm outer diameter vascular graft was anastomosed (end-to-side) to the main PA, and a VAD atrial cannula was placed into RA through the RA appendage. The pump and gas exchange device were interposed in circuit for RA-PA support.
All 6 sheep survived OxyRVAD insertion. Four sheep survived the 5-day experiment. One was euthanized at 48 hours owing to pump electrical failure (wiring) and another at 72 hours owing to pump bearing failure (broken heparin purge line). One sheep needed replacement of a BioLung due to internal thrombi. OxyRVAD flow was stable (range, 3.57-4.30 liters/min). Carbon dioxide removal was constant during experiment (range, 88.35 +/- 6.12 ml/min at onset to 141.38 +/- 5.48 ml/min at the 96th hour). Oxygen transfer decreased from 161.8 +/- 8.8 to 79.7 +/- 31.4 ml/min at the 96th hour (p = 0.045).
Our ambulatory OxyRVAD provided total assistance of right heart and lungs in normal awake sheep for up to 5 days.
The Journal of heart and lung transplantation: the official publication of the International Society for Heart Transplantation 11/2007; 26(10):974-9. · 3.54 Impact Factor
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ABSTRACT: Our group has developed a paracorporeal artificial lung (PAL) attached in a pulmonary artery (PA) to PA in series configuration to address profound respiratory failure and serve as a bridge to transplant and/or recovery. We recently designed, developed and converted our passive pre-PAL compliance chamber to an active, synchronized, counterpulsating assist device to relieve right heart strain and offset increased work placed on the right ventricle when the PAL is attached. In this study, we evaluated the safety and performance of both a valved and non-valved optional active compliance chamber (OACC) in a PA-PA PAL for right heart assistance in normal adult sheep.
Eleven sheep (30-50 kg) were divided into non-valved OACC (n = 6) and valved (n = 5) OACC groups. To mimic pulmonary hypertension, a C-clamp was placed distal to the OACC-PAL and occluded until a 20% decrease in cardiac output (CO) was achieved. The OACC was activated, and right ventricular pressure (RVP), pulmonary artery pressure (PAP), mean arterial pressure (MAP) and CO were recorded.
All eleven animals tolerated the implantation of the OACC PAL. Activation of the OACC resulted in a significant increase in CO. Systolic and diastolic right ventricular pressure decreased in both groups. Lastly, counterpulsation increased the mean PAP in all animals and peak PAP reached 89 mmHg. Despite providing right heart assistance, synchronizing the counterpulsation was technically difficult, and the high peak PA pressures resulted in anastomotic bleeding in all animals and anastomotic breakdown in 4/11 animals.
An OACC PAL perfused by the right ventricle applied in series with the pulmonary circulation reduces ventricular load and improves cardiac efficiency. These preliminary data suggest the potential of an artificial lung in unloading the strained right ventricle and acting as a bridge to transplantation. The augmented peak PA pressures, resulting in bleeding and anastomotic breakdown, and complexity in synchronizing the cardiac cycle with the pulsations of the augmented OACC, compromise this configuration.
Perfusion 04/2007; 22(2):81-6. · 0.92 Impact Factor
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ABSTRACT: Our TransApical to Aorta pump, a simple and minimally invasive left ventricular (LV) assist device, has a flexible, thin-wall conduit connected by six struts to a motor with ball bearings and a turbine extending into the blood path. Pulsatile flow is inherent in the design as the native heart contraction preloads the turbine. In six healthy sheep, the LV apex was exposed by a fifth intercostal left thoracotomy. The pump was inserted from the cardiac apex through the LV cavity into the ascending aorta. Aortic and LV pressure waveforms, pump flow, motor current, and pressure were directly measured. All six cannula pumps were smoothly advanced on the first attempt. Pump implantation was <15 minutes (13.6 +/- 1.8 minutes). Blood flow was 2.8 l/min to 4.4 l/min against 86 +/- 8.9 mm Hg mean arterial blood pressure at maximum flow. LV systemic pressure decreased significantly from 102.5 +/- 5.55 mm Hg to 58.8 +/- 15.5 mm Hg at the fourth hour of pumping (p = 0.042), and diastolic LV pressure decreased from 8.4 +/- 3.7 to 6.1 +/- 2.3 mm Hg (p > 0.05). The pump operated with a current of 0.4 to 0.7 amps and rotation speed of 28,000 to 33,000 rpm. Plasma free hemoglobin was 4 +/- 1.41 mg/dl (range, 2 to 5 mg/dl) at termination. No thrombosis was observed at necropsy.A left ventricular assist device using the transapical to aorta approach is quick, reliable, minimally invasive, and achieves significant LV unloading with minimal blood trauma.
ASAIO journal (American Society for Artificial Internal Organs: 1992) 02/2007; 53(2):171-5. · 1.39 Impact Factor
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ABSTRACT: We have extended our model of the ovine pulmonary circulation to include a model of a paracorporeal artificial lung (AL) and its attachments to the natural pulmonary circulation in two configurations: in series and in parallel. Our model of the natural lung (NL) circulation is first shown to be in agreement with hemodynamic and input impedance data from the open literature. We then study design efficacy of the AL in terms of its housing and attachments. A sensitivity analysis of the modified pulmonary circulation model reveals that there are three key parameters: inlet graft length (IGL) and the compliances of the inlet compliance chamber (CC) and housing of the artificial lung. Based on literature reports, we assume the right ventricle is well-matched to the impedance of the natural pulmonary circulation and adjust the parameters of the modeled AL circuit to achieve the best least-squares fit to natural pulmonary input impedance data. Best-fit parameters produce impedance curves that fit natural impedance well, particularly below 3 Hz, where both compliance and graft length have their largest effects. Of these parameters, the impedance profile is most sensitive to IGL. However, the compliances are important, as well, particularly at low frequencies.
Cardiovascular Engineering 04/2006; 6(1):10-29. · 0.81 Impact Factor
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ABSTRACT: Acute respiratory failure is complicated by acidosis and altered end-organ perfusion. NOVA-LUNG iLA is an interventional lung assist (ILA) device for arteriovenous carbon dioxide removal (AVCO2R). The present study was conducted to evaluate the device for short-term CO2 removal performance and hemodynamic response.
Six adult sheep received cannulation of the jugular vein and carotid artery. The ILA-AVCO2R circuit was placed on the sheep for 72 hours. Hemodynamics and PaCO2 were measured; CO2 removal was calculated while varying sweep gas flow rates (Qg), device blood flow rates (Qb), and PaCO2.
Hemodynamic variables remained normal throughout the 72 hour study. CO2 removal increased with increases in Qg or Qb. Mean CO2 removal was 119.3 ml/min for Qb 1 L/ min, Qg 5 L/min, and PaCO2 40-50 mmHg. PaCO2 was directly proportional to CO2 clearance (R=0.72, p <0.001).
NOVALUNG iLA can provide near total CO2 removal with Qb 1-2 L/min, Qg 5 L/min, and minimal flow resistance (3.88+/-0.82 mmHg/L/min). PaCO2 correlates with CO2 removal and is dependent on Qb and Qg.
Perfusion 11/2005; 20(6):303-8. · 0.92 Impact Factor
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Conference proceedings: ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Conference 02/2005; 1:413-6.
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ABSTRACT: Current implantable LVADs are bulky and expensive. They all require high-risk surgery for insertion including a need for a heart/lung machine and complex connection to the heart or major blood vessels. This paper presents a newly designed "plug and play" transventricle LVAD that can be plugged into the circulation easily and work instantly with no complicated surgical procedure, no prime, no de-airing and no anastomosis. The device was tested on six sheep for 4 hours under general anesthesia to evaluate its performance and blood trauma. Results show that the simple transventricle pump generated pulsatile flow and achieved LV unloading in short term healthy sheep with acceptable blood trauma
Engineering in Medicine and Biology Society, 2005. IEEE-EMBS 2005. 27th Annual International Conference of the; 02/2005
