unidirectional valve
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2020 ◽  
Vol 14 (4) ◽  
Author(s):  
Oscar I. Quintero ◽  
Paola A. Chavarro ◽  
William Martínez ◽  
Carlos García ◽  
Andrés M. Castro ◽  
...  

Abstract Lung expansion techniques (LETs) are a key component of pulmonary rehabilitation. Nevertheless, these can be limited in tracheostomized patients because of the infraglottic position of tracheostomy cannulas. We propose a novel pulmonary expansion device (PED) that allows deep inspiration with a postinspiratory pause for a few seconds by means of a unidirectional valve and an occlusion/flow release cap. It is equipped with a relief valve that opens at 60 cm H2O in cases in which this threshold is attained. We aimed to evaluate the impact on lung volume and pressure in spontaneously breathing tracheostomized patients subjected to LETs. A single-arm pilot interventional study was conducted in an adult intensive care unit (ICU), including spontaneously breathing tracheostomized patients. 80 treatments were performed on 10 patients with tracheostomies with PED over a period of 3 months. The maximal inspiratory volume (MIV) was significantly increased by using PED (MIV-PED) at both day 1 (725 (600–820) mL versus 1550 (1250–1700) mL, P < 0.001) and day 3 (870 (750–950) mL versus 1662 (1550–1900) mL, P < 0.001). Inspiratory pause pressure (PIP-PED) did not significantly change from day 1 to day 3 (18 (14–20) cm H2O versus 14 (12–22) cm H2O, P = 0.36). The use of the PED in tracheostomy patients acted as an artificial glottis by performing a novel pulmonary re-expansion maneuver, and increased volumes and intrapulmonary pressure with prolongation of maximum inspiration were achieved.


2020 ◽  
pp. 021849232096292
Author(s):  
Abbas Afrasiabirad ◽  
Mahmoud Samadi ◽  
Parisa Vatani ◽  
Yousef Faridvand

Objective This study aimed to show the long-term results in patients who underwent unidirectional valve patch repair of ventricular septal defect with pulmonary artery hypertension. Methods Thirty-five acyanotic patients aged 2 to 26 years (mean 9.3 years) with a large ventricular septal defect and elevated pulmonary vascular resistance (mean 9.5 Wood units) underwent surgery in Madani Heart Hospital. The medical records and clinical outcomes were reviewed from March 1998 to March 2017. Results Five patients died in the first postoperative week. In the long-term follow-up (mean 11 years), two patients were lost to follow-up. Pulmonary artery hypertension gradually decreased in 17 patients within 6–12 months with significant improvement in right ventricular end-diastolic diameter, New York Heart Association functional class, and tricuspid regurgitation. Eleven patients with persistent pulmonary artery hypertension were divided into tolerable and non-tolerable groups. Six patients in the tolerable group had satisfactory conditions compared to before the operation, and gained weight with improved functional class despite echocardiographic findings of persistent elevated pulmonary artery pressure. One had a full-term delivery by caesarean section in the fifth postoperative year. Five patients in the non-tolerable group gradually developed right heart failure and complications such as extremity edema, ascites, pleural effusions, and died after 10–30 months. Conclusion Although relatively high mortality occurred during long-term follow-up, surviving patients were in a better condition and functional class despite persistent pulmonary artery hypertension. Therefore, fear of persistent pulmonary artery hypertension should not prohibit surgery in this group of patients.


2020 ◽  
Vol 39 (01) ◽  
pp. 022-026
Author(s):  
Jose Augusto Malheiros Filho ◽  
Antonio Gilson Prates Junior ◽  
Emmanuel Oliveira Vasconcelos e Sá ◽  
Luiza Cançado Guerra D'Assumpção ◽  
Lucas Rodrigues de Souza

AbstractArachnoid cysts are benign intracranial lesions. They are usually located in the middle fossa, but can be found in other locations. We present a case of symptomatic Meckel cave (MC) arachnoid cyst - a very rare location - and a treatment strategy not elsewhere described before for this condition. A 54-year-old female with trigeminal neuralgia with previous history of radiofrequency rhizotomy treatment 6 years before admission had been experiencing pain recurrence with progression, which required successive increases in carbamazepine dosage. Magnetic Resonance Imaging (MRI) showed dilatation of the right MC with extension to the petrous apex. The lesion was compatible with arachnoid cyst, and due to the worsening of the clinical condition, surgical treatment was chosen. Percutaneous puncture of the cyst through the foramen ovale with injection of intracystic fibrin sealant was performed. The patient woke up from anesthesia with pain improvement and was discharged asymptomatic the next day. After 12 months of follow-up, she remained pain-free. In the literature review, we found only eight cases reported as MC arachnoid cyst. These are likely to progress and become symptomatic owing to their communication with the subarachnoid space and a unidirectional valve mechanism. Pain improvement with this technique is probably secondary to the interruption of these mechanisms.


2018 ◽  
Vol 14 (21) ◽  
pp. 318 ◽  
Author(s):  
Iqbal Mahmud

Electricity is the most general forms of energy used across the world. This paper focuses on designing a setup that leads to the generation of electrical energy which is going to waste when humans are walking. Footsteps are an untapped natural resources. This generated energy is, however, costeffective and nonhazardous for human. Electrical energy can be produced by converting mechanical energy using footsteps. Generating the electric power through the fabrication of footstep arrangement by a prototype comprises of a pipe, nozzle, unidirectional valve, water reservoir, turbine, and DC motor. Whenever pressure is exerted on the reservoir, water flows through the nozzle into the turbine and generates electrical energy. This energy is stored in the battery. This project will reduce the global warming and load shedding in a much cleaner cost-effective way. Since this project is related directly to the human movement, the weight of the setup is a crucial factor.


2017 ◽  
Vol 96 (3) ◽  
pp. 4847-4868
Author(s):  
Siping Liu ◽  
Yuezhi Zhou ◽  
Yaoxue Zhang

2015 ◽  
Vol 9 (9) ◽  
pp. 1248-1257 ◽  
Author(s):  
Siping Liu ◽  
Xiaoxin Liu ◽  
Yuezhi Zhou ◽  
Yaoxue Zhang ◽  
Changming Zhang

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Abdo Khoury ◽  
Sylvère Hugonnot ◽  
Johan Cossus ◽  
Alban De Luca ◽  
Thibaut Desmettre ◽  
...  

Manual ventilation is a vital procedure, which remains difficult to achieve for patients who require ventilatory support. It has to be performed by experienced healthcare providers that are regularly trained for the use of bag-valve-mask (BVM) in emergency situations. We will give in this paper, a historical view on manual ventilation’s evolution throughout the last decades and describe the technical characteristics, advantages, and hazards of the main devices currently found in the market. Artificial ventilation has developed progressively and research is still going on to improve the actual devices used. Throughout the past years, a brand-new generation of ventilators was developed, but little was done for manual ventilation. Many adverse outcomes due to faulty valve or misassembly were reported in the literature, as well as some difficulties to ensure efficient insufflation according to usual respiratory parameters. These serious incidents underline the importance of BVM system routine check and especially the unidirectional valve reassembly after sterilization, by only experienced and trained personnel. Single use built-in devices may prevent disassembly problems and are safer than the reusable ones. Through new devices and technical improvements, the safety of BVM might be increased.


2013 ◽  
Vol 305 (10) ◽  
pp. H1538-H1547 ◽  
Author(s):  
Arvind Santhanakrishnan ◽  
Kevin O. Maher ◽  
Elaine Tang ◽  
Reza H. Khiabani ◽  
Jacob Johnson ◽  
...  

The Fontan surgical procedure used for treating patients with single ventricle congenital heart disorders results in a total cavopulmonary connection (TCPC) of the vena cavae to the pulmonary arteries (PAs). Sluggish TCPC flow and elevated hepatic venous pressures are commonly observed in this altered physiology, which in turn can lead to long-term complications including liver congestion and cirrhosis. The hypothesis of this study is that placement of a unidirectional valve within the inferior vena cava (IVC) will improve hemodynamics of the Fontan circulation by preventing retrograde flow and lowering hepatic venous pressure. An in vitro experimental setup consisting of an idealized TCPC model with flexible walls was used for investigation, and a bovine venous valve was inserted in the IVC below the TCPC. Pressure fluctuations were introduced in the flow through the model to simulate venous pulsatility. Hemodynamics of baseline and valve-implanted conditions were compared across total caval flows ranging from 1.0 to 2.5 l/min with varying caval flow distributions. The results indicated that valve closure occurred for 15–20% of the total cycle, with consequent reduction in the upstream hepatic venous pressure by 5 to 10 mmHg. Energy loss (EL) through the TCPC was lowered with valve implantation to 20–50% of baseline, occurring across all flow conditions considered with mean caval and PA pressures greater than 10 mmHg. The results of this in vitro modeling suggest that IVC valve placement has the potential to improve hemodynamics in the Fontan circulation by decreasing hepatic venous hypertension and EL.


2013 ◽  
Vol 65 (4) ◽  
pp. 337 ◽  
Author(s):  
Chol Lee ◽  
Kyu Chang Lee ◽  
Hye Young Kim ◽  
Mi Na Kim ◽  
Eun Kyung Choi ◽  
...  

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