COMPUTER MODELING IN THE DEVELOPMENT OF ARTIFICIAL VENTRICLES OF HEART

Directory of Open Access Journals (Sweden)

L. V. Belyaev

2011-01-01

Full Text Available In article modern researches of processes of development of artificial ventricles of heart are described. Advanta- ges of application computer (CAD/CAE technologies are shown by development of artificial ventricles of heart. The systems developed with application of the given technologies are submitted. 

Percutaneous dilatational tracheostomy following total artificial heart implantation.

Science.gov (United States)

Spiliopoulos, Sotirios; Dimitriou, Alexandros Merkourios; Serrano, Maria Rosario; Guersoy, Dilek; Autschbach, Ruediger; Goetzenich, Andreas; Koerfer, Reiner; Tenderich, Gero

2015-07-01

Coagulation disorders and an immune-altered state are common among total artificial heart patients. In this context, we sought to evaluate the safety of percutaneous dilatational tracheostomy in cases of prolonged need for mechanical ventilatory support. We retrospectively analysed the charts of 11 total artificial heart patients who received percutaneous dilatational tracheostomy. We focused on early and late complications. We observed no major complications and no procedure-related deaths. Early minor complications included venous oozing (45.4%) and one case of local infection. Late complications, including subglottic stenosis, stomal infection or infections of the lower respiratory tract, were not observed. In conclusion, percutaneous dilatational tracheostomy in total artificial heart patients is safe. Considering the well-known benefits of early tracheotomy over prolonged translaryngeal intubation, we advocate early timing of therapy in cases of prolonged mechanical ventilation. © The Author 2015. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

Nuclear-powered artificial heart system

International Nuclear Information System (INIS)

Pouchot, W.D.; Lehrfeld, D.

1976-01-01

As reported to the 9th IECEC, a bench model version of a nuclear-powered artificial heart system to be used as a replacement for the natural heart was constructed and tested as part of a broader U.S. ERDA program. A report is given of the system design and integration, bench testing, and field support equipment of an implantable and advanced version of the bench model incorporating some of the component developments reported to the 10th IECEC. The basic elements of the system are a 32-watt Pu-238 heat source, a Stirling engine thermal converter, a coupling mechanism, and a mechanical blood pump drive actuating, alternatively, two artificial ventricles of polymeric material. As tested on the bench using a mock circulation, the system provides approximately 9 liters/minute at 120/80 mm Hg aortic pressure. At 190/145 mm Hg aortic pressure, the maximum flow decreases to about 7 liters/minute

Successful heart transplant after 1374 days living with a total artificial heart.

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Gerosa, Gino; Gallo, Michele; Bottio, Tomaso; Tarzia, Vincenzo

2016-04-01

The CardioWest Total Artificial Heart (CW-TAH) has been approved as a temporary device for bridge to cardiac transplantation and is under investigation for destination therapy by US Food and Drug Administration (FDA). We herein report the longest worldwide survival out of hospital (1374 days) of a patient supported with Cardio West Total Artificial Heart (CW-TAH). This experience is intended as a proof of concept of using CW-TAH as the destination therapy in patients with biventricular failure. © The Author 2016. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

Initial in vitro testing of a paediatric continuous-flow total artificial heart.

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Fukamachi, Kiyotaka; Karimov, Jamshid H; Horvath, David J; Sunagawa, Gengo; Byram, Nicole A; Kuban, Barry D; Moazami, Nader

2018-06-01

Mechanical circulatory support has become standard therapy for adult patients with end-stage heart failure; however, in paediatric patients with congenital heart disease, the options for chronic mechanical circulatory support are limited to paracorporeal devices or off-label use of devices intended for implantation in adults. Congenital heart disease and cardiomyopathy often involve both the left and right ventricles; in such cases, heart transplantation, a biventricular assist device or a total artificial heart is needed to adequately sustain both pulmonary and systemic circulations. We aimed to evaluate the in vitro performance of the initial prototype of our paediatric continuous-flow total artificial heart. The paediatric continuous-flow total artificial heart pump was downsized from the adult continuous-flow total artificial heart configuration by a scale factor of 0.70 (1/3 of total volume) to enable implantation in infants. System performance of this prototype was evaluated using the continuous-flow total artificial heart mock loop set to mimic paediatric circulation. We generated maps of pump performance and atrial pressure differences over a wide range of systemic vascular resistance/pulmonary vascular resistance and pump speeds. Performance data indicated left pump flow range of 0.4-4.7 l/min at 100 mmHg delta pressure. The left/right atrial pressure difference was maintained within ±5 mmHg with systemic vascular resistance/pulmonary vascular resistance ratios between 1.4 and 35, with/without pump speed modulation, verifying expected passive self-regulation of atrial pressure balance. The paediatric continuous-flow total artificial heart prototype met design requirements for self-regulation and performance; in vivo pump performance studies are ongoing.

Total artificial heart implantation in a young Marfan syndrome patient.

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Rao, Prashant; Keenan, Jack B; Rajab, Taufiek K; Kim, Samuel; Smith, Richard; Amabile, Orazio; Khalpey, Zain

2018-03-01

Cardiovascular complications represent the leading cause of morbidity and mortality in patients with Marfan syndrome. Here, we describe a unique case where a total artificial heart was implanted in a young Marfan syndrome woman. A 22-year-old postpartum African American female with Marfan syndrome developed multiple severe valve dysfunction and biventricular failure that was refractory to medical management. She previously had a Bentall procedure for Type A aortic dissection and repair of a Type B dissection. We implanted a total artificial heart with a good outcome. Total artificial heart is a durable option for severe biventricular failure and multiple valvular dysfunction as a bridge to transplant in a young patient with Marfan syndrome.

System overview of the fully implantable destination therapy--ReinHeart-total artificial heart.

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Pelletier, Benedikt; Spiliopoulos, Sotirios; Finocchiaro, Thomas; Graef, Felix; Kuipers, Kristin; Laumen, Marco; Guersoy, Dilek; Steinseifer, Ulrich; Koerfer, Reiner; Tenderich, Gero

2015-01-01

Owing to the lack of suitable allografts, the demand for long-term mechanical circulatory support in patients with biventricular end-stage heart failure is rising. Currently available Total Artificial Heart (TAH) systems consist of pump units with only limited durability, percutaneous tubes and bulky external equipment that limit the quality of life. Therefore we are focusing on the development of a fully implantable, highly durable destination therapy total artificial heart. The ReinHeart-TAH system consists of a passively filling pump unit driven by a low-wear linear drive between two artificial ventricles, an implantable control unit and a compliance chamber. The TAH is powered by a transcutaneous energy transmission system. The flow distribution inside the ventricles was analysed by fluid structure interaction simulation and particle image velocimetry measurements. Along with durability tests, the hydrodynamic performance and flow balance capability were evaluated in a mock circulation loop. Animal trials are ongoing. Based on fluid structure interaction simulation and particle image velocimetry, blood stagnation areas have been significantly reduced. In the mock circulation loop the ReinHeart-TAH generated a cardiac output of 5 l/min at an operating frequency of 120 bpm and an aortic pressure of 120/80 mmHg. The highly effective preload sensitivity of the passively filling ventricles allowed the sensorless integration of the Frank Starling mechanism. The ReinHeart-TAH effectively replaced the native heart's function in animals for up to 2 days. In vitro and in vivo testing showed a safe and effective function of the ReinHeart-TAH system. This has the potential to become an alternative to transplantation. However, before a first-in-man implant, chronic animal trials still have to be completed. © The Author 2014. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

Perioperative Care of the Patient With the Total Artificial Heart.

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Yaung, Jill; Arabia, Francisco A; Nurok, Michael

2017-05-01

Advanced heart failure continues to be a leading cause of morbidity and mortality despite improvements in pharmacologic therapy. High demand for cardiac transplantation and shortage of donor organs have led to an increase in the utilization of mechanical circulatory support devices. The total artificial heart is an effective biventricular assist device that may be used as a bridge to transplant and that is being studied for destination therapy. This review discusses the history, indications, and perioperative management of the total artificial heart with emphasis on the postoperative concerns.

Human technology after cardiac epigenesis. Artificial heart versus cardiac transplantation.

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Losman, J G

1977-09-24

Cardiovascular disease is the chief cause of death in technologically advanced countries and accounts for more than 50% of all deaths in the USA. For a patient with end-stage cardiac failure the only treatment presently available is organ replacement, either by transplantation or by the use of a mechanical heart. Transplantation has demonstrated its value: survival of more than 8 years and restoration of a normal quality of life to patients who were in end-stage cardiac decompensation. However, the prospect of routine clinical application of an artificial heart remains distant. The development of a totally implantable artificial heart still presents a series of challenging engineering problems with regard to strict constraints of size, weight, blood-material compatibility, adaptability of output to demand, efficiency and reliability of the power supply, and safety if nuclear fuel is used. The totally artificial heart is presently not an alternative to the cardiac allograft, but could provide short-term support for patients awaiting cardiac transplantation.

Mechanism of artificial heart

CERN Document Server

Yamane, Takashi

2016-01-01

This book first describes medical devices in relation to regenerative medicine before turning to a more specific topic: artificial heart technologies. Not only the pump mechanisms but also the bearing, motor mechanisms, and materials are described, including expert information. Design methods are described to enhance hemocompatibility: main concerns are reduction of blood cell damage and protein break, as well as prevention of blood clotting. Regulatory science from R&D to clinical trials is also discussed to verify the safety and efficacy of the devices.

Summary of the clinical use of the Symbion total artificial heart: a registry report.

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Johnson, K E; Prieto, M; Joyce, L D; Pritzker, M; Emery, R W

1992-01-01

Several models of total artificial hearts have been used for transient or permanent circulatory support in patients with decompensation. The most successful and widely used device, however, has been the Symbion total artificial heart. From Dec. 12, 1982, to Jan. 1, 1991, 180 Symbion total artificial hearts were implanted in 176 patients in 28 centers. Five patients received a Symbion total artificial heart as a permanent circulatory support device, whereas 171 patients received the device as a bridge to heart transplantation. Of the 175 bridge devices (171 patients) 141 were Symbion J7-70 hearts and 34 were Symbion J7-100 hearts. Four patients received two total artificial hearts, the second one after the failure of a transplanted heart because of either rejection (two patients) or donor heart failure (2 patients). Most of the recipients were males (152). The age was 42 +/- 12 years (mean +/- SD) with a weight of 74 +/- 14 kg. The most common indications for implantation included deterioration while awaiting heart transplant (36%) and acute cardiogenic shock (32%). The cause of heart disease was primarily ischemic (52%) and idiopathic (35%) cardiomyopathy. Duration of implantation ranged from 0 to 603 days (mean 25 +/- 64 days). One hundred three (60%) patients had the device less than 2 weeks, 37 (22%) between 2 to 4 weeks and 31 (18%) more than 4 weeks. Complications during implantation included infection (37%), thromboembolic events (stroke 7%, transient ischemic attack 4%), kidney failure requiring dialysis (20%), bleeding requiring intervention (26%), and device malfunction (4%). Of the 171 patients, 118 (69%) underwent orthotopic heart transplantation. Actuarial survival for all patients with implants was 62% for 30 days and 42% for 1 year, and for patients with transplants was 72% for 30 days and 57% for 1 year. The main causes of death were sepsis (33%), multiorgan failure (21%), and posttransplant rejection (10%). The results indicate a relative success of

Moderate hypothermia technique for chronic implantation of a total artificial heart in calves.

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Karimov, Jamshid H; Grady, Patrick; Sinkewich, Martin; Sunagawa, Gengo; Dessoffy, Raymond; Byram, Nicole; Moazami, Nader; Fukamachi, Kiyotaka

2017-06-01

The benefit of whole-body hypothermia in preventing ischemic injury during cardiac surgical operations is well documented. However, application of hypothermia during in vivo total artificial heart implantation has not become widespread because of limited understanding of the proper techniques and restrictions implied by constitutional and physiological characteristics specific to each animal model. Similarly, the literature on hypothermic set-up in total artificial heart implantation has also been limited. Herein we present our experience using hypothermia in bovine models implanted with the Cleveland Clinic continuous-flow total artificial heart.

The Total Artificial Heart in End-Stage Congenital Heart Disease.

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Villa, Chet R; Morales, David L S

2017-01-01

The development of durable ventricular assist devices (VADs) has improved mortality rates and quality of life in patients with end stage heart failure. While the use of VADs has increased dramatically in recent years, there is limited experience with VAD implantation in patients with complex congenital heart disease (CHD), despite the fact that the number of patients with end stage CHD has grown due to improvements in surgical and medical care. VAD use has been limited in patients with CHD and end stage heart failure due to anatomic (systemic right ventricle, single ventricle, surgically altered anatomy, valve dysfunction, etc.) and physiologic constraints (diastolic dysfunction). The total artificial heart (TAH), which has right and left sided pumps that can be arranged in a variety of orientations, can accommodate the anatomic variation present in CHD patients. This review provides an overview of the potential use of the TAH in patients with CHD.

Liver failure in total artificial heart therapy.

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Dimitriou, Alexandros Merkourios; Dapunt, Otto; Knez, Igor; Wasler, Andrae; Oberwalder, Peter; Koerfer, Reiner; Tenderich, Gero; Spiliopoulos, Sotirios

2016-07-01

Congestive hepatopathy (CH) and acute liver failure (ALF) are common among biventricular heart failure patients. We sought to evaluate the impact of total artificial heart (TAH) therapy on hepatic function and associated clinical outcomes. A total of 31 patients received a Syncardia Total Artificial Heart. Preoperatively 17 patients exhibited normal liver function or mild hepatic derangements that were clinically insignificant and did not qualify as acute or chronic liver failure, 5 patients exhibited ALF and 9 various hepatic derangements owing to CH. Liver associated mortality and postoperative course of liver values were prospectively documented and retrospectively analyzed. Liver associated mortality in normal liver function, ALF and CH cases was 0%, 20% (P=0.03) and 44.4% (P=0.0008) respectively. 1/17 (5.8%) patients with a normal liver function developed an ALF, 4/5 (80%) patients with an ALF experienced a markedly improvement of hepatic function and 6/9 (66.6%) patients with CH a significant deterioration. TAH therapy results in recovery of hepatic function in ALF cases. Patients with CH prior to surgery form a high risk group with increased liver associated mortality.

Total Artificial Heart Implantation Blood Pressure Management as Resolving Treatment for Massive Hemolysis following Total Artificial Heart Implantation.

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Ghodsizad, Ali; Koerner, Michael M; El-Banayosy, A; Zeriouh, Mohamed; Ruhparwar, Arjang; Loebe, Matthias

2016-10-21

The SynCardia Total Artificial Heart (TAH) has been used for patients with biventricular failure, who cannot be managed with implantation of a left ventricular (LV) assist device. Following TAH implantation, our patient developed severe hemolysis, which could only be managed successfully by aggressive blood pressure control [Ohashi 2003; Nakata 1998].

Inspection of an artificial heart by the neutron radiography technique

International Nuclear Information System (INIS)

Pugliesi, R.; Geraldo, L.P.; Andrade, M.L.G.; Menezes, M.O.; Pereira, M.A.S.; Maizato, M.J.S.

1999-01-01

The neutron radiography technique was employed to inspect an artificial heart prototype which is being developed to provide blood circulation for patients expecting heart transplant surgery. The radiographs have been obtained by the direct method with a gadolinium converter screen along with the double coated Kodak-AA emulsion film. The artificial heart consists of a flexible plastic membrane located inside a welded metallic cavity, which is employed for blood pumping purposes. The main objective of the present inspection was to identify possible damages in this plastic membrane, produced during the welding process of the metallic cavity. The obtained radiographs were digitized as well as analysed in a PC and the improved images clearly identify several damages in the plastic membrane, suggesting changes in the welding process

Inspection of an artificial heart by the neutron radiography technique

CERN Document Server

Pugliesi, R; Andrade, M L G; Menezes, M O; Pereira, M A S; Maizato, M J S

1999-01-01

The neutron radiography technique was employed to inspect an artificial heart prototype which is being developed to provide blood circulation for patients expecting heart transplant surgery. The radiographs have been obtained by the direct method with a gadolinium converter screen along with the double coated Kodak-AA emulsion film. The artificial heart consists of a flexible plastic membrane located inside a welded metallic cavity, which is employed for blood pumping purposes. The main objective of the present inspection was to identify possible damages in this plastic membrane, produced during the welding process of the metallic cavity. The obtained radiographs were digitized as well as analysed in a PC and the improved images clearly identify several damages in the plastic membrane, suggesting changes in the welding process.

Demikhov's "Mechanical Heart": The Circumstances Surrounding Creation of the World's First Implantable Total Artificial Heart in 1937.

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Glyantsev, Sergey P; Tchantchaleishvili, Vakhtang; Bockeria, Leo A

2016-01-01

The world's first implantable total artificial heart was designed by Vladimir Demikhov as a fourth year biology student in Voronezh, Soviet Union, in 1937. As a prototype of his device, Demikhov must have used an apparatus for extracorporeal blood circulation invented by Sergei Bryukhonenko of Moscow. The device was the size of a dog's native heart and consisted of two diaphragm pumps brought into motion by an electric motor. A dog with an implanted device lived for 2.5 hours. In addition to having the prototype, the preconditions for Demikhov's artificial heart creation were his manual dexterity, expertise in animal physiology, and his mechanistic worldview.

Hybrid Continuous-Flow Total Artificial Heart.

Science.gov (United States)

Fox, Carson; Chopski, Steven; Murad, Nohra; Allaire, Paul; Mentzer, Robert; Rossano, Joseph; Arabia, Francisco; Throckmorton, Amy

2018-05-01

Clinical studies using total artificial hearts (TAHs) have demonstrated that pediatric and adult patients derive quality-of-life benefits from this form of therapy. Two clinically-approved TAHs and other pumps under development, however, have design challenges and limitations, including thromboembolic events, neurologic impairment, infection risk due to large size and percutaneous drivelines, and lack of ambulation, to name a few. To address these limitations, we are developing a hybrid-design, continuous-flow, implantable or extracorporeal, magnetically-levitated TAH for pediatric and adult patients with heart failure. This TAH has only two moving parts: an axial impeller for the pulmonary circulation and a centrifugal impeller for the systemic circulation. This device will utilize the latest generation of magnetic bearing technology. Initial geometries were established using pump design equations, and computational modeling provided insight into pump performance. The designs were the basis for prototype manufacturing and hydraulic testing. The study results demonstrate that the TAH is capable of delivering target blood flow rates of 1-6.5 L/min with pressure rises of 1-92 mm Hg for the pulmonary circulation and 24-150 mm Hg for the systemic circulation at 1500-10 000 rpm. This initial design of the TAH was successful and serves as the foundation to continue its development as a novel, more compact, nonthrombogenic, and effective therapeutic alternative for infants, children, adolescents, and adults with heart failure. © 2018 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

Establishing the framework to support bioartificial heart fabrication using fibrin-based three-dimensional artificial heart muscle.

Science.gov (United States)

Hogan, Matthew; Mohamed, Mohamed; Tao, Ze-Wei; Gutierrez, Laura; Birla, Ravi

2015-02-01

Only 3000 heart transplants are performed in the USA every year, leaving some 30 000-70 000 Americans without proper care. Current treatment modalities for heart failure have saved many lives yet still do not correct the underlying problems of congestive heart failure. Tissue engineering represents a potential field of study wherein a combination of cells, scaffolds, and/or bioreactors can be utilized to create constructs to mimic, replace, and/or repair defective tissue. The focus of this study was to generate a bioartificial heart (BAH) model using artificial heart muscle (AHM), composed of fibrin gel and neonatal rat cardiac myocytes, and a decellularized scaffold, formed by subjecting an adult rat heart to a series of decellularization solutions. By suturing the AHM around the outside of the decellularized heart and culturing while suspended in media, we were able to retain functional cardiac cells on the scaffold as evinced by visible contractility. Observed contractility rate was correlated with biopotential measurements to confirm essential functionality of cardiac constructs. Cross-sections of the BAH show successful decellularization of the scaffold and contiguous cell-rich AHM around the perimeter of the heart. Copyright © 2014 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

Hemodynamic deterioration during extracorporeal membrane oxygenation weaning in a patient with a total artificial heart.

Science.gov (United States)

Hosseinian, Leila; Levin, Matthew A; Fischer, Gregory W; Anyanwu, Anelechi C; Torregrossa, Gianluca; Evans, Adam S

2015-01-01

The Total Artificial Heart (Syncardia, Tucson, AZ) is approved for use as a bridge-to-transplant or destination therapy in patients who have irreversible end-stage biventricular heart failure. We present a unique case, in which the inferior vena cava compression by a total artificial heart was initially masked for days by the concurrent placement of an extracorporeal membrane oxygenation cannula. This is the case of a 33-year-old man admitted to our institution with recurrent episodes of ventricular tachycardia requiring emergent total artificial heart and venovenous extracorporeal membrane oxygenation placement. This interesting scenario highlights the importance for critical care physicians to have an understanding of exact anatomical localization of a total artificial heart, extracorporeal membrane oxygenation, and their potential interactions. In total artificial heart patients with hemodynamic compromise or reduced device filling, consideration should always be given to venous inflow compression, particularly in those with smaller body surface area. Transesophageal echocardiogram is a readily available diagnostic tool that must be considered standard of care, not only in the operating room but also in the ICU, when dealing with this complex subpopulation of cardiac patients.

Total Artificial Heart as Rescue Therapy for Primary Graft Failure in an Infant.

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Ziegler, Luke A; Sainathan, Sandeep; Morell, Victor O; Sharma, Mahesh S

2018-04-01

An infant unable to be weaned from cardiopulmonary bypass after orthotopic heart transplantation was cannulated for extracorporeal membrane oxygenation. During the next 3 days, allograft failure and intracardiac thrombosis necessitated cardiectomy. To provide acute mechanical circulatory support, artificial atrial chambers were constructed with Gore-Tex conduits and PediMag centrifugal pumps were connected to each by Berlin Heart EXCOR cannulae. The PediMag pumps were subsequently exchanged for 10-mL Berlin Heart EXCOR pumps. After 60 days of support by total artificial heart, the patient was bridged successfully to a second heart transplant. Copyright © 2018 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

Anatomy studies for an artificial heart. Final summary report

International Nuclear Information System (INIS)

Kiraly, R.J.; Nose, Y.

1977-12-01

In the interval from February of 1972 through December of 1977, studies were conducted relating to the anatomical feasibility of implanting a total artificial heart system. These studies included both the calf as an experimental animal as well as the ultimate human recipient of the artificial heart system. Studies with the calf included definition of the thoracic anatomy relative to the size, shape, and vascular connections for implanting the blood pump. To test the animal's tolerance to an implanted engine system, mockups of the thermal converter were implanted chronically in various locations within the calf. No problems developed in retroperitoneal or intraperitoneal implants ranging from 8 to 15 months. A study to determine accelerations experienced by an abdominally implanted thermal converter was performed in calves. Under the most severe conditions, accelerations of a maximum of 34 Gs were experienced. The largest effort was devoted to defining the human anatomy relative to implanting an artificial heart in the thorax. From a number of data sources, including cadavers as well as living patients, a quantitative, statistical analysis of the size and shape of the male thorax was obtained. Finally, an in vivo study of a functional intrathoracic compliance bag in a calf demonstrated the feasibility of this method

Minimally Invasive Implantation of HeartWare Assist Device and Simultaneous Tricuspid Valve Reconstruction Through Partial Upper Sternotomy.

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Hillebrand, Julia; Hoffmeier, Andreas; Djie Tiong Tjan, Tonny; Sindermann, Juergen R; Schmidt, Christoph; Martens, Sven; Scherer, Mirela

2017-05-01

Left ventricular assist device (LVAD) implantation is a well-established therapy to support patients with end-stage heart failure. However, the operative procedure is associated with severe trauma. Third generation LVADs like the HeartWare assist device (HeartWare, Inc., Framingham, MA, USA) are characterized by enhanced technology despite smaller size. These devices offer new minimally invasive surgical options. Tricuspid regurgitation requiring valve repair is frequent in patients with the need for mechanical circulatory support as it is strongly associated with ischemic and nonischemic cardiomyopathy. We report on HeartWare LVAD implantation and simultaneous tricuspid valve reconstruction through minimally invasive access by partial upper sternotomy to the fifth left intercostal space. Four male patients (mean age 51.72 ± 11.95 years) suffering from chronic heart failure due to dilative (three patients) and ischemic (one patient) cardiomyopathy and also exhibiting concomitant tricuspid valve insufficiency due to annular dilation underwent VAD implantation and tricuspid valve annuloplasty. Extracorporeal circulation was established via the ascending aorta, superior vena cava, and right atrium. In all four cases the LVAD implantation and tricuspid valve repair via partial median sternotomy was successful. During the operative procedure, no conversion to full sternotomy was necessary. One patient needed postoperative re-exploration because of pericardial effusion. No postoperative focal neurologic injury was observed. New generation VADs are advantageous because of the possibility of minimally invasive implantation procedure which can therefore minimize surgical trauma. Concomitant tricuspid valve reconstruction can also be performed simultaneously through partial upper sternotomy. Nevertheless, minimally invasive LVAD implantation is a challenging operative technique. © 2016 International Center for Artificial Organs and Transplantation and Wiley Periodicals

Modeling treatment of ischemic heart disease with partially observable Markov decision processes.

Science.gov (United States)

Hauskrecht, M; Fraser, H

1998-01-01

Diagnosis of a disease and its treatment are not separate, one-shot activities. Instead they are very often dependent and interleaved over time, mostly due to uncertainty about the underlying disease, uncertainty associated with the response of a patient to the treatment and varying cost of different diagnostic (investigative) and treatment procedures. The framework of Partially observable Markov decision processes (POMDPs) developed and used in operations research, control theory and artificial intelligence communities is particularly suitable for modeling such a complex decision process. In the paper, we show how the POMDP framework could be used to model and solve the problem of the management of patients with ischemic heart disease, and point out modeling advantages of the framework over standard decision formalisms.

Planning treatment of ischemic heart disease with partially observable Markov decision processes.

Science.gov (United States)

Hauskrecht, M; Fraser, H

2000-03-01

Diagnosis of a disease and its treatment are not separate, one-shot activities. Instead, they are very often dependent and interleaved over time. This is mostly due to uncertainty about the underlying disease, uncertainty associated with the response of a patient to the treatment and varying cost of different diagnostic (investigative) and treatment procedures. The framework of partially observable Markov decision processes (POMDPs) developed and used in the operations research, control theory and artificial intelligence communities is particularly suitable for modeling such a complex decision process. In this paper, we show how the POMDP framework can be used to model and solve the problem of the management of patients with ischemic heart disease (IHD), and demonstrate the modeling advantages of the framework over standard decision formalisms.

Artificial muscle for end-stage heart failure.

Science.gov (United States)

Tozzi, Piergiorgio; Michalis, Alexandre; Hayoz, Daniel; Locca, Didier; von Segesser, Ludwig K

2012-01-01

We describe a device made of artificial muscle for the treatment of end-stage heart failure as an alternative to current heart assist devices. The key component is a matrix of nitinol wires and aramidic fibers called Biometal muscle (BM). When heated electrically, it produces a motorless, smooth, and lifelike motion. The BM is connected to a carbon fiber scaffold, tightening the heart and providing simultaneous assistance to the left and right ventricles. A pacemaker-like microprocessor drives the contraction of the BM. We tested the device in a dedicated bench model of diseased heart. It generated a systolic pressure of 75 mm Hg and ejected a maximum of 330 ml/min, with an ejection fraction of 12%. The device required a power supply of 6 V, 250 mA. This could be the beginning of an era in which BMs integrate or replace the mechanical function of natural muscles.

[History, present and future of biomaterials used for artificial heart valves].

Science.gov (United States)

Kostrzewa, Benita; Rybak, Zbigniew

2013-01-01

Artificial heart valves can be classified into mechanical and biological. We have three types of mechanical heart valves: caged ball, tilting disc and bileaflet. Mechanical heart valves are made from various materials. They may be produced from metals, ceramics and polymers, e.g.: stainless steel, titanium, silicone, pyrolytic carbon. Biological valves are made from synthetic components (e.g.: PTFE, Dacron) and materials of biological origin (e.g.: cow pericardium, pig heart valve). We have also identified transcatheter aortic valve implantation (TAVI). TAVI may be produced from metals, ceramics and polymers (e.g.: stainless steel, titanium, Dacron) and biological material (e.g.: pig heart valve). This paper describes advantages and disadvantages of different types of artificial heart valves. The lifespan of mechanical valves is 20-30 years and they can be used for patients of any age. Mechanical valves have also disadvantages--anticoagulants are required to prevent thrombosis. Biological valves are made from natural materials, so they do not require prolonged anticoagulation. Their lifetime is 10-15 years, so they are offered to patients over 40 years. Another problem is the occurrence of calcification.

Domestic and foreign trends in the prevalence of heart failure and the necessity of next-generation artificial hearts: a survey by the Working Group on Establishment of Assessment Guidelines for Next-Generation Artificial Heart Systems.

Science.gov (United States)

Tatsumi, Eisuke; Nakatani, Takeshi; Imachi, Kou; Umezu, Mitsuo; Kyo, Shun-Ei; Sase, Kazuhiro; Takatani, Setsuo; Matsuda, Hikaru

2007-01-01

A series of guidelines for development and assessment of next-generation medical devices has been drafted under an interagency collaborative project by the Ministry of Health, Labor and Welfare and the Ministry of Economy, Trade and Industry. The working group for assessment guidelines of next-generation artificial hearts reviewed the trend in the prevalence of heart failure and examined the potential usefulness of such devices in Japan and in other countries as a fundamental part of the process of establishing appropriate guidelines. At present, more than 23 million people suffer from heart failure in developed countries, including Japan. Although Japan currently has the lowest mortality from heart failure among those countries, the number of patients is gradually increasing as our lifestyle becomes more Westernized; the associated medical expenses are rapidly growing. The number of heart transplantations, however, is limited due to the overwhelming shortage of donor hearts, not only in Japan but worldwide. Meanwhile, clinical studies and surveys have revealed that the major causes of death in patients undergoing long-term use of ventricular assist devices (VADs) were infection, thrombosis, and mechanical failure, all of which are typical of VADs. It is therefore of urgent and universal necessity to develop next-generation artificial hearts that have excellent durability to provide at least 2 years of event-free operation with a superior quality of life and that can be used for destination therapy to save patients with irreversible heart failure. It is also very important to ensure that an environment that facilitates the development, testing, and approval evaluation processes of next-generation artificial hearts be established as soon as possible.

Artificial heart thermal converter component research and development

International Nuclear Information System (INIS)

Goldowsky, M.; Lehrfeld, D.

1977-01-01

Under U.S. ERDA contract, a radioisotope powered artificial heart system to be used as a replacement for the diseased natural heart is under development by the Westinghouse Advanced Energy Systems Division and Philips Laboratories. A portion of the program activity is in research and development of components for the Stirling cycle thermal converter. Developments in current areas of thermal converter R and D investigation are discussed, including the control system, lubrication system, magnetic shaft coupling, rotary seals, and materials joining

ERDA artificial heart program workshop. Final report, September 1, 1975--August 31, 1976

International Nuclear Information System (INIS)

Kantrowitz, A.; Altieri, F.; Beall, A.

1976-08-01

The major conclusions of the ERDA Artificial Heart Program Workshop are that the concept of a biologically compatible mechanical device which can totally replace the heart is sound, that such a device is needed as an alternative to cardiac transplantation and that its development is a realistic goal. The major recommendation of the committee is that an ERDA program with primary orientation toward development of a total heart replacement should continue, with assured funding about 50 percent higher than at present, for a minimum of 3 additional years at which time another major review should take place. To achieve better management of the program it is recommended that the present contract effort be reorganized under one prime contractor with responsibility for development and demonstration of the ERDA artificial heart system. The formation of a joint artificial heart advisory committee to improve coordination between ERDA and NHLI is also recommended. The committee suggests future policies and directions which it believes will lead to more effective use of funds available for specific aspects of the program. These include the nuclear heart source, engine, blood pump, biomaterials and overall system reliability. Possible future goals for the program are also proposed

Machines versus medication for biventricular heart failure: focus on the total artificial heart.

Science.gov (United States)

Arabia, Francisco A; Moriguchi, Jaime D

2014-09-01

The medical/surgical management of advanced heart failure has evolved rapidly over the last few decades. With better understanding of heart failure pathophysiology, new pharmacological agents have been introduced that have resulted in improvements in survival. For those patients that fail to improve, mechanical circulatory support with left ventricular assist devices and total artificial hearts (TAHs) have served as a beneficial bridge to transplantation. The TAH has continued to play a significant role as a bridge to transplantation in patients with biventricular failure and more selected indications that could not be completely helped with left ventricular assist devices. Improved survival with the TAH has resulted in more patients benefiting from this technology. Improvements will eventually lead to a totally implantable device that will permanently replace the failing human heart.

Artificial Heart Research: An Historical Perspective

OpenAIRE

Joshi, Rayan

2001-01-01

This paper tracks the historical evolution of artificial heart technology, from its humble beginnings, to its relatively staggering current potential. While examining various milestones along this fascinating timeline, the paper attempts to shed light on some of the ethical, economic, and social dilemmas that have infused this history. In doing so, it strives to provide the reader with a sense of the various factors, some technical in nature and others purely societal, that have wielded influ...

Radionuclide power source for artificial heart autonomic apparatus

Energy Technology Data Exchange (ETDEWEB)

Lazarenko, Yu V; Gusev, V V; Pustovalov, A A

1988-02-01

Works on creating autonomous artificial heart devices with radionuclide heat source are described. Calculated and experimental parameters of /sup 238/Pu base radionuclide thermoelectric RITEG generators designed for supplying perspective blood pump electric drives are presented. RITEG structure is described and the prospects of increasing its efficiency are shown.

Total artificial heart implantation for biventricular failure due to eosinophilic myocarditis.

Science.gov (United States)

Kawabori, Masashi; Kurihara, Chitaru; Miller, Yair; Heck, Kent A; Bogaev, Roberta C; Civitello, Andrew B; Cohn, William E; Frazier, O H; Morgan, Jeffrey A

2017-09-01

Idiopathic hypereosinophilic syndrome is a condition of unknown etiology characterized by proliferation of eosinophils and their infiltration into tissues. Although cardiac involvement is rare, eosinophilic myocarditis can lead to life-threating fulminant congestive heart failure. Treatment of patients with eosinophilic myocarditis is challenging as heart failure can be caused by biventricular dysfunction. To our knowledge, this is the first case reported in the literature describing a patient with acute severe biventricular heart failure caused by eosinophilic myocarditis with mural left ventricular apical thrombus who was successfully treated with implantation of a total artificial heart as a bridge to heart transplant.

Renal Function Recovery with Total Artificial Heart Support.

Science.gov (United States)

Quader, Mohammed A; Goodreau, Adam M; Shah, Keyur B; Katlaps, Gundars; Cooke, Richard; Smallfield, Melissa C; Tchoukina, Inna F; Wolfe, Luke G; Kasirajan, Vigneshwar

2016-01-01

Heart failure patients requiring total artificial heart (TAH) support often have concomitant renal insufficiency (RI). We sought to quantify renal function recovery in patients supported with TAH at our institution. Renal function data at 30, 90, and 180 days after TAH implantation were analyzed for patients with RI, defined as hemodialysis supported or an estimated glomerular filtration rate (eGFR) less than 60 ml/min/1.73 m. Between January 2008 and December 2013, 20 of the 46 (43.5%) TAH recipients (age 51 ± 9 years, 85% men) had RI, mean preoperative eGFR of 48 ± 7 ml/min/1.73 m. Renal function recovery was noted at each follow-up interval: increment in eGFR (ml/min/1.73 m) at 30, 90, and 180 days was 21 ± 35 (p = 0.1), 16.5 ± 18 (p = 0.05), and 10 ± 9 (p = 0.1), respectively. Six patients (30%) required preoperative dialysis. Of these, four recovered renal function, one remained on dialysis, and one died. Six patients (30%) required new-onset dialysis. Of these, three recovered renal function and three died. Overall, 75% (15 of 20) of patients' renal function improved with TAH support. Total artificial heart support improved renal function in 75% of patients with pre-existing significant RI, including those who required preoperative dialysis.

Reliability studies for the nuclear-powered artificial heart program

International Nuclear Information System (INIS)

Horita, M.; Zeigler, R.K.

1976-04-01

By assuming that the failures of an artificial heart system with a mean life of 10 y can be modeled by a particular probability distribution, both the probability of a failure in the system within t years and the reliability required of each subsystem and component were investigated

Novel technique for airless connection of artificial heart to vascular conduits.

Science.gov (United States)

Karimov, Jamshid H; Gao, Shengqiang; Dessoffy, Raymond; Sunagawa, Gengo; Sinkewich, Martin; Grady, Patrick; Sale, Shiva; Moazami, Nader; Fukamachi, Kiyotaka

2017-12-01

Successful implantation of a total artificial heart relies on multiple standardized procedures, primarily the resection of the native heart, and exacting preparation of the atrial and vascular conduits for pump implant and activation. Achieving secure pump connections to inflow/outflow conduits is critical to a successful outcome. During the connection process, however, air may be introduced into the circulation, traveling to the brain and multiple organs. Such air emboli block blood flow to these areas and are detrimental to long-term survival. A correctly managed pump-to-conduit connection prevents air from collecting in the pump and conduits. To further optimize pump-connection techniques, we have developed a novel connecting sleeve that enables airless connection of the Cleveland Clinic continuous-flow total artificial heart (CFTAH) to the conduits. In this brief report, we describe the connecting sleeve design and our initial results from two acute in vivo implantations using a scaled-down version of the CFTAH.

A Physical Heart Failure Simulation System Utilizing the Total Artificial Heart and Modified Donovan Mock Circulation.

Science.gov (United States)

Crosby, Jessica R; DeCook, Katrina J; Tran, Phat L; Betterton, Edward; Smith, Richard G; Larson, Douglas F; Khalpey, Zain I; Burkhoff, Daniel; Slepian, Marvin J

2017-07-01

With the growth and diversity of mechanical circulatory support (MCS) systems entering clinical use, a need exists for a robust mock circulation system capable of reliably emulating and reproducing physiologic as well as pathophysiologic states for use in MCS training and inter-device comparison. We report on the development of such a platform utilizing the SynCardia Total Artificial Heart and a modified Donovan Mock Circulation System, capable of being driven at normal and reduced output. With this platform, clinically relevant heart failure hemodynamics could be reliably reproduced as evidenced by elevated left atrial pressure (+112%), reduced aortic flow (-12.6%), blunted Starling-like behavior, and increased afterload sensitivity when compared with normal function. Similarly, pressure-volume relationships demonstrated enhanced sensitivity to afterload and decreased Starling-like behavior in the heart failure model. Lastly, the platform was configured to allow the easy addition of a left ventricular assist device (HeartMate II at 9600 RPM), which upon insertion resulted in improvement of hemodynamics. The present configuration has the potential to serve as a viable system for training and research, aimed at fostering safe and effective MCS device use. © 2016 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

Functionality of albumin-derived perfluorocarbon-based artificial oxygen carriers in the Langendorff-heart †.

Science.gov (United States)

Wrobeln, Anna; Schlüter, Klaus D; Linders, Jürgen; Zähres, Manfred; Mayer, Christian; Kirsch, Michael; Ferenz, Katja B

2017-06-01

The aim of this study was to prove whether albumin-derived perfluorocarbon-based nanoparticles (capsules) can operate as a novel artificial oxygen carrier in a rat Langendorff-heart perfusion model. Hearts perfused with capsules showed increased left ventricular pressure and rate pressure product compared to hearts perfused with pure Krebs-Henseleit (KH)-buffer. The capsules prevented the myocardium from functional fail when in their absence a noxious ischemia was observed. Capsules did not change rheological properties of KH-buffer and could repeatedly reload with oxygen. This albumin-derived perfluorocarbon-based artificial oxygen carrier preserved the function of rat hearts due to the transport of oxygen in a satisfactory manner. Because of these positive results, the functionality of the applied capsules should be verified in living animals.

Physical principles of artificial stimulation of the heart : Stimulation of the canine heart in situ

NARCIS (Netherlands)

Schneider, H.

1. 1. In artificial heart stimulation, the essential quantity is the density of current, , in the intramyocardial wall. Dosage of the pulse amplitude in volts can have serious consequences for the patient. Curve indications in volts on pacemakers and in publications and records must, therefore, be

An original valveless artificial heart providing pulsatile flow tested in mock circulatory loops.

Science.gov (United States)

Tozzi, Piergiorgio; Maertens, Audrey; Emery, Jonathan; Joseph, Samuel; Kirsch, Matthias; Avellan, François

2017-11-24

We present the test bench results of a valveless total artificial heart that is potentially compatible with the pediatric population. The RollingHeart is a valveless volumetric pump generating pulsatile flow. It consists of a single spherical cavity divided into 4 chambers by 2 rotating disks. The combined rotations of both disks produce changes in the volumes of the 4 cavities (suction and ejection). The blood enters/exits the spherical cavity through 4 openings that are symmetrical to the fixed rotation axis of the first disk.Mock circulatory system: The device pumps a 37% glycerin solution through 2 parallel circuits, simulating the pulmonary and systemic circulations. Flow rates are acquired with a magnetic inductive flowmeter, while pressure sensors collect pressure in the left and right outflow and inflow tracts.In vitro test protocol: The pump is run at speeds ranging from 20 to 180 ejections per minute. The waveform of the pressure generated at the inflow and outflow of the 4 chambers and the flow rate in the systemic circulation are measured. At an ejection rate of 178 min-1, the RollingHeart pumps 5.3 L/min for a systemic maximal pressure gradient of 174 mmHg and a pulmonary maximal pressure gradient of 75 mmHg. The power input was 14 W, corresponding to an efficiency of 21%. The RollingHeart represents a new approach in the domain of total artificial heart. This preliminary study endorses the feasibility of a single valveless device acting as a total artificial heart.

Pulmonary Hypertension After Heart Transplantation in Patients Bridged with the Total Artificial Heart.

Science.gov (United States)

Shah, Rachit; Patel, Dhavalkumar B; Mankad, Anit K; Rennyson, Stephen L; Tang, Daniel G; Quader, Mohammed A; Smallfield, Melissa C; Kasirajan, Vigneshwar; Shah, Keyur B

2016-01-01

Pulmonary hypertension (PH) among heart transplant recipients is associated with an increased risk of mortality. Pulmonary hemodynamics improves after left ventricular assist device (LVAD) implantation; however, the impact of PH before total artificial heart (TAH) implantation on posttransplant hemodynamics and survival is unknown. This is a single center retrospective study aimed to evaluate the impact of TAH implantation on posttransplant hemodynamics and mortality in two groups stratified according to severity of PH: high (≥3 Woods units [WU]) and low (heart catheterization performed at baseline (before TAH) and posttransplant at 1 and 12 months. Patients in the high PVR group (n = 12) experienced improvement in PVR (baseline = 4.31 ± 0.7; 1-month = 1.69 ± 0.7, p heart transplantation (HT), but remained elevated. There was no significant difference in survival between the two groups at 12 months follow-up. Patients with high PVR who are bridged to transplant with TAH had improvement in PVR at 12 months after transplant, and the degree of PVR did not impact posttransplant survival.

Total Artificial Heart Implantation after Excision of Right Ventricular Angiosarcoma.

Science.gov (United States)

Bruckner, Brian A; Abu Saleh, Walid K; Al Jabbari, Odeaa; Copeland, Jack G; Estep, Jerry D; Loebe, Matthias; Reardon, Michael J

2016-06-01

Primary cardiac sarcomas, although rare, are aggressive and lethal, requiring thorough surgical resection and adjuvant chemotherapy for the best possible outcome. We report the case of a 32-year-old woman who underwent total artificial heart implantation for right-sided heart failure caused by right ventricular angiosarcoma. For the first several weeks in intensive care, the patient recovered uneventfully. However, a postoperative liver biopsy indicated hepatocellular injury consistent with preoperative chemotherapy. She developed continuing liver failure, from which she died despite good cardiac function.

On the feasibility of detecting flaws in artificial heart valves

NARCIS (Netherlands)

Lepelaars, E.S.A.M.; Ooijen, van W.D.R.; Tijhuis, A.G.

2000-01-01

Investigates the feasibility of detecting defects in certain artificial heart valves by determining the electromagnetic behavior of some simple models with the aid of thin-wire integral equations. The idea is to use the stationary current that occurs at late times after the excitation of a closed

Past and Present of Total Artificial Heart Therapy: A Success Story

Science.gov (United States)

Samak, Mostafa; Fatullayev, Javid; Sabashnikov, Anton; Zeriouh, Mohamed; Rahmanian, Parwis B.; Choi, Yeong-Hoon; Wippermann, Jens; Wahlers, Thorsten; Schmack, Bastian; Ruhparwar, Arjang; Dohmen, Pascal M.; Karck, Matthias; Popov, Aron-Frederik; Simon, André R.; Weymann, Alexander

2015-01-01

The totally artificial heart (TAH) is among the most prominent medical innovations of the 21st century, especially due to the increasing population with end-stage heart failure. The progressive course of the disease, its resistance to conventional therapy, and the scarcity of hearts available for transplantation were the prime impetus for developing a TAH, especially when other options of mechanical circulatory assist devices are exhausted. In this review, we narrate the history of TAH, give an overview of its technology, and address the pros and cons of the currently available TAH models in light of published clinical experience. PMID:26343363

Past and Present of Total Artificial Heart Therapy: A Success Story.

Science.gov (United States)

Samak, Mostafa; Fatullayev, Javid; Sabashnikov, Anton; Zeriouh, Mohamed; Rahmanian, Parwis B; Choi, Yeong-Hoon; Wippermann, Jens; Wahlers, Thorsten; Schmack, Bastian; Ruhparwar, Arjang; Dohmen, Pascal M; Karck, Matthias; Popov, Aron-Frederik; Simon, André R; Weymann, Alexander

2015-09-07

The totally artificial heart (TAH) is among the most prominent medical innovations of the 21st century, especially due to the increasing population with end-stage heart failure. The progressive course of the disease, its resistance to conventional therapy, and the scarcity of hearts available for transplantation were the prime impetus for developing a TAH, especially when other options of mechanical circulatory assist devices are exhausted. In this review, we narrate the history of TAH, give an overview of its technology, and address the pros and cons of the currently available TAH models in light of published clinical experience.

A Soft Total Artificial Heart-First Concept Evaluation on a Hybrid Mock Circulation.

Science.gov (United States)

Cohrs, Nicholas H; Petrou, Anastasios; Loepfe, Michael; Yliruka, Maria; Schumacher, Christoph M; Kohll, A Xavier; Starck, Christoph T; Schmid Daners, Marianne; Meboldt, Mirko; Falk, Volkmar; Stark, Wendelin J

2017-10-01

The technology of 3D-printing has allowed the production of entirely soft pumps with complex chamber geometries. We used this technique to develop a completely soft pneumatically driven total artificial heart from silicone elastomers and evaluated its performance on a hybrid mock circulation. The goal of this study is to present an innovative concept of a soft total artificial heart (sTAH). Using the form of a human heart, we designed a sTAH, which consists of only two ventricles and produced it using a 3D-printing, lost-wax casting technique. The diastolic properties of the sTAH were defined and the performance of the sTAH was evaluated on a hybrid mock circulation under various physiological conditions. The sTAH achieved a blood flow of 2.2 L/min against a systemic vascular resistance of 1.11 mm Hg s/mL (afterload), when operated at 80 bpm. At the same time, the mean pulmonary venous pressure (preload) was fixed at 10 mm Hg. Furthermore, an aortic pulse pressure of 35 mm Hg was measured, with a mean aortic pressure of 48 mm Hg. The sTAH generated physiologically shaped signals of blood flow and pressures by mimicking the movement of a real heart. The preliminary results of this study show a promising potential of the soft pumps in heart replacements. Further work, focused on increasing blood flow and in turn aortic pressure is required. © 2017 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

Total Artificial Heart Implantation as a Bridge to Heart Transplantation in an Active Duty Service Member With Amyloid Cardiomyopathy.

Science.gov (United States)

Scully, Michael S; Wessman, Dylan E; McKee, James M; Francisco, Gregory M; Nayak, Keshav R; Kobashigawa, Jon A

2017-03-01

Cardiac involvement by light-chain (AL) amyloid occurs in up to 50% of patients with primary AL amyloidosis. The prognosis of amyloid heart disease is poor with 1-year survival rates of 35 to 40%. Historically, heart transplantation was considered controversial for patients with AL amyloid cardiomyopathy (CM) given the systemic nature of the disease and poor survival. We present a case report of an active duty service member diagnosed with advanced cardiac amyloid who underwent total artificial heart transplant as a bridge to heart transplant and eventual autologous stem cell transplant. A 47-year-old active duty male initially evaluated for atypical chest pain was found to have severe concentric left ventricular hypertrophy on echocardiogram but normal voltage on electrocardiogram. Cardiac magnetic resonance imaging, laboratory studies, and bone marrow biopsy established the diagnosis of cardiac amyloidosis. At the time of diagnosis, the patient's prognosis was very poor with a median survival of 5 months on the basis of the Mayo Clinic revised prognostic staging system for amyloidosis. The patient developed rapidly progressive left ventricular dysfunction and heart failure leading to cardiac arrest. The patient received a total artificial heart as a bridge to orthotopic heart and kidney transplantation and eventual stem cell transplant. He continues to be in remission and has a fair functional capacity without restriction in activities of daily living or moderate exercise. Amyloid CM is a rare and devastating disease. The natural course of the disease has made heart transplant in these patients controversial. Modern advancements in chemotherapies and advanced heart failure treatments have improved outcomes for select patients with AL amyloid CM undergoing heart transplantation. There is ongoing research seeking improvement in treatment options and outcomes for patients with this deadly disease. Reprint & Copyright © 2017 Association of Military Surgeons of the U.S.

First North American 50 cc Total Artificial Heart Experience: Conversion from a 70 cc Total Artificial Heart.

Science.gov (United States)

Khalpey, Zain; Kazui, Toshinobu; Ferng, Alice S; Connell, Alana; Tran, Phat L; Meyer, Mark; Rawashdeh, Badi; Smith, Richard G; Sweitzer, Nancy K; Friedman, Mark; Lick, Scott; Slepian, Marvin J; Copeland, Jack G

2016-01-01

The 70 cc total artificial heart (TAH) has been utilized as bridge to transplant (BTT) for biventricular failure. However, the utilization of 70 cc TAH has been limited to large patients for the low output from the pulmonary as well as systemic vein compression after chest closure. Therefore, the 50 cc TAH was developed by SynCardia (Tucson, AZ) to accommodate smaller chest cavity. We report the first TAH exchange from a 70 to 50 cc due to a fit difficulty. The patient failed to be closed with a 70 cc TAH, although the patient met the conventional 70 cc TAH fit criteria. We successfully closed the chest with a 50 cc TAH.

Anatomy of the bovine ascending aorta and brachiocephalic artery found unfavorable for total artificial heart implant.

Science.gov (United States)

Karimov, Jamshid H; Sunagawa, Gengo; Such, Kimberly A; Sale, Shiva; Golding, Leonard A R; Moazami, Nader; Fukamachi, Kiyotaka

2015-12-01

The biocompatibility assessment of the Cleveland Clinic continuous-flow total artificial heart is an important part of the device developmental program. Surgical and postoperative management are key factors in achieving optimal outcomes. However, the presence of vascular anatomical abnormalities in experimental animal models is often unpredictable and may worsen the expected outcomes. We report a technical impediment encountered during total artificial heart implantation complicated by unfavorable bovine anatomy of the ascending aorta and brachiocephalic arterial trunk.

Total Artificial Heart as Bridge to Heart Transplantation in Chagas Cardiomyopathy: Case Report.

Science.gov (United States)

Ruzza, A; Czer, L S C; De Robertis, M; Luthringer, D; Moriguchi, J; Kobashigawa, J; Trento, A; Arabia, F

2016-01-01

Chagas disease (CD) is becoming an increasingly recognized cause of dilated cardiomyopathy outside of Latin America, where it is endemic, due to population shifts and migration. Heart transplantation (HTx) is a therapeutic option for end-stage cardiomyopathy due to CD, but may be considered a relative contraindication due to potential reactivation of the causative organism with immunosuppression therapy. The total artificial heart (TAH) can provide mechanical circulatory support in decompensated patients with severe biventricular dysfunction until the time of HTx, while avoiding immunosuppressive therapy and removing the organ most affected by the causative organism. We report herein a patient with CD and severe biventricular dysfunction, who had mechanical circulatory support with a TAH for more than 6 months, followed by successful orthotopic HTx and treatment with benznidazole for 3 months. The patient had no evidence of recurrent disease in the transplanted heart based on endomyocardial biopsy up to 1 year post-transplantation, and remains alive more than 30 months after insertion of a TAH and 24 months after HTx. Copyright © 2016 Elsevier Inc. All rights reserved.

Automatic Emboli Detection System for the Artificial Heart

Science.gov (United States)

Steifer, T.; Lewandowski, M.; Karwat, P.; Gawlikowski, M.

In spite of the progress in material engineering and ventricular assist devices construction, thromboembolism remains the most crucial problem in mechanical heart supporting systems. Therefore, the ability to monitor the patient's blood for clot formation should be considered an important factor in development of heart supporting systems. The well-known methods for automatic embolus detection are based on the monitoring of the ultrasound Doppler signal. A working system utilizing ultrasound Doppler is being developed for the purpose of flow estimation and emboli detection in the clinical artificial heart ReligaHeart EXT. Thesystem will be based on the existing dual channel multi-gate Doppler device with RF digital processing. A specially developed clamp-on cannula probe, equipped with 2 - 4 MHz piezoceramic transducers, enables easy system setup. We present the issuesrelated to the development of automatic emboli detection via Doppler measurements. We consider several algorithms for the flow estimation and emboli detection. We discuss their efficiency and confront them with the requirements of our experimental setup. Theoretical considerations are then met with preliminary experimental findings from a) flow studies with blood mimicking fluid and b) in-vitro flow studies with animal blood. Finally, we discuss some more methodological issues - we consider several possible approaches to the problem of verification of the accuracy of the detection system.

Chest radiographic findings and complications of the temporary implantation of the Jarvik-7 artificial heart while patients await orthotopic heart transplantation

International Nuclear Information System (INIS)

Sadler, L.; Fuhrman, C.; Hardesty, R.; Griffith, B.

1987-01-01

At the University of Pittsburgh, the authors have had 15 patients in whom Jarvik-7 hearts were implanted as a temporary measure while the patients awaited suitable donors for cardiac transplantation. The paper presents a brief description of the Jarvik-7 artificial heart, factors affecting patient selection, and the radiographic appearance of a normally functioning Jarvik-7 heart, and reviews the chest radiographic complications seen in this patient group, along with eventual patient outcome

Dose-to-the-population exposure estimates for use of plutonium-238-powered artificial hearts

Energy Technology Data Exchange (ETDEWEB)

McKee, R.W.; Clark, L.L.; Cole, B.M.

1976-09-01

Estimates of dose to the population from /sup 238/Pu-powered artificial hearts were developed using a calculational model called REPRIEVE. This model develops the projected user population by incorporating assumptions regarding future heart disease death rates, the fraction dying who would be eligible candidates for artificial hearts, population projections, beginning implant rates, death rates after implant due to natural causes, and deaths caused by device failure. The user population was characterized by age, sex, household description, employment status and occupation. Census data on household descriptions and special surveys in selected cities provided the information necessary to describe persons exposed during both household and public activities. These surveys further defined distance and time of contact factors for these persons. Calculations using a dosemetry computer code defined the relationships between distance and dose. The validity of these calculations has been substantiated by experimental measurements.

Dose-to-the-population exposure estimates for use of plutonium-238-powered artificial hearts

International Nuclear Information System (INIS)

McKee, R.W.; Clark, L.L.; Cole, B.M.

1976-09-01

Estimates of dose to the population from 238 Pu-powered artificial hearts were developed using a calculational model called REPRIEVE. This model develops the projected user population by incorporating assumptions regarding future heart disease death rates, the fraction dying who would be eligible candidates for artificial hearts, population projections, beginning implant rates, death rates after implant due to natural causes, and deaths caused by device failure. The user population was characterized by age, sex, household description, employment status and occupation. Census data on household descriptions and special surveys in selected cities provided the information necessary to describe persons exposed during both household and public activities. These surveys further defined distance and time of contact factors for these persons. Calculations using a dosemetry computer code defined the relationships between distance and dose. The validity of these calculations has been substantiated by experimental measurements

Physiological characterization of the SynCardia total artificial heart in a mock circulation system.

Science.gov (United States)

Crosby, Jessica R; DeCook, Katrina J; Tran, Phat L; Smith, Richard G; Larson, Douglas F; Khalpey, Zain I; Burkhoff, Daniel; Slepian, Marvin J

2015-01-01

The SynCardia total artificial heart (TAH) has emerged as an effective, life-saving biventricular replacement system for a wide variety of patients with end-stage heart failure. Although the clinical performance of the TAH is established, modern physiological characterization, in terms of elastance behavior and pressure-volume (PV) characterization has not been defined. Herein, we examine the TAH in terms of elastance using a nonejecting left ventricle, and then characterize the PV relation of the TAH by varying preload and afterload parameters using a Donovan Mock Circulatory System. We demonstrate that the TAH does not operate with time-varying elastance, differing from the human heart. Furthermore, we show that the TAH has a PV relation behavior that also differs from that of the human heart. The TAH does exhibit Starling-like behavior, with output increasing via preload-dependent mechanisms, without reliance on an alteration of inotropic state within the operating window of the TAH. Within our testing range, the TAH is insensitive to variations in afterload; however, this insensitivity has a limit, the limit being the maximum driving pressure of the pneumatic driver. Understanding the physiology of the TAH affords insight into the functional parameters that govern artificial heart behavior providing perspective on differences compared with the human heart.

The OregonHeart Total Artificial Heart: Design and Performance on a Mock Circulatory Loop.

Science.gov (United States)

Glynn, Jeremy; Song, Howard; Hull, Bryan; Withers, Stanley; Gelow, Jill; Mudd, James; Starr, Albert; Wampler, Richard

2017-10-01

Widespread use of heart transplantation is limited by the scarcity of donor organs. Total artificial heart (TAH) development has been pursued to address this shortage, especially to treat patients who require biventricular support. We have developed a novel TAH that utilizes a continuously spinning rotor that shuttles between two positions to provide pulsatile, alternating blood flow to the systemic and pulmonary circulations without artificial valves. Flow rates and pressures generated by the TAH are controlled by adjusting rotor speed, cycle frequency, and the proportion of each cycle spent pumping to either circulation. To validate the design, a TAH prototype was placed in a mock circulatory loop that simulates vascular resistance, pressure, and compliance in normal and pathophysiologic conditions. At a systemic blood pressure of 120/80 mm Hg, nominal TAH output was 7.4 L/min with instantaneous flows reaching 17 L/min. Pulmonary artery, and left and right atrial pressures were all maintained within normal ranges. To simulate implant into a patient with severe pulmonary hypertension, the pulmonary vascular resistance of the mock loop was increased to 7.5 Wood units. By increasing pump speed to the pulmonary circulation, cardiac output could be maintained at 7.4 L/min as mean pulmonary artery pressure increased to 56 mm Hg while systemic blood pressures remained normal. This in vitro testing of a novel, shuttling TAH demonstrated that cardiac output could be maintained across a range of pathophysiologic conditions including pulmonary hypertension. These experiments serve as a proof-of-concept for the design, which has proceeded to in vivo testing. © 2017 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

Simulation of a pulsatile total artificial heart: Development of a partitioned Fluid Structure Interaction model

Science.gov (United States)

Sonntag, Simon J.; Kaufmann, Tim A. S.; Büsen, Martin R.; Laumen, Marco; Linde, Torsten; Schmitz-Rode, Thomas; Steinseifer, Ulrich

2013-04-01

Heart disease is one of the leading causes of death in the world. Due to a shortage in donor organs artificial hearts can be a bridge to transplantation or even serve as a destination therapy for patients with terminal heart insufficiency. A pusher plate driven pulsatile membrane pump, the Total Artificial Heart (TAH) ReinHeart, is currently under development at the Institute of Applied Medical Engineering of RWTH Aachen University.This paper presents the methodology of a fully coupled three-dimensional time-dependent Fluid Structure Interaction (FSI) simulation of the TAH using a commercial partitioned block-Gauss-Seidel coupling package. Partitioned coupling of the incompressible fluid with the slender flexible membrane as well as a high fluid/structure density ratio of about unity led inherently to a deterioration of the stability (‘artificial added mass instability’). The objective was to conduct a stable simulation with high accuracy of the pumping process. In order to achieve stability, a combined resistance and pressure outlet boundary condition as well as the interface artificial compressibility method was applied. An analysis of the contact algorithm and turbulence condition is presented. Independence tests are performed for the structural and the fluid mesh, the time step size and the number of pulse cycles. Because of the large deformation of the fluid domain, a variable mesh stiffness depending on certain mesh properties was specified for the fluid elements. Adaptive remeshing was avoided. Different approaches for the mesh stiffness function are compared with respect to convergence, preservation of mesh topology and mesh quality. The resulting mesh aspect ratios, mesh expansion factors and mesh orthogonalities are evaluated in detail. The membrane motion and flow distribution of the coupled simulations are compared with a top-view recording and stereo Particle Image Velocimetry (PIV) measurements, respectively, of the actual pump.

Artificial heart for humanoid robot using coiled SMA actuators

Science.gov (United States)

Potnuru, Akshay; Tadesse, Yonas

2015-03-01

Previously, we have presented the design and characterization of artificial heart using cylindrical shape memory alloy (SMA) actuators for humanoids [1]. The robotic heart was primarily designed to pump a blood-like fluid to parts of the robot such as the face to simulate blushing or anger by the use of elastomeric substrates for the transport of fluids. It can also be used for other applications. In this paper, we present an improved design by using high strain coiled SMAs and a novel pumping mechanism that uses sequential actuation to create peristalsis-like motions, and hence pump the fluid. Various placements of actuators will be investigated with respect to the silicone elastomeric body. This new approach provides a better performance in terms of the fluid volume pumped.

Radiological symptoms of the disfunction of artificial heart valves

Energy Technology Data Exchange (ETDEWEB)

Erdelyi, M Jr [Orszagos Roentgen es Sugarfizikai Intezet, Budapest (Hungary)

1981-01-31

The possible causes of the disfunction of artificial valves are detailed. Routine X-ray examinations of the chest only rarely reveal direct signs of disfunction, but the haemodynamic alterations (dilated heart chambers, or veins) must be considered as important indirect signs. The characteristics and possibly the cause of the valve insufficience can be analyzed on the basis of kino- and spot radiograms. The symptoms observed by these methods are reported in detail.

[Percutaneous catheter-based implantation of artificial pulmonary valves in patients with congenital heart defects].

Science.gov (United States)

Wyller, Vegard Bruun; Aaberge, Lars; Thaulow, Erik; Døhlen, Gaute

2011-07-01

Percutaneous catheter-based implantation of artificial heart valves is a new technique that may supplement surgery and which may be used more in the future. We here report our first experience with implantation of artificial pulmonary valves in children with congenital heart defects. Eligible patients were those with symptoms of heart failure combined with stenosis and/or insufficiency in an established artificial right ventricular outflow tract. The valve was inserted through a catheter from a vein in the groin or neck. Symptoms, echocardiography, invasive measurements and angiography were assessed for evaluation of treatment effect. Our treatment results are reported for the period April 2007-September 2009. Ten patients (seven men and three women, median age 17 years) were assessed. The procedure reduced pressure in the right ventricle (p = 0.008) and resolved the pulmonary insufficiency in all patients. The median time in hospital was two days. No patients had complications that were directly associated with the implantation procedure. One patient developed a pseudoaneurysm in the femoral artery, another had a short-lasting fever two days after the procedure and one patient experienced a stent fracture that required surgery 9 months after the implantation. After 6 months all patients had a reduced pressure gradient in the right ventricular outflow tract (p = 0.008), the pulmonary insufficiency had improved (p = 0.006) and they all reported improval of symptoms. These results persisted for at least 24 months for the four patients who were monitored until then. Percutaneous catheter-based implantation of artificial pulmonary valves improves hemodynamics in the right ventricle of selected patients with congenital heart defects. A randomized controlled study should be undertaken to provide a stronger evidence-base for usefulness of this procedure.

Design of a portable artificial heart drive system based on efficiency analysis.

Science.gov (United States)

Kitamura, T

1986-11-01

This paper discusses a computer simulation of a pneumatic portable piston-type artificial heart drive system with a linear d-c-motor. The purpose of the design is to obtain an artificial heart drive system with high efficiency and small dimensions to enhance portability. The design employs two factors contributing the total efficiency of the drive system. First, the dimensions of the pneumatic actuator were optimized under a cost function of the total efficiency. Second, the motor performance was studied in terms of efficiency. More than 50 percent of the input energy of the actuator with practical loads is consumed in the armature circuit in all linear d-c-motors with brushes. An optimal design is: the piston cross-sectional area of 10.5 cm2 cylinder longitudinal length of 10 cm. The total efficiency could be up to 25 percent by improving the gasket to reduce the frictional force.

Thrombotic Depositions on Right Impeller of Double-Ended Centrifugal Total Artificial Heart In Vivo.

Science.gov (United States)

Karimov, Jamshid H; Horvath, David J; Okano, Shinji; Goodin, Mark; Sunagawa, Gengo; Byram, Nicole; Moazami, Nader; Golding, Leonard A R; Fukamachi, Kiyotaka

2017-05-01

The development of total artificial heart devices is a complex undertaking that includes chronic biocompatibility assessment of the device. It is considered particularly important to assess whether device design and features can be compatible long term in a biological environment. As part of the development program for the Cleveland Clinic continuous-flow total artificial heart (CFTAH), we evaluated the device for signs of thrombosis and biological material deposition in four animals that had achieved the intended 14-, 30-, or 90-day durations in each respective experiment. Explanted CFTAHs were analyzed for possible clot buildup at "susceptible" areas inside the pump, particularly the right pump impeller. Depositions of various consistency and shapes were observed. We here report our findings, along with macroscopic and microscopic analysis post explant, and provide computational fluid dynamics data with its potential implications for thrombus formation. © 2016 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

Successful heart transplantation in patients with total artificial heart infections.

Science.gov (United States)

Taimur, Sarah; Sullivan, Timothy; Rana, Mennakshi; Patel, Gopi; Roldan, Julie; Ashley, Kimberly; Pinney, Sean; Anyanwu, Anelechi; Huprikar, Shirish

2018-02-01

Data are limited on clinical outcomes in patients awaiting heart transplant (HT) with total artificial heart (TAH) infections. We retrospectively reviewed all TAH recipients at our center. TAH infection was classified as definite if a microorganism was isolated in cultures from the exit site or deep tissues around the TAH; as probable in patients without surgical or microbiologic evidence of infection but no other explanation for persistent or recurrent bloodstream infection (BSI); or possible in patients with clinical suspicion and radiographic findings suggestive of TAH infection, but without surgical intervention or microbiologic evidence. From 2012 to 2015, a total of 13 patients received a TAH, with a median age at implantation of 52 years (range: 28-60). TAH infection occurred in nine patients (seven definite, one probable, one possible) a median of 41 days after implant (range: 17-475). The majority of TAH infections were caused by Staphylococcus species. Seven of nine patients underwent HT (four had pre-HT mediastinal washout, and five had positive HT operative cultures). Three patients had an active BSI caused by the same pathogen causing TAH infection at the time of HT, with one developing a post-HT BSI with the same bacteria. No patient developed post-HT surgical site infection caused by the TAH infection pathogen. No deaths among HT recipients were attributed to infection. TAH infection is frequently associated with BSI and mediastinitis and Staphylococcus was the most common pathogen. A multimodal approach of appropriate pre- and post-HT antimicrobial therapy, surgical drainage, and heart transplantation with radical mediastinal debridement was successful in curing infection. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

A first step beyond traditional boundaries: destination therapy with the SynCardia total artificial heart.

Science.gov (United States)

Spiliopoulos, Sotirios; Koerfer, Reiner; Tenderich, Gero

2014-06-01

The SynCardia total artificial heart is currently used as a bridge to transplantation therapy in cases of irreversible, acute or chronic, biventricular heart failure. We describe the implementation of this technology in the context of destination therapy in a patient with an end-stage heart failure on grounds of primary amyloidosis. © The Author 2014. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

Materials testing and requirements for the ERDA nuclear-powered artificial heart. Technical progress report, July 15, 1974--May 1, 1975

International Nuclear Information System (INIS)

Andrade, J.D.; Coleman, D.L.; Leigh, A.; Hufferd, W.L.

1975-01-01

Progress on the materials research and development effort for the ERDA-sponsored nuclear-powered artificial heart program is presented. Progress made during the first three years on hydrogel grafting and biological studies is summarized. Progress during the fourth year on studies of implanted artificial hearts, development of albumin surfaces, and in vitro mechanical studies is presented. (U.S.)

Application of Artificial Neural Networks in the Heart Electrical Axis Position Conclusion Modeling

Science.gov (United States)

Bakanovskaya, L. N.

2016-08-01

The article touches upon building of a heart electrical axis position conclusion model using an artificial neural network. The input signals of the neural network are the values of deflections Q, R and S; and the output signal is the value of the heart electrical axis position. Training of the network is carried out by the error propagation method. The test results allow concluding that the created neural network makes a conclusion with a high degree of accuracy.

Reconstructed image of human heart for total artificial heart implantation, based on MR image and cast silicone model of heart

International Nuclear Information System (INIS)

Komoda, Takashi; Maeta, Hajime; Uyama, Chikao.

1991-01-01

Based on transverse (TRN) and LV long axis (LAX) MR images of two cadaver hearts, three-dimensional (3-D) computer models of the connecting interface between remaining heart and total artificial heart, i.e., mitral and tricuspid valvular annuli (MVA and TVA), ascending aorta (Ao) and pulmonary artery (PA), were reconstructed to compare the shape and the size of MVA and those of TVA, the distance between the center of MVA and TVA (D G ), the angle between the plane of MVA and that of TVA (R T ), and the angles of Ao and PA, respectively, to the plane of MVA (R A , R P ), with those obtained in cast silicone models. It was found that based on LAX rather than TRN MR image, MVA and TVA might be more precisely reconstructed. The data obtained in 3-D images of MVA, TVA, Ao and PA based on silicone models of 32 hearts were as follows: D G (cm): 4.17±0.43, R T (degrees): 22.1±11.3, R A (degrees): 54.9±15.3, R P (degrees): 30.8±17.1. (author)

Future Prospects for the Total Artificial Heart.

Science.gov (United States)

Sunagawa, Gengo; Horvath, David J; Karimov, Jamshid H; Moazami, Nader; Fukamachi, Kiyotaka

2016-01-01

A total artificial heart (TAH) is the sole remaining option for patients with biventricular failure who cannot be rescued by left ventricular assist devices (LVADs) alone. However, the pulsatile TAH in clinical use today has limitations: large pump size, unknown durability, required complex anticoagulation regimen, and association with significant postsurgical complications. That pump is noisy; its large pneumatic driving lines traverse the body, with bulky external components for its drivers. Continuous-flow pumps, which caused a paradigm shift in the LVAD field, have already contributed to the rapidly evolving development of TAHs. Novel continuous-flow TAHs are only in preclinical testing or developmental stages. We here review the current state of TAHs, with recommended requirements for the TAH of the future.

Prototype Development of an Implantable Compliance Chamber for a Total Artificial Heart.

Science.gov (United States)

Schmitz, Stephanie; Unthan, Kristin; Sedlaczek, Marc; Wald, Felix; Finocchiaro, Thomas; Spiliopoulos, Sotirios; Koerfer, Reiner; Steinseifer, Ulrich

2017-02-01

At our institute a total artificial heart is being developed. It is directly actuated by a linear drive in between two ventricles, which comprise membranes to separate the drive and blood flow. A compliance chamber (CC) is needed to reduce pressure peaks in the ventricles and to increase the pump capacity. Therefore, the movement of the membrane is supported by applying a negative pressure to the air volume inside the drive unit. This study presents the development of the implantable CC which is connected to the drive unit of the total artificial hearts (TAH). The anatomical fit of the CC is optimized by analyzing CT data and adapting the outer shape to ensure a proper fit. The pressure peaks are reduced by the additional volume and the flexible membrane of the CC. The validation measurements of change in pressure peaks and flow are performed using the complete TAH system connected to a custom mock circulation loop. Using the CC, the pressure peaks could be damped below 5 mm Hg in the operational range. The flow output was increased by up to 14.8% on the systemic side and 18.2% on the pulmonary side. The described implantable device can be used for upcoming chronic animal trials. © 2016 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

Worldwide Experience with the Syncardia Total Artificial Heart in the Pediatric Population.

Science.gov (United States)

Morales, David L S; Lorts, Angela; Rizwan, Raheel; Zafar, Farhan; Arabia, Francisco A; Villa, Chet R

Individual centers have documented the use of the Syncardia Total Artificial Heart (TAH) in adolescents with heart failure; however, the number of patients at any given center is small. Herein, we describe the worldwide experience for all patients ≤21 years old supported with the TAH between May 2005 and May 2015 (n = 43). The number of patients experiencing a positive outcome at 60, 90, and 120 days were 30 (70%), 27 (63%), and 25 (58%), respectively. Successful bridge to transplantation varied by diagnosis, but outcomes reported are similar to adults supported with the TAH or biventricular assist devices.

A monitoring device for pressurised-air-driven diaphragm-based artificial heart assist devices

NARCIS (Netherlands)

Hoeben, F.P.; Hoeben, F.P.; de Mul, F.F.M.; Stokkink, J.S.D.; Stokkink, H.S.D.; Koelink, M.H.; Koelink, M.H.; Greve, Jan

1992-01-01

A non-invasive device has been developed to monitor the diaphragm position and the blood flow in artificial heart assist devices equipped with a pressurised-air-driven diaphragm. Light scattering from the diaphragm is used as a mechanism for measuring. Information about the position of several

First clinical use of a bioprosthetic total artificial heart: report of two cases.

Science.gov (United States)

Carpentier, Alain; Latrémouille, Christian; Cholley, Bernard; Smadja, David M; Roussel, Jean-Christian; Boissier, Elodie; Trochu, Jean-Noël; Gueffet, Jean-Pierre; Treillot, Michèle; Bizouarn, Philippe; Méléard, Denis; Boughenou, Marie-Fazia; Ponzio, Olivier; Grimmé, Marc; Capel, Antoine; Jansen, Piet; Hagège, Albert; Desnos, Michel; Fabiani, Jean-Noël; Duveau, Daniel

2015-10-17

The development of artificial hearts in patients with end-stage heart disease have been confronted with the major issues of thromboembolism or haemorrhage. Since valvular bioprostheses are associated with a low incidence of these complications, we decided to use bioprosthetic materials in the construction of a novel artificial heart (C-TAH). We report here the device characteristics and its first clinical applications in two patients with end-stage dilated cardiomyopathy. The aim of the study was to evaluate safety and feasibility of the CARMAT TAH for patients at imminent risk of death from biventricular heart failure and not eligible for transplant. The C-TAH is an implantable electro-hydraulically actuated pulsatile biventricular pump. All components, batteries excepted, are embodied in a single device positioned in the pericardial sac after excision of the native ventricles. We selected patients admitted to hospital who were at imminent risk of death, having irreversible biventricular failure, and not eligible for heart transplantation, from three cardiac surgery centres in France. The C-TAH was implanted in two male patients. Patient 1, aged 76 years, had the C-TAH implantation on Dec 18, 2013; patient 2, aged 68 years, had the implantation on Aug 5, 2014. The cardiopulmonary bypass times for C-TAH implantation were 170 min for patient 1 and 157 min for patient 2. Both patients were extubated within the first 12 postoperative hours and had a rapid recovery of their respiratory and circulatory functions as well as a normal mental status. Patient 1 presented with a tamponade on day 23 requiring re-intervention. Postoperative bleeding disorders prompted anticoagulant discontinuation. The C-TAH functioned well with a cardiac output of 4·8-5·8 L/min. On day 74, the patient died due to a device failure. Autopsy did not detect any relevant thrombus formation within the bioprosthesis nor the different organs, despite a 50-day anticoagulant-free period. Patient 2

Total artificial heart in the pediatric patient with biventricular heart failure.

Science.gov (United States)

Park, S S; Sanders, D B; Smith, B P; Ryan, J; Plasencia, J; Osborn, M B; Wellnitz, C M; Southard, R N; Pierce, C N; Arabia, F A; Lane, J; Frakes, D; Velez, D A; Pophal, S G; Nigro, J J

2014-01-01

Mechanical circulatory support emerged for the pediatric population in the late 1980s as a bridge to cardiac transplantation. The Total Artificial Heart (TAH-t) (SynCardia Systems Inc., Tuscon, AZ) has been approved for compassionate use by the Food and Drug Administration for patients with end-stage biventricular heart failure as a bridge to heart transplantation since 1985 and has had FDA approval since 2004. However, of the 1,061 patients placed on the TAH-t, only 21 (2%) were under the age 18. SynCardia Systems, Inc. recommends a minimum patient body surface area (BSA) of 1.7 m(2), thus, limiting pediatric application of this device. This unique case report shares this pediatric institution's first experience with the TAH-t. A 14-year-old male was admitted with dilated cardiomyopathy and severe biventricular heart failure. The patient rapidly decompensated, requiring extracorporeal life support. An echocardiogram revealed severe biventricular dysfunction and diffuse clot formation in the left ventricle and outflow tract. The decision was made to transition to biventricular assist device. The biventricular failure and clot formation helped guide the team to the TAH-t, in spite of a BSA (1.5 m(2)) below the recommendation of 1.7 m(2). A computed tomography (CT) scan of the thorax, in conjunction with a novel three-dimensional (3D) modeling system and team, assisted in determining appropriate fit. Chest CT and 3D modeling following implantation were utilized to determine all major vascular structures were unobstructed and the bronchi were open. The virtual 3D model confirmed appropriate device fit with no evidence of compression to the left pulmonary veins. The postoperative course was complicated by a left lung opacification. The left lung anomalies proved to be atelectasis and improved with aggressive recruitment maneuvers. The patient was supported for 11 days prior to transplantation. Chest CT and 3D modeling were crucial in assessing whether the device would

The 50/50 cc Total Artificial Heart Trial: Extending the Benefits of the Total Artificial Heart to Underserved Populations.

Science.gov (United States)

Wells, Dennis; Villa, Chet R; Simón Morales, David Luís

2017-01-01

While use of the total artificial heart (TAH) is growing, the use of the device is not uniform across the gender and age spectrum because the vast majority of implants are in adult males. SynCardia has recently developed a smaller 50 cc TAH that was designed to accommodate patients with a body surface area as low as 1.2 m 2 (potentially even lower using virtual implantation). Herein, we describe the early use of the 50 cc TAH (10 implants in the US and 18 outside the US). Twenty-eight devices have been implanted worldwide. Nineteen (68%) patients were female, 4 (14%) were 21 years of age or younger, and 2 (7%) had a diagnosis of congenital heart disease (1 Fontan). The smallest patient, by body surface area, was 1.35 m 2 . Six patients (21%) have been placed on the Freedom Driver, all of whom have survived. Fourteen patients (50%) have had a positive outcome to date. The development of the 50 cc TAH has expanded the population of patients who may benefit from TAH support and thus may help improve outcomes for patients who have had limited biventricular support options to date. Copyright © 2017 Elsevier Inc. All rights reserved.

AbioCor totally implantable artificial heart. How will it impact hospitals?

Science.gov (United States)

2002-09-01

Although heart transplantation remains the most effective treatment for severe heart failure, there are far fewer donor hearts available than there are patients who could benefit from them. One approach to addressing this shortfall is the total artificial heart, or TAH. To date, however, no TAH design has been able to achieve one of the ultimate goals of heart replacement: to allow a patient to live a reasonably normal life without being connected to external machinery. A new design, the AbioCor TAH developed by Abiomed Inc., may make this goal achievable. Thanks to a power system that transfers energy through the skin without the aid of wires, the AbioCor--currently undergoing clinical trials in the United States--allows the patient to be completely mobile. The lack of transcutaneous wires also eliminates the primary source of the infections that have plagued TAH patients in the past. Though it is not without drawbacks, the AbioCor could represent a crucial advance in TAH technology. In this Technology Overview, we describe the operation of the AbioCor and discuss its likely impact on hospitals if it is approved for marketing in the United States. We also discuss a related cardiac-support technology: ventricular assist devices (VADs), which may also be used for permanent cardiac support someday.

An example of the use of the DELPHI method: future prospects of artificial heart techniques in France

International Nuclear Information System (INIS)

Derian, Jean-Claude; Morize, Francoise; Vernejoul, Pierre de; Vial, Renee

1971-01-01

The artificial heart is still only a research project surrounded by numerous uncertainties which make it very difficult to estimate, at the moment, the possibilities for future development of this technique in France. A systematic analysis of the hazards which characterize this project has been undertaken in the following report: restricting these uncertainties has required a taking into account of opinions of specialists concerned with type of research or its upshot. We have achieved this by adapting an investigation technique which is still unusual in France, the DELPHI method. This adaptation has allowed the confrontation and statistical aggregation of the opinions given by a body of a hundred experts who were consulted through a program of sequential interrogations which studied in particular, the probable date of the research issue, the clinical cases which require the use of an artificial heart, as well as the probable future needs. After having taken into account the economic constraints, we can deduce from these results the probable amount of plutonium 238 needed in the hypothesis where isotopic generator would be retained for the energetics feeding of the artificial heart [fr

Total Artificial Heart Bridge to Transplantation for a Patient With Occult Intracardiac Malignancy: Case Report.

Science.gov (United States)

Reich, H; Czer, L; Bannykh, S; De Robertis, M; Wolin, E; Amersi, F; Moriguchi, J; Kobashigawa, J; Arabia, F

2015-09-01

Malignancy is the leading cause of long-term morbidity and mortality after heart and other solid organ transplantation; therefore, great emphasis is placed on pre- and post-transplantation cancer screening. Even with meticulous screening during evaluation for heart transplant candidacy, an occult cancer may not be apparent. Here, we share the case of a 51-year-old man with refractory heart failure who underwent total artificial heart implantation as a bridge to transplantation with the surprise finding of an isolated deposit of metastatic carcinoid tumor nested within a left ventricular papillary muscle in his explanted heart. The primary ileal carcinoid tumor was identified and resected completely. After remaining cancer-free for 14 months, he was listed for heart transplantation and was transplanted 2 months later. He is currently 3.5 months out from heart transplantation and doing well, without evidence of recurring malignancy. Copyright © 2015 Elsevier Inc. All rights reserved.

Surface Modifications of Polymeric Materials for Application in Artificial Heart and Circulatory Assist Devices

NARCIS (Netherlands)

Feijen, J.; Engbers, G.H.M.; Terlingen, J.G.A.; van Delden, C.J.; Poot, A.A.; Vaudaux, P.; Akutsu, Tetsuzo; Koyanagi, Hitoshi

1996-01-01

Several methods have been developed to modify the surfaces of materials used in artificial hearts and circulatory assist devices to suppress the host response, especially with respect to the occurrence of clotting, cellular damage, and infections. In this review, special attention is paid to

Artificial heart pumps: bridging the gap between science, technology and personalized medicine by relational medicine.

Science.gov (United States)

Raia, Federica; Deng, Mario C

2017-01-01

In the US population of 300 million, 3 million have heart failure with reduced ejection fraction and 300,000 have advanced heart failure. Long-term mechanical circulatory support will, within the next decade, be recommended to 30,000 patients annually in the USA, 3000 undergo heart transplantation annually. What do these advances mean for persons suffering from advanced heart failure and their loved ones/caregivers? In this perspective article, we discuss - by exemplifying a case report of a 27-year-old man receiving a Total Artificial Heart - a practice concept of modern medicine that fully incorporates the patient's personhood perspective which we have termed Relational Medicine™. From this case study, it becomes apparent that the successful practice of modern cardiovascular medicine requires the person-person encounter as a core practice element.

Validation of measurements of Fourier phase and amplitude analysis of technetium99 gated cardiac scans using artificial hearts

International Nuclear Information System (INIS)

Yiannikas, J.; Takatani, S.; MacIntyre, W.J.; Underwood, D.A.; Cook, S.A.; Go, R.T.; Napoli, C.; Nose, Y.

1982-01-01

The use of artificial hearts, developed for total heart replacement programs, allows assessment of the accuracy of measuring the first Fourier component phase and amplitude when applied to gated cardiac technetium 99 scans. In the extreme example of asynchrony of ventricular contraction in coronary artery disease that of ventricular aneurysms, the first Fourier component measurements of amplitude were highly correlated to volume increases suggesting that the calculated amplitude accurately reflects volume changes. The calculated asynchrony using Fourier analysis of the gated technetium 99 studies of two artificial hearts was highly accurate when compared to the predetermined calculation of phase angle difference and hence degree of asynchrony. The studies suggest that measurement of phase and amplitude using the first Fourier component of time-activity waves of gated cardiac technetium 99 studies accurately measure degree of asynchrony and volume changes respectively

Stirling engine with hydraulic power output for powering artificial hearts

International Nuclear Information System (INIS)

Johnston, R.P.; Noble, J.E.; Emigh, S.G.; White, M.A.; Griffith, W.R.; Perrone, R.E.

1975-01-01

The DWDL heart power source combines the high efficiency of Stirling engines with the reliability, efficiency, and flexibility of hydraulic power transfer and control to ensure long system life and physiological effectiveness. Extended life testing has already been achieved with an engine module; animal in-vivo tests with an assist heart have consistently demonstrated required performance by biological synchronization and effective ventricle relief. The present System 5 can reliably meet near-term thousand-hour animal in-vivo test goals as far as the durability and efficacy of the power source are concerned. Carefully planned development of System 6 has produced major reductions in size and required input power. Research engine tests have provided the basis for achieving performance goals and the approach for further improvement is well established. The near term goal is 33 W heat input with 16 W input projected for normal physical activity. The goal of reduction of engine module volume to 0.9 liter has been achieved. Demonstrated reliability of 292 d for the engine and 35 d for the full system, as well as effectiveness of the artificial heart power source in short-term in-vivo tests indicate that life-limiting problems are now blood pump reliability and the machine-animal interface

Selective attenuation of norepinephrine release and stress-induced heart rate increase by partial adenosine A1 agonism.

Directory of Open Access Journals (Sweden)

Lorenz Bott-Flügel

Full Text Available The release of the neurotransmitter norepinephrine (NE is modulated by presynaptic adenosine receptors. In the present study we investigated the effect of a partial activation of this feedback mechanism. We hypothesized that partial agonism would have differential effects on NE release in isolated hearts as well as on heart rate in vivo depending on the genetic background and baseline sympathetic activity. In isolated perfused hearts of Wistar and Spontaneously Hypertensive Rats (SHR, NE release was induced by electrical stimulation under control conditions (S1, and with capadenoson 6 · 10(-8 M (30 µg/l, 6 · 10(-7 M (300 µg/l or 2-chloro-N(6-cyclopentyladenosine (CCPA 10(-6 M (S2. Under control conditions (S1, NE release was significantly higher in SHR hearts compared to Wistar (766+/-87 pmol/g vs. 173+/-18 pmol/g, p<0.01. Capadenoson led to a concentration-dependent decrease of the stimulation-induced NE release in SHR (S2/S1  =  0.90 ± 0.08 with capadenoson 6 · 10(-8 M, 0.54 ± 0.02 with 6 · 10(-7 M, but not in Wistar hearts (S2/S1  =  1.05 ± 0.12 with 6 · 10(-8 M, 1.03 ± 0.09 with 6 · 10(-7 M. CCPA reduced NE release to a similar degree in hearts from both strains. In vivo capadenoson did not alter resting heart rate in Wistar rats or SHR. Restraint stress induced a significantly greater increase of heart rate in SHR than in Wistar rats. Capadenoson blunted this stress-induced tachycardia by 45% in SHR, but not in Wistar rats. Using a [(35S]GTPγS assay we demonstrated that capadenoson is a partial agonist compared to the full agonist CCPA (74+/-2% A(1-receptor stimulation. These results suggest that partial adenosine A(1-agonism dampens stress-induced tachycardia selectively in rats susceptible to strong increases in sympathetic activity, most likely due to a presynaptic attenuation of NE release.

Rapid Speed Modulation of a Rotary Total Artificial Heart Impeller.

Science.gov (United States)

Kleinheyer, Matthias; Timms, Daniel L; Tansley, Geoffrey D; Nestler, Frank; Greatrex, Nicholas A; Frazier, O Howard; Cohn, William E

2016-09-01

Unlike the earlier reciprocating volume displacement-type pumps, rotary blood pumps (RBPs) typically operate at a constant rotational speed and produce continuous outflow. When RBP technology is used in constructing a total artificial heart (TAH), the pressure waveform that the TAH produces is flat, without the rise and fall associated with a normal arterial pulse. Several studies have suggested that pulseless circulation may impair microcirculatory perfusion and the autoregulatory response and may contribute to adverse events such as gastrointestinal bleeding, arteriovenous malformations, and pump thrombosis. It may therefore be beneficial to attempt to reproduce pulsatile output, similar to that generated by the native heart, by rapidly modulating the speed of an RBP impeller. The choice of an appropriate speed profile and control strategy to generate physiologic waveforms while minimizing power consumption and blood trauma becomes a challenge. In this study, pump operation modes with six different speed profiles using the BiVACOR TAH were evaluated in vitro. These modes were compared with respect to: hemodynamic pulsatility, which was quantified as surplus hemodynamic energy (SHE); maximum rate of change of pressure (dP/dt); pulse power index; and motor power consumption as a function of pulse pressure. The results showed that the evaluated variables underwent different trends in response to changes in the speed profile shape. The findings indicated a possible trade-off between SHE levels and flow rate pulsatility related to the relative systolic duration in the speed profile. Furthermore, none of the evaluated measures was sufficient to fully characterize hemodynamic pulsatility. © 2016 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

Post-explant visualization of thrombi in outflow grafts and their junction to a continuous-flow total artificial heart using a high-definition miniaturized camera.

Science.gov (United States)

Karimov, Jamshid H; Horvath, David; Sunagawa, Gengo; Byram, Nicole; Moazami, Nader; Golding, Leonard A R; Fukamachi, Kiyotaka

2015-12-01

Post-explant evaluation of the continuous-flow total artificial heart in preclinical studies can be extremely challenging because of the device's unique architecture. Determining the exact location of tissue regeneration, neointima formation, and thrombus is particularly important. In this report, we describe our first successful experience with visualizing the Cleveland Clinic continuous-flow total artificial heart using a custom-made high-definition miniature camera.

A bioprosthetic total artificial heart for end-stage heart failure: Results from a pilot study.

Science.gov (United States)

Latrémouille, Christian; Carpentier, Alain; Leprince, Pascal; Roussel, Jean-Christian; Cholley, Bernard; Boissier, Elodie; Epailly, Eric; Capel, Antoine; Jansen, Piet; Smadja, David M

2018-01-01

The electro-hydraulically actuated Carmat total artificial heart (C-TAH) is designed to replace the heart in patients with end-stage heart failure, either as bridge to transplant or destination therapy. It provides pulsatile flow and contains bio-prosthetic blood contacting materials. A clinical feasibility study was conducted to evaluate the C-TAH safety and performance. Hospitalized patients, at imminent risk of death from irreversible biventricular failure despite optimal medical management, and not eligible for transplant or eligible but on extracorporeal life support, were enrolled. The primary endpoint was 30-days survival. Four patients were implanted with the C-TAH, three as destination therapy (ages 76, 68, 74) and one as bridge to transplant (age 58). They had implant times of 74, 270, 254 and 20 days respectively. All patients were free from hemolysis, clinical neurologic events, clinical evidence of thrombus and device-related infections. Hemodynamic and physical recovery allowed two patients to be discharged home for a cumulative duration of 7 months. The anticoagulation management strategy comprised initial unfractionated heparin, from postoperative day 2, followed by low molecular weight heparin and aspirin. An increased D-dimer level was observed in all patients during months 1 to 4. Temporary suspension of heparin anticoagulation resulted in thrombocytopenia and increased fibrin monomer, reversed by resuming anticoagulation with heparin. Causes of death were device-related (2 cases), respiratory failure and multi-organ failure. Preliminary clinical results with the C-TAH demonstrated good safety and performance profiles in patients suffering from biventricular failure, which need to be confirmed in a pivotal study. Copyright © 2018 International Society for the Heart and Lung Transplantation. Published by Elsevier Inc. All rights reserved.

The evolving role of the total artificial heart in the management of end-stage congenital heart disease and adolescents.

Science.gov (United States)

Ryan, Thomas D; Jefferies, John L; Zafar, Farhan; Lorts, Angela; Morales, David L S

2015-01-01

Advances in medical therapies have yielded improvement in morbidity and a decrease in mortality for patients with congenital heart disease, both surgically palliated and uncorrected. An unintended consequence is a cohort of adolescent and adult patients with heart failure who require alternative therapies. One intriguing option is placement of a total artificial heart (TAH) either as a bridge to transplant or as a destination therapy. Of the 1091 Jarvik-7 type TAH (Symbion, CardioWest and SynCardia) placed between 1985 and 2012, only 24 have been performed in patients with congenital heart disease, and a total of 51 were placed in patients younger than 21. At our institution, the SynCardia TAH was implanted in a 19-year-old patient with cardiac allograft failure because of chronic rejection and related multisystem organ failure including need for hemodialysis. Over the next year, she was nutritionally and physically rehabilitated, as were her end organs, allowing her to come off dialysis, achieve normal renal function and eventually be successfully transplanted. Given the continued growth of adolescent and adult congenital heart disease populations with end-stage heart failure, the TAH may offer therapeutic options where previously there were few. In addition, smaller devices such as the SynCardia 50/50 will open the door for applications in smaller children. The Freedom Driver offers the chance for patients to leave the hospital with a TAH, as does the AbioCor, which is a fully implantable TAH option. In this report, we review the history of the TAH and potential applications in adolescent patients and congenital heart disease.

[Hydrodynamics of disk artificial heart valves with different design characteristics].

Science.gov (United States)

Dobrova, N B; Zaretskiĭ, Iu V

1989-01-01

Bench tests for 38 models of artificial heart valves (AHV) with different design parameters allowed us to decide in favour of the valves with reduced eccentricity (compared to the serial AHV of the EMAHV type) according to its resistance in the constant flow. Out of the compatibility checks of the design parameters tested it was concluded that the disk did not make the complete calculated angle when rotated. The dependence of AHV resistance on the disk rotation angle showed that there is no necessity to increase that angle more than 70 degrees for the mitral valve and more than 75 degrees for the aortic AHV.

Perioperative Prophylaxis for Total Artificial Heart Transplantation.

Science.gov (United States)

Chambers, H E; Pelish, P; Qiu, F; Florescu, D F

2017-11-01

Practice variation regarding perioperative antimicrobial prophylaxis in total artificial heart transplantations (TAH-t) across institutions is unknown. The aim of our survey was to assess the current practices for prevention of infection in TAH-t recipients among different programs. An electronic survey was sent to programs that implant Syncardia TAH (Syncardia Systems, Tuscon, Ariz, USA). Proportions were analyzed for categorical variables; means and SDs were analyzed for continuous variables. The majority of centers (80.8%) had a formal surgical infection prophylaxis protocol. For non-penicillin-allergic patients, five (20.1%) institutions reported using a 4-drug regimen, seven (29.2%) used a 3-drug regimen, five (20.1%) used a 2-drug regimen, and seven (29.2%) used a cephalosporin alone. Similar data was seen in the penicillin-allergic patients. Infections were reported to occur postoperatively in 52.2% centers. During the first month after TAH-t, bacteremia represented 27.3%, driveline infections 27.2%, pulmonary infections 9%, and mediastinal infections 18.2%. The most common organisms seen within the first month were Candida spp., Escherichia coli, and Pseudomonas aeruginosa (21.4%). In 65% of centers, the mean rate of death post-TAH-t due to infection was 14.5% (SD, 22.3%). The mean rate of patients surviving until orthotopic heart transplantation was 58.6% (SD, 27.7%). Preventing infections post-TAH-t is key to decreasing morbidity and mortality. All institutions administered perioperative prophylaxis for TAH-t with significant variation among the centers. The majority of the centers have a formal perioperative prophylactic protocol. Copyright © 2017. Published by Elsevier Inc.

Chest radiographic findings and complications of the temporary implantation of the Jarvik-7 artificial heart while awaiting orthotopic heart transplantation: Experience with five cases

International Nuclear Information System (INIS)

Sadler, L.R.; Fuhrman, C.R.; Hardesty, R.A.; Griffith, B.P.

1986-01-01

The Jarvik-7 artificial heart was originally introduced as a therapeutic alternative to cardiac transplantation in patients with endstage refractory cardiac disease. Its use has been expanded to those patients awaiting cardiac transplantation in whom death is impending and for whom a suitable donor match is unavailable. At Presbyterian-University Hospital of Pittsburgh five patients have had Jarvik-7 hearts implanted as a temporary measure while awaiting compatible donors for cardiac transplantation. The authors believe this is the largest patient group to undergo this procedure at a single institution. They present a brief description of the Jarvik-7 heart, the clinical factors affecting patient selection, and the radiographic appearance of a normally functioning Jarvik-7 heart, and review the chest radiographic complications seen in the patient group, along with eventual patient outcome

Making Artificial Heart Components – Selected Aspects Of Casting Technology

Directory of Open Access Journals (Sweden)

Sobczak J.J.

2015-09-01

Full Text Available This study shown possibilities of Rapid Prototyping techniques (RP and metal casting simulation software (MCSS, including non inertial reference systems. RP and MCSS have been used in order to design and produce essential elements for artificial heart. Additionally it has been shown possibilities of Fused Deposition Modeling (FDM technique and DodJet technology using prototyped elements of rotodynamic pump. MAGMASOFT® software allowed to verify the cast kit heart valves model. Optical scanner Atos III enabled size verification of experimental elements supplied by rapid prototyping together with metal casting elements. Due to the selection of ceramic materials and assessment of molten metal – ceramic reactivity at high temperatures together with pattern materials selection model it was possible to design, manufacture a ceramic mould for titanium based alloys. The casting structure modification has been carried out by means of high isostatic pressure technique (HIP. The quality assessment of the casting materials has been performed using X-ray fluorescence (XRF, ARL 4460 Optical Emission Spectrometer, metallographic techniques and X-ray computed tomography.

[Artificial organs].

Science.gov (United States)

Raguin, Thibaut; Dupret-Bories, Agnès; Debry, Christian

2017-01-01

Research has been fighting against organ failure and shortage of donations by supplying artificial organs for many years. With the raise of new technologies, tissue engineering and regenerative medicine, many organs can benefit of an artificial equivalent: thanks to retinal implants some blind people can visualize stimuli, an artificial heart can be proposed in case of cardiac failure while awaiting for a heart transplant, artificial larynx enables laryngectomy patients to an almost normal life, while the diabetic can get a glycemic self-regulation controlled by smartphones with an artificial device. Dialysis devices become portable, as well as the oxygenation systems for terminal respiratory failure. Bright prospects are being explored or might emerge in a near future. However, the retrospective assessment of putative side effects is not yet sufficient. Finally, the cost of these new devices is significant even if the advent of three dimensional printers may reduce it. © 2017 médecine/sciences – Inserm.

Artificial heart system thermal converter and blood pump component research and development

International Nuclear Information System (INIS)

Pouchot, W.D.; Bifano, N.J.; Hanson, J.P.

1975-01-01

A bench model version of a nuclear-powered artificial heart system to be used as a replacement for the natural heart was constructed and tested as a part of a broader U. S. ERDA program. The objective of the broader program has been to develop a prototype of a fully implantable nuclear-powered total artificial heart system powered by the thermal energy of plutonium-238 and having minimum weight and volume and a minimum life of ten years. As a forward step in this broader program, component research and development has been carried out directed towards a fully implantable and advanced version of the bench model (IVBM). Some of the results of the component research and development effort on a Stirling engine, blood pump drive mechanisms, and coupling mechanisms are presented. The Stirling-mechanical system under development is shown. There are three major subassemblies: the thermal converter, the coupling mechanism, and the blood pump drive mechanism. The thermal converter uses a Stirling cycle to convert the heat of the plutonium-238 fueled heat source to a rotary shaft power output. The coupling mechanism changes the orientation of the output shaft by 90 degrees and transmits the pumping power by wire-wound core flexible shafting to the pumping mechanism. The coupling mechanism also provides routing of the coolant lines which carry the cycle waste heat from the thermal converter to the blood pump. The change in orientation of the thermal converter output shaft is for convenience in implanting in a calf. This orientation of thermal converter to blood pump seemed to give the best overall system fit in a calf based on fit trials with wooden models in a calf cadaver

Total Artificial Heart and Chronic Haemodialysis: A Possible Bridge to Transplantation?

Science.gov (United States)

Demiselle, Julien; Besson, Virginie; Sayegh, Johnny; Subra, Jean-François; Augusto, Jean-François

2016-01-01

Total artificial heart (TAH) device is sometimes necessary to treat end stage heart failure (HF). After surgery, renal impairment can occur with the need of renal replacement therapy. We report the case of a 51-year-old man who was treated with conventional hemodialysis (HD) while on support with TAH. The patient underwent HD while on TAH support during 14 months. He benefited from conventional HD, 6 sessions per week. HD sessions were well tolerated, and patient's condition and quality of life improved significantly. The main difficulty was to maintain red blood cell level because of chronic hemolysis due to TAH, which required repetitive blood transfusions, resulting in a high rate of human leukocyte antigen sensitization. Unfortunately, the patient died of mesenteric ischemia due to anticoagulation under dosing. We conclude that HD treatment is possible despite TAH and should be considered in patients with both end stage renal and HF. © 2016 S. Karger AG, Basel.

Effect of partial sports massage on blood pressure and heart rate

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T.D. Pystupa

2013-12-01

Full Text Available With the growing popularity and demand for different types of massages (including sports is a growing need for research on specific forms. There is also a need to study the advantages and effects on various body functions. The objective was to study the effect of partial sports massage on blood pressure and heart rate in both men and women. Material and methods. Research has been extended 80 healthy men and women are physically active (age 20-25 years. Blood pressure and heart rate were made on the left arm automatic digital device (model HEM - 907. The device is intended to measure blood pressure. It is established that it is possible to verify the existing beliefs. This promotes more efficient use of massage therapy. Conclusions . Sports massage has an effect on hemodynamic changes, the increase (decrease in blood pressure acceleration (deceleration of the heart rate. It depends on what part of the body exposed to the massage procedure.

Artificial heart system thermal insulation component development

International Nuclear Information System (INIS)

Svedberg, R.C.; Buckman, R.W. Jr.

1975-01-01

A concentric cup vacuum multifoil insulation system has been selected by virtue of its size, weight, and thermal performance to insulate the hot radioisotope portion of the thermal converter of an artificial implantable heart system. A factor of 2 improvement in thermal performance, based on the heat loss per number of foil layers (minimum system weight and volume) has been realized over conventional spiral wrapped multifoil vacuum insulation. This improvement is the result of the concentric cup construction to maintain a uniform interfoil spacing and the elimination of corner heat losses. Based on external insulation system dimensions (surface area in contact with host body), heat losses of 0.019 W/ cm 2 at 1140 0 K (1600 0 F) and 0.006 W/cm 2 at 920 0 K (1200 0 F) have been achieved. Factors which influence thermal performance of the nickel foil concentric cup insulation system include the number of cups, configuration and method of application of zirconia (ZrO 2 ) spacer material, system pressure, emittance of the cups, and operating temperature

Deairing Techniques for Double-Ended Centrifugal Total Artificial Heart Implantation.

Science.gov (United States)

Karimov, Jamshid H; Horvath, David J; Byram, Nicole; Sunagawa, Gengo; Grady, Patrick; Sinkewich, Martin; Moazami, Nader; Sale, Shiva; Golding, Leonard A R; Fukamachi, Kiyotaka

2017-06-01

The unique device architecture of the Cleveland Clinic continuous-flow total artificial heart (CFTAH) requires dedicated and specific air-removal techniques during device implantation in vivo. These procedures comprise special surgical techniques and intraoperative manipulations, as well as engineering design changes and optimizations to the device itself. The current study evaluated the optimal air-removal techniques during the Cleveland Clinic double-ended centrifugal CFTAH in vivo implants (n = 17). Techniques and pump design iterations consisted of developing a priming method for the device and the use of built-in deairing ports in the early cases (n = 5). In the remaining cases (n = 12), deairing ports were not used. Dedicated air-removal ports were not considered an essential design requirement, and such ports may represent an additional risk for pump thrombosis. Careful passive deairing was found to be an effective measure with a centrifugal pump of this design. In this report, the techniques and design changes that were made during this CFTAH development program to enable effective residual air removal and prevention of air embolism during in vivo device implantation are explained. © 2016 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

Investigation of the Durability of a Diaphragm for a Total Artificial Heart.

Science.gov (United States)

Gräf, Felix; Rossbroich, Ralf; Finocchiaro, Thomas; Steinseifer, Ulrich

2016-10-01

One of the most critical components regarding the durability of the ReinHeart total artificial heart (TAH) is its biocompatible diaphragm, which separates the drive unit from the ventricles. Hence, a durability tester was designed to investigate its required 5-year lifetime. The aim of this study was to prove the validity of accelerated testing of the polyurethane diaphragm. The durability tester allows simultaneous testing of 12 diaphragms and mimics physiological conditions. To accelerate the time of testing, it operates with an increased speed at a frequency of 8 Hz. To prove the correctness of this acceleration, a servo-hydraulic testing machine was used to study the effect of different frequencies and their corresponding loads. Thereby the viscoelastic behavior of the polyurethane was investigated. Additionally, high-speed video measurements were performed. The force against frequency and the high-speed video measurements showed constant behavior. In the range of 1-10 Hz, the maximum resulting forces varied by 3%, and the diaphragm movement was identical. Frequencies below 10 Hz allow a valid statement of the diaphragm's mechanical durability. Viscoelasticity of the polyurethane in the considered frequency-range is negligible. The accelerated durability test is applicable to polyurethane diaphragms, and the results are applicable to TAH use. The reliability of the diaphragm for a lifetime of 5 years was found to be 80% with a confidence of 62%. Copyright © 2015 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

Elective Inactivation of Total Artificial Heart Technology in Non-Futile Situations: Inpatients, Outpatients and Research Participants

Science.gov (United States)

Bramstedt, Katrina A.

2004-01-01

Total artificial heart technology as a potential clinical therapy raises the issue of elective device inactivation in both futile and non-futile situations. This article explores elective device inactivation in non-futile situations. In reply to such requests for inactivation, the medical team should reflect on the individual's decision-making…

Heart rate and leukocytes after air and ground transportation in artificially ventilated neonates: a prospective observational study.

Science.gov (United States)

Grosek, Stefan; Mlakar, Gorazd; Vidmar, Ivan; Ihan, Alojz; Primozic, Janez

2009-01-01

To evaluate the effect of interhospital air and ground transportation of artificially ventilated neonates on heart rate and peripheral blood leukocyte counts. Prospective, observational study. Level III multidisciplinary Neonatal and Pediatric Intensive Care Unit. Fifty-eight near-term artificially ventilated transported neonates between May 2006 and April 2007. Day-helicopter, day- and night-ground transportation. Heart rate at retrieval, on admission to the ICU and 1 h later, and peripheral blood leukocyte counts on admission and 1 d later were compared. Fifteen neonates were transported by helicopter during the daytime (D-HEL), 20 by daytime ground and 23 by nighttime ground transportation (D-GROUND, N-GROUND). No differences in delivery mode, birth weight, gestational age, gender, primary diagnoses for transportation, response time and duration of transportation were found between the groups. Similarly, no differences in pH, pCO(2), blood pressure and skin temperature at retrieval and on admission to the ICU were found between the three groups. The mean heart rate at retrieval did not differ significantly, while on arrival in the ICU and 1 h later the D-GROUND group of patients showed a significantly higher mean heart rate compared to the D-HEL and N-GROUND groups. Moreover, leukocyte counts on arrival in the ICU showed significantly higher leukocyte counts in the D-GROUND group of patients compared to the D-HEL group of patients. These results demonstrate that there is an association between daytime ground transportation and higher heart rate and peripheral blood leukocytes.

Incorporating an Exercise Detection, Grading, and Hormone Dosing Algorithm Into the Artificial Pancreas Using Accelerometry and Heart Rate

OpenAIRE

Jacobs, Peter G.; Resalat, Navid; El Youssef, Joseph; Reddy, Ravi; Branigan, Deborah; Preiser, Nicholas; Condon, John; Castle, Jessica

2015-01-01

In this article, we present several important contributions necessary for enabling an artificial endocrine pancreas (AP) system to better respond to exercise events. First, we show how exercise can be automatically detected using body-worn accelerometer and heart rate sensors. During a 22 hour overnight inpatient study, 13 subjects with type 1 diabetes wearing a Zephyr accelerometer and heart rate monitor underwent 45 minutes of mild aerobic treadmill exercise while controlling their glucose ...

Research on micro-structure and hemo-compatibility of the artificial heart valve surface

International Nuclear Information System (INIS)

Ye Xia; Shao Yunliang; Zhou Ming; Li Jian; Cai Lan

2009-01-01

In order to seek the method to improve the hemo-compatibility of artificial mechanical heart valve, the surface of rabbit's heart valve was observed using the scanning electron microscopy (SEM). The results showed that the dual-scale structure which consists of cobblestones-like structure of 8 μm in underside diameter and 3 μm in height, and the fine cilia of about 150 nm in diameter, was helpful to the hemo-compatibility of the heart valve. Therefore, the polydimethylsiloxane (PDMS) surface with hierarchical micro-structure was fabricated using femtosecond laser fabrication technique and soft lithography. At the same time, the tests of apparent contact angle and platelet adhesion on both smooth and textured PDMS surfaces were carried out to study their wettability and hemo-compatibility. The results demonstrated that the surface with textured structure displayed more excellent wettabililty and anti-coagulation property than that of smooth surface. The apparent contact angle of textured surface enhanced from 113.1 deg. to 163.6 deg. and the amount of adsorbed platelet on such surface was fewer, no distortion and no activation were found.

Prediction of octanol-water partition coefficients of organic compounds by multiple linear regression, partial least squares, and artificial neural network.

Science.gov (United States)

Golmohammadi, Hassan

2009-11-30

A quantitative structure-property relationship (QSPR) study was performed to develop models those relate the structure of 141 organic compounds to their octanol-water partition coefficients (log P(o/w)). A genetic algorithm was applied as a variable selection tool. Modeling of log P(o/w) of these compounds as a function of theoretically derived descriptors was established by multiple linear regression (MLR), partial least squares (PLS), and artificial neural network (ANN). The best selected descriptors that appear in the models are: atomic charge weighted partial positively charged surface area (PPSA-3), fractional atomic charge weighted partial positive surface area (FPSA-3), minimum atomic partial charge (Qmin), molecular volume (MV), total dipole moment of molecule (mu), maximum antibonding contribution of a molecule orbital in the molecule (MAC), and maximum free valency of a C atom in the molecule (MFV). The result obtained showed the ability of developed artificial neural network to prediction of partition coefficients of organic compounds. Also, the results revealed the superiority of ANN over the MLR and PLS models. Copyright 2009 Wiley Periodicals, Inc.

Noninvasive Measurement of EKG Properties of 3D Artificial Heart Muscle

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Betsy H. Salazar

2017-06-01

Full Text Available Developing and testing a custom fabricated 16-electrode noninvasive direct contact system was necessary to assess the electrical properties of bioengineered heart muscle and to further evaluate the efficacy of cardiac constructs. By culturing neonatal rat primary cardiac cells on a fibrin gel, we constructed 3D artificial heart muscle (3D-AHM, as described in previous studies, which were used in validating this novel system. Electrical and mechanical functional assessment of the tissues was performed, which yielded contractile forces of the tissues, electrical field potential characteristics, and tissue conduction velocities (CV (20–170 cm/s. Immunohistological evaluation revealed the formation of cardiac tissue structures and cardiomyocyte proliferation. EKG data analysis also yielded time delays between signals in the range of 0–38 ms with electrical maps showing some evidence of synchronous contraction within the fabricated tissues. This study demonstrates the effectiveness and practicality of our novel EKG measuring system to acquire distinct electrical metrics of 3D-AHM, which will aid in increasing the viability and applicability of cardiac tissue constructs.

Functional and structural regeneration in the axolotl heart (Ambystoma mexicanum) after partial ventricular amputation.

Science.gov (United States)

Cano-Martínez, Agustina; Vargas-González, Alvaro; Guarner-Lans, Verónica; Prado-Zayago, Esteban; León-Oleda, Martha; Nieto-Lima, Betzabé

2010-01-01

"In the present study we evaluated the effect of partial ventricular amputation (PVA) in the heart of the adult urodele amphibian (Ambystoma mexicanum) in vivo on spontaneous heart contractile activity recorded in vitro in association to the structural recovery at one, five, 30 and 90 days after injury. One day after PVA, ventricular-tension (VT) (16 ± 3%), atrium-tension (AT) (46 ± 4%) and heart rate (HR) (58+10%) resulted lower in comparison to control hearts. On days five, 30 and 90 after damage, values achieved a 61 ± 5, 93 ± 3, and 98 ± 5% (VT), 60 ± 4, 96 ± 3 and 99 ± 5% (AT) and 74 ± 5, 84 ± 10 and 95 ± 10% (HR) of the control values, respectively. Associated to contractile activity recovery we corroborated a gradual tissue restoration by cardiomyocyte proliferation. Our results represent the first quantitative evidence about the recovery of heart of A. mexicanum restores its functional capacity concomitantly to the structural recovery of the myocardium by proliferation of cardiomyocytes after PVA. These properties make the heart of A. mexicanum a potential model to study the mechanisms underlying heart regeneration in adult vertebrates in vivo.

Development of a nuclear-powered artificial heart

International Nuclear Information System (INIS)

Mott, W.E.; Cole, D.W. Jr.

1972-01-01

Of the few known methods of furnishing power for a completely implantable artificial heart one of the most promising involves the conversion of the thermal energy from the decay of man-made radioisotopes. Serious consideration of radioisotopic, or nuclear, heat sources for implantable power supplies began in early 1964. Since then there have been some notable accomplishments on the road to a nuclear-powered system but a large number of important and difficult problems remain to be clarified. The overall objective of the Atomic Energy Commission's current program is to examine critically these problems and to provide information so that the reasonableness and practicability of the nuclear approach can be assessed at an early date. Research and development projects are underway on radioisotope heat source fuel and containment materials, on a highly reliable, long-life thermal energy conversion system and its requisite high performance thermal insulation package, on the coupling of the converter output power to the diaphragm of a suitable blood pump in such a manner that the system is fully responsive to the needs of the body, and on the radiobiological implications of large-scale heat source implantation. (auth)

Heart murmur detection based on wavelet transformation and a synergy between artificial neural network and modified neighbor annealing methods.

Science.gov (United States)

Eslamizadeh, Gholamhossein; Barati, Ramin

2017-05-01

Early recognition of heart disease plays a vital role in saving lives. Heart murmurs are one of the common heart problems. In this study, Artificial Neural Network (ANN) is trained with Modified Neighbor Annealing (MNA) to classify heart cycles into normal and murmur classes. Heart cycles are separated from heart sounds using wavelet transformer. The network inputs are features extracted from individual heart cycles, and two classification outputs. Classification accuracy of the proposed model is compared with five multilayer perceptron trained with Levenberg-Marquardt, Extreme-learning-machine, back-propagation, simulated-annealing, and neighbor-annealing algorithms. It is also compared with a Self-Organizing Map (SOM) ANN. The proposed model is trained and tested using real heart sounds available in the Pascal database to show the applicability of the proposed scheme. Also, a device to record real heart sounds has been developed and used for comparison purposes too. Based on the results of this study, MNA can be used to produce considerable results as a heart cycle classifier. Copyright © 2017 Elsevier B.V. All rights reserved.

[Artificial muscle and its prospect in application for direct cardiac compression assist].

Science.gov (United States)

Dong, Jing; Yang, Ming; Zheng, Zhejun; Yan, Guozheng

2008-12-01

Artificial heart is an effective device in solving insufficient native heart supply for heart transplant, and the research and application of novel actuators play an important role in the development of artificial heart. In this paper, artificial muscle is introduced as the actuators of direct cardiac compression assist, and some of its parameters are compared with those of native heart muscle. The open problems are also discussed.

Interagency registry for mechanically assisted circulatory support report on the total artificial heart.

Science.gov (United States)

Arabía, Francisco A; Cantor, Ryan S; Koehl, Devin A; Kasirajan, Vigneshwar; Gregoric, Igor; Moriguchi, Jaime D; Esmailian, Fardad; Ramzy, Danny; Chung, Joshua S; Czer, Lawrence S; Kobashigawa, Jon A; Smith, Richard G; Kirklin, James K

2018-04-26

We sought to better understand the patient population who receive a temporary total artificial heart (TAH) as bridge to transplant or as bridge to decision by evaluating data from the Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) database. We examined data related to survival, adverse events, and competing outcomes from patients who received TAHs between June 2006 and April 2017 and used hazard function analysis to explore risk factors for mortality. Data from 450 patients (87% men; mean age, 50 years) were available in the INTERMACS database. The 2 most common diagnoses were dilated cardiomyopathy (50%) and ischemic cardiomyopathy (20%). Risk factors for right heart failure were present in 82% of patients. Most patients were INTERMACS Profile 1 (43%) or 2 (37%) at implantation. There were 266 patients who eventually underwent transplantation, and 162 died. Overall 3-, 6-, and 12-month actuarial survival rates were 73%, 62%, and 53%, respectively. Risk factors for death included older age (p = 0.001), need for pre-implantation dialysis (p = 0.006), higher creatinine (p = 0.008) and lower albumin (p Heart and Lung Transplantation. Published by Elsevier Inc. All rights reserved.

Cyclic stress-strain behavior of polymeric nonwoven structures for the use as artificial leaflet material for transcatheter heart valve prostheses

Directory of Open Access Journals (Sweden)

Arbeiter Daniela

2017-09-01

Full Text Available Xenogenic leaflet material, bovine and porcine pericardium, is widely used for the fabrication of surgically implanted and transcatheter heart valve prostheses. As a biological material, long term durability of pericardium is limited due to calcification, degeneration and homogeneity. Therefore, polymeric materials represent a promising approach for a next generation of artificial heart valve leaflets with improved durability. Within the current study we analyzed the mechanical performance of polymeric structures based on elastomeric materials. Polymeric cast films were prepared and nonwovens were manufactured in an electrospinning process. Analysis of cyclic stress-strain behavior was performed, using a universal testing machine. The uniaxial cyclic tensile experiments of the elastomeric samples yielded a non-linear elastic response due to viscoelastic behavior with hysteresis. Equilibrium of stress-strain curves was found after a specific number of cycles, for cast films and nonwovens, respectively. In conclusion, preconditioning was found obligatory for the evaluation of the mechanical performance of polymeric materials for the use as artificial leaflet material for heart valve prostheses.

Examination of mitral regurgitation with a goat heart model for the development of intelligent artificial papillary muscle.

Science.gov (United States)

Shiraishi, Y; Yambe, T; Yoshizawa, M; Hashimoto, H; Yamada, A; Miura, H; Hashem, M; Kitano, T; Shiga, T; Homma, D

2012-01-01

Annuloplasty for functional mitral or tricuspid regurgitation has been made for surgical restoration of valvular diseases. However, these major techniques may sometimes be ineffective because of chamber dilation and valve tethering. We have been developing a sophisticated intelligent artificial papillary muscle (PM) by using an anisotropic shape memory alloy fiber for an alternative surgical reconstruction of the continuity of the mitral structural apparatus and the left ventricular myocardium. This study exhibited the mitral regurgitation with regard to the reduction in the PM tension quantitatively with an originally developed ventricular simulator using isolated goat hearts for the sophisticated artificial PM. Aortic and mitral valves with left ventricular free wall portions of isolated goat hearts (n=9) were secured on the elastic plastic membrane and statically pressurized, which led to valvular leaflet-papillary muscle positional change and central mitral regurgitation. PMs were connected to the load cell, and the relationship between the tension of regurgitation and PM tension were measured. Then we connected the left ventricular specimen model to our hydraulic ventricular simulator and achieved hemodynamic simulation with the controlled tension of PMs.

Histopathology Image Analysis in Two Long-Term Animal Experiments with Helical Flow Total Artificial Heart.

Science.gov (United States)

Wotke, Jiri; Homolka, Pavel; Vasku, Jaromír; Dobsak, Petr; Palanova, Petra; Mrkvicova, Veronika; Konecny, Petr; Soska, Vladimir; Pohanka, Michal; Novakova, Marie; Yurimoto, Terumi; Saito, Itsuro; Inoue, Yusuke; Isoyama, Takashi; Abe, Yusuke

2016-12-01

Histopathological analysis can provide important information in long-term experiments with total artificial heart (TAH). Recently, a new type of blood pump, the helical flow total artificial heart (HF-TAH) was developed. This study aimed to investigate the changes in selected vital organs in animal experiments with implanted HF-TAH. Samples from lung, liver, and kidneys from two female goats (No. 1301 and No. 1304) with implanted HF-TAH were analyzed. Tissue samples were fixed in 10% formaldehyde and 4 µm thick transverse sections were stained with hematoxylin-eosin (HE). Additional staining was done for detection of connective tissue (Masson-Goldner stain) and for detection of iron (hemosiderin) deposits (Perls stain). Sections were scanned at 100× and 500× magnification with a light microscope. Experiment no. 1301 survived 100 days (cause of termination was heavy damage of the right pump); experimental goat no.1304 survived 68 days and was sacrificed due to severe right hydrodynamic bearing malfunction. Histopathological analysis of liver samples proved signs of chronic venostasis with limited focal necrotic zones. Dilated tubules, proteinaceous material in tubular lumen, and hemosiderin deposits were detected in kidney samples. Contamination of the organs by embolized micro-particles was suspected at the autopsy after discovery of visible damage (scratches) of the pump impeller surface (made from titanium alloy) in both experiments. Sporadic deposits of foreign micro-particles (presumably titanium) were observed in most of the analyzed parenchymal organs. However, the described deposits were not in direct connection with inflammatory reactions in the analyzed tissues. Histopathological analysis showed the presence of minimal contamination of the lung, kidney, and liver tissue samples by foreign material (titanium very likely). The analysis showed only limited pathological changes, especially in liver and kidneys, which might be attributed to the influence of

Design and analysis of a field modulated magnetic screw for artificial heart

Science.gov (United States)

Ling, Zhijian; Ji, Jinghua; Wang, Fangqun; Bian, Fangfang

2017-05-01

This paper proposes a new electromechanical energy conversion system, called Field Modulated Magnetic Screw (FMMS) as a high force density linear actuator for artificial heart. This device is based on the concept of magnetic screw and linear magnetic gear. The proposed FMMS consists of three parts with the outer and inner carrying the radially magnetized helically permanent-magnet (PM), and the intermediate having a set of helically ferromagnetic pole pieces, which modulate the magnetic fields produced by the PMs. The configuration of the newly designed FMMS is presented and its electromagnetic performances are analyzed by using the finite-element analysis, verifying the advantages of the proposed structure.

Development of new experimental platform 'MARS'-Multiple Artificial-gravity Research System-to elucidate the impacts of micro/partial gravity on mice.

Science.gov (United States)

Shiba, Dai; Mizuno, Hiroyasu; Yumoto, Akane; Shimomura, Michihiko; Kobayashi, Hiroe; Morita, Hironobu; Shimbo, Miki; Hamada, Michito; Kudo, Takashi; Shinohara, Masahiro; Asahara, Hiroshi; Shirakawa, Masaki; Takahashi, Satoru

2017-09-07

This Japan Aerospace Exploration Agency project focused on elucidating the impacts of partial gravity (partial g) and microgravity (μg) on mice using newly developed mouse habitat cage units (HCU) that can be installed in the Centrifuge-equipped Biological Experiment Facility in the International Space Station. In the first mission, 12 C57BL/6 J male mice were housed under μg or artificial earth-gravity (1 g). Mouse activity was monitored daily via downlinked videos; μg mice floated inside the HCU, whereas artificial 1 g mice were on their feet on the floor. After 35 days of habitation, all mice were returned to the Earth and processed. Significant decreases were evident in femur bone density and the soleus/gastrocnemius muscle weights of μg mice, whereas artificial 1 g mice maintained the same bone density and muscle weight as mice in the ground control experiment, in which housing conditions in the flight experiment were replicated. These data indicate that these changes were particularly because of gravity. They also present the first evidence that the addition of gravity can prevent decreases in bone density and muscle mass, and that the new platform 'MARS' may provide novel insights on the molecular-mechanisms regulating biological processes controlled by partial g/μg.

Assessment of the interface of beating heart with total artificial heart using magnetic resonance imaging

International Nuclear Information System (INIS)

Komoda, Tsuyoshi; Maeta, Hajime; Uyama, Chikao; Sanou, Kazuo.

1992-01-01

We have studied three-dimensionally (3-D) reconstructed images of atrioventricular (AV) annuli based on four-chamber magnetic resonance (MR) images for total artificial heart (TAH) implantation. To assess the interrelationship among the AV annuli and the thorax, we applied the frame of reference of the vertebral canal to these images. The Z-axis was along the vertebral canal, the Y-axis in the anteroposterior direction. The angle alpha was defined as the angle between the X-axis and the intersection between the plane of the annulus and the X-Y plane. The angle beta was defined as the angle between the Z-axis and the intersection between the plane of annulus and X-Z plane. The angle gamma was defined as the angle between the plane of the annulus and the anterior thoracic wall. We determined each angle for the mitral annulus (MVA) and tricuspid annulus (TVA) in four normal subjects to be as follows: alpha-MVA, 20.5-39.5 degrees; alpha-TVA, 26.1-43.5 degrees; beta-MVA, 4.7-49.4 degrees; beta-TVA, 4.4-40.9 degrees; and gamma-TVA, 35.2-44.1 degrees. It is suggested that reconstruction of the thoracic wall and AV annuli using the frame of reference of the diaphragmatic surface of the heart would facilitate evaluation of the spacial requirements for TAH implantation. Research to define this new frame of reference is in progress. (author)

Early in vivo experience with the pediatric continuous-flow total artificial heart.

Science.gov (United States)

Karimov, Jamshid H; Horvath, David J; Byram, Nicole; Sunagawa, Gengo; Kuban, Barry D; Gao, Shengqiang; Dessoffy, Raymond; Fukamachi, Kiyotaka

2018-03-30

Heart transplantation in infants and children is an accepted therapy for end-stage heart failure, but donor organ availability is low and always uncertain. Mechanical circulatory support is another standard option, but there is a lack of intracorporeal devices due to size and functional range. The purpose of this study was to evaluate the in vivo performance of our initial prototype of a pediatric continuous-flow total artificial heart (P-CFTAH), comprising a dual pump with one motor and one rotating assembly, supported by a hydrodynamic bearing. In acute studies, the P-CFTAH was implanted in 4 lambs (average weight: 28.7 ± 2.3 kg) via a median sternotomy under cardiopulmonary bypass. Pulmonary and systemic pump performance parameters were recorded. The experiments showed good anatomical fit and easy implantation, with an average aortic cross-clamp time of 98 ± 18 minutes. Baseline hemodynamics were stable in all 4 animals (pump speed: 3.4 ± 0.2 krpm; pump flow: 2.1 ± 0.9 liters/min; power: 3.0 ± 0.8 W; arterial pressure: 68 ± 10 mm Hg; left and right atrial pressures: 6 ± 1 mm Hg, for both). Any differences between left and right atrial pressures were maintained within the intended limit of ±5 mm Hg over a wide range of ratios of systemic-to-pulmonary vascular resistance (0.7 to 12), with and without pump-speed modulation. Pump-speed modulation was successfully performed to create arterial pulsation. This initial P-CFTAH prototype met the proposed requirements for self-regulation, performance, and pulse modulation. Copyright © 2018 International Society for the Heart and Lung Transplantation. Published by Elsevier Inc. All rights reserved.

Materials testing and requirement for the ERDA nuclear-powered artificial heart. Technical progress report, July 15, 1975--May 30, 1976

International Nuclear Information System (INIS)

Andrade, J.D.; Hufferd, W.L.; Lyman, D.J.

1976-01-01

The two materials currently being used for the artificial heart fabrication are BIOMER and AVCOTHANE. BIOMER is a polyether urethane polymer. AVCOTHANE is a proprietary polyurethane/polydimethylsiloxane polymer blend. Research progress on the chemical degradation, mechanical strength, and blood compatibility is reported

Human Fitting Studies of Cleveland Clinic Continuous-Flow Total Artificial Heart

Science.gov (United States)

Karimov, Jamshid H.; Steffen, Robert J.; Byram, Nicole; Sunagawa, Gengo; Horvath, David; Cruz, Vincent; Golding, Leonard A.R.; Fukamachi, Kiyotaka; Moazami, Nader

2015-01-01

Implantation of mechanical circulatory support devices is challenging, especially in patients with a small chest cavity. We evaluated how well the Cleveland Clinic continuous-flow total artificial heart (CFTAH) fit the anatomy of patients about to receive a heart transplant. A mock pump model of the CFTAH was rapid-prototyped using biocompatible materials. The model was brought to the operative table, and the direction, length, and angulation of the inflow/outflow ports and outflow conduits were evaluated after the recipient's ventricles had been resected. Thoracic cavity measurements were based on preoperative computed tomographic data. The CFTAH fit well in all five patients (height, 170 ± 9 cm; weight, 75 ± 24 kg). Body surface area was 1.9 ± 0.3 m2 (range, 1.6-2.1 m2). The required inflow and outflow port orientation of both the left and right housings appeared consistent with the current version of the CFTAH implanted in calves. The left outflow conduit remained straight, but the right outflow direction necessitated a 73 ± 22 degree angulation to prevent potential kinking when crossing over the connected left outflow. These data support the fact that our design achieves the proper anatomical relationship of the CFTAH to a patient's native vessels. PMID:25806613

Estimation of Filling and Afterload Conditions by Pump Intrinsic Parameters in a Pulsatile Total Artificial Heart.

Science.gov (United States)

Cuenca-Navalon, Elena; Laumen, Marco; Finocchiaro, Thomas; Steinseifer, Ulrich

2016-07-01

A physiological control algorithm is being developed to ensure an optimal physiological interaction between the ReinHeart total artificial heart (TAH) and the circulatory system. A key factor for that is the long-term, accurate determination of the hemodynamic state of the cardiovascular system. This study presents a method to determine estimation models for predicting hemodynamic parameters (pump chamber filling and afterload) from both left and right cardiovascular circulations. The estimation models are based on linear regression models that correlate filling and afterload values with pump intrinsic parameters derived from measured values of motor current and piston position. Predictions for filling lie in average within 5% from actual values, predictions for systemic afterload (AoPmean , AoPsys ) and mean pulmonary afterload (PAPmean ) lie in average within 9% from actual values. Predictions for systolic pulmonary afterload (PAPsys ) present an average deviation of 14%. The estimation models show satisfactory prediction and confidence intervals and are thus suitable to estimate hemodynamic parameters. This method and derived estimation models are a valuable alternative to implanted sensors and are an essential step for the development of a physiological control algorithm for a fully implantable TAH. Copyright © 2015 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

Veno-venous extracorporeal membrane oxygenation using an innovative dual-lumen cannula following implantation of a total artificial heart.

Science.gov (United States)

Youdle, Jemma; Penn, Sarah; Maunz, Olaf; Simon, Andre

2017-01-01

We report our first clinical use of the new Protek Duo TM cannula for peripheral veno-venous extra-corporeal life support (ECLS). A 53-year-old male patient underwent implantation of a total artificial heart (TAH) for biventricular failure. However, due to the development of post-operative respiratory dysfunction, the patient required ECLS for six days.

Getting a New Heart

Science.gov (United States)

... may be able to replace it with an artificial (man-made) valve. Cardiac size reduction . During this procedure, your doctor removes a piece of the heart muscle from an enlarged heart. This makes your heart ...

Implantation technique of the 50-cm3 SynCardia Total Artificial Heart: does size make a difference?

Science.gov (United States)

Spiliopoulos, Sotirios; Guersoy, Dilek; Dimitriou, Alexandros Merkourios; Koerfer, Reiner; Tenderich, Gero

2015-01-01

Despite downsizing, implantation technique of the 50-cm(3) SynCardia Total Artificial Heart and settings of the Companion driver remain unchanged. Owing to the absence of de-airing nipples, de-airing procedure is even more crucial and has to be performed carefully. © The Author 2015. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

[Flowmetric assessment of coronary bypass grafts in the conditions of artificial circulation and on the beating heart].

Science.gov (United States)

Bazylev, V V; Nemchenko, E V; Karnakhin, V A; Pavlov, A A; Mikulyak, A I

2016-01-01

Advantages and shortcomings of aortocoronary bypass grafting on the beating heart and in the conditions of artificial circulation (AC) have long been discussed. The data on patency of bypass grafts in the remote period are indicative of comparable results of operations with and without AC or advantages of using AC. In order to determine benefits of each method it is necessary to reveal intraoperative predictors of bypass grafts occlusion in the remote period. We analyzed the results of ultrasound flowmetry of the blood flow through the left internal thoracic artery during bypass grafting of the anterior descending artery with the use of AC and on the beating heart. A retrospective study included a total of 352 patients subdivided into 2 groups: Group One was composed of 120 patients undergoing surgery in the conditions of AC and Group Two comprised 232 patients subjected to similar operations on the beating heart. Blood flow was measured with the help of flowmeter VeryQ MediStim® after termination of AC and inactivation of heparin by protamine, with systolic pressure of 100-110 mm Hg. There were no statistically significant differences between the groups by the diameter and degree of stenosis of the anterior descending artery, diameter of the left internal thoracic artery. The mean volumetric blood flow velocity (Qmean) along the shunts in Group One was higher (p=0.01). No statistically significant differences by the pulsatility index (PI) between the groups were revealed (p=0.2). A conclusion was drawn that coronary bypass grafting of the anterior descending artery by the left internal thoracic artery in the conditions of artificial circulation made it possible to achieve higher volumetric velocity of blood flow through the conduit as compared with operations on the beating heart, with similar resistance index. The immediate results of the operations with the use of the both techniques did not differ.

Numerical model of total artificial heart hemodynamics and the effect of its size on stress accumulation.

Science.gov (United States)

Marom, Gil; Chiu, Wei-Che; Slepian, Marvin J; Bluestein, Danny

2014-01-01

The total artificial heart (TAH) is a bi-ventricular mechanical circulatory support device that replaces the heart in patients with end-stage congestive heart failure. The device acts as blood pump via pneumatic activation of diaphragms altering the volume of the ventricular chambers. Flow in and out of the ventricles is controlled by mechanical heart valves. The aim of this study is to evaluate the flow regime in the TAH and to estimate the thrombogenic potential during systole. Toward that goal, three numerical models of TAHs of differing sizes, that include the deforming diaphragm and the blood flow from the left chamber to the aorta, are introduced. A multiphase model with injection of platelet particles is employed to calculate their trajectories. The shear stress accumulation in the three models are calculated along the platelets trajectories and their probability density functions, which represent the `thrombogenic footprint' of the device are compared. The calculated flow regime successfully captures the mitral regurgitation and the flows that open and close the aortic valve during systole. Physiological velocity magnitudes are found in all three models, with higher velocities and increased stress accumulation predicted for smaller devices.

Electrical Stimulation of Artificial Heart Muscle: a look into the electrophysiological and genetic implications

Science.gov (United States)

Mohamed, Mohamed A; Islas, Jose F; Schwartz, Robert J; Birla, Ravi K

2016-01-01

Development of tissue-engineered hearts for treatment of myocardial infarction or biological pacemakers has been hindered by the production of mostly arrhythmic or in-synergistic constructs. Electrical stimulation (ES) of these constructs has been shown to produce tissues with greater twitch force and better adrenergic response. In order to further our understanding of the mechanisms underlying the effect of ES, we fabricated a bioreactor capable of delivering continuous or intermittent waveforms of various types to multiple constructs simultaneously. In this study, we examined the effect of an intermittent biphasic square wave on our artificial heart muscle (AHM) composed of neonatal rat cardiac cells and fibrin gel. Twitch forces, spontaneous contraction rates, biopotentials, gene expression profiles, and histological observations were examined for the ES protocol over a 12 day culture period. We demonstrate improved consistency between samples for twitch force and contraction rate, and higher normalized twitch force amplitudes for electrically stimulated AHM. Improvements in electrophysiology within the AHM was noted by higher conduction velocities and lower latency in electrical response for electrically stimulated AHM. Genes expressing key electrophysiological and structural markers peaked at days 6 and 8 of culture, only a few days after the initiation of ES. These results may be used for optimization strategies to establish protocols for producing AHM capable of replacing damaged heart tissue in either a contractile or electrophysiological capacity. Optimized AHM can lead to alternative treatments to heart failure and alleviate the limited donor supply crisis. PMID:28459744

Electrical Stimulation of Artificial Heart Muscle: A Look Into the Electrophysiologic and Genetic Implications.

Science.gov (United States)

Mohamed, Mohamed A; Islas, Jose F; Schwartz, Robert J; Birla, Ravi K

Development of tissue-engineered hearts for treatment of myocardial infarction or biologic pacemakers has been hindered by the production of mostly arrhythmic or in-synergistic constructs. Electrical stimulation (ES) of these constructs has been shown to produce tissues with greater twitch force and better adrenergic response. To further our understanding of the mechanisms underlying the effect of ES, we fabricated a bioreactor capable of delivering continuous or intermittent waveforms of various types to multiple constructs simultaneously. In this study, we examined the effect of an intermittent biphasic square wave on our artificial heart muscle (AHM) composed of neonatal rat cardiac cells and fibrin gel. Twitch forces, spontaneous contraction rates, biopotentials, gene expression profiles, and histologic observations were examined for the ES protocol over a 12 day culture period. We demonstrate improved consistency between samples for twitch force and contraction rate, and higher normalized twitch force amplitudes for electrically stimulated AHMs. Improvements in electrophysiology within the AHM were noted by higher conduction velocities and lower latency in electrical response for electrically stimulated AHMs. Genes expressing key electrophysiologic and structural markers peaked at days 6 and 8 of culture, only a few days after the initiation of ES. These results may be used for optimization strategies to establish protocols for producing AHMs capable of replacing damaged heart tissue in either a contractile or electrophysiologic capacity. Optimized AHMs can lead to alternative treatments to heart failure and alleviate the limited donor supply crisis.

Control system for an artificial heart

Science.gov (United States)

Gebben, V. D.; Webb, J. A., Jr.

1970-01-01

Inexpensive industrial pneumatic components are combined to produce control system to drive sac-type heart-assistance blood pump with controlled pulsatile pressure that makes pump rate of flow sensitive to venous /atrial/ pressure, while stroke is centered about set operating point and pump is synchronized with natural heart.

Impact of INTERMACS Profile on Clinical Outcomes for Patients Supported With the Total Artificial Heart.

Science.gov (United States)

Shah, Keyur B; Thanavaro, Kristin L; Tang, Daniel G; Quader, Mohammed A; Mankad, Anit K; Tchoukina, Inna; Thacker, Leroy R; Smallfield, Melissa C; Katlaps, Gundars; Hess, Michael L; Cooke, Richard H; Kasirajan, Vigneshwar

2016-11-01

Insufficient data delineate outcomes for Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) profile 1 patients with the total artificial heart (TAH). We studied 66 consecutive patients implanted with the TAH at our institution from 2006 through 2012 and compared outcome by INTERMACS profile. INTERMACS profiles were adjudicated retrospectively by a reviewer blinded to clinical outcomes. Survival after TAH implantation at 6 and 12 months was 76% and 71%, respectively. INTERMACS profile 1 patients had decreased 6-month survival on the device compared with those in profiles 2-4 (74% vs 95%, log rank: P = .015). For the 50 patients surviving to heart transplantation, the 1-year posttransplant survival was 82%. There was no difference in 1-year survival when comparing patients in the INTERMACS 1 profile with less severe profiles (79% vs 84%; log rank test P = .7; hazard ratio [confidence interval] 1.3 [0.3-4.8]). Patients implanted with the TAH as INTERMACS profile 1 had reduced survival to transplantation compared with less sick profiles. INTERMACS profile at the time of TAH implantation did not affect 1-year survival after heart transplantation. Copyright © 2016 Elsevier Inc. All rights reserved.

The Syncardia™ total artificial heart: in vivo, in vitro, and computational modeling studies

Science.gov (United States)

Slepian, Marvin J.; Alemu, Yared; Soares, João Silva; Smith, Richard G.; Einav, Shmuel; Bluestein, Danny

2014-01-01

The SynCardia™ total artificial heart (TAH) is the only FDA-approved TAH in the world. The SynCardia™ TAH is a pneumatically driven, pulsatile system capable of flows of >9 L/min. The TAH is indicated for use as a bridge to transplantation (BTT) in patients at imminent risk of death from non-reversible bi-ventricular failure. In the Pivotal US approval trial the TAH achieved a BTT rate of >79%. Recently a multi-center, post-market approval study similarly demonstrated a comparable BTT rate. A major milestone was recently achieved for the TAH, with over 1100 TAHs having been implanted to date, with the bulk of implantation occurring at an ever increasing rate in the past few years. The TAH is most commonly utilized to save the lives of patients dying from end-stage bi-ventricular heart failure associated with ischemic or non-ischemic dilated cardiomyopathy. Beyond progressive chronic heart failure, the TAH has demonstrated great efficacy in supporting patients with acute irreversible heart failure associated with massive acute myocardial infarction. In recent years several diverse clinical scenarios have also proven to be well served by the TAH including severe heart failure associated with advanced congenital heart disease. failed or burned-out transplants, infiltrative and restrictive cardiomyopathies and failed ventricular assist devices. Looking to the future a major unmet need remains in providing total heart support for children and small adults. As such, the present TAH design must be scaled to fit the smaller patient, while providing equivalent, if not superior flow characteristics, shear profiles and overall device thrombogenicity. To aid in the development of a new “pediatric,” TAH an engineering methodology known as “Device Thrombogenicity Emulation (DTE)”, that we have recently developed and described, is being employed. Recently, to further our engineering understanding of the TAH, as steps towards next generation designs we have: (1

Heart pacemaker

Science.gov (United States)

Cardiac pacemaker implantation; Artificial pacemaker; Permanent pacemaker; Internal pacemaker; Cardiac resynchronization therapy; CRT; Biventricular pacemaker; Arrhythmia - pacemaker; Abnormal heart ...

Experimental method to reveal the effect of rotor magnet size and air gap on artificial heart driving motor torque and efficiency.

Science.gov (United States)

Qian, K X; Yuan, H Y; Ru, W M; Zeng, P

2002-01-01

To investigate experimentally the effect of rotor magnet design on artificial heart driving motor performance, seven rotors with different magnet lengths or thicknesses, as well as different peripheral angles, were manufactured and tested in the same motor stator with different rotating speeds. The input power (voltage and current) and output torque were measured and the motor efficiency was computed. The results demonstrated that the reduction of rotor magnet size and the enlargement of the air gap between the rotor magnets and the stator coil core have no significant effect on motor efficiency, but will reduce the torque value on which the motor achieves the highest efficiency; it could be remedied however by increasing the rotating speed, because the torque at the high efficiency point will increase along with the rotating speed. These results may provide a basis for developing small rotor magnets, large air gap and high efficiency motors for driving an artificial heart pump.

Estimating the Acquisition Price of Enshi Yulu Young Tea Shoots Using Near-Infrared Spectroscopy by the Back Propagation Artificial Neural Network Model in Conjunction with Backward Interval Partial Least Squares Algorithm

Science.gov (United States)

Wang, Sh.-P.; Gong, Z.-M.; Su, X.-Zh.; Liao, J.-Zh.

2017-09-01

Near infrared spectroscopy and the back propagation artificial neural network model in conjunction with backward interval partial least squares algorithm were used to estimate the purchasing price of Enshi yulu young tea shoots. The near-infrared spectra regions most relevant to the tea shoots price model (5700.5-5935.8, 7613.6-7848.9, 8091.8-8327.1, 8331-8566.2, 9287.5-9522.5, and 9526.6-9761.9 cm-1) were selected using backward interval partial least squares algorithm. The first five principal components that explained 99.96% of the variability in those selected spectral data were then used to calibrate the back propagation artificial neural tea shoots purchasing price model. The performance of this model (coefficient of determination for prediction 0.9724; root-mean-square error of prediction 4.727) was superior to those of the back propagation artificial neural model (coefficient of determination for prediction 0.8653, root-mean-square error of prediction 5.125) and the backward interval partial least squares model (coefficient of determination for prediction 0.5932, root-mean-square error of prediction 25.125). The acquisition price model with the combined backward interval partial least squares-back propagation artificial neural network algorithms can evaluate the price of Enshi yulu tea shoots accurately, quickly and objectively.

Heart failure analysis dashboard for patient's remote monitoring combining multiple artificial intelligence technologies.

Science.gov (United States)

Guidi, G; Pettenati, M C; Miniati, R; Iadanza, E

2012-01-01

In this paper we describe an Heart Failure analysis Dashboard that, combined with a handy device for the automatic acquisition of a set of patient's clinical parameters, allows to support telemonitoring functions. The Dashboard's intelligent core is a Computer Decision Support System designed to assist the clinical decision of non-specialist caring personnel, and it is based on three functional parts: Diagnosis, Prognosis, and Follow-up management. Four Artificial Intelligence-based techniques are compared for providing diagnosis function: a Neural Network, a Support Vector Machine, a Classification Tree and a Fuzzy Expert System whose rules are produced by a Genetic Algorithm. State of the art algorithms are used to support a score-based prognosis function. The patient's Follow-up is used to refine the diagnosis.

Report on the results of the FY 1999 R and D of the medical welfare equipment technology and the development of an implantable total artificial heart system using a non-pulsatile pump. R and D of an implantable total artificial heart system using a non-pulsatile pump (R and D of the functional/cure artificial heart); Iryo fukushi kiki gijutsu no kenkyu kaihatsu tainai umekomigata jinko shinzo system 1999 nendo seika hokokusho. 5. Renzokuryu pump wo mochiita tainai umekomigata jinko shinzo system no kenkyu kaihatsu (kinoteki chiryoteki jinko shinzo no kenkyu kaihatsu)

Energy Technology Data Exchange (ETDEWEB)

NONE

2000-07-01

The R and D of element technology were made on non-pulsatile pump, drive/controller, energy supply storage system, structural coating materials, etc., and the prescribed target was achieved. In the R and D of a total system, a blood-removing conduit with movability was designed to avoid the functional inlet obstruction, and the animal experiment was carried out. In the short-term chronic animal experiment on the implantation of a single bypass model using this artificial conduit and in the animal experiment for implantation of functional/cure artificial heart, it was confirmed that the operation was conducted easily, the flow rate of the blood of the artificial heart is extremely stable, and the blood-removing conduit functions favorably. In the R and D on Tele-TAH with the aim of future home medical treatment, it became possible to acquire via monitor the pump drive information and blood circulation state information on the animals tested in the breeding farm. The remote medical simulation was made. (NEDO)

Median Sternotomy or Right Thoracotomy Techniques for Total Artificial Heart Implantation in Calves.

Science.gov (United States)

Karimov, Jamshid H; Moazami, Nader; Sunagawa, Gengo; Kobayashi, Mariko; Byram, Nicole; Sale, Shiva; Such, Kimberly A; Horvath, David J; Golding, Leonard A R; Fukamachi, Kiyotaka

2016-10-01

The choice of optimal operative access technique for mechanical circulatory support device implantation ensures successful postoperative outcomes. In this study, we retrospectively evaluated the median sternotomy and lateral thoracotomy incisions for placement of the Cleveland Clinic continuous-flow total artificial heart (CFTAH) in a bovine model. The CFTAH was implanted in 17 calves (Jersey calves; weight range, 77.0-93.9 kg) through a median sternotomy (n = 9) or right thoracotomy (n = 8) for elective chronic implantation periods of 14, 30, or 90 days. Similar preoperative preparation, surgical techniques, and postoperative care were employed. Implantation of the CFTAH was successfully performed in all cases. Both methods provided excellent surgical field visualization. After device connection, however, the median sternotomy approach provided better visualization of the anastomoses and surgical lines for hemostasis confirmation and repair due to easier device displacement, which is severely limited following right thoracotomy. All four animals sacrificed after completion of the planned durations (up to 90 days) were operated through full median sternotomy. Our data demonstrate that both approaches provide excellent initial field visualization. Full median sternotomy provides larger viewing angles at the anastomotic suture line after device connection to inflow and outflow ports. Copyright © 2015 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

Partial scan artifact reduction (PSAR) for the assessment of cardiac perfusion in dynamic phase-correlated CT.

Science.gov (United States)

Stenner, Philip; Schmidt, Bernhard; Bruder, Herbert; Allmendinger, Thomas; Haberland, Ulrike; Flohr, Thomas; Kachelriess, Marc

2009-12-01

Cardiac CT achieves its high temporal resolution by lowering the scan range from 2pi to pi plus fan angle (partial scan). This, however, introduces CT-value variations, depending on the angular position of the pi range. These partial scan artifacts are of the order of a few HU and prevent the quantitative evaluation of perfusion measurements. The authors present the new algorithm partial scan artifact reduction (PSAR) that corrects a dynamic phase-correlated scan without a priori information. In general, a full scan does not suffer from partial scan artifacts since all projections in [0, 2pi] contribute to the data. To maintain the optimum temporal resolution and the phase correlation, PSAR creates an artificial full scan pn(AF) by projectionwise averaging a set of neighboring partial scans pn(P) from the same perfusion examination (typically N approximately 30 phase-correlated partial scans distributed over 20 s and n = 1, ..., N). Corresponding to the angular range of each partial scan, the authors extract virtual partial scans pn(V) from the artificial full scan pn(AF). A standard reconstruction yields the corresponding images fn(P), fn(AF), and fn(V). Subtracting the virtual partial scan image fn(V) from the artificial full scan image fn(AF) yields an artifact image that can be used to correct the original partial scan image: fn(C) = fn(P) - fn(V) + fn(AF), where fn(C) is the corrected image. The authors evaluated the effects of scattered radiation on the partial scan artifacts using simulated and measured water phantoms and found a strong correlation. The PSAR algorithm has been validated with a simulated semianthropomorphic heart phantom and with measurements of a dynamic biological perfusion phantom. For the stationary phantoms, real full scans have been performed to provide theoretical reference values. The improvement in the root mean square errors between the full and the partial scans with respect to the errors between the full and the corrected scans is

Partial scan artifact reduction (PSAR) for the assessment of cardiac perfusion in dynamic phase-correlated CT

International Nuclear Information System (INIS)

Stenner, Philip; Schmidt, Bernhard; Bruder, Herbert; Allmendinger, Thomas; Haberland, Ulrike; Flohr, Thomas; Kachelriess, Marc

2009-01-01

Purpose: Cardiac CT achieves its high temporal resolution by lowering the scan range from 2π to π plus fan angle (partial scan). This, however, introduces CT-value variations, depending on the angular position of the π range. These partial scan artifacts are of the order of a few HU and prevent the quantitative evaluation of perfusion measurements. The authors present the new algorithm partial scan artifact reduction (PSAR) that corrects a dynamic phase-correlated scan without a priori information. Methods: In general, a full scan does not suffer from partial scan artifacts since all projections in [0, 2π] contribute to the data. To maintain the optimum temporal resolution and the phase correlation, PSAR creates an artificial full scan p n AF by projectionwise averaging a set of neighboring partial scans p n P from the same perfusion examination (typically N≅30 phase-correlated partial scans distributed over 20 s and n=1,...,N). Corresponding to the angular range of each partial scan, the authors extract virtual partial scans p n V from the artificial full scan p n AF . A standard reconstruction yields the corresponding images f n P , f n AF , and f n V . Subtracting the virtual partial scan image f n V from the artificial full scan image f n AF yields an artifact image that can be used to correct the original partial scan image: f n C =f n P -f n V +f n AF , where f n C is the corrected image. Results: The authors evaluated the effects of scattered radiation on the partial scan artifacts using simulated and measured water phantoms and found a strong correlation. The PSAR algorithm has been validated with a simulated semianthropomorphic heart phantom and with measurements of a dynamic biological perfusion phantom. For the stationary phantoms, real full scans have been performed to provide theoretical reference values. The improvement in the root mean square errors between the full and the partial scans with respect to the errors between the full and the

Materials testing and requirement for the ERDA nuclear-powered artificial heart. Technical progress report, July 15, 1975--May 30, 1976. [BIOMER and AVCOTHANE

Energy Technology Data Exchange (ETDEWEB)

Andrade, J. D.; Hufferd, W. L.; Lyman, D. J.

1976-01-01

The two materials currently being used for the artificial heart fabrication are BIOMER and AVCOTHANE. BIOMER is a polyether urethane polymer. AVCOTHANE is a proprietary polyurethane/polydimethylsiloxane polymer blend. Research progress on the chemical degradation, mechanical strength, and blood compatibility is reported. (TFD)

Fiscal 2000 achievement report on the research and development of medical and welfare apparatus/technology. Totally implantable artificial heart for clinical use; 2000 nendo iryo fukushi kiki gijutsu kenkyu kaihatsu seika hokokusho. Rinsho oyo ni muketa tainai umekomigata jinko shinzo system

Energy Technology Data Exchange (ETDEWEB)

NONE

2001-05-01

In the development of control technologies for a pulsatile pump, studies proceeded with a view to using a mixed venous blood oxygen saturation sensor, an ultrasonic sensor, and an absolute pressure sensor. Efforts were started to downsize the hydraulic actuator and to enhance its efficiency. In the development of a non-pulsatile artificial heart, the GyroP1710 series of artificial heart systems of Japanese make was developed, which employed a curved inlet known to be highly compatible from the anatomical point of view. In the development of a total system, a pulsatile auxiliary artificial heart was given a chronic animal test which continued approximately three weeks, when it yielded a flow of approximately 4 liters/minute showing that it would be practical as an auxiliary heart. As for the non-pulsatile artificial heart, a cardiopulmonary bypass test was conducted, when the blood circulation behavior was normal and organ functions were sustained. The free hemoglobin level was 9.3mg/dl achieving the target value, and the test animal lived as long as 50 days. (NEDO)

The surface microstructure of cusps and leaflets in rabbit and mouse heart valves

Directory of Open Access Journals (Sweden)

Xia Ye

2014-05-01

Full Text Available In this investigation, scanning electron microscopy was used to characterize the microstructure on the surfaces of animal heart valve cusps/leaflets. The results showed that though these surfaces appear smooth to the naked eye, they are actually comprised of a double hierarchical structure consisting of a cobblestone-like microstructure and nano-cilia along with mastoids with a directional arrangement. Such nanostructures could play a very important role in the hemocompatibility characteristics of heart valves. On this basis, the model of the microstructure was constructed and theoretical analysis was used to obtain optimal geometric parameters for the rough surface of artificial valve cusps/leaflets. This model may help improve reconstructive techniques and it may be beneficial in the design and fabrication of valve substitutes or partial substitutes. Namely, the model may help ameliorate heart valve replacement surgery.

Attitude of the Saudi community towards heart donation, transplantation, and artificial hearts.

Science.gov (United States)

AlHabeeb, Waleed; AlAyoubi, Fakhr; Tash, Adel; AlAhmari, Leenah; AlHabib, Khalid F

2017-07-01

To understand the attitudes of the Saudi population towards heart donation and transplantation. Methods: A survey using a questionnaire addressing attitudes towards organ transplantation and donation was conducted across 18 cities in Saudi Arabia between September 2015 and March 2016.  Results: A total of 1250 respondents participated in the survey. Of these, approximately 91% agree with the concept of organ transplantation but approximately 17% do not agree with the concept of heart transplantation; 42.4% of whom reject heart transplants for religious reasons. Only 43.6% of respondents expressed a willingness to donate their heart and approximately 58% would consent to the donation of a relative's organ after death. A total of 59.7% of respondents believe that organ donation is regulated and 31.8% fear that the doctors will not try hard enough to save their lives if they consent to organ donation. Approximately 77% believe the heart is removed while the donor is alive; although, the same proportion of respondents thought they knew what brain death meant. Conclusion: In general, the Saudi population seem to accept the concept of transplantation and are willing to donate, but still hold some reservations towards heart donation.

Extracorporeal total artificial heart as bailout surgery.

Science.gov (United States)

Perrodin, Stéphanie F; Muller, Olivier; Gronchi, Fabrizio; Liaudet, Lucas; Hullin, Roger; Kirsch, Matthias

2017-03-01

We report the use of a total extracorporeal heart for uncontrolled bleeding following a proximal left anterior descending artery perforation, using two centrifugal ventricular assist devices after heart explantation. The literature describing similar techniques and patient outcomes for this "bailout" technique are reviewed. © 2017 Wiley Periodicals, Inc.

Comparison of multiple linear regression, partial least squares and artificial neural networks for prediction of gas chromatographic relative retention times of trimethylsilylated anabolic androgenic steroids.

Science.gov (United States)

Fragkaki, A G; Farmaki, E; Thomaidis, N; Tsantili-Kakoulidou, A; Angelis, Y S; Koupparis, M; Georgakopoulos, C

2012-09-21

The comparison among different modelling techniques, such as multiple linear regression, partial least squares and artificial neural networks, has been performed in order to construct and evaluate models for prediction of gas chromatographic relative retention times of trimethylsilylated anabolic androgenic steroids. The performance of the quantitative structure-retention relationship study, using the multiple linear regression and partial least squares techniques, has been previously conducted. In the present study, artificial neural networks models were constructed and used for the prediction of relative retention times of anabolic androgenic steroids, while their efficiency is compared with that of the models derived from the multiple linear regression and partial least squares techniques. For overall ranking of the models, a novel procedure [Trends Anal. Chem. 29 (2010) 101-109] based on sum of ranking differences was applied, which permits the best model to be selected. The suggested models are considered useful for the estimation of relative retention times of designer steroids for which no analytical data are available. Copyright © 2012 Elsevier B.V. All rights reserved.

Hemodynamics of a functional centrifugal-flow total artificial heart with functional atrial contraction in goats.

Science.gov (United States)

Shiga, Takuya; Shiraishi, Yasuyuki; Sano, Kyosuke; Taira, Yasunori; Tsuboko, Yusuke; Yamada, Akihiro; Miura, Hidekazu; Katahira, Shintaro; Akiyama, Masatoshi; Saiki, Yoshikatsu; Yambe, Tomoyuki

2016-03-01

Implantation of a total artificial heart (TAH) is one of the therapeutic options for the treatment of patients with end-stage biventricular heart failure. There is no report on the hemodynamics of the functional centrifugal-flow TAH with functional atrial contraction (fCFTAH). We evaluated the effects of pulsatile flow by atrial contraction in acute animal models. The goats received fCFTAH that we created from two centrifugal-flow ventricular assist devices. Some hemodynamic parameters maintained acceptable levels: heart rate 115.5 ± 26.3 bpm, aortic pressure 83.5 ± 10.1 mmHg, left atrial pressure 18.0 ± 5.9 mmHg, pulmonary pressure 28.5 ± 9.7 mmHg, right atrial pressure 13.6 ± 5.2 mmHg, pump flow 4.0 ± 1.1 L/min (left) 3.9 ± 1.1 L/min (right), and cardiac index 2.13 ± 0.14 L/min/m(2). fCFTAH with atrial contraction was able to maintain the TAH circulation by forming a pulsatile flow in acute animal experiments. Taking the left and right flow rate balance using the low internal pressure loss of the VAD pumps may be easier than by other pumps having considerable internal pressure loss. We showed that the remnant atrial contraction effected the flow rate change of the centrifugal pump, and the atrial contraction waves reflected the heart rate. These results indicate that remnant atria had the possibility to preserve autonomic function in fCFTAH. We may control fCFTAH by reflecting the autonomic function, which is estimated with the flow rate change of the centrifugal pump.

Artificial heart development program. Volume I. System development. Phase III summary report, July 1, 1973--September 30, 1977

International Nuclear Information System (INIS)

1977-01-01

Efforts and results in the development of the power system portions of a calf implantable model of nuclear-powered artificial heart are discussed. The primary objective in developing the implantable model was to solve the packaging problems for total system implantation. The power system's portion is physically that portion of the implantable model between the 238 Pu heat sources and the blood pump ventricles. The 238 Pu heat sources and blood pump ventricles were provided as Government Furnished Equipment as developed and fabricated by other contractors

Cardiopulmonary exercise testing responses to different external portable drivers in a patient with a CardioWest Total Artificial Heart.

Science.gov (United States)

Tarzia, Vincenzo; Braccioni, Fausto; Bortolussi, Giacomo; Buratto, Edward; Gallo, Michele; Bottio, Tomaso; Vianello, Andrea; Gerosa, Gino

2016-06-01

Management of patients treated with CardioWest Total Artificial Heart (CW-TAH) as a bridge to heart transplantation (HTx) is complicated by difficulties in determining the optimal timing of transplantation. We present a case of a 53-year-old man supported as an outpatient with a CW-TAH, whose condition deteriorated following exchange of the portable driver. The patient was followed-up with serial cardiopulmonary exercise testing (CPET) which demonstrated a fall of peak VO2 to below 12 ml/kg/min following driver substitution, and the patient was subsequently treated with urgent orthotopic HTx. This case highlights the potential utility of CPET as a means for monitoring and indicating timing of HTx in patients with CW-TAH, as well as the potential for clinical deterioration following portable driver substitution.

Partial scan artifact reduction (PSAR) for the assessment of cardiac perfusion in dynamic phase-correlated CT

Energy Technology Data Exchange (ETDEWEB)

Stenner, Philip; Schmidt, Bernhard; Bruder, Herbert; Allmendinger, Thomas; Haberland, Ulrike; Flohr, Thomas; Kachelriess, Marc [Institute of Medical Physics, Henkestrasse 91, 91052 Erlangen (Germany); Siemens AG, Healthcare Sector, Siemensstrasse 1, 91301 Forchheim (Germany); Institute of Medical Physics, Henkestrasse. 91, 91052 Erlangen (Germany)

2009-12-15

Purpose: Cardiac CT achieves its high temporal resolution by lowering the scan range from 2{pi} to {pi} plus fan angle (partial scan). This, however, introduces CT-value variations, depending on the angular position of the {pi} range. These partial scan artifacts are of the order of a few HU and prevent the quantitative evaluation of perfusion measurements. The authors present the new algorithm partial scan artifact reduction (PSAR) that corrects a dynamic phase-correlated scan without a priori information. Methods: In general, a full scan does not suffer from partial scan artifacts since all projections in [0, 2{pi}] contribute to the data. To maintain the optimum temporal resolution and the phase correlation, PSAR creates an artificial full scan p{sub n}{sup AF} by projectionwise averaging a set of neighboring partial scans p{sub n}{sup P} from the same perfusion examination (typically N{approx_equal}30 phase-correlated partial scans distributed over 20 s and n=1,...,N). Corresponding to the angular range of each partial scan, the authors extract virtual partial scans p{sub n}{sup V} from the artificial full scan p{sub n}{sup AF}. A standard reconstruction yields the corresponding images f{sub n}{sup P}, f{sub n}{sup AF}, and f{sub n}{sup V}. Subtracting the virtual partial scan image f{sub n}{sup V} from the artificial full scan image f{sub n}{sup AF} yields an artifact image that can be used to correct the original partial scan image: f{sub n}{sup C}=f{sub n}{sup P}-f{sub n}{sup V}+f{sub n}{sup AF}, where f{sub n}{sup C} is the corrected image. Results: The authors evaluated the effects of scattered radiation on the partial scan artifacts using simulated and measured water phantoms and found a strong correlation. The PSAR algorithm has been validated with a simulated semianthropomorphic heart phantom and with measurements of a dynamic biological perfusion phantom. For the stationary phantoms, real full scans have been performed to provide theoretical reference

[Generation of Superoxide Radicals by Complex III in Heart Mitochondria and Antioxidant Effect of Dinitrosyl Iron Complexes at Different Partial Pressure of Oxygen].

Science.gov (United States)

Dudylina, A L; Ivanova, M V; Shumaev, K B; Ruuge, E K

2016-01-01

The EPR spin-trapping technique and EPR-oximetry were used to study generation of superoxide radicals in heart mitochondria isolated from Wistar rats under conditions of variable oxygen concentration. Lithium phthalocyanine and TEMPONE-15N-D16 were chosen to determine oxygen content in a gas-permeable capillary tube containing mitochondria. TIRON was used as a spin trap. We investigated the influence of different oxygen concentrations in incubation mixture and demonstrated that heart mitochondria can generate superoxide in complex III at different partial pressure of oxygen as well as under the conditions of deep hypoxia (partial pressure of oxygen, but the magnitude and kinetic characteristics of the effect depended on the concentration of the drug.

Development of a microcontroller-based automatic control system for the electrohydraulic total artificial heart.

Science.gov (United States)

Kim, H C; Khanwilkar, P S; Bearnson, G B; Olsen, D B

1997-01-01

An automatic physiological control system for the actively filled, alternately pumped ventricles of the volumetrically coupled, electrohydraulic total artificial heart (EHTAH) was developed for long-term use. The automatic control system must ensure that the device: 1) maintains a physiological response of cardiac output, 2) compensates for an nonphysiological condition, and 3) is stable, reliable, and operates at a high power efficiency. The developed automatic control system met these requirements both in vitro, in week-long continuous mock circulation tests, and in vivo, in acute open-chested animals (calves). Satisfactory results were also obtained in a series of chronic animal experiments, including 21 days of continuous operation of the fully automatic control mode, and 138 days of operation in a manual mode, in a 159-day calf implant.

Partial IGF-1 deficiency is sufficient to reduce heart contractibility, angiotensin II sensibility, and alter gene expression of structural and functional cardiac proteins.

Science.gov (United States)

González-Guerra, José Luis; Castilla-Cortazar, Inma; Aguirre, Gabriel A; Muñoz, Úrsula; Martín-Estal, Irene; Ávila-Gallego, Elena; Granado, Miriam; Puche, Juan E; García-Villalón, Ángel Luis

2017-01-01

Circulating levels of IGF-1 may decrease under several circumstances like ageing, metabolic syndrome, and advanced cirrhosis. This reduction is associated with insulin resistance, dyslipidemia, progression to type 2 diabetes, and increased risk for cardiovascular diseases. However, underlying mechanisms between IGF-1 deficiency and cardiovascular disease remain elusive. The specific aim of the present work was to study whether the partial IGF-1 deficiency influences heart and/or coronary circulation, comparing vasoactive factors before and after of ischemia-reperfusion (I/R). In addition, histology of the heart was performed together with cardiac gene expression for proteins involved in structure and function (extracellular matrix, contractile proteins, active peptides); carried out using microarrays, followed by RT-qPCR confirmation of the three experimental groups. IGF-1 partial deficiency is associated to a reduction in contractility and angiotensin II sensitivity, interstitial fibrosis as well as altered expression pattern of genes involved in extracellular matrix proteins, calcium dynamics, and cardiac structure and function. Although this work is descriptive, it provides a clear insight of the impact that partial IGF-1 deficiency on the heart and establishes this experimental model as suitable for studying cardiac disease mechanisms and exploring therapeutic options for patients under IGF-1 deficiency conditions.

Partial IGF-1 deficiency is sufficient to reduce heart contractibility, angiotensin II sensibility, and alter gene expression of structural and functional cardiac proteins.

Directory of Open Access Journals (Sweden)

José Luis González-Guerra

Full Text Available Circulating levels of IGF-1 may decrease under several circumstances like ageing, metabolic syndrome, and advanced cirrhosis. This reduction is associated with insulin resistance, dyslipidemia, progression to type 2 diabetes, and increased risk for cardiovascular diseases. However, underlying mechanisms between IGF-1 deficiency and cardiovascular disease remain elusive. The specific aim of the present work was to study whether the partial IGF-1 deficiency influences heart and/or coronary circulation, comparing vasoactive factors before and after of ischemia-reperfusion (I/R. In addition, histology of the heart was performed together with cardiac gene expression for proteins involved in structure and function (extracellular matrix, contractile proteins, active peptides; carried out using microarrays, followed by RT-qPCR confirmation of the three experimental groups. IGF-1 partial deficiency is associated to a reduction in contractility and angiotensin II sensitivity, interstitial fibrosis as well as altered expression pattern of genes involved in extracellular matrix proteins, calcium dynamics, and cardiac structure and function. Although this work is descriptive, it provides a clear insight of the impact that partial IGF-1 deficiency on the heart and establishes this experimental model as suitable for studying cardiac disease mechanisms and exploring therapeutic options for patients under IGF-1 deficiency conditions.

Artificial heart development program. Volume I. System development. Phase III summary report, July 1, 1973--September 30, 1977

Energy Technology Data Exchange (ETDEWEB)

1977-01-01

Efforts and results in the development of the power system portions of a calf implantable model of nuclear-powered artificial heart are discussed. The primary objective in developing the implantable model was to solve the packaging problems for total system implantation. The power system's portion is physically that portion of the implantable model between the /sup 238/Pu heat sources and the blood pump ventricles. The /sup 238/Pu heat sources and blood pump ventricles were provided as Government Furnished Equipment as developed and fabricated by other contractors.

The Artificial Hamiltonian, First Integrals, and Closed-Form Solutions of Dynamical Systems for Epidemics

Science.gov (United States)

Naz, Rehana; Naeem, Imran

2018-03-01

The non-standard Hamiltonian system, also referred to as a partial Hamiltonian system in the literature, of the form {\\dot q^i} = {partial H}/{partial {p_i}},\\dot p^i = - {partial H}/{partial {q_i}} + {Γ ^i}(t,{q^i},{p_i}) appears widely in economics, physics, mechanics, and other fields. The non-standard (partial) Hamiltonian systems arise from physical Hamiltonian structures as well as from artificial Hamiltonian structures. We introduce the term `artificial Hamiltonian' for the Hamiltonian of a model having no physical structure. We provide here explicitly the notion of an artificial Hamiltonian for dynamical systems of ordinary differential equations (ODEs). Also, we show that every system of second-order ODEs can be expressed as a non-standard (partial) Hamiltonian system of first-order ODEs by introducing an artificial Hamiltonian. This notion of an artificial Hamiltonian gives a new way to solve dynamical systems of first-order ODEs and systems of second-order ODEs that can be expressed as a non-standard (partial) Hamiltonian system by using the known techniques applicable to the non-standard Hamiltonian systems. We employ the proposed notion to solve dynamical systems of first-order ODEs arising in epidemics.

Experience with the SynCardia total artificial heart in a Canadian centre.

Science.gov (United States)

Nguyen, Anthony; Pellerin, Michel; Perrault, Louis P; White, Michel; Ducharme, Anique; Racine, Normand; Carrier, Michel

2017-12-01

The SynCardia total artificial heart (TAH) provides complete circulatory support by replacing both native ventricles. Accepted indications include bridge to transplantation and destination therapy. We review our experience with TAH implantation during a period when axial flow pump became available. We retrospectively analyzed the demographics, clinical characteristics and survival of all patients receiving the TAH. From September 2004 to November 2016, 13 patients (12 men, mean age 45 ± 13 yr) received the TAH for refractory cardiogenic shock secondary to idiopathic (56%) or ischemic (17%) cardiomyopathy and to other various causes (33%). Before implantation, mean ejection fraction was 14% ± 4%, 7 (54%) patients had previous cardiac surgery, 4 (31%) were on mechanical ventilation, and 3 (23%) patients were on dialysis. The mean duration of TAH support was 46 ± 40 days. Three (23%) patients died while on support after a mean of 15 days. Actuarial survival on support was 77% ± 12% at 30 days after implantation. Complications on support included stroke ( n = 1, 8%), acute respiratory distress syndrome requiring prolonged intubation ( n = 5, 38%) and acute renal failure requiring temporary dialysis ( n = 5, 38%). Ten (77%) patients survived to be transplanted after a mean of 52 ± 42 days of support. Actuarial survival rates after transplant were 67% ± 16% at 1 month and 56% ± 17% at 1 year after transplantation. The TAH provides an alternative with low incidence of neurologic events in extremely fragile and complex patients waiting for heart transplantation. Complex and unusual anatomic conditions explained the current use of TAH.

A novel dynamic cardiac simulator utilizing pneumatic artificial muscle.

Science.gov (United States)

Liu, Hao; Yan, Jie; Zhou, Yuanyuan; Li, Hongyi; Li, Changji

2013-01-01

With the development of methods and skills of minimally invasive surgeries, equipments for doctors' training and practicing are in high demands. Especially for the cardiovascular surgeries, operators are requested to be familiar with the surgical environment of a beating heart. In this paper, we present a new dynamic cardiac simulator utilizing pneumatic artificial muscle to realize heartbeat. It's an artificial left ventricular of which the inner chamber is made of thermoplastic elastomers (TPE) with an anatomical structure of the real human heart. It is covered by another layer of material forming the artificial muscle which actuates the systole and diastole uniformly and omnidirectionally as the cardiac muscle does. Preliminary experiments were conducted to evaluate the performance of the simulator. The results indicated that the pressure at the terminal of the aorta could be controlled within the range of normal human systolic pressure, which quantitatively validated the new actuating mode of the heart-beating is effective.

Electromagnetic Compatibility of Transcutaneous Energy Transmission Systemfor Totally Implantable Artificial Heart

Science.gov (United States)

Shiba, Kenji; Koshiji, Kohji

Transcutaneous Energy Transmission (TET) is one way of providing the energy needed to power a totally implantable artificial heart (TIAH). In the present study, an externally coupled TET system was implanted in a prototype human phantom to evaluate emission and immunity. In the emission evaluation, measurements were conducted based on CISPR Pub.11 and VDE 0871 standards, while immunity tests were based on the standards of the IEC 61000-4 series. The magnetic field of the radiated emission was measured using a loop antenna. At 0.1[MHz], we found the greatest magnetic field of 47.8 [dBμA/m], somewhat less than CISPR’s upper limit of 54 [dBμA/m]. For the conducted emission, by installing a noise filter and ferrite beads in the input section of the DC-power supply, conducted emission could be kept within the allowable limits of CISPR Pub.11 and VDE 0871. Finally, the immunity tests against radiated and conducted emission, electrostatic discharge and voltage fluctuation proved that the prototype could withstand the maximum level of disturbance. These results confirmed that the TET system implanted in a human phantom could, through modification, meet the emission and immunity standards.

Prospects for using implanted systems of assisted circulation and artificial heart with a radioisotope power source (biomedical, thermal, and radiation aspects)

Energy Technology Data Exchange (ETDEWEB)

Kiselev, I M; Dubrovskii, G P; Mosidze, T G; Bazhanov, A I.U.

1983-02-01

The capacity of dogs to diffuse heat (up to 50 W) from an artificial heart and to tolerate prolonged intracorporeal ionizing radiation from a radioisotope power source (/sup 238/Pu) was investigated, using electrical models of vascular blood heat exchangers that permit reproduction of elimination and heat transmission in autonomous systems. It was shown that up to 50 W can be discharged at temperatures of the wall-blood interface that do not exceed 43 degrees C. Clotting indexes, concentration of total protein, hemolysis, and serum enzyme activity during 1-1.5 months of heating remained within physiologically normal limits. A specific power load of up to 1.5 W/kg at ambient temperatures of 18-20 degrees C revealed no evidence of changes in heat production. By measuring the distribution of power of the dose absorbed around a 45-W plutonium source it was possible to estimate dose loads on critical organs and to assess overall risk of death from malignant tumors induced by radiation over a 10-year period: 6-12% for males and 8-14% for females. It is not very probable that use of the artificial heart with a radioisotope power source will be limited by thermal and radiational effects.

Artificial heart development program. Volume I. System development. Phase III summary report

Energy Technology Data Exchange (ETDEWEB)

1977-01-01

The report documents efforts and results in the development of the power system portions of a calf implantable model of nuclear-powered artificial heart. The primary objective in developing the implantable model was to solve the packaging problems for total system implantation. The power systems portion is physically that portion of the implantable model between the Pu-238 heat sources and the blood pump ventricles. The work performed had two parallel themes. The first of these was the development of an integrated implantable model for bench and animal experiments plus design effort on a more advanced model. The second was research and development on components of the system done in conjunction with the development of the implantable model and to provide technology for incorporation into advanced models plus support to implantations, at the University of Utah, of the systems blood pumping elements when driven by electric motor. The efforts and results of implantable model development are covered, mainly, in the text of the report. The research and development efforts and results are reported, primarily, in the appendices (Vol. 2).

Artificial heart development program. Volume I. System development. Phase III summary report

International Nuclear Information System (INIS)

1977-01-01

The report documents efforts and results in the development of the power system portions of a calf implantable model of nuclear-powered artificial heart. The primary objective in developing the implantable model was to solve the packaging problems for total system implantation. The power systems portion is physically that portion of the implantable model between the Pu-238 heat sources and the blood pump ventricles. The work performed had two parallel themes. The first of these was the development of an integrated implantable model for bench and animal experiments plus design effort on a more advanced model. The second was research and development on components of the system done in conjunction with the development of the implantable model and to provide technology for incorporation into advanced models plus support to implantations, at the University of Utah, of the systems blood pumping elements when driven by electric motor. The efforts and results of implantable model development are covered, mainly, in the text of the report. The research and development efforts and results are reported, primarily, in the appendices

Quantitative structure-retention relationship studies with immobilized artificial membrane chromatography II: partial least squares regression.

Science.gov (United States)

Li, Jie; Sun, Jin; He, Zhonggui

2007-01-26

We aimed to establish quantitative structure-retention relationship (QSRR) with immobilized artificial membrane (IAM) chromatography using easily understood and obtained physicochemical molecular descriptors and to elucidate which descriptors are critical to affect the interaction process between solutes and immobilized phospholipid membranes. The retention indices (logk(IAM)) of 55 structurally diverse drugs were determined on an immobilized artificial membrane column (IAM.PC.DD2) directly or obtained by extrapolation method for highly hydrophobic compounds. Ten simple physicochemical property descriptors (clogP, rings, rotatory bond, hydro-bond counting, etc.) of these drugs were collected and used to establish QSRR and predict the retention data by partial least squares regression (PLSR). Five descriptors, clogP, rotatory bond (RotB), rings, molecular weight (MW) and total surface area (TSA), were reserved by using the Variable Importance for Projection (VIP) values as criterion to build the final PLSR model. An external test set was employed to verify the QSRR based on the training set with the five variables, and QSRR by PLSR exhibited a satisfying predictive ability with R(p)=0.902 and RMSE(p)=0.400. Comparison of coefficients of centered and scaled variables by PLSR demonstrated that, for the descriptors studied, clogP and TSA have the most significant positive effect but the rotatable bond has significant negative effect on drug IAM chromatographic retention.

Radiochemicals used to scan the heart

International Nuclear Information System (INIS)

Anon.

1975-01-01

Techniques for heart scanning using 201 Tl and /sup 99m/Tc pyrophosphate are discussed. Thallium-201, produced artificially in a cyclotron, concentrates in normal heart muscle but not in abnormal tissue. Technetium-99m is deposited in mitochondria of heart cells that are irreversibly damaged. The combined use of 201 Tl and /sup 99m/Tc makes it possible to identify regions of recent heart damage as well as older heart damage. Advantages of using 129 Cs for heart scanning are also discussed

On the Design of Artificial Stock Markets

NARCIS (Netherlands)

K. Boer-Sorban (Katalin); A. de Bruin (Arie); U. Kaymak (Uzay)

2005-01-01

textabstractArtificial stock markets are designed with the aim to study and understand market dynamics by representing (part of) real stock markets. Since there is a large variety of real stock markets with several partially observable elements and hidden processes, artificial markets differ

The gut hormone ghrelin partially reverses energy substrate metabolic alterations in the failing heart.

Science.gov (United States)

Mitacchione, Gianfranco; Powers, Jeffrey C; Grifoni, Gino; Woitek, Felix; Lam, Amy; Ly, Lien; Settanni, Fabio; Makarewich, Catherine A; McCormick, Ryan; Trovato, Letizia; Houser, Steven R; Granata, Riccarda; Recchia, Fabio A

2014-07-01

The gut-derived hormone ghrelin, especially its acylated form, plays a major role in the regulation of systemic metabolism and exerts also relevant cardioprotective effects; hence, it has been proposed for the treatment of heart failure (HF). We tested the hypothesis that ghrelin can directly modulate cardiac energy substrate metabolism. We used chronically instrumented dogs, 8 with pacing-induced HF and 6 normal controls. Human des-acyl ghrelin [1.2 nmol/kg per hour] was infused intravenously for 15 minutes, followed by washout (rebaseline) and infusion of acyl ghrelin at the same dose. (3)H-oleate and (14)C-glucose were coinfused and arterial and coronary sinus blood sampled to measure cardiac free fatty acid and glucose oxidation and lactate uptake. As expected, cardiac substrate metabolism was profoundly altered in HF because baseline oxidation levels of free fatty acids and glucose were, respectively, >70% lower and >160% higher compared with control. Neither des-acyl ghrelin nor acyl ghrelin significantly affected function and metabolism in normal hearts. However, in HF, des-acyl and acyl ghrelin enhanced myocardial oxygen consumption by 10.2±3.5% and 9.9±3.7%, respectively (Pmetabolism in normal dogs, whereas they enhance free fatty acid oxidation and reduce glucose oxidation in HF dogs, thus partially correcting metabolic alterations in HF. This novel mechanism might contribute to the cardioprotective effects of ghrelin in HF. © 2014 American Heart Association, Inc.

Multi-Targeted Antithrombotic Therapy for Total Artificial Heart Device Patients.

Science.gov (United States)

Ramirez, Angeleah; Riley, Jeffrey B; Joyce, Lyle D

2016-03-01

To prevent thrombotic or bleeding events in patients receiving a total artificial heart (TAH), agents have been used to avoid adverse events. The purpose of this article is to outline the adoption and results of a multi-targeted antithrombotic clinical procedure guideline (CPG) for TAH patients. Based on literature review of TAH anticoagulation and multiple case series, a CPG was designed to prescribe the use of multiple pharmacological agents. Total blood loss, Thromboelastograph(®) (TEG), and platelet light-transmission aggregometry (LTA) measurements were conducted on 13 TAH patients during the first 2 weeks of support in our institution. Target values and actual medians for postimplant days 1, 3, 7, and 14 were calculated for kaolinheparinase TEG, kaolin TEG, LTA, and estimated blood loss. Protocol guidelines were followed and anticoagulation management reduced bleeding and prevented thrombus formation as well as thromboembolic events in TAH patients postimplantation. The patients in this study were susceptible to a variety of possible complications such as mechanical device issues, thrombotic events, infection, and bleeding. Among them all it was clear that patients were at most risk for bleeding, particularly on postoperative days 1 through 3. However, bleeding was reduced into postoperative days 3 and 7, indicating that acceptable hemostasis was achieved with the anticoagulation protocol. The multidisciplinary, multi-targeted anticoagulation clinical procedure guideline was successful to maintain adequate antithrombotic therapy for TAH patients.

Burst Activity and Heart Rhythm Modulation in the Sympathetic Outflow to the Heart

National Research Council Canada - National Science Library

Baselli, G

2001-01-01

In 13 decerebrate, artificially ventilated cats preganglionic sympathetic outflow to the heart was recorded with ECG and ventilation signal, A novel algorithm was implemented that extracts weighted...

Artificial organs and transplantation.

Science.gov (United States)

Splendiani, G; Cipriani, S; Vega, A; Casciani, C U

2003-05-01

Nowadays artificial devices are not able to totally and undefinitely replace the loss of function of all vital organs and artificial organs can be used only to bridge the time to transplantation, which must be considered the first choice in the therapeutical approach for many chronic diseases. Since general population aging process is leading to an increase of organ demand, the gap between performed and requested transplantation is hard to fill. Xenotransplantation is nowadays only an experimental alternative solution and we have to do our best using available artificial organs to increase and improve the survival of patients waiting for transplantation. In this meeting we particularly dealt about organ function replacing therapy, especially regarding the kidney, heart, liver, pancreas and ear.

The Japanese artificial organs scene: current status.

Science.gov (United States)

Mitamura, Yoshinori; Murabayashi, Shun

2005-08-01

Artificial organs and regenerative medicine are the subjects of very active research and development (R&D) in Japan and various artificial organs are widely used in patients. Results of the R&D are presented at the annual conference of the Japanese Society for Artificial Organs (JSAO). Progress in the fields of artificial organs and regenerative medicine are reviewed annually in the Japanese Journal of Artificial Organs. The official English-language journal of JSAO, Journal of Artificial Organs, also publishes many original articles by Japanese researchers. Although the annual conference and the publications of JSAO provide the world with update information on artificial organs and regenerative medicine in Japan, the information is not always understood appropriately in the rest of the world, mainly due to language problems. This article therefore introduces the current status of artificial organs and regenerative medicine in Japan. Artificial hearts and metabolic support systems are reviewed here and other interesting areas such as regenerative medicine can be found elsewhere.

Driver electronics design and control for a total artificial heart linear motor.

Science.gov (United States)

Unthan, Kristin; Cuenca-Navalon, Elena; Pelletier, Benedikt; Finocchiaro, Thomas; Steinseifer, Ulrich

2018-01-27

For any implantable device size and efficiency are critical properties. Thus, a linear motor for a Total Artificial Heart was optimized with focus on driver electronics and control strategies. Hardware requirements were defined from power supply and motor setup. Four full bridges were chosen for the power electronics. Shunt resistors were set up for current measurement. Unipolar and bipolar switching for power electronics control were compared regarding current ripple and power losses. Here, unipolar switching showed smaller current ripple and required less power to create the necessary motor forces. Based on calculations for minimal power losses Lorentz force was distributed to the actor's four coils. The distribution was determined as ratio of effective magnetic flux through each coil, which was captured by a force test rig. Static and dynamic measurements under physiological conditions analyzed interaction of control and hardware and all efficiencies were over 89%. In conclusion, the designed electronics, optimized control strategy and applied current distribution create the required motor force and perform optimal under physiological conditions. The developed driver electronics and control offer optimized size and efficiency for any implantable or portable device with multiple independent motor coils. Graphical Abstract ᅟ.

Recycling ground granulated blast furnace slag as cold bonded artificial aggregate partially used in self-compacting concrete.

Science.gov (United States)

Gesoğlu, Mehmet; Güneyisi, Erhan; Mahmood, Swara Fuad; Öz, Hatice Öznur; Mermerdaş, Kasım

2012-10-15

Ground granulated blast furnace slag (GGBFS), a by-product from iron industry, was recycled as artificial coarse aggregate through cold bonding pelletization process. The artificial slag aggregates (ASA) replaced partially the natural coarse aggregates in production of self-compacting concrete (SCC). Moreover, as being one of the most widely used mineral admixtures in concrete industry, fly ash (FA) was incorporated as a part of total binder content to impart desired fluidity to SCCs. A total of six concrete mixtures having various ASA replacement levels (0%, 20%, 40%, 60%, and 100%) were designed with a water-to-binder (w/b) ratio of 0.32. Fresh properties of self-compacting concretes (SCC) were observed through slump flow time, flow diameter, V-funnel flow time, and L-box filling height ratio. Compressive strength of hardened SCCs was also determined at 28 days of curing. It was observed that increasing the replacement level of ASA resulted in decrease in the amount of superplasticizer to achieve a constant slump flow diameter. Moreover, passing ability and viscosity of SCC's enhanced with increasing the amount of ASA in the concrete. The maximum compressive strength was achieved for the SCC having 60% ASA replacement. Copyright © 2012 Elsevier B.V. All rights reserved.

An innovative, sensorless, pulsatile, continuous-flow total artificial heart: device design and initial in vitro study.

Science.gov (United States)

Fukamachi, Kiyotaka; Horvath, David J; Massiello, Alex L; Fumoto, Hideyuki; Horai, Tetsuya; Rao, Santosh; Golding, Leonard A R

2010-01-01

We are developing a very small, innovative, continuous-flow total artificial heart (CFTAH) that passively self-balances left and right pump flows and atrial pressures without sensors. This report details the CFTAH design concept and our initial in vitro data. System performance of the CFTAH was evaluated using a mock circulatory loop to determine the range of systemic and pulmonary vascular resistance (SVR and PVR) levels over which the design goal of a maximum absolute atrial pressure difference of 10 mm Hg is achieved for a steady-state flow condition. Pump speed was then modulated at 2,600 +/- 900 rpm to induce flow and arterial pressure pulsation to evaluate the effects of speed pulsations on the system performance. An automatic control mode was also evaluated. Using only passive self-regulation, pump flows were balanced and absolute atrial pressure differences were maintained at mode adjusted pump speed to achieve targeted pump flows based on sensorless calculations of SVR and CFTAH flow. The initial in vitro testing of the CFTAH with a single, valveless, continuous-flow pump demonstrated its passive self-regulation of flows and atrial pressures and a new automatic control mode. Copyright (c) 2010 International Society for Heart and Lung Transplantation. Published by Elsevier Inc. All rights reserved.

Experimental study of physical properties of artificial materials for the development of the tissue-engineered valvular heart apparatus in comparison with biological analogs

Science.gov (United States)

Chiryatyeva, Aleksandra; Trebushat, Dmitry; Prokhorokhin, Aleksei; Khakhalkin, Vladimir; Andreev, Mark; Novokhreschenov, Aleksei; Kretov, Evgeny

2017-12-01

Cardiovascular diseases are the leading cause of death worldwide. Valvular heart disease often requires valve repair or replacement. Today, surgery uses xenograft—porcine or bovine pericardium. However, bioprosthetic valves do not ensure sufficient durability. We investigated 0.6% glutaraldehyde-treated porcine pericardium to define its properties. Using a tensile test stand, we studied characteristics of the polymeric material—expanded polytetrafluoroethylene (ePTFE)—and compared it to xenopericardium. The artificial material provides a better durability; it has higher elastic modulus and ultimate tensile strength. However, ePTFE samples demonstrated direction anisotropy due to extrusion features. It requires the enhancement of quality of the ePTFE sheet or investigation of other polymeric materials to find the adequate replacement for bioprosthetic heart valves.

Artificial intelligence: Deep neural reasoning

Science.gov (United States)

Jaeger, Herbert

2016-10-01

The human brain can solve highly abstract reasoning problems using a neural network that is entirely physical. The underlying mechanisms are only partially understood, but an artificial network provides valuable insight. See Article p.471

Hydro-mechanical foundation for blood swirling vortex flows formation in the cardio-vascular system and the problem of artificial heart creation

Directory of Open Access Journals (Sweden)

Sergey G. Chefranov

2013-11-01

Full Text Available Leonardo da Vinci perhaps was the first who paid attention to the energetic efficiency of existence of vortices emerging near sines of Valsalva and defining normal functioning (opening of aortal valve. However up to now a fundamental problem of defining of mechanisms of mysterious energetic efficiency of functioning of cardio-vascular system (CVS of blood feeding of the organism is still remaining significantly not solved and this is, for example, one of the main restriction for the creation of artificial heart and corresponding valve systems. In the present paper, results witnessing possible important role of the very hydro-mechanical mechanism in the realization of the noted energetic efficiency of CVS due to formation in the CVS of spiral structural organization of the arterial blood flow observed by methods of MRT and color Doppler-measuring in the left ventricular of the heart and in aorta.

Animal studies with the Carmat bioprosthetic total artificial heart.

Science.gov (United States)

Latrémouille, Christian; Duveau, Daniel; Cholley, Bernard; Zilberstein, Luca; Belbis, Guillaume; Boughenou, Marie-Fazia; Meleard, Denis; Bruneval, Patrick; Adam, Clovis; Neuschwander, Arthur; Perles, Jean-Christophe; Jansen, Piet; Carpentier, Alain

2015-05-01

The Carmat bioprosthetic total artificial heart (TAH) contains bioprosthetic blood-contacting surfaces, and is designed for orthotopic cardiac replacement. In preparation for clinical studies, we evaluated the TAH performance and its effects on end-organ function in an animal model. Twelve female Charolais calves, 2-3 months of age and weighing 102-122 kg, were implanted with the TAH through a mid-sternotomy to ensure an adequate anatomic fit. The intended support duration was 4-10 days. Haematological values, creatinine, bilirubin and lactate levels were measured and mean arterial and central venous pressure, central venous oxygen saturation and TAH parameters were monitored. The calves were placed in a cage immediately postoperatively, and extubated on postoperative day 1 in most cases. Average support duration was 3 days, with 4 of 12 calves supported for 4, 4, 8 and 10 days. The initial procedures were used to refine surgical techniques and postoperative care. Pump output ranged from 7.3 to 10 l/min. Haemodynamic parameters and blood analysis were within acceptable ranges. No device failures occurred. No anticoagulation was used in the postoperative phase. The calves were euthanized in case of discomfort compromising the animal well-being, such as respiratory dysfunction, severe blood loss and cerebral dysfunction. Device explant analysis showed no thrombus formation inside the blood cavities. Histological examination of kidneys showed isolated micro-infarction in 2/12 animals; brain histology revealed no thromboembolic depositions. The Carmat bioprosthetic TAH implanted in calves up to 10 days provided adequate blood flow to organs and tissues. Low levels of haemolysis and no visible evidence of thromboembolic depositions in major organs and device cavities, without the use of anticoagulation, may indicate early-phase haemocompatibility of the TAH. © The Author 2015. Published by Oxford University Press on behalf of the European Association for Cardio

Partial purification and characterization of a wortmannin-sensitive and insulin-stimulated protein kinase that activates heart 6-phosphofructo-2-kinase.

OpenAIRE

Deprez, J; Bertrand, L; Alessi, D R; Krause, U; Hue, L; Rider, M H

2000-01-01

A wortmannin-sensitive and insulin-stimulated protein kinase (WISK), which phosphorylates and activates cardiac 6-phosphofructo-2-kinase (PFK-2), was partially purified from perfused rat hearts. Immunoblotting showed that WISK was devoid of protein kinase B (PKB), serum- and glucocorticoid-regulated protein kinase and protein kinase Czeta (PKCzeta). Comparison of the inhibition of WISK, PKCalpha and PKCzeta by different protein kinase inhibitors suggested that WISK was not a member of the PKC...

Initial Experience with IV Ketamine Infusion for Treatment of Post Sternotomy Pain in a Patient with a Total Artificial Heart.

Science.gov (United States)

Maher, Dermot P; Loyferman, Rusty; Yumul, Roya; Louy, Charles

2015-01-01

The implantation of total artificial hearts (TAH) via midline sternotomy for the treatment of severe biventricular cardiac dysfunction is associated with complex postoperative pain management. Ketamaine increases blood pressure by raising sympathetic outflow and cardiac output; however, ketamine is a direct vasodilator on isolated arterial tissues. In the setting of a TAH with a mechanically fixed cardiac output, a ketamine infusion for postoperative pain control has the potential to decrease blood pressure due to direct arterial vasodilation. We present the initial experience with a ketamine infusion in a patient with a TAH with minimal observed decreases in blood pressure and significantly improved postoperative pain.

Comparative analysis of von Willebrand factor profiles after implantation of left ventricular assist device and total artificial heart.

Science.gov (United States)

Reich, H J; Morgan, J; Arabia, F; Czer, L; Moriguchi, J; Ramzy, D; Esmailian, F; Lam, L; Dunhill, J; Volod, O

2017-08-01

Essentials Bleeding is a major source of morbidity during mechanical circulatory support. von Willebrand factor (VWF) multimer loss may contribute to bleeding. Different patterns of VWF multimer loss were seen with the two device types. This is the first report of total artificial heart associated VWF multimer loss. Background Bleeding remains a challenge during mechanical circulatory support and underlying mechanisms are incompletely understood. Functional von Willebrand factor (VWF) impairment because of loss of high-molecular-weight multimers (MWMs) produces acquired von Willebrand disease (VWD) after left ventricular assist device (LVAD). Little is known about VWF multimers with total artificial hearts (TAHs). Here, VWF profiles with LVADs and TAHs are compared using a VWD panel. Methods VWD evaluations for patients with LVAD or TAH (2013-14) were retrospectively analyzed and included: VWF activity (ristocetin cofactor, VWF:RCo), VWF antigen (VWF:Ag), ratio of VWF:RCo to VWF:Ag, and quantitative VWF multimeric analysis. Results Twelve patients with LVADs and 12 with TAHs underwent VWD evaluation. All had either normal (47.8%) or elevated (52.2%) VWF:RCo, normal (26.1%) or elevated (73.9%) VWF:Ag and 50.0% were disproportional (ratio ≤ 0.7). Multimeric analysis showed abnormal patterns in all patients with LVADs: seven with high MWM loss; five with highest MWM loss. With TAH, 10/12 patients had abnormal patterns: all with highest MWM loss. High MWM loss correlated with presence of LVAD and highest MWM loss with TAH. Increased low MWMs were detected in 22/24. Conclusion Using VWF multimeric analysis, abnormalities after LVAD or TAH were detected that would be missed with measurements of VWF level alone: loss of high MWM predominantly in LVAD, loss of highest MWM in TAH, and elevated levels of low MWM in both. This is the first study to describe TAH-associated highest MWM loss, which may contribute to bleeding. © 2017 International Society on Thrombosis and

Antithrombotic Therapy in Atrial Fibrillation Associated with Valvular Heart Disease: Executive Summary of a Joint Consensus Document from the European Heart Rhythm Association (EHRA) and European Society of Cardiology Working Group on Thrombosis, Endorsed by the ESC Working Group on Valvular Heart Disease, Cardiac Arrhythmia Society of Southern Africa (CASSA), Heart Rhythm Society (HRS), Asia Pacific Heart Rhythm Society (APHRS), South African Heart (SA Heart) Association and Sociedad Latinoamericana de Estimulación Cardíaca y Electrofisiología (SOLEACE).

Science.gov (United States)

Lip, Gregory Y H; Collet, Jean Philippe; de Caterina, Raffaele; Fauchier, Laurent; Lane, Deirdre A; Larsen, Torben B; Marin, Francisco; Morais, Joao; Narasimhan, Calambur; Olshansky, Brian; Pierard, Luc; Potpara, Tatjana; Sarrafzadegan, Nizal; Sliwa, Karen; Varela, Gonzalo; Vilahur, Gemma; Weiss, Thomas; Boriani, Giuseppe; Rocca, Bianca

2017-12-01

Management strategies for patients with atrial fibrillation (AF) in association with valvular heart disease (VHD) have been less informed by randomized trials, which have largely focused on ‘non-valvular AF’ patients. Thromboembolic risk also varies according to valve lesion and may also be associated with CHA2DS2-VASc score risk factor components, rather than only the valve disease being causal. Given the need to provide expert recommendations for professionals participating in the care of patients presenting with AF and associated VHD, a task force was convened by the European Heart Rhythm Association (EHRA) and European Society of Cardiology (ESC) Working Group (WG) on Thrombosis, with representation from the ESC WG on Valvular Heart Disease, Heart Rhythm Society (HRS), Asia Pacific Heart Rhythm Society (APHRS), South African Heart (SA Heart) Association and Sociedad Latinoamericana de Estimulación Cardíaca y Electrofisiología (SOLEACE) with the remit to comprehensively review the published evidence, and to produce a consensus document on the management of patients with AF and associated VHD, with up-to-date consensus statements for clinical practice for different forms of VHD, based on the principles of evidence-based medicine. This is an executive summary of a consensus document which proposes that the term ‘valvular AF’ is outdated and given that any definition ultimately relates to the evaluated practical use of oral anticoagulation (OAC) type, we propose a functional EHRA (Evaluated Heartvalves, Rheumatic or Artificial) categorization in relation to the type of OAC use in patients with AF, as follows: (1) EHRA (Evaluated Heartvalves, Rheumatic or Artificial) type 1 VHD, which refers to AF patients with ‘VHD needing therapy with a vitamin K antagonist (VKA)’ and (2) EHRA (Evaluated Heartvalves, Rheumatic or Artificial) type 2 VHD, which refers to AF patients with ‘VHD needing therapy with a VKA or a non-VKA oral anticoagulant also taking

Artificial heart development program. Volume II. System support. Phase III summary report, July 1, 1973--September 30, 1977

International Nuclear Information System (INIS)

1977-01-01

Volume 2 covers major activities of the Artificial Heart Development program that supported the design, fabrication, and test of the system demonstration units. Section A.1.0 provides a listing beyond that of the body of the report on the components needed for an implantation. It also presents glove box sterilization calibration results and results of an extensive mock circulation calibration. Section A.2.0 provides detailed procedures for assembly, preparing for use, and the use of the system and major components. Section A.3.0 covers the component research and development activities undertaken to improve components of the existing system units and to prepare for a future prototype system. Section A.4.0 provides a listing of the top assembly drawings of the major systems variations fabricated and tested

Artificial heart development program. Volume II. System support. Phase III summary report, July 1, 1973--September 30, 1977

Energy Technology Data Exchange (ETDEWEB)

1977-01-01

Volume 2 covers major activities of the Artificial Heart Development program that supported the design, fabrication, and test of the system demonstration units. Section A.1.0 provides a listing beyond that of the body of the report on the components needed for an implantation. It also presents glove box sterilization calibration results and results of an extensive mock circulation calibration. Section A.2.0 provides detailed procedures for assembly, preparing for use, and the use of the system and major components. Section A.3.0 covers the component research and development activities undertaken to improve components of the existing system units and to prepare for a future prototype system. Section A.4.0 provides a listing of the top assembly drawings of the major systems variations fabricated and tested.

Artificial muscle: the human chimera is the future.

Science.gov (United States)

Tozzi, P

2011-12-14

Severe heart failure and cerebral stroke are broadly associated with the impairment of muscular function that conventional treatments struggle to restore. New technologies enable the construction of "smart" materials that could be of great help in treating diseases where the main problem is muscle weakness. These materials "behave" similarly to biological systems, because the material directly converts energy, for example electrical energy into movement. The extension and contraction occur silently like in natural muscles. The real challenge is to transfer this amazing technology into devices that restore or replace the mechanical function of failing muscle. Cardiac assist devices based on artificial muscle technology could envelope a weak heart and temporarily improve its systolic function, or, if placed on top of the atrium, restore the atrial kick in chronic atrial fibrillation. Artificial sphincters could be used to treat urinary incontinence after prostatectomy or faecal incontinence associated with stomas. Artificial muscles can restore the ability of patients with facial paralysis due to stroke or nerve injury to blink. Smart materials could be used to construct an artificial oesophagus including peristaltic movement and lower oesophageal sphincter function to replace the diseased oesophagus thereby avoiding the need for laparotomy to mobilise stomach or intestine. In conclusion, in the near future, smart devices will integrate with the human body to fill functional gaps due to organ failure, and so create a human chimera.

Knowledge representation an approach to artificial intelligence

CERN Document Server

Bench-Capon, TJM

1990-01-01

Although many texts exist offering an introduction to artificial intelligence (AI), this book is unique in that it places an emphasis on knowledge representation (KR) concepts. It includes small-scale implementations in PROLOG to illustrate the major KR paradigms and their developments.****back cover copy:**Knowledge representation is at the heart of the artificial intelligence enterprise: anyone writing a program which seeks to work by encoding and manipulating knowledge needs to pay attention to the scheme whereby he will represent the knowledge, and to be aware of the consequences of the ch

Biocompatibility of Hydrogen-Diluted Amorphous Silicon Carbide Thin Films for Artificial Heart Valve Coating

Science.gov (United States)

Rizal, Umesh; Swain, Bhabani S.; Rameshbabu, N.; Swain, Bibhu P.

2018-01-01

Amorphous silicon carbide (a-SiC:H) thin films were synthesized using trichloromethylsilane by a hot wire chemical vapor deposition process. The deposited films were characterized by Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, x-ray diffraction and x-ray photoelectron spectroscopy to confirm its chemical bonding, structural network and composition of the a-SiC:H films. The optical microscopy images reveal that hydrogen dilution increased the surface roughness and pore density of a-SiC:H thin film. The Raman spectroscopy and FTIR spectra reveal chemical network consisting of Si-Si, C-C and Si-C bonds, respectively. The XRD spectroscopy and Raman spectroscopy indicate a-SiC:H still has short-range order. In addition, in vitro cytotoxicity test ensures the behavior of cell-semiconductor hybrid to monitor the proper coordination. The live-dead assays and MTT assay reveal an increase in green nucleus cell, and cell viability is greater than 88%, respectively, showing non-toxic nature of prepared a-SiC:H film. Moreover, the result indicated by direct contact assay, and cell prefers to adhere and proliferate on a-SiC:H thin films having a positive effect as artificial heart valve coating material.

The challenge of home discharge with a total artificial heart: the La Pitie Salpetriere experience.

Science.gov (United States)

Demondion, Pierre; Fournel, Ludovic; Niculescu, Michaela; Pavie, Alain; Leprince, Pascal

2013-11-01

The total artificial heart (TAH) helps to counteract the current decrease in heart donors and is likely to bridge patients to transplant under favourable conditions. Today's mobile consoles facilitate home discharge. The aim of this study was to report on the La Pitie Hospital experience with CardioWest TAH recipients, and more particularly, on generally successful outpatient' management. A retrospective analysis was performed on clinical and biological data from patients implanted with a TAH between December 2006 and July 2010 in a single institution. Morbi-mortality during hospital stay, number and causes of rehospitalizations, quality of life during home discharge, bridge to transplant results and survival have all been analysed. Twenty-seven patients were implanted with the CardioWest. Fifteen patients (55.5%) died during support. Prior to home discharge, the most frequent cause of death was multi-organ failure (46.6%). Twelve patients were discharged home from hospital within a median of 88 days [range 35-152, interquartile range 57] postimplantation. Mean rehospitalization rate was 1.2 by patient, on account of device infection (n = 7), technical problems with the console (n = 3) and other causes (n = 4). Between discharge and transplant, patients spent 87% of their support time out of hospital. All patients who returned home with the TAH were subsequently transplanted, and 1 died in post-transplant. Despite the morbidity and mortality occurring during the postimplantation period, home discharge with a TAH is possible. Portables drivers allow for a safe return home. Aside from some remaining weak points such as infectious complications or noise, CardioWest TAH allows for successful rehabilitation of graft candidates, and assures highly satisfactory transplant results.

Clinicohemodynamic and roentgenologic correlations in patients with artificial pacemakers

International Nuclear Information System (INIS)

Tatarchenko, I.P.; Iskenderov, B.G.; Koledinov, V.I.; Zhivotovskaya, G.G.

1987-01-01

The clinical pattern, central hemodynamics and roentgenologic data are studied in 34 patients with artificial cardiac pacemaker (ACP) to solve the problem on adequate medicamental therapy of heart failure (HF). Heart sizes and the state of a pulmonary image are estimated roentgenologically. Two types of cardiac-vessel system reactions on physical load: adequate and nonadequate - are detected. Implantation of ACP in patients with the nonadequate reaction does not lead to total liquidation of HF

Clinicohemodynamic and roentgenologic correlations in patients with artificial pacemakers

Energy Technology Data Exchange (ETDEWEB)

Tatarchenko, I P; Iskenderov, B G; Koledinov, V I; Zhivotovskaya, G G

1987-05-01

The clinical pattern, central hemodynamics and roentgenologic data are studied in 34 patients with artificial cardiac pacemaker (ACP) to solve the problem on adequate medicamental therapy of heart failure (HF). Heart sizes and the state of a pulmonary image are estimated roentgenologically. Two types of cardiac-vessel system reactions on physical load: adequate and nonadequate - are detected. Implantation of ACP in patients with the nonadequate reaction does not lead to total liquidation of HF.

Prediction of ferric iron precipitation in bioleaching process using partial least squares and artificial neural network

Directory of Open Access Journals (Sweden)

Golmohammadi Hassan

2013-01-01

Full Text Available A quantitative structure-property relationship (QSPR study based on partial least squares (PLS and artificial neural network (ANN was developed for the prediction of ferric iron precipitation in bioleaching process. The leaching temperature, initial pH, oxidation/reduction potential (ORP, ferrous concentration and particle size of ore were used as inputs to the network. The output of the model was ferric iron precipitation. The optimal condition of the neural network was obtained by adjusting various parameters by trial-and-error. After optimization and training of the network according to back-propagation algorithm, a 5-5-1 neural network was generated for prediction of ferric iron precipitation. The root mean square error for the neural network calculated ferric iron precipitation for training, prediction and validation set are 32.860, 40.739 and 35.890, respectively, which are smaller than those obtained by PLS model (180.972, 165.047 and 149.950, respectively. Results obtained reveal the reliability and good predictivity of neural network model for the prediction of ferric iron precipitation in bioleaching process.

Comparison of total artificial heart and biventricular assist device support as bridge-to-transplantation.

Science.gov (United States)

Cheng, Allen; Trivedi, Jaimin R; Van Berkel, Victor H; Massey, H Todd; Slaughter, Mark S

2016-10-01

The use of left ventricular assist devices (LVAD) has increased significantly in the last decade. However, right heart dysfunction remains a problem despite the improved outcomes with continuous-flow LVADs. Surgical options for bridge to transplantation (BTT) in patients with biventricular failure are total artificial heart (TAH) or biventricular support (BiVAD). This study examines the differences in pre- and post-transplantation outcomes and survival in patients with TAH or BiVAD support as BTT. The United Network of Organ Sharing database was retrospectively queried from January 2005 to December 2014 to identify adult patients undergoing heart transplantation (n = 17,022). Patients supported with either TAH (n = 212) or BiVAD (n = 366) at the time of transplantation were evaluated. Pre- and post-transplantation Kaplan-Meier survival curves were examined. Cox regression model was used to study the hazard ratios of the association between TAH versus BiVAD support and post-transplant survival. The median age of the study groups was 49.8 ± 12.9 (TAH) and 47.2 ± 13.9 (BiVAD) years (range 18-74 years). There were more men, 87% versus 74%, in the TAH group (p < 0.0001) with greater body mass index, 27.3 ± 5.2 versus 25.6 ± 4.7 (p < 0.0001), compared to those with BiVADs. Creatinine was higher, 1.7 + 1.2 versus 1.3 + 0.8 mg/dL (p < 0.0001), in the TAH group before transplant. The 30-day, one-, and three-year post-transplantation survival was 88%, 78%, and 67%, respectively, for patients with TAH support versus 93%, 83%, and 73% (p = 0.06) for patients with BiVAD support. Cox regression model shows pre-transplant creatinine (HR = 1.21, p = 0.008) is associated with a lower post-transplant survival. TAH is not associated with a worse post-transplant survival (p = 0.1). There was no difference in wait-list survival in patients supported with TAH or BiVAD (p = 0.8). Although there has been a recent

Biological effects of implanted nuclear energy sources for artificial heart devices. Progress report, September 1, 1975--August 31, 1976

International Nuclear Information System (INIS)

Kallfelz, F.A.; Wentworth, R.A.; Cady, K.B.

1976-01-01

A total of sixty dogs were implanted with radioisotope-powered artificial heart systems producing radiation fluxes similar to that of plutonium-238, but having no associated heat, at levels of from one to seventy times the radiation flux expected from a 30-watt plutonium-238 source. Results from studies lasting up to 6 years after implantation indicate that these animals, and by inference human beings, may be able to tolerate the radiation flux from 30-watt 238 Pu power sources. Results of heat dissipation studies in calves indicate that it may be possible to induce a vascularized connective tissue capsule sufficient to dissipate 30 watts of additional heat from a surface area of approximately 500 cm sq., allowing a heat flux of 0.06 watts per cm sq

New concepts and new design of permanent maglev rotary artificial heart blood pumps.

Science.gov (United States)

Qian, K X; Zeng, P; Ru, W M; Yuan, H Y

2006-05-01

According to tradition, permanent maglev cannot achieve stable equilibrium. The authors have developed, to the contrary, two stable permanent maglev impeller blood pumps. The first pump is an axially driven uni-ventricular assist pump, in which the rotor with impeller is radially supported by two passive magnetic bearings, but has one point contact with the stator axially at standstill. As the pump raises its rotating speed, the increasing hydrodynamic force of fluid acting on the impeller will make the rotor taking off from contacting point and disaffiliate from the stator. Then the rotor becomes fully suspended. The second pump is a radially driven bi-ventricular assist pump, i.e., an impeller total artificial heart. Its rotor with two impellers on both ends is supported by two passive magnetic bearings, which counteract the attractive force between rotor magnets and stator coil iron core. The rotor is affiliated to the stator radially at standstill and becomes levitated during rotation. Therefore, the rotor keeps concentric with stator during rotation but eccentric at standstill, as is confirmed by rotor position detection with Honeywell sensors. It concludes that the permanent maglev needs action of a non-magnetic force to achieve stability but a rotating magnetic levitator with high speed and large inertia can maintain its stability merely with passive magnetic bearings.

Internet advertising of artificial tanning in Australia.

Science.gov (United States)

Team, Victoria; Markovic, Milica

2006-08-01

Artificial tanning, defined as deliberate exposure to ultraviolet rays produced by artificial tanning devices, is a new and emerging public health issue in Australia and globally. Epidemiological research suggests that artificial tanning may contribute to the incidence of melanoma, nonmelanoma skin cancer as well as other health problems. Given that Australia has a high incidence of skin cancer, we have undertaken a study to explore how artificial tanning has been promoted to its users. The aim was to analyze the completeness and accuracy of information about artificial tanning. A content analysis of web sites of tanning salons and distributors of tanning equipment in Australia was conducted. A total of 22 web sites were analyzed. None of the solarium operators or distributors of equipment provided full information about the risks of artificial tanning. Fifty-nine percent of web advertisements had no information and 41% provided only partial information regarding the risks of artificial tanning. Pictures with the image of bronze-tanned bodies, predominantly women, were used by all web advertisers. In light of the success of sun-safety campaigns in Australia, the findings of future epidemiological research on the prevalence of artificial tanning and sociological and anthropological research on why people utilize artificial tanning should be a basis for developing effective targeted health promotion on the elimination of artificial tanning in the country.

Critical hematocrit and oxygen partial pressure in the beating heart of pigs.

Science.gov (United States)

Hiebl, B; Mrowietz, C; Ploetze, K; Matschke, K; Jung, F

2010-12-01

In cardiac surgery the substitution of lost blood volume by plasma substitutes is a common therapeutical approach. None of the currently available blood substitutes has a sufficient oxygen transport capacity. This can limit the functional integrity of the myocardium known as highly oxygen consumptive. The study was aimed to get information about the minimal hematocrit, also known as critical hematocrit (cHct), which guarantees a stable and adequate oxygen partial pressure in the myocardium (pO2). In adult female pigs (n=7) the hematocrit was reduced by isovolemic blood dilution with an intravenous infusion of isotonic 4% gelatine polysuccinate solution, The substituted blood volume ranged between 3000ml and 7780ml (mean: 5254±1672ml). In all animals the pO2 of the myocardium of the beating heart and of the resting skeletal muscle increased until blood dilution resulted in a Hct decrease down to 15%. Further blood dilution resulted in a decrease of the pO2. Only after the Hct was <10% the pO2 was lower than before blood dilution and accompanied by a lethal ischemia of the myocardium. These data indicate a cHct of about 10% in the pig animal model. Copyright © 2010 Elsevier Inc. All rights reserved.

The man who feels two hearts: the different pathways of interoception.

Science.gov (United States)

Couto, Blas; Salles, Alejo; Sedeño, Lucas; Peradejordi, Margarita; Barttfeld, Pablo; Canales-Johnson, Andrés; Dos Santos, Yamil Vidal; Huepe, David; Bekinschtein, Tristán; Sigman, Mariano; Favaloro, Roberto; Manes, Facundo; Ibanez, Agustin

2014-09-01

Recent advances in neuroscience have provided new insights into the understanding of heart-brain interaction and communication. Cardiac information to the brain relies on two pathways, terminating in the insular cortex (IC) and anterior cingulate cortex (ACC), along with the somatosensory cortex (S1-S2). Interoception relying on these neuroanatomical pathways has been shown to modulate social cognition. We report the case study of C.S., a patient with an 'external heart' (an extracorporeal left-univentricular cardiac assist device, LVAD). The patient was assessed with neural/behavioral measures of cardiac interoception complemented by neuropsychological and social cognition measures. The patient's performance on the interoception task (heartbeat detection) seemed to be guided by signals from the artificial LVAD, which provides a somatosensory beat rather than by his endogenous heart. Cortical activity (HEP, heartbeat-evoked potential) was found decreased in comparison with normal volunteers, particularly during interoceptive states. The patient accurately performed several cognitive tasks, except for interoception-related social cognition domains (empathy, theory of mind and decision making). This evidence suggests an imbalance in the patient's cardiac interoceptive pathways that enhances sensation driven by the artificial pump over that from the cardiac vagal-IC/ACC pathway. A patient with two hearts, one endogenous and one artificial, presents a unique opportunity to explore models of interoception and heart-brain interaction. © The Author (2013). Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.

Wireless patient monitoring system for a moving-actuator type artificial heart.

Science.gov (United States)

Nam, K W; Chung, J; Choi, S W; Sun, K; Min, B G

2006-10-01

In this study, we developed a wireless monitoring system for outpatients equipped with a moving-actuator type pulsatile bi-ventricular assist device, AnyHeart. The developed monitoring system consists of two parts; a Bluetooth-based short-distance self-monitoring system that can monitor and control the operating status of a VAD using a Bluetooth-embedded personal digital assistant or a personal computer within a distance of 10 meters, and a cellular network-based remote monitoring system that can continuously monitor and control the operating status of AnyHeart at any location. Results of in vitro experiments demonstrate the developed system's ability to monitor the operational status of an implanted AnyHeart.

Antithrombotic artificial organs

Energy Technology Data Exchange (ETDEWEB)

Takamatsu, T; Fukada, E; Saegusa, M; Hasegawa, T

1971-07-12

A new antithrombotic material useful for making artificial organs (artificial blood vessel, artificial heart, etc.) can be prepared by graft-polymerizing an acrylic ester (methyl methacrylate, methyl acrylate, ethyl acrylate, etc.) with a synthetic fiber (teflon, etc.). The graft-polymerization can be carried out by means of gamma radiation with cobalt 60 (dose rate 2.6x10/sup 3/ r/min., total dose 8x10/sup 4/ to 3.5x10/sup 5/ r). A graft ratio of 5 to 80% is attainable. In one example, a tubular sample made of teflon fiber having an inner diameter of 5 to 10 mm was immersed into methyl methacrylate in an ampoule in the absence of air and exposed to cobalt 60 gamma ray at the dose rate of 3.18x10/sup 3/ rad/min. After extraction with acetone, the sample was dried. The total dose was 3.5x10/sup 5/ rad and the graft ratio was ca. 25%. The sample was transplanted to vena cava of dog. No formation of thrombus was observed by autopsy (4 months after the transplantation). In control (teflon tube not graft-polymerized) thrombus was observed by autopsy 7 days after the transplantation.

Artificial Neural Network Application for Partial Discharge Recognition: Survey and Future Directions

Directory of Open Access Journals (Sweden)

Abdullahi Abubakar Mas’ud

2016-07-01

Full Text Available In order to investigate how artificial neural networks (ANNs have been applied for partial discharge (PD pattern recognition, this paper reviews recent progress made on ANN development for PD classification by a literature survey. Contributions from several authors have been presented and discussed. High recognition rate has been recorded for several PD faults, but there are still many factors that hinder correct recognition of PD by the ANN, such as high-amplitude noise or wide spectral content typical from industrial environments, trial and error approaches in determining an optimum ANN, multiple PD sources acting simultaneously, lack of comprehensive and up to date databank of PD faults, and the appropriate selection of the characteristics that allow a correct recognition of the type of source which are currently being addressed by researchers. Several suggestions for improvement are proposed by the authors include: (1 determining the optimum weights in training the ANN; (2 using PD data captured over long stressing period in training the ANN; (3 ANN recognizing different PD degradation levels; (4 using the same resolution sizes of the PD patterns when training and testing the ANN with different PD dataset; (5 understanding the characteristics of multiple concurrent PD faults and effectively recognizing them; and (6 developing techniques in order to shorten the training time for the ANN as applied for PD recognition Finally, this paper critically assesses the suitability of ANNs for both online and offline PD detections outlining the advantages to the practitioners in the field. It is possible for the ANNs to determine the stage of degradation of the PD, thereby giving an indication of the seriousness of the fault.

Generating pulsatility by pump speed modulation with continuous-flow total artificial heart in awake calves.

Science.gov (United States)

Fukamachi, Kiyotaka; Karimov, Jamshid H; Sunagawa, Gengo; Horvath, David J; Byram, Nicole; Kuban, Barry D; Dessoffy, Raymond; Sale, Shiva; Golding, Leonard A R; Moazami, Nader

2017-12-01

The purpose of this study was to evaluate the effects of sinusoidal pump speed modulation of the Cleveland Clinic continuous-flow total artificial heart (CFTAH) on hemodynamics and pump flow in an awake chronic calf model. The sinusoidal pump speed modulations, performed on the day of elective sacrifice, were set at ±15 and ± 25% of mean pump speed at 80 bpm in four awake calves with a CFTAH. The systemic and pulmonary arterial pulse pressures increased to 12.0 and 12.3 mmHg (±15% modulation) and to 15.9 and 15.7 mmHg (±25% modulation), respectively. The pulsatility index and surplus hemodynamic energy significantly increased, respectively, to 1.05 and 1346 ergs/cm at ±15% speed modulation and to 1.51 and 3381 ergs/cm at ±25% speed modulation. This study showed that it is feasible to generate pressure pulsatility with pump speed modulation; the platform is suitable for evaluating the physiologic impact of pulsatility and allows determination of the best speed modulations in terms of magnitude, frequency, and profiles.

Willem J Kolff (1911-2009): physician, inventor and pioneer: father of artificial organs.

Science.gov (United States)

Morrissey, Megan

2012-08-01

Medical pioneer Willem Johan Kolff was an inspirational father, son, physician and inventor. He founded the development of the first kidney dialysis machine, pioneered advances in the heart and lung machine, laid down the foundations for the first mainland blood bank in Europe and successfully implanted the first artificial heart into humans.

Artificial Gravity with Ergometric Exercise Training Improves Cardiovascular Function in Ambulatory Men

Science.gov (United States)

Sun, Xi-Qing; Zhu, Chao; Shang, Shu; Yao, Yong-Jie

2008-06-01

The necessity of preventing physiological deconditioning in astronauts exposed to long-term space flights is well known. Artificial gravity training via short-arm centrifugation as a countermeasure to microgravity has been considered for many years. However, an optimal duration, level and rate of exposure to artificial gravity have not yet been determined. The purpose of the present study was to investigate the cardiovascular effects of three weeks of intermittent artificial gravity with ergometric exercise training on normal ambulatory men. During 3 weeks experiment, eight healthy male subjects received alternate +1 to +2 Gz (at the foot) short-arm centrifuge training with 30 W ergometric exercise for 30 min per day. Cardiac function, heart rate variability, heart rate and blood pressure were measured before and after training. Stroke volume and total peripheral resistance increased significantly after 3 weeks training, compared with the pre-training baseline. Left ventricular ejection time (LVET) and ejection fraction increased significantly after 3 weeks training, while heart rate, the ratio of pre-ejection period to LVET, and the ratio of low frequency to high frequency power decreased significantly after 3 weeks training. These results suggest that three weeks short-arm centrifuge training with ergometric exercise could improve human cardiac systolic and pumping functions, and increase cardiac vagal modulation.

Artificial heart development program. Volume II. System support. Phase III summary report. Period covered: July 1, 1973--September 30, 1977

International Nuclear Information System (INIS)

1977-01-01

Appendix A covers major activities of the Artificial Heart Development program that supported the design, fabrication, and test of the system demonstration units. Section A.1.0 provides a listing beyond that of the body of the report on the components needed for an implantation. It also presents glove box sterilization calibration results and results of an extensive mock circulation calibration. Section A.2.0 provides detail procedures for assembly, preparing for use, and the use of the system and major components. Section A.3.0 covers the component research and development activities undertaken to improve components of the existing system units and to prepare for a future prototype system. Section A.4.0 provides a listing of the top assembly drawings of the major systems variations fabricated and tested

Artificial heart development program. Volume II. System support. Phase III summary report. Period covered: July 1, 1973--September 30, 1977

Energy Technology Data Exchange (ETDEWEB)

1977-01-01

Appendix A covers major activities of the Artificial Heart Development program that supported the design, fabrication, and test of the system demonstration units. Section A.1.0 provides a listing beyond that of the body of the report on the components needed for an implantation. It also presents glove box sterilization calibration results and results of an extensive mock circulation calibration. Section A.2.0 provides detail procedures for assembly, preparing for use, and the use of the system and major components. Section A.3.0 covers the component research and development activities undertaken to improve components of the existing system units and to prepare for a future prototype system. Section A.4.0 provides a listing of the top assembly drawings of the major systems variations fabricated and tested.

Biomaterials for artificial organs

CERN Document Server

Lysaght, Michael J

2010-01-01

The worldwide demand for organ transplants far exceeds available donor organs. Consequently some patients die whilst waiting for a transplant. Synthetic alternatives are therefore imperative to improve the quality of, and in some cases, save people's lives. Advances in biomaterials have generated a range of materials and devices for use either outside the body or through implantation to replace or assist functions which may have been lost through disease or injury. Biomaterials for artificial organs reviews the latest developments in biomaterials and investigates how they can be used to improve the quality and efficiency of artificial organs. Part one discusses commodity biomaterials including membranes for oxygenators and plasmafilters, titanium and cobalt chromium alloys for hips and knees, polymeric joint-bearing surfaces for total joint replacements, biomaterials for pacemakers, defibrillators and neurostimulators and mechanical and bioprosthetic heart valves. Part two goes on to investigate advanced and ...

Dynamic cardiomyoplasty using artificial muscle.

Science.gov (United States)

Suzuki, Yasuyuki; Daitoku, Kazuyuki; Minakawa, Masahito; Fukui, Kozo; Fukuda, Ikuo

2008-01-01

Dynamic cardiomyoplasty using latissimus dorsi muscle was previously used to compensate for congestive heart failure. Now, however, this method is not acceptable because the long-term result was not as expected owing to fatigue of the skeletal muscle. BioMetal fiber developed by Toki Corporation is one of the artificial muscles activated by electric current. The behavior of this fiber is similar to that of organic muscle. We made an artificial muscle like the latissimus dorsi using BioMetal fiber and tested whether we could use this new muscle as a cardiac supporting device. Testing one Biometal fiber showed the following performance: practical use maximal generative force was 30 g, exercise variation was 50%, and the standard driving current was 220 mA. We created a 4 x 12-cm tabular artificial muscle using 8 BioMetal fibers as a cardiac support device. We also made a simulation circuit composed of a 6 x 8-cm soft bag with unidirectional valves, reservoir, and connecting tube. The simulation circuit was filled with water and the soft bag was wrapped with the artificial muscle device. After powering the device electrically at 9 V with a current of 220 mA for each fiber, we measured the inside pressure and observed the movement of the artificial device. The artificial muscle contracted in 0.5 s for peak time and squeezed the soft bag. The peak pressure inside the soft bag was measured as 10 mmHg. Although further work will be needed to enhance the speed of deformability and movement simulating contraction, we conclude that artificial muscle may be potentially useful as a cardiac assistance device that can be developed for dynamic cardiomyoplasty.

Artificial organs versus regenerative medicine: is it true?

Science.gov (United States)

Nosé, Yukihiko; Okubo, Hisashi

2003-09-01

Individuals engaged in the fields of artificial kidney and artificial heart have often mistakenly stated that "the era of artificial organs is over; regenerative medicine is the future." Contrarily, we do not believe artificial organs and regenerative medicine are different medical technologies. As a matter of fact, artificial organs developed during the last 50 years have been used as a bridge to regeneration. The only difference between regenerative medicine and artificial organs is that artificial organs for the bridge to regeneration promote tissue regeneration in situ, instead of outside the body (for example, vascular prostheses, neuroprostheses, bladder substitutes, skin prostheses, bone prostheses, cartilage prostheses, ligament prostheses, etc.). All of these artificial organs are successful because tissue regeneration over a man-made prosthesis is established inside the patient's body (artificial organs to support regeneration). Another usage of the group of artificial organs for the bridge to regeneration is to sustain the functions of the patient's diseased organs during the regeneration process of the body's healthy tissues and/or organs. This particular group includes artificial kidney, hepatic assist, respiratory assist, and circulatory assist. Proof of regeneration of these healthy tissues and/or organs is demonstrated in the short-term recovery of end-stage organ failure patients (artificial organs for bridge to regeneration). A third group of artificial organs for the bridge to regeneration accelerates the regenerating process of the patient's healthy tissues and organs. This group includes neurostimulators, artificial blood (red cells) blood oxygenators, and plasmapheresis devices, including hemodiafiltrators. So-called "therapeutic artificial organs" fall into this category (artificial organs to accelerate regeneration). Thus, almost all of today's artificial organs are useful in the bridge to regeneration of healthy natural tissues and organs

Binding and release of artificial radionuclides in sediments

International Nuclear Information System (INIS)

Foerstner, U.; Schoer, J.

1980-01-01

Artificial radionuclides in aquatic systems are generally associated with more labile solid phases than are their stable counterparts. This implies that special attention must be paid to the possible effects on the biological uptake of artificial isotopes from contamined dredged materials following deposition or land application. An estimation of possible effects could be made from chemical extraction experiments similar to those already applied to stable heavy metal isotopes. Within the aquatic system the changes of the physico-chemical conditions, such as pH-values, oxygen content, salinity, and the concentration of complexing organic substances, may effect a partial remobilization of artificial radionuclides from the solids, which occurs more readily than with the respective stable isotopes. (orig.) [de

Artificial hearts-recent progress: republication of the article published in the Japanese Journal of Artificial Organs.

Science.gov (United States)

Nishida, Masahiro

2017-09-01

This review was created based on a translation of the Japanese review written in the Japanese Journal of Artificial Organs in 2015 (Vol.44, No. 3, pp.130-135), with some modifications regarding several references published in 2015 or later.

Fluid mechanics of heart valves.

Science.gov (United States)

Yoganathan, Ajit P; He, Zhaoming; Casey Jones, S

2004-01-01

Valvular heart disease is a life-threatening disease that afflicts millions of people worldwide and leads to approximately 250,000 valve repairs and/or replacements each year. Malfunction of a native valve impairs its efficient fluid mechanic/hemodynamic performance. Artificial heart valves have been used since 1960 to replace diseased native valves and have saved millions of lives. Unfortunately, despite four decades of use, these devices are less than ideal and lead to many complications. Many of these complications/problems are directly related to the fluid mechanics associated with the various mechanical and bioprosthetic valve designs. This review focuses on the state-of-the-art experimental and computational fluid mechanics of native and prosthetic heart valves in current clinical use. The fluid dynamic performance characteristics of caged-ball, tilting-disc, bileaflet mechanical valves and porcine and pericardial stented and nonstented bioprostheic valves are reviewed. Other issues related to heart valve performance, such as biomaterials, solid mechanics, tissue mechanics, and durability, are not addressed in this review.

Artificial intelligence in medicine: the challenges ahead.

Science.gov (United States)

Coiera, E W

1996-01-01

The modern study of artificial intelligence in medicine (AIM) is 25 years old. Throughout this period, the field has attracted many of the best computer scientists, and their work represents a remarkable achievement. However, AIM has not been successful-if success is judged as making an impact on the practice of medicine. Much recent work in AIM has been focused inward, addressing problems that are at the crossroads of the parent disciplines of medicine and artificial intelligence. Now, AIM must move forward with the insights that it has gained and focus on finding solutions for problems at the heart of medical practice. The growing emphasis within medicine on evidence-based practice should provide the right environment for that change.

Mathematical Model Analysis of Heart-Arterial Interaction in Hypertension

Science.gov (United States)

2001-10-25

conscious dogs with dilated cardiomyopathy ,” ! " # , vol. 260, pp. H1903-H1911, 1991. [7] P. Segers, N...with data measured in the isolated canine [14] or cat [15] heart, pumping into an artificial load or in the intact sheep [16] and human [7]. Left...instantaneous pressure-volume ratio of the canine left ventricle and effects of epinephrine and heart rate on the ratio,” , vol. 32, pp. 314

Stirling/hydraulic artificial heart power source

International Nuclear Information System (INIS)

Johnston, R.P.; Bennett, A.; Emigh, S.G.; Griffith, W.R.; Noble, J.E.; Perrone, R.E.; White, M.A.; Martini, W.R.; Alexander, J.E.

1977-01-01

The REL power source combines the high efficiency of Stirling engines with the reliability, efficiency, and flexibility of hydraulic power transfer and control to ensure long system life and physiological effectiveness. Extended life testing has been achieved with an engine (2.6 years) and hydraulic actuator/controller (1.6 years). Peak power source efficiency is 15.5 percent on 5 to 10 watts delivered to the blood pump push plate with 33 watts steady thermal input. Planned incorporation of power source output control is expected to reduce daily average thermal input to 18 watts. Animal in-vivo tests with an assist heart have consistently demonstrated required performance by biological synchronization and effective ventricle relief. Volume and weight are 0.93 liter and 2.4 kg (excluding blood pump) with an additional 0.4 liter of low temperature foam insulation required to preclude tissue thermal damage. Carefully planned development of System 7 is expected to produce major reductions in size

Home Discharge and Out-of-Hospital Follow-Up of Total Artificial Heart Patients Supported by a Portable Driver System

Science.gov (United States)

2014-01-01

To enhance ambulation and facilitate hospital discharge of total artificial heart (TAH)–supported patients, we adapted a mobile ventricular assistance device (VAD) driver (Excor) for TAH use and report on the performance of Excor-driven TAH patients discharged home. Ten patients stabilized on a TAH, driven by the CSS (“Circulatory Support System”), were progressively switched over to the Excor in hospital over 14 days as a pilot, with daily hemodynamics and laboratory parameters measured. Twenty-two stable TAH patients were subsequently placed on the Excor, trained, and discharged home. Clinical and hemodynamic parameters were followed. All pilot study patients were clinically stable on the Excor, with no decrease in TAH output noted (6.3 + 0.3 L/min [day 1] vs. 5.8 + 0.2 L/min [day 14], p = 0.174), with a trend suggesting improvement of both hepatic and renal function. Twenty-two TAH patients were subsequently successfully discharged home on the portable driver and were supported out of hospital for up to 598 days (range, 2–598; mean = 179 ± 140 days), remaining ambulatory, New York Heart Association (NYHA) class I or II, and free of readmission for 88.5% of the time of support. TAH patients may be effectively and safely supported by a mobile drive system. As such, the utility of the TAH may be extended to support patients beyond the hospital, at home, with overall ambulatory freedom. PMID:24577369

Comparison of thallium scintiscanning of heart and coronarography in ischemic heart disease patients

International Nuclear Information System (INIS)

Duska, F.; Kvasnicka, J.; Kubicek, J.; Vizda, J.; Kafka, P.; Bartak, K.; Mazurova, Y.; Palicka, V.

1986-01-01

In 22 patients with the preliminary diagnosis of ischemic heart disease, coronarography and thallium scintigraphy of the heart muscle were performed. In seven patients (31.8%) the two methods were in agreement, partial agreement was recorded in nine instances (40.9%) and disagreement in six patients (27.3%). When only one artery was affected the results were better (agreement in 71.4%). From the aspect of practical application it is thus obvious that our scintigraphic technique cannot replace coronarography, not even partly. (author)

Three-dimentional simulation of flow-induced platelet activation in artificial heart valves

Science.gov (United States)

Hedayat, Mohammadali; Asgharzadeh, Hafez; Borazjani, Iman

2015-11-01

Since the advent of heart valve, several valve types such as mechanical and bio-prosthetic valves have been designed. Mechanical Heart Valves (MHV) are durable but suffer from thromboembolic complications that caused by shear-induced platelet activation near the valve region. Bio-prosthetic Heart Valves (BHV) are known for better hemodynamics. However, they usually have a short average life time. Realistic simulations of heart valves in combination with platelet activation models can lead to a better understanding of the potential risk of thrombus formation in such devices. In this study, an Eulerian approach is developed to calculate the platelet activation in three-dimensional simulations of flow through MHV and BHV using a parallel overset-curvilinear immersed boundary technique. A curvilinear body-fitted grid is used for the flow simulation through the anatomic aorta, while the sharp-interface immersed boundary method is used for simulation of the Left Ventricle (LV) with prescribed motion. In addition, dynamics of valves were calculated numerically using under-relaxed strong-coupling algorithm. Finally, the platelet activation results for BMV and MHV are compared with each other.

Translation of First North American 50 and 70 cc Total Artificial Heart Virtual and Clinical Implantations: Utility of 3D Computed Tomography to Test Fit Devices.

Science.gov (United States)

Ferng, Alice S; Oliva, Isabel; Jokerst, Clinton; Avery, Ryan; Connell, Alana M; Tran, Phat L; Smith, Richard G; Khalpey, Zain

2017-08-01

Since the creation of SynCardia's 50 cc Total Artificial Hearts (TAHs), patients with irreversible biventricular failure now have two sizing options. Herein, a case series of three patients who have undergone successful 50 and 70 cc TAH implantation with complete closure of the chest cavity utilizing preoperative "virtual implantation" of different sized devices for surgical planning are presented. Computed tomography (CT) images were used for preoperative planning prior to TAH implantation. Three-dimensional (3D) reconstructions of preoperative chest CT images were generated and both 50 and 70 cc TAHs were virtually implanted into patients' thoracic cavities. During the simulation, the TAHs were projected over the native hearts in a similar position to the actual implantation, and the relationship between the devices and the atria, ventricles, chest wall, and diaphragm were assessed. The 3D reconstructed images and virtual modeling were used to simulate and determine for each patient if the 50 or 70 cc TAH would have a higher likelihood of successful implantation without complications. Subsequently, all three patients received clinical implants of the properly sized TAH based on virtual modeling, and their chest cavities were fully closed. This virtual implantation increases our confidence that the selected TAH will better fit within the thoracic cavity allowing for improved surgical outcome. Clinical implantation of the TAHs showed that our virtual modeling was an effective method for determining the correct fit and sizing of 50 and 70 cc TAHs. © 2016 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

Artificial life: The coming evolution

Energy Technology Data Exchange (ETDEWEB)

Farmer, J.D. (Los Alamos National Lab., NM (USA) Santa Fe Inst., NM (USA)); Belin, A.d' A. (Shute, Mihaly, and Weinberger, Santa Fe, NM (USA))

1990-01-01

Within fifty to a hundred years a new class of organisms is likely to emerge. These organisms will be artificial in the sense that they will originally be designed by humans. However, they will reproduce, and will evolve into something other than their initial form; they will be alive'' under any reasonable definition of the word. These organisms will evolve in a fundamentally different manner than contemporary biological organisms, since their reproduction will be under at least partial conscious control, giving it a Lamarckian component. The pace of evolutionary change consequently will be extremely rapid. The advent of artificial life will be the most significant historical event since the emergence of human beings. The impact on humanity and the biosphere could be enormous, larger than the industrial revolution, nuclear weapons, or environmental pollution. We must take steps now to shape the emergence of artificial organisms; they have potential to be either the ugliest terrestrial disaster, or the most beautiful creation of humanity. 22 refs., 3 figs.

Analysis, design, and control of a transcutaneous power regulator for artificial hearts.

Science.gov (United States)

Qianhong Chen; Siu Chung Wong; Tse, C K; Xinbo Ruan

2009-02-01

Based on a generic transcutaneous transformer model, a remote power supply using a resonant topology for use in artificial hearts is analyzed and designed for easy controllability and high efficiency. The primary and secondary windings of the transcutaneous transformer are positioned outside and inside the human body, respectively. In such a transformer, the alignment and gap may change with external positioning. As a result, the coupling coefficient of the transcutaneous transformer is also varying, and so are the two large leakage inductances and the mutual inductance. Resonant-tank circuits with varying resonant-frequency are formed from the transformer inductors and external capacitors. For a given range of coupling coefficients, an operating frequency corresponding to a particular coupling coefficient can be found, for which the voltage transfer function is insensitive to load. Prior works have used frequency modulation to regulate the output voltage under varying load and transformer coupling. The use of frequency modulation may require a wide control frequency range which may extend well above the load insensitive frequency. In this paper, study of the input-to-output voltage transfer function is carried out, and a control method is proposed to lock the switching frequency at just above the load insensitive frequency for optimized efficiency at heavy loads. Specifically, operation at above resonant of the resonant circuits is maintained under varying coupling-coefficient. Using a digital-phase-lock-loop (PLL), zero-voltage switching is achieved in a full-bridge converter which is also programmed to provide output voltage regulation via pulsewidth modulation (PWM). A prototype transcutaneous power regulator is built and found to to perform excellently with high efficiency and tight regulation under variations of the alignment or gap of the transcutaneous transformer, load and input voltage.

Dual Component Removable Partial Denture shows improved ...

African Journals Online (AJOL)

Dual Component Removable Partial Denture (DuCo RPD) is composed of a double base; lower and upper. The lower base, where the artificial teeth are attached, acts as a support and is in contact with the alveolar ridges and oral mucosa. Clasps are designed on the upper base, which acts towards the retention and ...

Influence of artificial aging on the load-bearing capability of straight or angulated zirconia abutments in implant/tooth-supported fixed partial dentures.

Science.gov (United States)

Nothdurft, Frank P; Doppler, Klaus E; Erdelt, Kurt J; Knauber, Andreas W; Pospiech, Peter R

2010-01-01

The aim of the study was to evaluate the influence of artificial aging on the fracture behavior of straight and angulated zirconia implant abutments used in ZirDesign (Astra Tech) implant/tooth-supported fixed partial dentures (FPDs) in the maxilla. Four different test groups (n = 8) representing anterior implant/tooth-supported FPDs were prepared. Groups 1 and 2 simulated a clinical situation with an ideal implant position (maxillary left central incisor) from a prosthetic point of view, which allowed for the use of a straight, prefabricated zirconia abutment. Groups 3 and 4 simulated a situation with a compromised implant position that required an angulated (20-degree) abutment. OsseoSpeed implants (4.5 3 13 mm, Astra Tech) as well as metal tooth analogs (maxillary right lateral incisor) with simulated periodontal mobility were mounted in polymethyl methacrylate. The FPDs (chromium-cobalt alloy) were cemented with glass ionomer. Groups 2 and 4 were thermomechanically loaded and subjected to static loading until failure. Statistical analysis of force data at the fracture site was performed using nonparametric tests. All samples survived thermomechanical loading. Artificial aging did not lead to a significant decrease in load-bearing capacity in either the straight abutments or the angulated abutments. The restorations that used angulated abutments exhibited higher fracture loads than the restorations with straight abutments (group 1: 209.13 ± 39.11 N; group 2: 233.63 ± 30.68 N; group 3: 324.62 ± 108.07 N; group 4: 361.75 ± 73.82 N). This difference in load-bearing performance was statistically significant, both with and without artificial aging. All abutment fractures occurred below the implant shoulder. Compensation for angulated implant positions with an angulated zirconia abutment is possible without reducing the load-bearing capacity of implant/tooth-supported anterior FPDs.

Heart rate informed artificial pancreas system enhances glycemic control during exercise in adolescents with T1D.

Science.gov (United States)

DeBoer, Mark D; Cherñavvsky, Daniel R; Topchyan, Katarina; Kovatchev, Boris P; Francis, Gary L; Breton, Marc D

2017-11-01

To evaluate the safety and performance of using a heart rate (HR) monitor to inform an artificial pancreas (AP) system during exercise among adolescents with type 1 diabetes (T1D). In a randomized, cross-over trial, adolescents with T1D age 13 - 18 years were enrolled to receive on separate days either the unmodified UVa AP (stdAP) or an AP system connected to a portable HR monitor (AP-HR) that triggered an exercise algorithm for blood glucose (BG) control. During admissions participants underwent a structured exercise regimen. Hypoglycemic events and CGM tracings were compared between the two admissions, during exercise and for the full 24-hour period. Eighteen participants completed the trial. While number of hypoglycemic events during exercise and rest was not different between visits (0.39 AP-HR vs 0.50 stdAP), time below 70 mg dL -1 was lower on AP-HR compared to stdAP, 0.5±2.1% vs 7.4±12.5% (P = 0.028). Time with BG within 70-180 mg dL -1 was higher for the AP-HR admission vs stdAP during the exercise portion and overall (96% vs 87%, and 77% vs 74%), but these did not reach statistical significance (P = 0.075 and P = 0.366). Heart rate signals can safely and efficaciously be integrated in a wireless AP system to inform of physical activity. While exercise contributes to hypoglycemia among adolescents, even when using an AP system, informing the system of exercise via a HR monitor improved time <70 mg dL -1 . Nonetheless, it did not significantly reduce the total number of hypoglycemic events, which were low in both groups. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Constructing general partial differential equations using polynomial and neural networks.

Science.gov (United States)

Zjavka, Ladislav; Pedrycz, Witold

2016-01-01

Sum fraction terms can approximate multi-variable functions on the basis of discrete observations, replacing a partial differential equation definition with polynomial elementary data relation descriptions. Artificial neural networks commonly transform the weighted sum of inputs to describe overall similarity relationships of trained and new testing input patterns. Differential polynomial neural networks form a new class of neural networks, which construct and solve an unknown general partial differential equation of a function of interest with selected substitution relative terms using non-linear multi-variable composite polynomials. The layers of the network generate simple and composite relative substitution terms whose convergent series combinations can describe partial dependent derivative changes of the input variables. This regression is based on trained generalized partial derivative data relations, decomposed into a multi-layer polynomial network structure. The sigmoidal function, commonly used as a nonlinear activation of artificial neurons, may transform some polynomial items together with the parameters with the aim to improve the polynomial derivative term series ability to approximate complicated periodic functions, as simple low order polynomials are not able to fully make up for the complete cycles. The similarity analysis facilitates substitutions for differential equations or can form dimensional units from data samples to describe real-world problems. Copyright © 2015 Elsevier Ltd. All rights reserved.

Functional requirements of a mathematical model of the heart.

Science.gov (United States)

Palladino, Joseph L; Noordergraaf, Abraham

2009-01-01

Functional descriptions of the heart, especially the left ventricle, are often based on the measured variables pressure and ventricular outflow, embodied as a time-varying elastance. The fundamental difficulty of describing the mechanical properties of the heart with a time-varying elastance function that is set a priori is described. As an alternative, a new functional model of the heart is presented, which characterizes the ventricle's contractile state with parameters, rather than variables. Each chamber is treated as a pressure generator that is time and volume dependent. The heart's complex dynamics develop from a single equation based on the formation and relaxation of crossbridge bonds. This equation permits the calculation of ventricular elastance via E(v) = partial differentialp(v)/ partial differentialV(v). This heart model is defined independently from load properties, and ventricular elastance is dynamic and reflects changing numbers of crossbridge bonds. In this paper, the functionality of this new heart model is presented via computed work loops that demonstrate the Frank-Starling mechanism and the effects of preload, the effects of afterload, inotropic changes, and varied heart rate, as well as the interdependence of these effects. Results suggest the origin of the equivalent of Hill's force-velocity relation in the ventricle.

Kant, Xunzi and the Artificiality of Manners

Directory of Open Access Journals (Sweden)

Anja BERNINGER

2017-01-01

Full Text Available Both Chinese and Western philosophers have argued for the ethical importance of manners. Their approaches are sometimes criticized on the grounds that manners are artificial. I compare Xunzi’s and Kant’s responses to this claim, and discuss the relevance of both positions for the development of a theory of manners. I show that there is no single artificiality claim, but rather four different claims: the claim that polite behavior lacks spontaneity, the claim that it is insincere, the claim that it goes against human nature, and the claim that it is arbitrary. While Kant is mainly concerned with the insincerity claim, Xunzi focusses on the claim that manners are arbitrary rules. Because of their different understandings of the function of manners both authors only provide a partial answer to the artificiality claim. To arrive at a full account of manners both perspectives must be combined.

An improved optimization algorithm of the three-compartment model with spillover and partial volume corrections for dynamic FDG PET images of small animal hearts in vivo

Science.gov (United States)

Li, Yinlin; Kundu, Bijoy K.

2018-03-01

The three-compartment model with spillover (SP) and partial volume (PV) corrections has been widely used for noninvasive kinetic parameter studies of dynamic 2-[18F] fluoro-2deoxy-D-glucose (FDG) positron emission tomography images of small animal hearts in vivo. However, the approach still suffers from estimation uncertainty or slow convergence caused by the commonly used optimization algorithms. The aim of this study was to develop an improved optimization algorithm with better estimation performance. Femoral artery blood samples, image-derived input functions from heart ventricles and myocardial time-activity curves (TACs) were derived from data on 16 C57BL/6 mice obtained from the UCLA Mouse Quantitation Program. Parametric equations of the average myocardium and the blood pool TACs with SP and PV corrections in a three-compartment tracer kinetic model were formulated. A hybrid method integrating artificial immune-system and interior-reflective Newton methods were developed to solve the equations. Two penalty functions and one late time-point tail vein blood sample were used to constrain the objective function. The estimation accuracy of the method was validated by comparing results with experimental values using the errors in the areas under curves (AUCs) of the model corrected input function (MCIF) and the 18F-FDG influx constant K i . Moreover, the elapsed time was used to measure the convergence speed. The overall AUC error of MCIF for the 16 mice averaged  -1.4  ±  8.2%, with correlation coefficients of 0.9706. Similar results can be seen in the overall K i error percentage, which was 0.4  ±  5.8% with a correlation coefficient of 0.9912. The t-test P value for both showed no significant difference. The mean and standard deviation of the MCIF AUC and K i percentage errors have lower values compared to the previously published methods. The computation time of the hybrid method is also several times lower than using just a stochastic

Surface Modification using Plasma treatments and Adhesion Peptide for Durable Tissue-Engineered Heart Valves

International Nuclear Information System (INIS)

Jung, Young mee; Kim, Soo Hyun

2010-01-01

Artificial heart valves are used in valvular heart diseases, but these valves have disadvantages that they cannot grow, repair and remodel. In current study, the strategies to development of in vitro cultured functional tissue by tissue engineering is available to heart valve disease. In the point of using viable autolougous cells, tissue engineered heart valves have some advantage to include that they can repair, remodel, and grow. Because heart valve is placed under the strong shear stress condition by pumping of heart, the durability of tissue-engineered heart valves is now questionable. The purpose of the study is to evaluate of the durability of tissue engineered heart valve with surface modified scaffolds under hemodynamic conditions

Incomplete response to artificial tears is associated with features of neuropathic ocular pain.

Science.gov (United States)

Galor, Anat; Batawi, Hatim; Felix, Elizabeth R; Margolis, Todd P; Sarantopoulos, Konstantinos D; Martin, Eden R; Levitt, Roy C

2016-06-01

Artificial tears are first-line therapy for patients with dry eye symptoms. It is not known, however, which patient factors associate with a positive response to therapy. The purpose of this study was to evaluate whether certain ocular and systemic findings are associated with a differential subjective response to artificial tears. Cross-sectional study of 118 individuals reporting artificial tears use (hypromellose 0.4%) to treat dry eye-associated ocular pain. An evaluation was performed to assess dry eye symptoms (via the dry eye questionnaire 5 and ocular surface disease index), ocular and systemic (non-ocular) pain complaints and ocular signs (tear osmolarity, tear breakup time, corneal staining, Schirmer testing with anaesthesia, and eyelid and meibomian gland assessment). The main outcome measures were factors associated with differential subjective response to artificial tears. By self-report, 23 patients reported no improvement, 73 partial improvement and 22 complete improvement in ocular pain with artificial tears. Patients who reported no or partial improvement in pain with artificial tears reported higher levels of hot-burning ocular pain and sensitivity to wind compared with those with complete improvement. Patients were also asked to rate the intensity of systemic pain elsewhere in the body (other than the eye). Patients who reported no or incomplete improvement with artificial tears had higher systemic pain scores compared with those with complete improvement. Both ocular and systemic (non-ocular) pain complaints are associated with a differential subjective response to artificial tears. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Evaluation of partial beta-adrenoceptor agonist activity.

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Lipworth, B J; Grove, A

1997-01-01

A partial beta-adrenoceptor (beta-AR) agonist will exhibit opposite agonist and antagonist activity depending on the prevailing degree of adrenergic tone or the presence of a beta-AR agonist with higher intrinsic activity. In vivo partial beta-AR agonist activity will be evident at rest with low endogenous adrenergic tone, as for example with chronotropicity (beta 1/beta 2), inotropicity (beta 1) or peripheral vasodilatation and finger tremor (beta 2). beta-AR blocking drugs which have partial agonist activity may exhibit a better therapeutic profile when used for hypertension because of maintained cardiac output without increased systemic vascular resistance, along with an improved lipid profile. In the presence of raised endogenous adrenergic tone such as exercise or an exogenous full agonist, beta-AR subtype antagonist activity will become evident in terms of effects on exercise induced heart rate (beta 1) and potassium (beta 2) responses. Reduction of exercise heart rate will occur to a lesser degree in the case of a beta-adrenoceptor blocker with partial beta 1-AR agonist activity compared with a beta-adrenoceptor blocker devoid of partial agonist activity. This may result in reduced therapeutic efficacy in the treatment of angina on effort when using beta-AR blocking drugs with partial beta 1-AR agonist activity. Effects on exercise hyperkalaemia are determined by the balance between beta 2-AR partial agonist activity and endogenous adrenergic activity. For predominantly beta 2-AR agonist such as salmeterol and salbutamol, potentiation of exercise hyperkalaemia occurs. For predominantly beta 2-AR antagonists such as carteolol, either potentiation or attenuation of exercise hyperkalaemia occurs at low and high doses respectively. beta 2-AR partial agonist activity may also be expressed as antagonism in the presence of an exogenous full agonist, as for example attenuation of fenoterol induced responses by salmeterol. Studies are required to investigate whether

The partial mediation effect of satisfaction with social support and coping effectiveness on health-related quality of life and perceived stress long-term after heart transplantation

Directory of Open Access Journals (Sweden)

White-Williams C

2014-12-01

Full Text Available Connie White-Williams,1 Kathleen L Grady,2 Pariya Fazeli,1 Susan Myers,1 Linda Moneyham,3 Karen Meneses,3 Bruce Rybarczyk4 1University of Alabama Medical Center, Birmingham, AL, USA; 2Division of Cardiac Surgery, Department of Surgery, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA; 3School of Nursing, University of Alabama at Birmingham, Birmingham, AL, USA; 4Department of Psychology, Clinical Psychology Program, Virginia Commonwealth University, Richmond, VA, USA Abstract: The purpose of this research was to examine whether satisfaction with social support and coping effectiveness mediate the relationship between stress and health-related quality of life (HRQOL 5 years after heart transplantation. Data were collected from 212 heart transplant patients (80% male, 92% white, mean age 59.9 years at four United States sites using the Heart Transplant Stressor Scale, Social Support Index, Jalowiec Coping Scale, and Quality of Life Index. Using Baron and Kenny's approach, a series of regression equations for mediation revealed that both satisfaction with social support and coping partially mediated the relationship between perceived stress and HRQOL. Understanding the relationships of social support, stress, and coping on patients' HRQOL is important for the development of interventions to provide optimal patient care. Keywords: heart transplantation, social support, coping, stress, mediation

Heterozygote loss of ACE2 is sufficient to increase the susceptibility to heart disease.

Science.gov (United States)

Wang, Wang; Patel, Vaibhav B; Parajuli, Nirmal; Fan, Dong; Basu, Ratnadeep; Wang, Zuocheng; Ramprasath, Tharmarajan; Kassiri, Zamaneh; Penninger, Josef M; Oudit, Gavin Y

2014-08-01

Angiotensin-converting enzyme 2 (ACE2) metabolizes Ang II into Ang 1-7 thereby negatively regulating the renin-angiotensin system. However, heart disease in humans and in animal models is associated with only a partial loss of ACE2. ACE2 is an X-linked gene; and as such, we tested the clinical relevance of a partial loss of ACE2 by using female ACE2(+/+) (wildtype) and ACE2(+/-) (heterozygote) mice. Pressure overload in ACE2(+/-) mice resulted in greater LV dilation and worsening systolic and diastolic dysfunction. These changes were associated with increased myocardial fibrosis, hypertrophy, and upregulation of pathological gene expression. In response to Ang II infusion, there was increased NADPH oxidase activity and myocardial fibrosis resulting in the worsening of Ang II-induced diastolic dysfunction with a preserved systolic function. Ang II-mediated cellular effects in cultured adult ACE2(+/-) cardiomyocytes and cardiofibroblasts were exacerbated. Ang II-mediated pathological signaling worsened in ACE2(+/-) hearts characterized by an increase in the phosphorylation of ERK1/2 and JNK1/2 and STAT-3 pathways. The ACE2(+/-) mice showed an exacerbated pressor response with increased vascular fibrosis and stiffness. Vascular superoxide and nitrotyrosine levels were increased in ACE2(+/-) vessels consistent with increased vascular oxidative stress. These changes occurred with increased renal fibrosis and superoxide production. Partial heterozygote loss of ACE2 is sufficient to increase the susceptibility to heart disease secondary to pressure overload and Ang II infusion. Heart disease in humans with idiopathic dilated cardiomyopathy is associated with a partial loss of ACE2. Heterozygote female ACE2 mutant mice showed enhanced susceptibility to pressure overload-induced heart disease. Heterozygote female ACE2 mutant mice showed enhanced susceptibility to Ang II-induced heart and vascular diseases. Partial loss of ACE2 is sufficient to enhance the susceptibility to

Living with heart disease and angina

Science.gov (United States)

... blood sugar at recommended levels. Living a Healthy Lifestyle Some controllable risk factors for heart disease are: ... and partially hydrogenated or hydrogenated fats. These are unhealthy fats that are often found in fried foods, ...

Correcting human heart 31P NMR spectra for partial saturation. Evidence that saturation factors for PCr/ATP are homogeneous in normal and disease states

Science.gov (United States)

Bottomley, Paul A.; Hardy, Christopher J.; Weiss, Robert G.

Heart PCr/ATP ratios measured from spatially localized 31P NMR spectra can be corrected for partial saturation effects using saturation factors derived from unlocalized chest surface-coil spectra acquired at the heart rate and approximate Ernst angle for phosphor creatine (PCr) and again under fully relaxed conditions during each 31P exam. To validate this approach in studies of normal and disease states where the possibility of heterogeneity in metabolite T1 values between both chest muscle and heart and normal and disease states exists, the properties of saturation factors for metabolite ratios were investigated theoretically under conditions applicable in typical cardiac spectroscopy exams and empirically using data from 82 cardiac 31P exams in six study groups comprising normal controls ( n = 19) and patients with dilated ( n = 20) and hypertrophic ( n = 5) cardiomyopathy, coronary artery disease ( n = 16), heart transplants ( n = 19), and valvular heart disease ( n = 3). When TR ≪ T1,(PCr), with T1(PCr) ⩾ T1(ATP), the saturation factor for PCr/ATP lies in the range 1.5 ± 0.5, regardless of the T1 values. The precise value depends on the ratio of metabolite T1 values rather than their absolute values and is insensitive to modest changes in TR. Published data suggest that the metabolite T1 ratio is the same in heart and muscle. Our empirical data reveal that the saturation factors do not vary significantly with disease state, nor with the relative fractions of muscle and heart contributing to the chest surface-coil spectra. Also, the corrected myocardial PCr/ATP ratios in each normal or disease state bear no correlation with the corresponding saturation factors nor the fraction of muscle in the unlocalized chest spectra. However, application of the saturation correction (mean value, 1.36 ± 0.03 SE) significantly reduced scatter in myocardial PCr/ATP data by 14 ± 11% (SD) ( p ⩽ 0.05). The findings suggest that the relative T1 values of PCr and ATP are

Biological effects of implanted nuclear energy sources for artificial heart devices. Progress report, September 1, 1974--August 31, 1975

International Nuclear Information System (INIS)

Kallfelz, F.A.; Wentworth, R.A.; Cady, K.B.

1975-01-01

Results are reported from a study of the biological effects of radiation from mock plutonium power sources in dogs and a study of the feasibility of a tissue heat sink for waste heat from such sources in calves. It is also designed to evaluate effects of heat and radiation from plutonium sources in calves. The work is part of a program to evaluate the use of plutonium as a power source for an artificial heart device. A total of 60 dogs have been implanted with mock plutonium sources (producing a similar radiation flux as plutonium but having no associated heat) at levels of from 1 to 70 times the expected radiation flux from a 30 watt plutonium source. Results up to 4.5 years after implantation indicate that mammals may be able to tolerate the radiation flux from such sources. Results in calves indicate that 30 watts of additional endogenous heat can be dissipated to a connective tissue covered heat exchanger with a surface area of 494 cm 2 providing a heat flux of 0.06 watts/cm 2 . (U.S.)

Classification of Partial Discharge Measured under Different Levels of Noise Contamination.

Directory of Open Access Journals (Sweden)

Wong Jee Keen Raymond

Full Text Available Cable joint insulation breakdown may cause a huge loss to power companies. Therefore, it is vital to diagnose the insulation quality to detect early signs of insulation failure. It is well known that there is a correlation between Partial discharge (PD and the insulation quality. Although many works have been done on PD pattern recognition, it is usually performed in a noise free environment. Also, works on PD pattern recognition in actual cable joint are less likely to be found in literature. Therefore, in this work, classifications of actual cable joint defect types from partial discharge data contaminated by noise were performed. Five cross-linked polyethylene (XLPE cable joints with artificially created defects were prepared based on the defects commonly encountered on site. Three different types of input feature were extracted from the PD pattern under artificially created noisy environment. These include statistical features, fractal features and principal component analysis (PCA features. These input features were used to train the classifiers to classify each PD defect types. Classifications were performed using three different artificial intelligence classifiers, which include Artificial Neural Networks (ANN, Adaptive Neuro-Fuzzy Inference System (ANFIS and Support Vector Machine (SVM. It was found that the classification accuracy decreases with higher noise level but PCA features used in SVM and ANN showed the strongest tolerance against noise contamination.

Prediction of Human Intestinal Absorption of Compounds Using Artificial Intelligence Techniques.

Science.gov (United States)

Kumar, Rajnish; Sharma, Anju; Siddiqui, Mohammed Haris; Tiwari, Rajesh Kumar

2017-01-01

Information about Pharmacokinetics of compounds is an essential component of drug design and development. Modeling the pharmacokinetic properties require identification of the factors effecting absorption, distribution, metabolism and excretion of compounds. There have been continuous attempts in the prediction of intestinal absorption of compounds using various Artificial intelligence methods in the effort to reduce the attrition rate of drug candidates entering to preclinical and clinical trials. Currently, there are large numbers of individual predictive models available for absorption using machine learning approaches. Six Artificial intelligence methods namely, Support vector machine, k- nearest neighbor, Probabilistic neural network, Artificial neural network, Partial least square and Linear discriminant analysis were used for prediction of absorption of compounds. Prediction accuracy of Support vector machine, k- nearest neighbor, Probabilistic neural network, Artificial neural network, Partial least square and Linear discriminant analysis for prediction of intestinal absorption of compounds was found to be 91.54%, 88.33%, 84.30%, 86.51%, 79.07% and 80.08% respectively. Comparative analysis of all the six prediction models suggested that Support vector machine with Radial basis function based kernel is comparatively better for binary classification of compounds using human intestinal absorption and may be useful at preliminary stages of drug design and development. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Application of Adaptive Starling-Like Controller to Total Artificial Heart Using Dual Rotary Blood Pumps.

Science.gov (United States)

Ng, Boon C; Smith, Peter A; Nestler, Frank; Timms, Daniel; Cohn, William E; Lim, Einly

2017-03-01

The successful clinical applicability of rotary left ventricular assist devices (LVADs) has led to research interest in devising a total artificial heart (TAH) using two rotary blood pumps (RBPs). The major challenge when using two separately controlled LVADs for TAH support is the difficulty in maintaining the balance between pulmonary and systemic blood flows. In this study, a starling-like controller (SLC) hybridized with an adaptive mechanism was developed for a dual rotary LVAD TAH. The incorporation of the adaptive mechanism was intended not only to minimize the risk of pulmonary congestion and atrial suction but also to match cardiac demand. A comparative assessment was performed between the proposed adaptive starling-like controller (A-SLC) and a conventional SLC as well as a constant speed controller. The performance of all controllers was evaluated by subjecting them to three simulated scenarios [rest, exercise, head up tilt (HUT)] using a mock circulation loop. The overall results showed that A-SLC was superior in matching pump flow to cardiac demand without causing hemodynamic instabilities. In contrast, improper flow regulation by the SLC resulted in pulmonary congestion during exercise. From resting supine to HUT, overpumping of the RBPs at fixed speed (FS) caused atrial suction, whereas implementation of SLC resulted in insufficient flow. The comparative study signified the potential of the proposed A-SLC for future TAH implementation particularly among outpatients, who are susceptible to variety of clinical scenarios.

Thermally induced magnetic relaxation in square artificial spin ice

Science.gov (United States)

Andersson, M. S.; Pappas, S. D.; Stopfel, H.; Östman, E.; Stein, A.; Nordblad, P.; Mathieu, R.; Hjörvarsson, B.; Kapaklis, V.

2016-11-01

The properties of natural and artificial assemblies of interacting elements, ranging from Quarks to Galaxies, are at the heart of Physics. The collective response and dynamics of such assemblies are dictated by the intrinsic dynamical properties of the building blocks, the nature of their interactions and topological constraints. Here we report on the relaxation dynamics of the magnetization of artificial assemblies of mesoscopic spins. In our model nano-magnetic system - square artificial spin ice - we are able to control the geometrical arrangement and interaction strength between the magnetically interacting building blocks by means of nano-lithography. Using time resolved magnetometry we show that the relaxation process can be described using the Kohlrausch law and that the extracted temperature dependent relaxation times of the assemblies follow the Vogel-Fulcher law. The results provide insight into the relaxation dynamics of mesoscopic nano-magnetic model systems, with adjustable energy and time scales, and demonstrates that these can serve as an ideal playground for the studies of collective dynamics and relaxations.

Difficult cases in heart failure: the challenge of neurocognitive dysfunction in severe heart failure.

Science.gov (United States)

Sangha, Sumadeep S; Uber, Patricia A; Park, Myung H; Scott, Robert L; Mehra, Mandeep R

2002-01-01

Often ignored, neurocognitive dysfunction in chronic heart failure represents a daunting morbidity progressing to loss of self-reliance. Although the precise mechanisms arbitrating the development of this disorder remain elusive, microembolization and cerebral hypoperfusion are implicated. Other causes of cognitive decline may include prior cardiac surgery, chronic hypertension, sleep disordered breathing, hyperhomocysteinemia, dementia of aging, and more traditional causes such as Alzheimer's disease. The discovery of neurocognitive defects in heart failure must prompt a well-constructed diagnostic evaluation to search for the underlying causes since this process may be at least partially reversible in many cases. Copyright 2002 CHF, Inc

Nonlinear analysis of fetal heart rate dynamics in fetuses compromised by asymptomatic partial placental abruption.

Science.gov (United States)

Choi, Won-Young; Hoh, Jeong-Kyu

2015-12-01

We analyzed fetal heart rate (FHR) parameters, dynamics, and outcomes in pregnancies with asymptomatic partial placental abruption (PPA) compared with those in normal pregnancies. We examined nonstress test (NST) data acquired from 2003 to 2012 at our institution. Normal pregnancies (N = 170) and PPA cases (N = 17) were matched for gestational age, fetal sex, and mean FHR. NSTs were performed at 33-42 weeks of gestation. FHR parameters obtained from the NST and perinatal outcomes were analyzed using linear methods. Nonlinear indices, including approximate entropy (ApEn), sample entropy (SampEn), short-term and long-term scaling exponents (α1 and α2), and correlation dimension (CD), were used to interpret FHR dynamics and system complexity. The area under a receiver operating characteristic curve (AUC) was used to evaluate the nonlinear indices. There were no significant differences in general characteristics and FHR parameters between the PPA and control groups. However, gestational age at delivery, birth weight, 5-min Apgar scores, ApEn, SampEn, and CD were significantly lower in the PPA group than in the control group (P Nonlinear dynamic indices of FHR in asymptomatic PPA were qualitatively different from those in normal pregnancies, whereas the conventional FHR parameters were not significantly different. Copyright © 2015 Elsevier Ltd. All rights reserved.

Simulation of blood flow through an artificial heart

Science.gov (United States)

Kiris, Cetin; Chang, I-Dee; Rogers, Stuart E.; Kwak, Dochan

1991-01-01

A numerical simulation of the incompressible viscous flow through a prosthetic tilting disk heart valve is presented in order to demonstrate the current capability to model unsteady flows with moving boundaries. Both steady state and unsteady flow calculations are done by solving the incompressible Navier-Stokes equations in 3-D generalized curvilinear coordinates. In order to handle the moving boundary problems, the chimera grid embedding scheme which decomposes a complex computational domain into several simple subdomains is used. An algebraic turbulence model for internal flows is incorporated to reach the physiological values of Reynolds number. Good agreement is obtained between the numerical results and experimental measurements. It is found that the tilting disk valve causes large regions of separated flow, and regions of high shear.

Correction for Eddy Current-Induced Echo-Shifting Effect in Partial-Fourier Diffusion Tensor Imaging.

Science.gov (United States)

Truong, Trong-Kha; Song, Allen W; Chen, Nan-Kuei

2015-01-01

In most diffusion tensor imaging (DTI) studies, images are acquired with either a partial-Fourier or a parallel partial-Fourier echo-planar imaging (EPI) sequence, in order to shorten the echo time and increase the signal-to-noise ratio (SNR). However, eddy currents induced by the diffusion-sensitizing gradients can often lead to a shift of the echo in k-space, resulting in three distinct types of artifacts in partial-Fourier DTI. Here, we present an improved DTI acquisition and reconstruction scheme, capable of generating high-quality and high-SNR DTI data without eddy current-induced artifacts. This new scheme consists of three components, respectively, addressing the three distinct types of artifacts. First, a k-space energy-anchored DTI sequence is designed to recover eddy current-induced signal loss (i.e., Type 1 artifact). Second, a multischeme partial-Fourier reconstruction is used to eliminate artificial signal elevation (i.e., Type 2 artifact) associated with the conventional partial-Fourier reconstruction. Third, a signal intensity correction is applied to remove artificial signal modulations due to eddy current-induced erroneous T2(∗) -weighting (i.e., Type 3 artifact). These systematic improvements will greatly increase the consistency and accuracy of DTI measurements, expanding the utility of DTI in translational applications where quantitative robustness is much needed.

Development of data communication system with ultra high frequency radio wave for implantable artificial hearts.

Science.gov (United States)

Tsujimura, Shinichi; Yamagishi, Hiroto; Sankai, Yoshiyuki

2009-01-01

In order to minimize infection risks of patients with artificial hearts, wireless data transmission methods with electromagnetic induction or light have been developed. However, these methods tend to become difficult to transmit data if the external data transmission unit moves from its proper position. To resolve this serious problem, the purpose of this study is to develop a prototype wireless data communication system with ultra high frequency radio wave and confirm its performance. Due to its high-speed communication rate, low power consumption, high tolerance to electromagnetic disturbances, and secure wireless communication, we adopted Bluetooth radio wave technology for our system. The system consists of an internal data transmission unit and an external data transmission unit (53 by 64 by 16 mm, each), and each has a Bluetooth module (radio field intensity: 4 dBm, receiver sensitivity: -80 dBm). The internal unit also has a micro controller with an 8-channel 10-bit A/D converter, and the external unit also has a RS-232C converter. We experimented with the internal unit implanted into pig meat, and carried out data transmission tests to evaluate the performance of this system in tissue thickness of up to 3 mm. As a result, data transfer speeds of about 20 kbps were achieved within the communication distance of 10 m. In conclusion, we confirmed that the system can wirelessly transmit the data from the inside of the body to the outside, and it promises to resolve unstable data transmission due to accidental movements of an external data transmission unit.

Prediction of the external work of the native heart from the dynamic H-Q curves of the rotary blood pumps during left heart bypass.

Science.gov (United States)

Yokoyama, Yoshimasa; Kawaguchi, Osamu; Kitao, Takashi; Kimura, Taro; Steinseifer, Ulrich; Takatani, Setsuo

2010-09-01

The ventricular performance is dependent on the drainage effect of rotary blood pumps (RBPs) and the performance of RBPs is affected by the ventricular pulsation. In this study, the interaction between the ventricle and RBPs was examined using the pressure-volume (P-V) diagram of the ventricle and dynamic head pressure-bypass flow (H-Q) curves (H, head pressure: arterial pressure minus ventricular pressure vs. Q, bypass flow) of the RBPs. We first investigated the relationships in a mock loop with a passive fill ventricle, followed by validation in ex vivo animal experiments. An apical drainage cannula with a micro-pressure sensor was especially fabricated to obtain ventricular pressure, while three pairs of ultrasonic crystals placed on the heart wall were used to derive ventricular volume. The mock loop-configured ventricular apical-descending aorta bypass revealed that the external work of the ventricle expressed by the area inside the P-V diagrams (EW(Heart) ) correlated strongly with the area inside dynamic H-Q curves (EW(VAD)), with the coefficients of correlation being R² = 0.869 ∼ 0.961. The results in the mock loop were verified in the ex vivo studies using three Shiba goats (10-25 kg in body weight), showing the correlation coefficients of R² = 0.802 ∼ 0.817. The linear regression analysis indicated that the increase in the bypass flow reduced pulsatility in the ventricle expressed in EW(Heart) as well as in EW(VAD) . Experimental results, both mock loop and animal studies, showed that the interaction between cardiac external work and H-Q performance of RBPs can be expressed by the relationships "EW(Heart) versus EW(VAD) ." The pulsatile nature of the native heart can be expressed in the area underneath the H-Q curves of RBPs EW(VAD) during left heart bypass indicating the status of the level of assistance by RBPs and the native heart function. © 2010, Copyright the Authors. Artificial Organs © 2010, International Center for Artificial Organs and

Fuzzy Expert System for Heart Attack Diagnosis

Science.gov (United States)

Hassan, Norlida; Arbaiy, Nureize; Shah, Noor Aziyan Ahmad; Afizah Afif@Afip, Zehan

2017-08-01

Heart attack is one of the serious illnesses and reported as the main killer disease. Early prevention is significant to reduce the risk of having the disease. The prevention efforts can be strengthen through awareness and education about risk factor and healthy lifestyle. Therefore the knowledge dissemination is needed to play role in order to distribute and educate public in health care management and disease prevention. Since the knowledge dissemination in medical is important, there is a need to develop a knowledge based system that can emulate human intelligence to assist decision making process. Thereby, this study utilized hybrid artificial intelligence (AI) techniques to develop a Fuzzy Expert System for Diagnosing Heart Attack Disease (HAD). This system integrates fuzzy logic with expert system, which helps the medical practitioner and people to predict the risk and as well as diagnosing heart attack based on given symptom. The development of HAD is expected not only providing expert knowledge but potentially become one of learning resources to help citizens to develop awareness about heart-healthy lifestyle.

Biomedical engineering support. Annual progress report, August 15, 1974--August 14, 1975. [/sup 238/PuO/sub 2/-powered mechanical heart

Energy Technology Data Exchange (ETDEWEB)

Kolff, W.J.; Smith, L.M.; Sandquist, G.M.

1975-01-01

The major responsibility of the Institute for Biomedical Engineering at the University of Utah under the ERDA Artificial Heart Program has been to provide in vitro and in vivo experimental data and evaluation of the anatomical fitting, accommodation, performance and adequacy of the artificial heart system and its components as they are developed in the ERDA Program and provided to the Institute for study. The Institute also has the responsibility of designing, constructing and testing the blood handling components of the Blood Pump and insuring reliability, durability and satisfactory performance of these system components. During the reporting period, nine total heart replacement experiments were performed in calves using the ERDA Blood Pump powered by an electric motor implanted in the abdomen. Results of the experiments are given. Ultimately the mechanical heart will be powered by a radioisotope heat source. (TFD)

Anti-tick monoclonal antibody applied by artificial capillary feeding in Rhipicephalus (Boophilus) microplus females.

Science.gov (United States)

Gonsioroski, Andressa Varella; Bezerra, Isis Abel; Utiumi, Kiyoko Uemura; Driemeier, David; Farias, Sandra Estrazulas; da Silva Vaz, Itabajara; Masuda, Aoi

2012-04-01

The tick Rhipicephalus microplus is an ectoparasite harmful to livestock, a vector of disease agents that affects meat and milk production. However, resistance to acaricides reflects the need for alternative tick control methods, among which vaccines have gained increasing relevance. In this scenario, monoclonal antibodies can be used to identify and characterize antigens that can be used as vaccine immunogens. Capillary tube artificial feeding of partially engorged R. microplus females with monoclonal antibodies against proteins from the gut of tick were used to test the effects of immunoglobulins in the physiology of the parasite. The results of artificial feeding showed that female ticks over 25mg and under 60 mg in weight performed better in the artificial feeding process, with a 94-168% weight increase after 24h of feeding. Results showed that artificial feeding of ticks proved to be a viable technique to study the effects of antibodies or drugs in the physiology of the parasite. One monoclonal antibody (BrBm2) induced decreased oviposition. Moreover, the antigen recognized by BrBm2 was identified as a 27-kDa protein and immunolabeled on digestive vesicles membranes of digestive cells of partially and fully engorged females. Copyright © 2012 Elsevier Inc. All rights reserved.

Favorable Effects of the Detergent and Enzyme Extraction Method for Preparing Decellularized Bovine Pericardium Scaffold for Tissue Engineered Heart Valves

NARCIS (Netherlands)

Yang, Min; Chen, Chang-Zhi; Wang, Xue-Ning; Zhu, Ya-Bin; Gu, Y. John

2009-01-01

Bovine pericardium has been extensively applied as the biomaterial for artificial heart valves and may potentially be used as a scaffold for tissue-engineered heart valves after decellularization. Although various methods of decellularization are currently available, it is unknown which method is

An example of the use of the DELPHI method: future prospects of artificial heart techniques in France; Un exemple d'utilisation de la methode DELPHI: perspectives de developpement en France des techniques de coeur artificiel

Energy Technology Data Exchange (ETDEWEB)

Derian, Jean-Claude [Commissariat a l' energie atomique et aux energies alternatives - CEA, Centre d' Etudes Nucleaires de Fontenay-aux-Roses, Departement des Programmes, Section des Etudes Economiques Generales (France); Morize, Francoise [Commissariat a l' energie atomique et aux energies alternatives - CEA, Centre d' Etudes Nucleaires de Saclay, Institut National des Sciences et Techniques Nucleaires (France); Vernejoul, Pierre de [Faculte de Medecine Necker - Enfants Malades (France); Service Hospitalier Frederic Joliot (France); Vial, Renee [Direction de Protection et Surete Radiologiques (France)

1971-07-01

The artificial heart is still only a research project surrounded by numerous uncertainties which make it very difficult to estimate, at the moment, the possibilities for future development of this technique in France. A systematic analysis of the hazards which characterize this project has been undertaken in the following report: restricting these uncertainties has required a taking into account of opinions of specialists concerned with type of research or its upshot. We have achieved this by adapting an investigation technique which is still unusual in France, the DELPHI method. This adaptation has allowed the confrontation and statistical aggregation of the opinions given by a body of a hundred experts who were consulted through a program of sequential interrogations which studied in particular, the probable date of the research issue, the clinical cases which require the use of an artificial heart, as well as the probable future needs. After having taken into account the economic constraints, we can deduce from these results the probable amount of plutonium 238 needed in the hypothesis where isotopic generator would be retained for the energetics feeding of the artificial heart [French] Le coeur artificiel n'est encore actuellement qu'un projet de recherche auquel sont attachees de nombreuses incertitudes qui rendent difficile l'appreciation des possibilites de developpement futures de cette technique en France. Une analyse systematique des aleas qui caracterisent ce projet est entreprise dans l'etude ci-apres: circonscrire ces aleas necessite la prise en compte d'opinions emanant des specialistes concernes par cette recherche ou par son issue: c'est ce qui a ete realise en adaptant une methodologie non classique en France, la methode DELPHI. Cette adaptation a permis la confrontation et l'agregation statistique des opinions fournies par un college d'une centaine d'experts consultes par un programme d'interrogations sequentielles, envisageant en particulier les

Use of Wearable Sensors and Biometric Variables in an Artificial Pancreas System

Science.gov (United States)

Turksoy, Kamuran; Monforti, Colleen; Park, Minsun; Griffith, Garett; Quinn, Laurie; Cinar, Ali

2017-01-01

An artificial pancreas (AP) computes the optimal insulin dose to be infused through an insulin pump in people with Type 1 Diabetes (T1D) based on information received from a continuous glucose monitoring (CGM) sensor. It has been recognized that exercise is a major challenge in the development of an AP system. The use of biometric physiological variables in an AP system may be beneficial for prevention of exercise-induced challenges and better glucose regulation. The goal of the present study is to find a correlation between biometric variables such as heart rate (HR), heat flux (HF), skin temperature (ST), near-body temperature (NBT), galvanic skin response (GSR), and energy expenditure (EE), 2D acceleration-mean of absolute difference (MAD) and changes in glucose concentrations during exercise via partial least squares (PLS) regression and variable importance in projection (VIP) in order to determine which variables would be most useful to include in a future artificial pancreas. PLS and VIP analyses were performed on data sets that included seven different types of exercises. Data were collected from 26 clinical experiments. Clinical results indicate ST to be the most consistently important (important for six out of seven tested exercises) variable over all different exercises tested. EE and HR are also found to be important variables over several types of exercise. We also found that the importance of GSR and NBT observed in our experiments might be related to stress and the effect of changes in environmental temperature on glucose concentrations. The use of the biometric measurements in an AP system may provide better control of glucose concentration. PMID:28272368

Physiological and Psychological Effects on High School Students of Viewing Real and Artificial Pansies

Directory of Open Access Journals (Sweden)

Miho Igarashi

2015-02-01

Full Text Available The relaxation effects of gardening have attracted attention; however, very few studies have researched its physiological effects on humans. This study aimed to clarify the physiological and psychological effects on high school students of viewing real and artificial pansies. Forty high school students (male: 19, female: 21 at Chiba Prefectural Kashiwanoha Senior High School, Japan, participated in this experiment. The subjects were presented with a visual stimulation of fresh yellow pansies (Viola x wittrockiana “Nature Clear Lemon” in a planter for 3 min. Artificial yellow pansies in a planter were used as the control. Heart rate variability was used as a physiological measurement and the modified semantic differential method was used for subjective evaluation. Compared with artificial pansies, visual stimulation with real flowers resulted in a significant decrease in the ratio of low- to high-frequency heart rate variability component, which reflects sympathetic nerve activity. In contrast, high frequency, which reflects parasympathetic nerve activity, showed no significant difference. With regard to the psychological indices, viewing real flowers resulted in “comfortable”, “relaxed”, and “natural” feelings. The findings indicate that visual stimulation with real pansies induced physiological and psychological relaxation effects in high school students.

Influences of Traction Load Shock on Artificial Partial Discharge Faults within Traction Transformer—Experimental Test for Pattern Recognition

Directory of Open Access Journals (Sweden)

Shuaibing Li

2017-10-01

Full Text Available Partial discharge (PD measurement and its pattern recognition are vital to fault diagnosis of transformers, especially to those traction substation transformers undergoing repetitive traction load shocks. This paper presents the primary factors induced by traction load shocks including high total harmonics distortion (THD, transient voltage impulse and high-temperature rise, and their effects on the feature parameters of PD. Experimental tests are conducted on six artificial PD models with these factors introduced one by one. Results reveal that the maximum PD quantity and the PD repetitive rate are favorable to be enlarged when the oil temperature exceeds 80 °C or the THD is higher than 16% with certain orders of harmonic. The decline in PD inception voltage can mainly be attributed to the transient voltage impulse. The variation in central frequency of the fast Fourier transformation (FFT spectra transformed from ultra-high frequency signals can mainly be attributed to high THD, especially when it exceeds 20%. The temperature rise has no significant influence on the FFT spectra; the transient voltage impulse, however, can result in a central frequency shift of the floating particle discharge. With the rapid development of high-speed railways, the study presented in this paper will be helpful for field PD detection and recognition of traction substation transformers in the future.

Markov decision processes in artificial intelligence

CERN Document Server

Sigaud, Olivier

2013-01-01

Markov Decision Processes (MDPs) are a mathematical framework for modeling sequential decision problems under uncertainty as well as Reinforcement Learning problems. Written by experts in the field, this book provides a global view of current research using MDPs in Artificial Intelligence. It starts with an introductory presentation of the fundamental aspects of MDPs (planning in MDPs, Reinforcement Learning, Partially Observable MDPs, Markov games and the use of non-classical criteria). Then it presents more advanced research trends in the domain and gives some concrete examples using illustr

Mechanical ventilation and the total artificial heart: optimal ventilator trigger to avoid post-operative autocycling - a case series and literature review

Directory of Open Access Journals (Sweden)

Arabia Francisco A

2010-05-01

Full Text Available Abstract Many patients with end-stage cardiomyopathy are now being implanted with Total Artificial Hearts (TAHs. We have observed individual cases of post-operative mechanical ventilator autocycling with a flow trigger, and subsequent loss of autocycling after switching to a pressure trigger. These observations prompted us to do a retrospective review of all TAH devices placed at our institution between August 2007 and May 2009. We found that in the immediate post-operative period following TAH placement, autocycling was present in 50% (5/10 of cases. There was immediate cessation of autocycling in all patients after being changed from a flow trigger of 2 L/minute to a pressure trigger of 2 cm H2O. The autocycling group was found to have significantly higher CVP values than the non-autocycling group (P = 0.012. Our data suggest that mechanical ventilator autocycling may be resolved or prevented by the use of a pressure trigger rather than a flow trigger setting in patients with TAHs who require mechanical ventilation.

Application of artificial neural network for heat transfer in porous cone

Science.gov (United States)

Athani, Abdulgaphur; Ahamad, N. Ameer; Badruddin, Irfan Anjum

2018-05-01

Heat transfer in porous medium is one of the classical areas of research that has been active for many decades. The heat transfer in porous medium is generally studied by using numerical methods such as finite element method; finite difference method etc. that solves coupled partial differential equations by converting them into simpler forms. The current work utilizes an alternate method known as artificial neural network that mimics the learning characteristics of neurons. The heat transfer in porous medium fixed in a cone is predicted using backpropagation neural network. The artificial neural network is able to predict this behavior quite accurately.

Proposed artificial recharge studies in northern Qatar

Science.gov (United States)

Kimrey, J.O.

1985-01-01

The aquifer system in northern Qatar comprises a water-table aquifer in the Rus Formation which is separated by an aquitard from a partially confined aquifer in the top of the overlying Umm er Radhuma Formation. These two aquifers are composed of limestone and dolomite of Eocene and Paleocene age and contain a fragile lens of freshwater which is heavily exploited as a source of water for agricultural irrigation. Net withdrawals are greatly in excess of total recharge, and quality of ground water is declining. Use of desalinated seawater for artificial recharge has been proposed for the area. Artificial recharge, on a large scale, could stabilize the decline in ground-water quality while allowing increased withdrawals for irrigation. The proposal appears technically feasible. Recharge should be by injection to the Umm er Radhuma aquifer whose average transmissivity is about 2,000 meters squared per day (as compared to an average of about 200 meters squared per day for the Rus aquifer). Implementation of artificial recharge should be preceded by a hydrogeologic appraisal. These studies should include test drilling, conventional aquifer tests, and recharge-recovery tests at four sites in northern Qatar. (USGS)

Artificial Consciousness or Artificial Intelligence

OpenAIRE

Spanache Florin

2017-01-01

Artificial intelligence is a tool designed by people for the gratification of their own creative ego, so we can not confuse conscience with intelligence and not even intelligence in its human representation with conscience. They are all different concepts and they have different uses. Philosophically, there are differences between autonomous people and automatic artificial intelligence. This is the difference between intelligence and artificial intelligence, autonomous versus a...

Flow Rate Through Pigtail Catheter Used for Left Heart Decompression in an Artificial Model of Extracorporeal Membrane Oxygenation Circuit.

Science.gov (United States)

Kim, Won Ho; Hong, Tae Hee; Byun, Joung Hun; Kim, Jong Woo; Kim, Sung Hwan; Moon, Sung Ho; Park, Hyun Oh; Choi, Jun Young; Yang, Jun Ho; Jang, In Seok; Lee, Chung Eun; Yun, Jeong Hee

In refractory cardiogenic shock, veno-arterial extracorporeal membrane oxygenation (ECMO) can be initiated. Although left heart decompression can be accomplished by insertion of a left atrial (LA) or left ventricular (LV) cannula using a percutaneous pigtail catheter, the venting flow rate according to catheter size and ECMO flow rate is unknown. We developed an artificial ECMO circuit. One liter saline bag with its pressure set to 20 mm Hg was connected to ECMO to mimic LV failure. A pigtail catheter was inserted into the 1 L saline bag to simulate LV unloading. For each pigtail catheter size (5-8 Fr) and ECMO flow rate (2.0-4.0 L/min), the moving distance of an air bubble that was injected through a three-way stopcock was measured in the arterial pressure line between the pigtail catheter and ECMO inflow limb. The flow rate was then calculated. We obtained the following equation to estimate the pigtail catheter flow rate.Pigtail vent catheter flow rate (ml/min) = 8×ECMOflow rate(L /min)+9×pigtail catheter size(Fr)- 57This equation would aid in designing of a further study to determine optimal venting flow rate. To achieve optimal venting flow, our equation would enable selection of an adequate catheter size.

Artificial heartbeat: design and fabrication of a biologically inspired pump

International Nuclear Information System (INIS)

Walters, Peter; Stephenson, Robert; Lewis, Amy; Stinchcombe, Andrew; Ieropoulos, Ioannis

2013-01-01

We present a biologically inspired actuator exhibiting a novel pumping action. The design of the ‘artificial heartbeat’ actuator is inspired by physical principles derived from the structure and function of the human heart. The actuator employs NiTi artificial muscles and is powered by electrical energy generated by microbial fuel cells (MFCs). We describe the design and fabrication of the actuator and report the results of tests conducted to characterize its performance. This is the first artificial muscle-driven pump to be powered by MFCs fed on human urine. Results are presented in terms of the peak pumping pressure generated by the actuator, as well as for the volume of fluid transferred, when the actuator was powered by energy stored in a capacitor bank, which was charged by 24 MFCs fed on urine. The results demonstrate the potential for the artificial heartbeat actuator to be employed as a fluid circulation pump in future generations of MFC-powered robots (‘EcoBots’) that extract energy from organic waste. We also envisage that the actuator could in the future form part of a bio-robotic artwork or ‘bio-automaton’ that could help increase public awareness of research in robotics, bio-energy and biologically inspired design. (paper)

Is our heart a well-designed pump? The heart along animal evolution.

Science.gov (United States)

Bettex, Dominique A; Prêtre, René; Chassot, Pierre-Guy

2014-09-07

A carrier system for gases and nutrients became mandatory when primitive animals grew larger and developed different organs. The first circulatory systems are peristaltic tubes pushing slowly the haemolymph into an open vascular tree without capillaries (worms). Arthropods developed contractile bulges on the abdominal aorta assisted by accessory hearts for wings or legs and by abdominal respiratory motions. Two-chamber heart (atrium and ventricle) appeared among mollusks. Vertebrates have a multi-chamber heart and a closed circulation with capillaries. Their heart has two chambers in fishes, three chambers (two atria and one ventricle) in amphibians and reptiles, and four chambers in birds and mammals. The ventricle of reptiles is partially divided in two cavities by an interventricular septum, leaving only a communication of variable size leading to a variable shunt. Blood pressure increases progressively from 15 mmHg (worms) to 170/70 mmHg (birds) according to the increase in metabolic rate. When systemic pressure exceeds 50 mmHg, a lower pressure system appears for the circulation through gills or lungs in order to improve gas exchange. A four-chamber heart allows a complete separation of systemic and pulmonary circuits. This review describes the circulatory pumping systems used in the different classes of animals, their advantages and failures, and the way they have been modified with evolution. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2014. For permissions please email: journals.permissions@oup.com.

Prologue: ventricular assist devices and total artificial hearts. A historical perspective.

Science.gov (United States)

Frazier, O H

2003-02-01

In the 1960s, when LVADs and TAHs were introduced into clinical use, researchers estimated that, with this technology, the problem of heart failure could be solved within 20 years. Unfortunately, the evolution of these devices has taken much longer than anticipated. Nevertheless, significant advances have been achieved in both cardiac assistance and replacement, and today's cardiac surgeons have a wide range of devices from which to choose (Table 4). This progress has largely been due to the support of the NHLBI, especially the Devices and Technology Division headed by John Watson, and of the devoted commitment of the investigators. Because of the long-term commitment required for both basic and clinical research, commercial medical technology companies are unable to assume this burden. Advances in mechanical circulatory support and replacement have benefited numerous patients worldwide who would otherwise have died of heart failure, and devices now exist for use as bridges to recovery, bridges to transplant, and destination therapy. The current challenge is to refine what we have and to apply these technologies to broader patient populations with maximal safety and at a reasonable cost.

Complete inhibition of creatine kinase in isolated perfused rat hearts

International Nuclear Information System (INIS)

Fossel, E.T.; Hoefeler, H.

1987-01-01

Transient exposure of an isolated isovolumic perfused rat heart to low concentrations (0.5 mM) of perfusate-born iodoacetamide resulted in complete inhibition of creatine kinase and partial inhibition of glyceraldehyde-3-phosphate dehydrogenase in the heart. At low levels of developed pressure, hearts maintained mechanical function, ATP, and creatine phosphate levels at control values. However, iodoacetamide-inhibited hearts were unable to maintain control values of end diastolic pressure or peak systolic pressure as work load increased. Global ischemia resulted in loss of all ATP without loss of creatine phosphate, indicating lack of active creatine kinase. These results indicate that isovolumic perfused rat hearts are able to maintain normal function and normal levels of high-energy phosphates without active creatine kinase at low levels of developed pressure. 31 P-NMR of the heart was carried out

Nuclear magnetic resonance zeugmatographic imaging of the heart: application to the study of ventricular septal defect

International Nuclear Information System (INIS)

Heneghan, M.A.; Biancaniello, T.M.; Heidel, E.; Peterson, S.B.; Marsh, M.J.; Lauterbur, P.C.

1982-01-01

The present work was undertaken to determine the applicability of nuclear magnetic resonance (NMR) imaging to the study of congenital heart disease. Three-dimensional proton density images of preserved lamb hearts with and without an artificially created ventricular septal defect were reconstructed and displayed in multiple planes. Sections obtained in the sagittal plane through the ventricular septum clearly showed the size, shape, and location of the defect. Results of these experiments suggest that NMR zeugmatography will become a valuable addition to existing imaging techniques for the study of congenital heart disease

Bridge to transplantation using paracorporeal biventricular assist devices or the syncardia temporary total artificial heart: is there a difference?

Science.gov (United States)

Nguyen, A; Pozzi, M; Mastroianni, C; Léger, P; Loisance, D; Pavie, A; Leprince, P; Kirsch, M

2015-06-01

Biventricular support can be achieved using paracorporeal ventricular assist devices (p-BiVAD) or the Syncardia temporary total artificial heart (t-TAH). The purpose of the present study was to compare survival and morbidity between these devices. Data from 2 French neighboring hospitals were reviewed. Between 1996 and 2009, 148 patients (67 p-BiVADs and 81 t-TAH) underwent primary, planned biventricular support. There were 128 (86%) males aged 44±13 years. Preoperatively, p-BiVAD recipients had significantly lower systolic and diastolic blood pressures, more severe hepatic cytolysis and higher white blood cell counts than t-TAH recipients. In contrast, t-TAH patients had significantly higher rates of pre-implant ECLS and hemofiltration. Mean support duration was 79±100 days for the p-BiVAD group and 71±92 for t-TAH group (P=0.6). Forty two (63%) p-BiVAD recipients were bridged to transplantation (39, 58%) or recovery (3, 5%), whereas 51 (63%) patients underwent transplantation in the t-TAH group. Death on support was similar between groups (p-BiVAD, 26 (39%); t-TAH, 30 (37%); P=0.87). Survival while on device was not significantly different between patient groups and multivariate analysis showed that only preimplant diastolic blood pressure and alanine amino-transferase levels were significant predictors of death. Post-transplant survival in the p-BiVAD group was 76±7%, 70±8%, and 58±9% at 1, 3, and 5 years after transplantation, respectively, and was similar to that of the t-TAH group (77±6%, 72±6%, and 70±7%, P=0.60). Survival while on support and up to 5 years after heart transplantation was not significantly different in patients supported by p-BiVADs or t-TAH. Multivariate analysis revealed that survival while on transplantation was not affected by the type of device implanted.

Stability Test of Partially Purified Bromelain from Pineapple (Ananas comosus (L.) Merr) Core Extract in Artificial Stomach Fluid

Science.gov (United States)

Setiasih, S.; Adimas, A. Ch. D.; Dzikria, V.; Hudiyono, S.

2018-01-01

This study aimed to isolate and purify bromelain from pineapple core (Ananascomosus (L.) Merr) accompanied by a stability test of its enzyme activity in artificial gastric juice. Purification steps start with fractionation by a precipitation method were carried out stepwise using several concentration of ammonium sulfate salt, followed by dialysis prosess and ion exchange chromatography on DEAE-cellulose column. Each step of purification produced an increasing specific activity in enzyme fraction, starting with crude extract, respectively: 0.276 U/mg; 14.591 U/mg; and 16.05 U/mg. Bromelain fraction with the highest level of purity was obtained in 50-80% ammonium sulphate fraction after dialyzed in the amount of 58.15 times compared to the crude extract. Further purification of the enzyme by DEAE-cellulose column produced bromelain which had a purity level 160-fold compared to crude enzyme. The result of bromelain stability test in artificial stomach juice by milk clotting units assay bromelain fraction have proteolytic activity in clotting milk substrate. Exposing bromelain fraction in artificial stomach juice which gave the highest core bromelain proteolytic activity was achieved at estimated volume of 0.4-0.5 mL. Exposure in a period of reaction time to artificial stomach juice that contained pepsin showed relatively stable proteolytic activity in the first 4 hours.

Totally implantable total artificial heart and ventricular assist device with multipurpose miniature electromechanical energy system.

Science.gov (United States)

Takatani, S; Orime, Y; Tasai, K; Ohara, Y; Naito, K; Mizuguchi, K; Makinouchi, K; Damm, G; Glueck, J; Ling, J

1994-01-01

A multipurpose miniature electromechanical energy system has been developed to yield a compact, efficient, durable, and biocompatible total artificial heart (TAH) and ventricular assist device (VAD). Associated controller-driver electronics were recently miniaturized and converted into hybrid circuits. The hybrid controller consists of a microprocessor and controller, motor driver, Hall sensor, and commutation circuit hybrids. The sizing study demonstrated that all these components can be incorporated in the pumping unit of the TAH and VAD, particularly in the centerpiece of the TAH and the motor housing of the VAD. Both TAH and VAD pumping units will start when their power line is connected to either the internal power pack or the external battery unit. As a redundant driving and diagnostic port, an emergency port was newly added and will be placed in subcutaneous location. In case of system failure, the skin will be cut down, and an external motor drive or a pneumatic driver will be connected to this port to run the TAH. This will minimize the circulatory arrest time. Overall efficiency of the TAH without the transcutaneous energy transmission system was 14-18% to deliver pump outputs of 4-9 L/min against the right and left afterload pressures of 25 and 100 mm Hg. The internal power requirement ranged from 6 to 13 W. The rechargeable batteries such as NiCd or NiMH with 1 AH capacity can run the TAH for 30-45 min. The external power requirement, when TETS efficiency of 75% was assumed, ranged from 8 to 18 W. The accelerated endurance test in the 42 degrees C saline bath demonstrated stable performance over 4 months. Long-term endurance and chronic animal studies will continue toward a system with 5 years durability by the year 2000.

Different approaches in Partial Least Squares and Artificial Neural Network models applied for the analysis of a ternary mixture of Amlodipine, Valsartan and Hydrochlorothiazide

Science.gov (United States)

Darwish, Hany W.; Hassan, Said A.; Salem, Maissa Y.; El-Zeany, Badr A.

2014-03-01

Different chemometric models were applied for the quantitative analysis of Amlodipine (AML), Valsartan (VAL) and Hydrochlorothiazide (HCT) in ternary mixture, namely, Partial Least Squares (PLS) as traditional chemometric model and Artificial Neural Networks (ANN) as advanced model. PLS and ANN were applied with and without variable selection procedure (Genetic Algorithm GA) and data compression procedure (Principal Component Analysis PCA). The chemometric methods applied are PLS-1, GA-PLS, ANN, GA-ANN and PCA-ANN. The methods were used for the quantitative analysis of the drugs in raw materials and pharmaceutical dosage form via handling the UV spectral data. A 3-factor 5-level experimental design was established resulting in 25 mixtures containing different ratios of the drugs. Fifteen mixtures were used as a calibration set and the other ten mixtures were used as validation set to validate the prediction ability of the suggested methods. The validity of the proposed methods was assessed using the standard addition technique.

Natural - synthetic - artificial!

DEFF Research Database (Denmark)

Nielsen, Peter E

2010-01-01

The terms "natural," "synthetic" and "artificial" are discussed in relation to synthetic and artificial chromosomes and genomes, synthetic and artificial cells and artificial life.......The terms "natural," "synthetic" and "artificial" are discussed in relation to synthetic and artificial chromosomes and genomes, synthetic and artificial cells and artificial life....

Partial anomalous pulmonary venous return in patients with pulmonary hypertension

International Nuclear Information System (INIS)

Sung, Won-kyung; Au, Virginia; Rose, Anand

2012-01-01

Anomalous pulmonary venous return is an uncommon congenital malformation, and may be partial or total. Partial anomalous pulmonary venous return (PAPVR) is more common than total anomalous pulmonary venous return, and is often associated with other congenital cardiac anomalies. Whilst many patients with PAPVR remain asymptomatic, some may present in later age with symptoms related to left-to-right shunt, right heart failure and pulmonary hypertension. We report two cases of PAPVR detected on Computed Tomography Pulmonary Angiogram (CTPA) for the work up of pulmonary hypertension. The cases demonstrate that, although uncommon, partial anomalous pulmonary venous return can be a contributing factor to pulmonary hypertension and pulmonary veins should be carefully examined when reading a CTPA study.

Artificial Intelligence, Evolutionary Computing and Metaheuristics In the Footsteps of Alan Turing

CERN Document Server

2013-01-01

Alan Turing pioneered many research areas such as artificial intelligence, computability, heuristics and pattern formation.  Nowadays at the information age, it is hard to imagine how the world would be without computers and the Internet. Without Turing's work, especially the core concept of Turing Machine at the heart of every computer, mobile phone and microchip today, so many things on which we are so dependent would be impossible. 2012 is the Alan Turing year -- a centenary celebration of the life and work of Alan Turing. To celebrate Turing's legacy and follow the footsteps of this brilliant mind, we take this golden opportunity to review the latest developments in areas of artificial intelligence, evolutionary computation and metaheuristics, and all these areas can be traced back to Turing's pioneer work. Topics include Turing test, Turing machine, artificial intelligence, cryptography, software testing, image processing, neural networks, nature-inspired algorithms such as bat algorithm and cuckoo sear...

Approximate thermodynamic state relations in partially ionized gas mixtures

International Nuclear Information System (INIS)

Ramshaw, John D.

2004-01-01

Thermodynamic state relations for mixtures of partially ionized nonideal gases are often approximated by artificially partitioning the mixture into compartments or subvolumes occupied by the pure partially ionized constituent gases, and requiring these subvolumes to be in temperature and pressure equilibrium. This intuitively reasonable procedure is easily shown to reproduce the correct thermal and caloric state equations for a mixture of neutral (nonionized) ideal gases. The purpose of this paper is to point out that (a) this procedure leads to incorrect state equations for a mixture of partially ionized ideal gases, whereas (b) the alternative procedure of requiring that the subvolumes all have the same temperature and free electron density reproduces the correct thermal and caloric state equations for such a mixture. These results readily generalize to the case of partially degenerate and/or relativistic electrons, to a common approximation used to represent pressure ionization effects, and to two-temperature plasmas. This suggests that equating the subvolume electron number densities or chemical potentials instead of pressures is likely to provide a more accurate approximation in nonideal plasma mixtures

First Report of 90-Day Support of Two Calves with a Continuous-Flow Total Artificial Heart

Science.gov (United States)

Karimov, Jamshid H.; Moazami, Nader; Kobayashi, Mariko; Sale, Shiva; Such, Kimberly; Byram, Nicole; Sunagawa, Gengo; Horvath, David; Gao, Shengqiang; Kuban, Barry; Golding, Leonard A.; Fukamachi, Kiyotaka

2015-01-01

Objective The Cleveland Clinic continuous-flow total artificial heart (CFTAH) is a compact, single-piece, valveless, pulsatile pump providing self-regulated hemodynamic output to left/right circulation. We evaluated chronic in vivo pump performance, physiologic and hemodynamic parameters, and biocompatibility of the CFTAH in a well-established calf model. Methods CFTAH pumps have been implanted in 17 calves total. Hemodynamics, pump performance, and device-related adverse events were evaluated during studies and at necropsy. Results In vivo experiments demonstrated good hemodynamic performance (pump flow, 7.3 ± 0.7 L/min; left atrial pressure [LAP], 16 ± 3 mm Hg; right atrial pressure [RAP], 17 ± 3 mm Hg; RAP-LAP difference, 1 ± 2 mm Hg; mean arterial pressure, 103 ± 7 mm Hg; arterial pulse pressure, 30 ± 11 mm Hg; pulmonary arterial pressure, 34 ± 5 mm Hg). The CFTAH has operated within design specifications and never failed. With ever-improving pump design, the implants have shown no chronic hemolysis. Three recent animals with the CFTAH recovered well, with no postoperative anticoagulation, during planned in vivo durations of 30, 90, and 90 days (last two were intended to be 90-day studies). All these longest-surviving cases showed good biocompatibility, with no thromboembolism in organs. Conclusions The current CFTAH has demonstrated reliable self-regulation of hemodynamic output and acceptable biocompatibility without anticoagulation throughout 90 days of chronic implantation in calves. Meeting these milestones is in accord with our strategy to achieve transfer of this unique technology to surgical practice, thus filling the urgent need for cardiac replacement devices as destination therapy. PMID:26173607

Optimizing risk stratification in heart failure and the selection of candidates for heart transplantation.

Science.gov (United States)

Pereira-da-Silva, Tiago; M Soares, Rui; Papoila, Ana Luísa; Pinto, Iola; Feliciano, Joana; Almeida-Morais, Luís; Abreu, Ana; Cruz Ferreira, Rui

2018-02-01

Selecting patients for heart transplantation is challenging. We aimed to identify the most important risk predictors in heart failure and an approach to optimize the selection of candidates for heart transplantation. Ambulatory patients followed in our center with symptomatic heart failure and left ventricular ejection fraction ≤40% prospectively underwent a comprehensive baseline assessment including clinical, laboratory, electrocardiographic, echocardiographic, and cardiopulmonary exercise testing parameters. All patients were followed for 60 months. The combined endpoint was cardiac death, urgent heart transplantation or need for mechanical circulatory support, up to 36 months. In the 263 enrolled patients (75% male, age 54±12 years), 54 events occurred. The independent predictors of adverse outcome were ventilatory efficiency (VE/VCO 2 ) slope (HR 1.14, 95% CI 1.11-1.18), creatinine level (HR 2.23, 95% CI 1.14-4.36), and left ventricular ejection fraction (HR 0.96, 95% CI 0.93-0.99). VE/VCO 2 slope was the most accurate risk predictor at any follow-up time analyzed (up to 60 months). The threshold of 39.0 yielded high specificity (97%), discriminated a worse or better prognosis than that reported for post-heart transplantation, and outperformed peak oxygen consumption thresholds of 10.0 or 12.0 ml/kg/min. For low-risk patients (VE/VCO 2 slope <39.0), sodium and creatinine levels and variations in end-tidal carbon dioxide partial pressure on exercise identified those with excellent prognosis. VE/VCO 2 slope was the most accurate parameter for risk stratification in patients with heart failure and reduced ejection fraction. Those with VE/VCO 2 slope ≥39.0 may benefit from heart transplantation. Copyright © 2018 Sociedade Portuguesa de Cardiologia. Publicado por Elsevier España, S.L.U. All rights reserved.

Patient with a total artificial heart maintained on outpatient dialysis while listed for combined organ transplant, a single center experience.

Science.gov (United States)

Hanna, Ramy M; Hasnain, Huma; Kamgar, Mohammad; Hanna, Mina; Minasian, Raffi; Wilson, James

2017-10-01

Advanced mechanical circulatory support is increasingly being used with more sophisticated devices that can deliver pulsatile rather than continuous flow. These devices are more portable as well, allowing patients to await cardiac transplantation in an outpatient setting. It is known that patients with renal failure are at increased risk for developing worsening acute kidney injury during implantation of a ventricular assist device (VAD) or more advanced modalities like a total artificial heart (TAH). Dealing with patients who have an implanted TAH who develop renal failure has been a challenge with the majority of such patients having to await a combined cardiac and renal transplant prior to transition to outpatient care. Protocols do exist for VAD implanted patients to be transitioned to outpatient dialysis care, but there are no reported cases of TAH patients with end stage renal disease (ESRD) being successfully transitioned to outpatient dialysis care. In this report, we identify a patient with a TAH and ESRD transitioned successfully to outpatient hemodialysis and maintained for more than 2 years, though he did not survive to transplant. It is hoped that this report will raise awareness of this possibility, and assist in the development of protocols for similar patients to be successfully transitioned to outpatient dialysis care. © 2017 International Society for Hemodialysis.

Gender differences in blood pressure regulation following artificial gravity exposure

Science.gov (United States)

Evans, Joyce; Goswami, Nandu; Kostas, Vladimir; Zhang, Qingguang; Ferguson, Connor; Moore, Fritz; Stenger, Michael, , Dr; Serrador, Jorge; W, Siqi

Introduction. Before countermeasures to space flight cardiovascular deconditioning are established, gender differences in cardiovascular responses to orthostatic stress, in general, and to orthostatic stress following exposure to artificial gravity (AG), in particular, need to be determined. Our recent determination that a short exposure to AG improved the orthostatic tolerance limit (OTL) of cardiovascularly deconditioned subjects drives the current effort to determine mechanisms of that improvement in men and in women. Methods. We determined the OTL of 9 men and 8 women following a 90 min exposure to AG compared to that following 90 min of head down bed rest (HDBR). On both days (21 days apart), subjects were made hypovolemic (low salt diet plus 20 mg intravenous furosemide) and orthostatic tolerance was determined from a combination of head up tilt and increasing lower body negative pressure until presyncope. Mean values and correlations with OTL were determined for heart rate, blood pressure, stroke volume, cardiac output, total peripheral resistance (Finometer), middle cerebral artery flow velocity (DWL), partial pressure of carbon dioxide (Novametrics) and body segmental impedance (UFI THRIM) at supine baseline, during orthostatic stress to presyncope and at supine recovery. Results. Orthostatic tolerance of these hypovolemic subjects was significantly greater following AG than following HDBR. Exposure to AG increased cardiac output in both men and women and increased stroke volume in women. In addition, AG decreased systolic blood pressure in men, but not women, and increased cerebral flow in women, but not men. In both men and women, AG exposure decreased peripheral resistance and decreased cerebrovascular resistance in women. Men’s heart rate rose more at the end of OTL on their AG, compared to their HDBR, day but women’s fell. Presyncopal stroke volume reached the same level on each day of study for both men and women. Conclusions. In the present

Development of a Simple Structured Artificial Muscle Using SMA Wire

International Nuclear Information System (INIS)

Ibuki, Ryuta; Maruyama, Shigenao; Komiya, Atsuki

2006-01-01

Artificial heart muscle using SMA wire is developed to assist weaken heartbeat. Simple structure design was adopted for large output force, large displacement and rapid cyclic motion of the actuator. The actuator was designed and fabricated from the viewpoint of heat transfer. Moving performance of the actuator was experimentally measured under 10N of loading condition. Under the maximum efficiency condition, the actuator shows cyclic motion with 1mm of displacement and time period of about 2 seconds in one cycle

Advancements in artificial heart valve disks using nano-sized thin films deposited by CVD and sol-gel techniques

International Nuclear Information System (INIS)

Kousar, Y.; Ali, N.; Neto, V.F.; Mei, S.; Gracio, J.

2003-01-01

Pyrolytic carbon (PyC) is widely used in manufacturing commercial artificial heart valve disks (HVD). Although, PyC is commonly used in HVD, it is not the best material for this application since its blood compatibility is not ideal for prolonged clinical use. As a result thrombosis often occurs and the patients are required to take anti- coagulation drugs on a regular basis in order to minimise the formation of thrombosis. However, the anti-coagulation therapy gives rise to some detrimental side effects in patients. Therefore, it is extremely urgent that newer and more technically advanced materials with better surface and bulk properties are developed. In this paper, we report the mechanical properties of PyC-HVD, namely, strength, wear resistance and coefficient of friction. The strength of the material was assessed using Brinell indentation tests. Furthermore, wear resistance and the coefficient of friction values were obtained from the pin-on-disk testing. The micro-structural properties of PyC were characterized using XRD, Raman spectroscopy and SEM analysis. Also, in this paper we report the preparation of free standing nanocrystalline diamond films (FSND) using the time-modulated chemical vapor deposition (TMCVD) process. Furthermore, the sol-gel technique was used to uniformly coat PyC-HVD with dense, nanocrystalline-titanium oxide (nc-TiO/sub 2/) coatings. The as-grown nc-TiO/sub 2/ coatings were characterized for microstructure using SEM and XRD analysis. (author)

Artificial gait in complete spinal cord injured subjects: how to assess clinical performance

Directory of Open Access Journals (Sweden)

Karla Rocha Pithon

2015-02-01

Full Text Available Objective Adapt the 6 minutes walking test (6MWT to artificial gait in complete spinal cord injured (SCI patients aided by neuromuscular electrical stimulation. Method Nine male individuals with paraplegia (AIS A participated in this study. Lesion levels varied between T4 and T12 and time post injured from 4 to 13 years. Patients performed 6MWT 1 and 6MWT 2. They used neuromuscular electrical stimulation, and were aided by a walker. The differences between two 6MWT were assessed by using a paired t test. Multiple r-squared was also calculated. Results The 6MWT 1 and 6MWT 2 were not statistically different for heart rate, distance, mean speed and blood pressure. Multiple r-squared (r2 = 0.96 explained 96% of the variation in the distance walked. Conclusion The use of 6MWT in artificial gait towards assessing exercise walking capacity is reproducible and easy to apply. It can be used to assess SCI artificial gait clinical performance.

67Ga imaging in the patients with infective endocarditis after surgery for congenital heart disease

International Nuclear Information System (INIS)

Kohata, Tohru; Ono, Yasuo; Kamiya, Tetsuro; Nishimura, Tsunehiko; Takamiya, Makoto; Yagihara, Toshikatsu

1991-01-01

67 Ga imaging was performed in sixteen patients (age: 8 m.-18 y.) who had persistent fever and positive acute phase reactants after surgery for congenital heart disease. Abnormal uptake of 67 Ga over the heart and the lungs was evaluated with a computer. Abnormal uptake of 67 Ga was observed in seven patients. Of them, three showed it in the area of peripheral pulmonary artery and the other four showed it in the area of artificial vessels for pulmonary artery reconstruction. In six patients with positive blood cultures, five showed abnormal uptake of 67 Ga and in ten patients with negative blood cultures, two showed it. Vegetation was detected with 2D-echocardiography in four patients and all of them showed abnormal uptake of 67 Ga, while in 12 patients without vegetation three showed it. In conclusion, 67 Ga imaging was useful to detect the foci of infective endocarditis or pulmonary embolism caused by the vegetation in infective endocarditis in the patients after surgery for congenital heart disease, especially in the peripheral pulmonary arteries and artificial vessels which could not be detected with 2D-echo. (author)

Artificial intelligence

CERN Document Server

Hunt, Earl B

1975-01-01

Artificial Intelligence provides information pertinent to the fundamental aspects of artificial intelligence. This book presents the basic mathematical and computational approaches to problems in the artificial intelligence field.Organized into four parts encompassing 16 chapters, this book begins with an overview of the various fields of artificial intelligence. This text then attempts to connect artificial intelligence problems to some of the notions of computability and abstract computing devices. Other chapters consider the general notion of computability, with focus on the interaction bet

Surgical approach to end-stage heart failure.

Science.gov (United States)

Klotz, Stefan; Scheld, Hans H

2011-02-01

End-stage heart failure is a challenging disease with growing incidence. With decreasing heart transplant rates worldwide organ preserving therapies become, again, of interest. The purpose of the present review is to examine the potential challenges of surgical therapies in patients with end-stage heart failure. The gold-standard for end-stage heart failure is and will be cardiac transplantation. However, due to organ shortage this therapy is limited to a few patients. Therefore implantation of ventricular assist devices (VADs) or long-term minimal-invasive partial support devices will increase. Improvements in device design with smaller devices, easier implantation techniques, and modified anticoagulation outcome and long-term success will likely improve. In addition, good quality of life as destination therapy is almost available. Organ conservation surgery (coronary artery bypass grafting and surgical ventricular restoration or surgical repair of mitral valve regurgitation) in end-stage heart failure patients could not prove the expected results. Transcatheter or minimal-invasive approaches of these therapies might become routine in the near future. Due to the overwhelming outcome rates, cardiac transplantation is the most established surgical therapy for end-stage heart failure. VAD therapy is increasing and minimized VADs might further open the market for destination therapy/permanent support.

Artificial suckling in Martina Franca donkey foals: effect on in vivo performances and carcass composition.

Science.gov (United States)

De Palo, Pasquale; Maggiolino, Aristide; Milella, Paola; Centoducati, Nicola; Papaleo, Alessandro; Tateo, Alessandra

2016-01-01

In recent years, there has been an increasing interest on donkey milk production, on its characteristics, and also on breeding techniques. Donkey milk is characterized by high economic value, although the productive level of jennies is poor. During the milking process, foals are usually separated from their dams, allowing the milk collection in the mammary gland of jennies before milking session. This takes 8 h per day of fastening period for lactating donkey foals. During this period, it could be possible to apply a partial artificial suckling system (artificial suckling during daytime and natural suckling during the night). The aim of the work is the evaluation of the effect of this innovative technique on in vivo performances and on meat production traits of Martina Franca donkey foals. Forty Martina Franca jennies with their foals were used for the trial. After colostrum assumption, 20 foals were partially artificially suckled (AS) during each day, and 20 foals were naturally suckled (NS). From 8.00 to 20.00, both groups were separated from their mothers in order to allow the milking procedures of the jennies. The AS group was in a stall equipped with an automatic calf-suckling machine. For each group, 10 foals were slaughtered at 12 months and 10 foals at 18 months. Artificial suckling system positively affected the growth rate of donkey foals, particularly in the first 6 months from birth, with higher weekly weight gain (P  0.05). Artificial suckling system permitted to extend the time of foal separation from their mothers increasing milk collection time per day, awarding fastening periods in foals.

Study of shape memory alloy fibers for the development of artificial myocardium.

Science.gov (United States)

Hassoulas, Ioannis A; Ladopoulos, Vlassios S; Kalogerakos, Paris-Dimitrios K

2010-01-01

Circulatory support devices are employed to treat heart failure. Such a device could be made from shape memory alloy (SMA) fibers. These Ni-Ti fibers contract when electric current flows through them, thus resembling artificial muscles. An artificial myocardium device made from SMA fibers can directly compress the epicardial surface of a failing heart, thus contributing to the pumping action. Unlike modern mechanical circulatory support devices, there is no blood-contacting surface to provoke thromboembolism, hemorrhage, inflammatory response or hemolysis. The experimental setup permitted a detailed study of a sample SMA fiber with great accuracy while the ambient temperature was controlled to resemble that of the human body. The current profile through the fiber was controlled (current shaping, CS) by a microcontroller and a portable computer. Parameters such as strain, contraction and relaxation velocities and the effect of ambient temperature were measured. The contraction and relaxation velocities were measured after applying various effective currents. It was found that the contraction velocity could be manipulated to reach that of the healthy myocardium through CS. On the other hand, the relaxation velocity was independent of the contraction velocity. A cardiac assist device can be made from SMA fibers. More studies need to be conducted in this direction.

Artificial Consciousness or Artificial Intelligence

Directory of Open Access Journals (Sweden)

Spanache Florin

2017-05-01

Full Text Available Artificial intelligence is a tool designed by people for the gratification of their own creative ego, so we can not confuse conscience with intelligence and not even intelligence in its human representation with conscience. They are all different concepts and they have different uses. Philosophically, there are differences between autonomous people and automatic artificial intelligence. This is the difference between intelligence and artificial intelligence, autonomous versus automatic. But conscience is above these differences because it is neither conditioned by the self-preservation of autonomy, because a conscience is something that you use to help your neighbor, nor automatic, because one’s conscience is tested by situations which are not similar or subject to routine. So, artificial intelligence is only in science-fiction literature similar to an autonomous conscience-endowed being. In real life, religion with its notions of redemption, sin, expiation, confession and communion will not have any meaning for a machine which cannot make a mistake on its own.

A PKM2 signature in the failing heart

Science.gov (United States)

Rees, Meredith L.; Subramaniam, Janani; Li, Yuanteng; Hamilton, Dale J.; Frazier, O. Howard; Taegtmeyer, Heinrich

2015-01-01

A salient feature of the failing heart is metabolic remodeling towards predominant glucose metabolism and activation of the fetal gene program. Sunitinib is a multitargeted receptor tyrosine kinase inhibitor used for the treatment of highly vascularized tumors. In diabetic patients, sunitinib significantly decreases blood glucose. However, a considerable proportion of sunitinib-treated patients develop cardiac dysfunction or failure. We asked whether sunitinib treatment results in shift towards glycolysis in the heart. Glucose uptake by the heart was increased fivefold in mice treated with sunitinib. Transcript analysis by qPCR revealed an induction of genes associated with glycolysis and reactivation of the fetal gene program. Additionally, we observed a shift in the enzyme pyruvate kinase from the adult M1 (PKM1) isoform to the fetal M2 (PKM2) isoform, a hallmark of the Warburg Effect. This novel observation led us to examine whether a similar shift occurs in human heart failure. Examination of tissue from patients with heart failure similarly displayed an induction of PKM2. Moreover, this phenomenon was partially reversed following mechanical unloading. We propose that pyruvate kinase isoform switching represents a novel feature of the fetal gene program in the failing heart. PMID:25735978

Artificial neural Network-Based modeling and monitoring of photovoltaic generator

Directory of Open Access Journals (Sweden)

H. MEKKI

2015-03-01

Full Text Available In this paper, an artificial neural network based-model (ANNBM is introduced for partial shading detection losses in photovoltaic (PV panel. A Multilayer Perceptron (MLP is used to estimate the electrical outputs (current and voltage of the photovoltaic module using the external meteorological data: solar irradiation G (W/m2 and the module temperature T (°C. Firstly, a database of the BP150SX photovoltaic module operating without any defect has been used to train the considered MLP. Subsequently, in the first case of this study, the developed model is used to estimate the output current and voltage of the PV module considering the partial shading effect. Results confirm the good ability of the ANNBM to detect the partial shading effect in the photovoltaic module with logical accuracy. The proposed strategy could also be used for the online monitoring and supervision of PV modules.

An ERP study of structural anomalies in native and semantic free artificial grammar: evidence for shared processing mechanisms.

Science.gov (United States)

Tabullo, Ángel; Sevilla, Yamila; Segura, Enrique; Zanutto, Silvano; Wainselboim, Alejandro

2013-08-21

Artificial grammars have been widely applied to the study of sequential learning in language, but few studies have directly compared the neural correlates of artificial and native grammar processing. In this study, we examined Event Related Potentials (ERPs) elicited by structural anomalies in semantic-free artificial grammar sequences and sentences in the subjects' native language (Spanish). Although ERPs differed during early stages, we observed similar posterior negativities (N400) and P600 effects in a late stage. We interpret these results as evidence of at least partially shared neural mechanisms for processing of language and artificial grammars. We suggest that in both the natural and artificial grammars, the N400 and P600 components we observed can be explained as the result of unfulfilled predictions about incoming stimuli. Copyright © 2013 Elsevier B.V. All rights reserved.

First report of 90-day support of 2 calves with a continuous-flow total artificial heart.

Science.gov (United States)

Karimov, Jamshid H; Moazami, Nader; Kobayashi, Mariko; Sale, Shiva; Such, Kimberly; Byram, Nicole; Sunagawa, Gengo; Horvath, David; Gao, Shengqiang; Kuban, Barry; Golding, Leonard A R; Fukamachi, Kiyotaka

2015-09-01

The Cleveland Clinic continuous-flow total artificial heart (CFTAH) is a compact, single-piece, valveless, pulsatile pump providing self-regulated hemodynamic output to left/right circulation. We evaluated chronic in vivo pump performance, physiologic and hemodynamic parameters, and biocompatibility of the CFTAH in a well-established calf model. CFTAH pumps have been implanted in 17 calves total. Hemodynamic parameters, pump performance, and device-related adverse events were evaluated during studies and at necropsy. In vivo experiments demonstrated good hemodynamic performance (pump flow, 7.3 ± 0.7 L/min; left atrial pressure, 16 ± 3 mm Hg; right atrial pressure, 17 ± 3 mm Hg; right atrial pressure-left atrial pressure difference, 1 ± 2 mm Hg; mean arterial pressure, 103 ± 7 mm Hg; arterial pulse pressure, 30 ± 11 mm Hg; and pulmonary arterial pressure, 34 ± 5 mm Hg). The CFTAH has operated within design specifications and never failed. With ever-improving pump design, the implants have shown no chronic hemolysis. Three animals with recent CFTAH implantation recovered well, with no postoperative anticoagulation, during planned in vivo durations of 30, 90, and 90 days (last 2 were intended to be 90-day studies). All these longest-surviving cases showed good biocompatibility, with no thromboembolism in organs. The current CFTAH has demonstrated reliable self-regulation of hemodynamic output and acceptable biocompatibility without anticoagulation throughout 90 days of chronic implantation in calves. Meeting these milestones is in accord with our strategy to achieve transfer of this unique technology to human surgical practice, thus filling the urgent need for cardiac replacement devices as destination therapy. Copyright © 2015 The American Association for Thoracic Surgery. Published by Elsevier Inc. All rights reserved.

Remote artificial eyes using micro-optical circuit for long-distance 3D imaging perception.

Science.gov (United States)

Thammawongsa, Nopparat; Yupapin, Preecha P

2016-01-01

A small-scale optical device incorporated with an optical nano-antenna is designed to operate as the remote artificial eye using a tiny conjugate mirror. A basic device known as a conjugate mirror can be formed using the artificial eye device, the partially reflected light intensities from input source are interfered and the 3D whispering gallery modes formed within the ring centers, which can be modulated and propagated to the object. The image pixel is obtained at the center ring and linked with the optic nerve in the remote area via the nano-antenna, which is useful for blind people.

sup 67 Ga imaging in the patients with infective endocarditis after surgery for congenital heart disease

Energy Technology Data Exchange (ETDEWEB)

Kohata, Tohru; Ono, Yasuo; Kamiya, Tetsuro; Nishimura, Tsunehiko; Takamiya, Makoto; Yagihara, Toshikatsu [National Cardiovascular Center, Suita, Osaka (Japan)

1991-11-01

{sup 67}Ga imaging was performed in sixteen patients (age: 8 m.-18 y.) who had persistent fever and positive acute phase reactants after surgery for congenital heart disease. Abnormal uptake of {sup 67}Ga over the heart and the lungs was evaluated with a computer. Abnormal uptake of {sup 67}Ga was observed in seven patients. Of them, three showed it in the area of peripheral pulmonary artery and the other four showed it in the area of artificial vessels for pulmonary artery reconstruction. In six patients with positive blood cultures, five showed abnormal uptake of {sup 67}Ga and in ten patients with negative blood cultures, two showed it. Vegetation was detected with 2D-echocardiography in four patients and all of them showed abnormal uptake of {sup 67}Ga, while in 12 patients without vegetation three showed it. In conclusion, {sup 67}Ga imaging was useful to detect the foci of infective endocarditis or pulmonary embolism caused by the vegetation in infective endocarditis in the patients after surgery for congenital heart disease, especially in the peripheral pulmonary arteries and artificial vessels which could not be detected with 2D-echo. (author).

Inteligência artificial aplicada à Zootecnia Artificial intelligence in Animal Science

Directory of Open Access Journals (Sweden)

Ernane José Xavier Costa

2009-07-01

Full Text Available Os sistemas biológicos são surpreendentemente flexíveis pra processar informação proveniente do mundo real. Alguns organismos biológicos possuem uma unidade central de processamento denominada de cérebro. O cérebro humano consiste de 10(11 neurônios e realiza processamento inteligente de forma exata e subjetiva. A Inteligência Artificial (IA tenta trazer para o mundo da computação digital a heurística dos sistemas biológicos de várias maneiras, mas, ainda resta muito para que isso seja concretizado. No entanto, algumas técnicas como Redes neurais artificiais e lógica fuzzy tem mostrado efetivas para resolver problemas complexos usando a heurística dos sistemas biológicos. Recentemente o numero de aplicação dos métodos da IA em sistemas zootécnicos tem aumentado significativamente. O objetivo deste artigo é explicar os princípios básicos da resolução de problemas usando heurística e demonstrar como a IA pode ser aplicada para construir um sistema especialista para resolver problemas na área de zootecnia.Biological systems are surprising flexible in processing information in the real world. Some biological organisms have a central unit processing named brain. The human's brain, consisting of 10(11 neurons, realizes intelligent information processing based on exact and commonsense reasoning. Artificial intelligence (AI has been trying to implement biological intelligence in computers in various ways, but is still far from real one. Therefore, there are approaches like Symbolic AI, Artificial Neural Network and Fuzzy system that partially successful in implementing heuristic from biological intelligence. Many recent applications of these approaches show an increased interest in animal science research. The main goal of this article is to explain the principles of heuristic problem-solving approach and to demonstrate how they can be applied to building knowledge-based systems for animal science problem solving.

The influx of amino acids into the heart of the rat

International Nuclear Information System (INIS)

Banos, G.; Moorhouse, S.R.; Pratt, O.E.; Wilson, P.A.; Daniel, P.M.

1978-01-01

The influx of nineteen amino acids into the heart of the living rat was studied by a method specially devised for experiments under controlled conditions in vivo. When, in separate experiments, the concentration of each amino acid in turn was artificially raised in the circulation, the influx of that amino acid into the heart increased. The data indicate that at least ten of these amino acids enter the heart in vivo by means of saturable carrier-mediated transport systems. The transport rates conform, at least approximately, to Michaelis kinetics and the transport systems are clearly, in the case of many amino acids, active, i.e. energy-dependent. The amino acids which were studied had rates of influx into the heart which differed from each other over a range of more than 10 to 1, even when allowances were made for the differences in their concentration in the circulating blood. These differences in influx were not related to such factors as the molecular size of the individual amino acids. The amino acids which have a high influx into the heart are mainly those which are needed either to re-synthesize contractile protein or as oxidizable substrates. (author)

Artificial recharge of groundwater and its role in water management

Science.gov (United States)

Kimrey, J.O.

1989-01-01

This paper summarizes and discusses the various aspects and methods of artificial recharge with particular emphasis on its uses and potential role in water management in the Arabian Gulf region. Artificial recharge occurs when man's activities cause more water to enter an aquifer, either under pumping or non-pumping conditions, than otherwise would enter the aquifer. Use of artificial recharge can be a practical means of dealing with problems of overdraft of groundwater. Methods of artificial recharge may be grouped under two broad types: (a) water spreading techniques, and (b) well-injection techniques. Successful use of artificial recharge requires a thorough knowledge of the physical and chemical characteristics of the aquifier system, and extensive onsite experimentation and tailoring of the artificial-recharge technique to fit the local or areal conditions. In general, water spreading techniques are less expensive than well injection and large quantities of water can be handled. Water spreading can also result in significant improvement in quality of recharge waters during infiltration and movement through the unsaturated zone and the receiving aquifer. In comparison, well-injection techniques are often used for emplacement of fresh recharge water into saline aquifer zones to form a manageable lens of fresher water, which may later be partially withdrawn for use or continue to be maintained as a barrier against salt-water encroachment. A major advantage in use of groundwater is its availability, on demand to wells, from a natural storage reservoir that is relatively safe from pollution and from damage by sabotage or other hostile action. However, fresh groundwater occurs only in limited quantities in most of the Arabian Gulf region; also, it is heavily overdrafted in many areas, and receives very little natural recharge. Good use could be made of artificial recharge by well injection in replenishing and managing aquifers in strategic locations if sources of

Charged particle reflection by a planar artificially structured boundary with electrostatic plugging

Directory of Open Access Journals (Sweden)

R. M. Hedlof

2017-11-01

Full Text Available A classical trajectory Monte Carlo simulation is used to investigate an artificially structured boundary for confinement and control of charged particles. The artificially structured boundary considered here incorporates a planar sequence of conducting wires, where adjacent wires carry current in opposite directions. Such a configuration creates a sequence of magnetic cusps and was studied previously [C. A. Ordonez, J. Appl. Phys. 106, 024905 (2009]. The effect of introducing a sequence of electrodes for electrostatic plugging of the cusps is investigated. The results of the simulations are used to identify regions of parameter space in which particle losses through the cusps may be negligible in the single particle limit. A trap based on a cylindrical generalization of the artificially structured boundary presented here may lead to a method for confining non-neutral and partially neutralized plasmas along the edge, such that the bulk of a confined plasma is effectively free of externally applied electromagnetic fields.

Surface engineering of artificial heart valve disks using nanostructured thin films deposited by chemical vapour deposition and sol-gel methods.

Science.gov (United States)

Jackson, M J; Robinson, G M; Ali, N; Kousar, Y; Mei, S; Gracio, J; Taylor, H; Ahmed, W

2006-01-01

Pyrolytic carbon (PyC) is widely used in manufacturing commercial artificial heart valve disks (HVD). Although PyC is commonly used in HVD, it is not the best material for this application since its blood compatibility is not ideal for prolonged clinical use. As a result thrombosis often occurs and the patients are required to take anti-coagulation drugs on a regular basis in order to minimize the formation of thrombosis. However, anti-coagulation therapy gives rise to some detrimental side effects in patients. Therefore, it is extremely urgent that newer and more technically advanced materials with better surface and bulk properties are developed. In this paper, we report the mechanical properties of PyC-HVD, i.e. strength, wear resistance and coefficient of friction. The strength of the material was assessed using Brinell indentation tests. Furthermore, wear resistance and coefficient of friction values were obtained from pin-on-disk testing. The micro-structural properties of PyC were characterized using XRD, Raman spectroscopy and SEM analysis. Also in this paper we report the preparation of freestanding nanocrystalline diamond films (FSND) using the time-modulated chemical vapour deposition (TMCVD) process. Furthermore, the sol-gel technique was used to uniformly coat PyC-HVD with dense, nanocrystalline-titanium oxide (nc-TiO2) coatings. The as-grown nc-TiO2 coatings were characterized for microstructure using SEM and XRD analysis.

Tracing artificial trans fat in popular foods in Europe

DEFF Research Database (Denmark)

Stender, Steen; Astrup, Arne; Dyerberg, Jørn

2014-01-01

OBJECTIVE: To minimise the intake of industrial artificial trans fat (I-TF), nearly all European countries rely on food producers to voluntarily reduce the I-TF content in food. The objective of this study was to investigate the effect of this strategy on I-TF content in prepackaged biscuits...... countries in Europe still consume I-TF in amounts that increase their risk of coronary heart disease. Under current European Union (EU) legislation, the sale of products containing I-TF is legal but conflicts with the WHO recommendation to minimise the intake of I-TF. An EU-legislative limit on I-TF content...

Implant-assisted removable partial dentures: practical considerations.

Science.gov (United States)

Omura, Aaron J; Latthe, Vaibhav; Marin, Mark M; Cagna, David R

2016-01-01

At the heart of prosthodontic treatment planning must be a sound understanding of the quality and reliability of the prosthodontic foundation. Implant prosthodontics relies almost entirely on the biological and mechanical properties of an osseous foundation. Initiation of therapy in the absence of a healthy and stable prosthodontic foundation risks unintended and suboptimal treatment outcomes. For conventional removable partial denture (RPD) therapy, consideration must be given to interactions between the soft and hard tissues available to support and stabilize planned prostheses. The strategic addition of implants to the partially edentulous foundation can improve the support, comfort, and esthetics of an RPD, resulting in elevated patient satisfaction and greater therapeutic success. This article discusses aspects of diagnosis, treatment planning, clinical management, laboratory execution, and maintenance that must be considered in order to obtain optimal results with implant-assisted RPDs.

Evolution and development of ventricular septation in the amniote heart

NARCIS (Netherlands)

Poelmann, Robert E.; Gittenberger-de Groot, Adriana C.; Vicente-Steijn, Rebecca; Wisse, Lambertus J.; Bartelings, Margot M.; Everts, Sonja; Hoppenbrouwers, Tamara; Kruithof, Boudewijn P. T.; Jensen, Bjarke; de Bruin, Paul W.; Hirasawa, Tatsuya; Kuratani, Shigeru; Vonk, Freek; van de Put, Jeanne M. M. S.; de Bakker, Merijn A.; Richardson, Michael K.

2014-01-01

During cardiogenesis the epicardium, covering the surface of the myocardial tube, has been ascribed several functions essential for normal heart development of vertebrates from lampreys to mammals. We investigated a novel function of the epicardium in ventricular development in species with partial

Application of artificial neural network for medical image recognition and diagnostic decision making

International Nuclear Information System (INIS)

Asada, N.; Eiho, S.; Doi, K.; MacMahon, H.; Montner, S.M.; Giger, M.L.

1989-01-01

An artificial neural network has been applied for pattern recognition and used as a tool in an expert system. The purpose of this study is to examine the potential usefulness of the neural network approach in medical applications for image recognition and decision making. The authors designed multilayer feedforward neural networks with a back-propagation algorithm for our study. Using first-pass radionuclide ventriculograms, we attempted to identify the right and left ventricles of the heart and the lungs by training the neural network from patterns of time-activity curves. In a preliminary study, the neural network enabled identification of the lungs and heart chambers once the network was trained sufficiently by means of repeated entries of data from the same case

Deranged Cardiac Metabolism and the Pathogenesis of Heart Failure

Science.gov (United States)

2016-01-01

Activation of the neuro-hormonal system is a pathophysiological consequence of heart failure. Neuro-hormonal activation promotes metabolic changes, such as insulin resistance, and determines an increased use of non-carbohydrate substrates for energy production. Fasting blood ketone bodies as well as fat oxidation are increased in patients with heart failure, yielding a state of metabolic inefficiency. The net result is additional depletion of myocardial adenosine triphosphate, phosphocreatine and creatine kinase levels with further decreased efficiency of mechanical work. In this context, manipulation of cardiac energy metabolism by modification of substrate use by the failing heart has produced positive clinical results. The results of current research support the concept that shifting the energy substrate preference away from fatty acid metabolism and towards glucose metabolism could be an effective adjunctive treatment in patients with heart failure. The additional use of drugs able to partially inhibit fatty acids oxidation in patients with heart failure may therefore yield a significant protective effect for clinical symptoms and cardiac function improvement, and simultaneously ameliorate left ventricular remodelling. Certainly, to clarify the exact therapeutic role of metabolic therapy in heart failure, a large multicentre, randomised controlled trial should be performed. PMID:28785448

Loading Variables on Implant-Supported Distal-Extension Removable Partial Dentures: An In Vitro Pilot Study.

Science.gov (United States)

Hirata, Kiyotaka; Takahashi, Toshihito; Tomita, Akiko; Gonda, Tomoya; Maeda, Yoshinobu

2016-01-01

The aim of this study was to investigate strain on implants used for adjunctive support of distal extension removable partial dentures. An implant with strain gauges was used for testing purposes in two positions, parallel and inclined. Three loading scenarios--loading apparatus (LA), artificial teeth via cotton roll (CR), and artificial teeth (UT)--were studied and strains compared via the Kruskal-Wallis test (P=.05). Strain under CR was significantly larger than UT in parallel (P<.05). However, the opposite was observed in inclined. Strain in parallel was smallest for UT, whereas in inclined it was largest for CR.

Tissue engineering and cell-based therapy toward integrated strategy with artificial organs.

Science.gov (United States)

Gojo, Satoshi; Toyoda, Masashi; Umezawa, Akihiro

2011-09-01

Research in order that artificial organs can supplement or completely replace the functions of impaired or damaged tissues and internal organs has been underway for many years. The recent clinical development of implantable left ventricular assist devices has revolutionized the treatment of patients with heart failure. The emerging field of regenerative medicine, which uses human cells and tissues to regenerate internal organs, is now advancing from basic and clinical research to clinical application. In this review, we focus on the novel biomaterials, i.e., fusion protein, and approaches such as three-dimensional and whole-organ tissue engineering. We also compare induced pluripotent stem cells, directly reprogrammed cardiomyocytes, and somatic stem cells for cell source of future cell-based therapy. Integrated strategy of artificial organ and tissue engineering/regenerative medicine should give rise to a new era of medical treatment to organ failure.

Biological effects of implanted nuclear energy sources for artificial heart devices. Progress report, September 1, 1975--August 31, 1976. [Heat dissipation from /sup 238/Pu power sources implanted in dogs

Energy Technology Data Exchange (ETDEWEB)

Kallfelz, F.A.; Wentworth, R.A.; Cady, K.B.

1976-01-01

A total of sixty dogs were implanted with radioisotope-powered artificial heart systems producing radiation fluxes similar to that of plutonium-238, but having no associated heat, at levels of from one to seventy times the radiation flux expected from a 30-watt plutonium-238 source. Results from studies lasting up to 6 years after implantation indicate that these animals, and by inference human beings, may be able to tolerate the radiation flux from 30-watt /sup 238/Pu power sources. Results of heat dissipation studies in calves indicate that it may be possible to induce a vascularized connective tissue capsule sufficient to dissipate 30 watts of additional heat from a surface area of approximately 500 cm sq., allowing a heat flux of 0.06 watts per cm sq.

Artificial skin and patient simulator comprising the artificial skin

NARCIS (Netherlands)

2011-01-01

The invention relates to an artificial skin (10, 12, 14), and relates to a patient simulator (100) comprising the artificial skin. The artificial skin is a layered structure comprising a translucent cover layer (20) configured for imitating human or animal skin, and comprising a light emitting layer

Immunohistochemical Distribution of Serum Proteins in Living Mouse Heart with In Vivo Cryotechnique

International Nuclear Information System (INIS)

Shi, Liye; Terada, Nobuo; Saitoh, Yurika; Saitoh, Sei; Ohno, Shinichi

2011-01-01

In vivo cryotechnique (IVCT), which immediately cryofixes target organs in situ, was used to clarify the morphological features of beating heart tissue of living mice. IVCT was performed for diastolic heart tissue under the condition of monitoring with electrocardiogram (ECG). Other mouse hearts were prepared with conventional perfusion-fixation (PF-DH) or immersion-fixation followed by dehydration (IM-DH), and quick-freezing of resected heart tissues (FQF). Immunolocalizations of albumin, immunoglobulin G1 (IgG1), intravenously injected bovine serum albumin (BSA), and connexin 43 were examined after different intervals of BSA injection. In the case of IVCT, the exact stop time of beating mouse hearts was recorded by ECG, and open blood vessels with flowing erythrocytes were observed with less artificial tissue shrinkage than with conventional preparation methods. Both albumin and BSA were well preserved in intercalated discs and t-tubules of cardiomyocytes in addition to blood vessels and interstitial matrices. IgG1 was immunolocalized in interstitial matrices of heart tissues in addition to their blood vessels. At 4 hr after BSA injection, it was immunolocalized in the intercalated discs of cardiomyocytes and lost later at 8 hr. IVCT should prove to be more useful for the morphofunctional examination of dynamically changing heart tissue than conventional preparation methods

Artificial Intelligence.

Science.gov (United States)

Information Technology Quarterly, 1985

1985-01-01

This issue of "Information Technology Quarterly" is devoted to the theme of "Artificial Intelligence." It contains two major articles: (1) Artificial Intelligence and Law" (D. Peter O'Neill and George D. Wood); (2) "Artificial Intelligence: A Long and Winding Road" (John J. Simon, Jr.). In addition, it contains two sidebars: (1) "Calculating and…

Artificial organs: recent progress in artificial hearing and vision.

Science.gov (United States)

Ifukube, Tohru

2009-01-01

Artificial sensory organs are a prosthetic means of sending visual or auditory information to the brain by electrical stimulation of the optic or auditory nerves to assist visually impaired or hearing-impaired people. However, clinical application of artificial sensory organs, except for cochlear implants, is still a trial-and-error process. This is because how and where the information transmitted to the brain is processed is still unknown, and also because changes in brain function (plasticity) remain unknown, even though brain plasticity plays an important role in meaningful interpretation of new sensory stimuli. This article discusses some basic unresolved issues and potential solutions in the development of artificial sensory organs such as cochlear implants, brainstem implants, artificial vision, and artificial retinas.

Integra artificial skin dermal regeneration templates in burn scar surgery

International Nuclear Information System (INIS)

Rexon Ngim

1999-01-01

Integra artificial skin is a porous matrix used as a permanent dermal replacement. Developed in the 1970's, it has been used successfully in the treatment of acute bums requiring full or deep partial thickness skin replacement. Three patients with burn scars received Integra Artificial Skin to resurface various areas of burn scars and also contractures. The first was a 24-year-old woman who had two pieces of Integra to resurface a forearm/elbow/wrist defect. The second was a 28-year-old woman who had two pieces of Integra to resurface a neck contracture. The third was a 44 year-old woman who had two pieces to correct severe burn contractures/ scars of her hands. The results of these three patients, probably the first time Integra was used for bum scar and contracture revision, indicate that there is a place for Integra in Burn Scar surgery. However, the basic principle of its application must be adhered to. These include excision to remove the complete scar, recreation of original size of skin defect and meticulous application of the Artificial Skin and its care post-operatively. Details of its application will be highlighted

Artificial muscle: facts and fiction.

Science.gov (United States)

Schaub, Marcus C

2011-12-19

Mechanical devices are sought to support insufficient or paralysed striated muscles including the failing heart. Nickel-titanium alloys (nitinol) present the following two properties: (i) super-elasticity, and (ii) the potential to assume different crystal structures depending on temperature and/or stress. Starting from the martensite state nitinol is able to resume the austenite form (state of low potential energy and high entropy) even against an external resistance. This one-way shape change is deployed in self-expanding vascular stents. Heating induces the force generating transformation from martensite to the austenite state while cooling induces relaxation back to the martensite state. This two-way shape change oscillating between the two states may be used in cyclically contracting support devices of silicon-coated nitinol wires. Such a contractile device sutured to the right atrium has been tested in vitro in a bench model and in vivo in sheep. The contraction properties of natural muscles, specifically of the myocardium, and the tight correlation with ATP production by oxidative phosphorylation in the mitochondria is briefly outlined. Force development by the nitinol device cannot be smoothly regulated as in natural muscle. Its mechanical impact is forced onto the natural muscle regardless of the actual condition with regard to metabolism and Ca2+-homeostasis. The development of artificial muscle on the basis of nitinol wires is still in its infancy. The nitinol artificial muscle will have to prove its viability in the various clinical settings.

Effects of Orthostatism and Hemodialysis on Mean Heart Period and Fractal Heart Rate Properties of Chronic Renal Failure Patients.

Science.gov (United States)

Echeverría, Juan C; Infante, Oscar; Pérez-Grovas, Héctor; González, Hortensia; José, Marco V; Lerma, Claudia

2017-11-01

The aim of this work was to evaluate the short-term fractal index (α 1 ) of heart rate variability (HRV) in chronic renal failure (CRF) patients by identifying the effects of orthostatism and hemodialysis (HD), and by evaluating the correlation between α 1 and the mean RR interval from sinus beats (meanNN). HRV time series were derived from ECG data of 19 CRF patients and 20 age-matched healthy subjects obtained at supine and orthostatic positions (lasting 5 min each). Data from CRF patients were collected before and after HD. α 1 was calculated from each time series and compared by analysis of variance. Pearson's correlations between meanNN and α 1 were calculated using the data from both positions by considering three groups: healthy subjects, CRF before HD and CRF after HD. At supine position, α 1 of CRF patients after HD (1.17 ± 0.30) was larger (P renal disease condition in itself. In conclusion, as in healthy subjects, α 1 of CRF patients correlates with meanNN after HD (indicating a more irregular-like HRV behavior at slower heart rates). This suggests that CRF patients with stable blood pressure preserve a regulatory adaptability despite a shifted setting point of the heart period (i.e., higher heart rate) in comparison with healthy subjects. © 2017 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

Mind-wandering and alterations to default mode network connectivity when listening to naturalistic versus artificial sounds.

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Gould van Praag, Cassandra D; Garfinkel, Sarah N; Sparasci, Oliver; Mees, Alex; Philippides, Andrew O; Ware, Mark; Ottaviani, Cristina; Critchley, Hugo D

2017-03-27

Naturalistic environments have been demonstrated to promote relaxation and wellbeing. We assess opposing theoretical accounts for these effects through investigation of autonomic arousal and alterations of activation and functional connectivity within the default mode network (DMN) of the brain while participants listened to sounds from artificial and natural environments. We found no evidence for increased DMN activity in the naturalistic compared to artificial or control condition, however, seed based functional connectivity showed a shift from anterior to posterior midline functional coupling in the naturalistic condition. These changes were accompanied by an increase in peak high frequency heart rate variability, indicating an increase in parasympathetic activity in the naturalistic condition in line with the Stress Recovery Theory of nature exposure. Changes in heart rate and the peak high frequency were correlated with baseline functional connectivity within the DMN and baseline parasympathetic tone respectively, highlighting the importance of individual neural and autonomic differences in the response to nature exposure. Our findings may help explain reported health benefits of exposure to natural environments, through identification of alterations to autonomic activity and functional coupling within the DMN when listening to naturalistic sounds.

Half a Gift Is Not Half-Hearted: A Giver-Receiver Asymmetry in the Thoughtfulness of Partial Gifts.

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Kupor, Daniella; Flynn, Frank; Norton, Michael I

2017-12-01

Four studies document an asymmetry in givers' and receivers' evaluations of gifts: Givers underestimate the extent to which receivers perceive partial (but more desirable) gifts to be thoughtful, valuable, and worthy of appreciation. Study 1 documents this asymmetry and suggests that givers underestimate the extent to which partial gifts signal thoughtfulness to receivers. Study 2 replicates this asymmetry in the context of a real gift exchange among friends. Study 3 shows that this asymmetry arises because givers believe that purchasing partial gifts is a greater violation of gift-giving norms than do receivers, leading givers to expect that partial gifts will damage receivers' perceptions of a gift's value. Study 4 offers an intervention that induces givers to select the (partial) gifts that receivers prefer more than givers expect: framing a gift's separate components as complete units.

Sterilization of the artificial blood circulation apparatus with ozone

Energy Technology Data Exchange (ETDEWEB)

Pisarevskii, A A; Korukhov, N I.U.; Brazhnikov, E M; Konstantinova, M L; Razumovskii, S D

1982-01-01

Presented in this paper is the sterilization method of the assisted circulation unit. The method has been approved by stand testing and then applied for sterilizing the unit Ae, yeK-5 m when experimental implanting artificial heart. According to the method, ozone in concentration of 5 x 10(-3) moles/1 and with flow rate of 0,5 1/min is passed through an internal circuit of the unit during I h and 15 min. Control wash-out samples from lines have demonstrated complete sterility of the internal circuit. The method makes the sterilization process of such units much easier and may be recommended for clinical application.

The Carmat Bioprosthetic Total Artificial Heart Is Associated With Early Hemostatic Recovery and no Acquired von Willebrand Syndrome in Calves.

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Smadja, David M; Susen, Sophie; Rauch, Antoine; Cholley, Bernard; Latrémouille, Christian; Duveau, Daniel; Zilberstein, Luca; Méléard, Denis; Boughenou, Marie-Fazia; Belle, Eric Van; Gaussem, Pascale; Capel, Antoine; Jansen, Piet; Carpentier, Alain

2017-10-01

To determine hemostasis perturbations, including von Willebrand factor (VWF) multimers, after implantation of a new bioprosthetic and pulsatile total artificial heart (TAH). Preclinical study SETTING: Single-center biosurgical research laboratory. Female Charolais calves, 2-to-6 months old, weighing 102-to-122 kg. Surgical implantation of TAH through a mid-sternotomy approach. Four of 12 calves had a support duration of several days (4, 4, 8, and 10 days), allowing for the exploration of early steps of hemostasis parameters, including prothrombin time; coagulation factor levels (II, V, VII+X, and fibrinogen); and platelet count. Multimeric analysis of VWF was performed to detect a potential loss of high-molecular weight (HMW) multimers, as previously described for continuous flow rotary blood pumps. Despite the absence of anticoagulant treatment administered in the postoperative phase, no signs of coagulation activation were detected. Indeed, after an immediate postsurgery decrease of prothrombin time, platelet count, and coagulation factor levels, most parameters returned to baseline values. HMW multimers of VWF remained stable either after initiation or during days of support. Coagulation parameters and platelet count recovery in the postoperative phase of the Carmat TAH (Camat SA, Velizy Villacoublay Cedex, France) implantation in calves, in the absence of anticoagulant treatment and associated with the absence of decrease in HMW multimers of VWF, is in line with early hemocompatibility that is currently being validated in human clinical studies. Copyright © 2017 Elsevier Inc. All rights reserved.

Simulation of Blood flow in Different Configurations Design of Bi-leaflet Mechanical Heart Valve

Science.gov (United States)

Hafizah Mokhtar, N.; Abas, Aizat

2018-05-01

In this work, two different designs of artificial heart valve were devised and then compared by considering the thrombosis, wear and valve orifice to anatomical orifice ratio of each mechanical heart valve. These different design configurations of bi-leaflet mechanical heart valves model are created through the use of Computer-aided design (CAD) modelling and simulated using Computational fluid dynamic (CFD) software. Design 1 is based on existing conventional bi-leaflet valve and design 2 based on modified bi-leaflet respectively. The flow pattern, velocity, vorticity and stress analysis have been done to justify the best design. Based on results, both of the designs show a Doppler velocity index of less than the allowable standard of 2.2 which is safe to be used as replacement of the human heart valve. However, design 2 shows that it has a lower possibility of cavitation issue which will lead to lower thrombosis and provide good central flow area of blood as compared to design 1.

Plasma Catecholamines, Sweat Electrolytes and Physiological Responses of Exercised Normal, Partial Anhidrotic and Anhidrotic Horses

OpenAIRE

A. Bashir; A. Rasedee

2009-01-01

Problem statement: Malaysia imports horses from temperate countries to develop equine sports in the country. Several of these horses developed partial and complete anhidrosis. Approach: Normal, partial anhidrotic and anhidrotic horses were exercised to determine their sweating and physiological responses to exercise. The heart and respiratory rates, rectal temperature and blood samples were obtained before the horses were lunged at 10 km h-­1 for 1 h and at again at 15, 30, 45, 60 min and 24 ...

Intelligent postoperative morbidity prediction of heart disease using artificial intelligence techniques.

Science.gov (United States)

Hsieh, Nan-Chen; Hung, Lun-Ping; Shih, Chun-Che; Keh, Huan-Chao; Chan, Chien-Hui

2012-06-01

Endovascular aneurysm repair (EVAR) is an advanced minimally invasive surgical technology that is helpful for reducing patients' recovery time, postoperative morbidity and mortality. This study proposes an ensemble model to predict postoperative morbidity after EVAR. The ensemble model was developed using a training set of consecutive patients who underwent EVAR between 2000 and 2009. All data required for prediction modeling, including patient demographics, preoperative, co-morbidities, and complication as outcome variables, was collected prospectively and entered into a clinical database. A discretization approach was used to categorize numerical values into informative feature space. Then, the Bayesian network (BN), artificial neural network (ANN), and support vector machine (SVM) were adopted as base models, and stacking combined multiple models. The research outcomes consisted of an ensemble model to predict postoperative morbidity after EVAR, the occurrence of postoperative complications prospectively recorded, and the causal effect knowledge by BNs with Markov blanket concept.

Relationship between exercise heart rate and music tempo preference.

Science.gov (United States)

Karageorghis, Costas I; Jones, Leighton; Low, Daniel C

2006-06-01

The present study examined the predicted positive and linear relationship (Iwanaga, 1995a, 1995b) between exercise heart rate and music tempo preference. Initially, 128 undergraduate students (M age = 20.0 years, SD = 0.9) were surveyed to establish their three favorite music artists. A separate experimental group of 29 undergraduates (M age = 20.3 years, SD = 1.2) selected the music of a single artist from the three highest-rated artists from the earlier survey. They reported their preference for slow, medium, and fast tempo selections from each artist for three treadmill walking conditions at 40%, 60%, and 75% maximal heart rate reserve. A mixed-model 3 x 3 x 2 (Exercise Intensity x Music Tempo x Gender) analysis of variance was used to analyze the data. Results indicated there was no three-way interaction for music preference. There was, however, a significant (p Music Tempo (partial eta2 = .09) and a significant (p effect for music tempo, with large differences evident between preference for medium versus slow tempo and fast versus slow tempo music at all exercise intensities (partial eta2 = .78). Participants reported a preference for both medium and fast tempo music at low and moderate exercise intensities and for fast tempo music at high intensity. Only partial support was found for the expected linear relationship between exercise intensity and music tempo preference.

Divergent Requirements for EZH1 in Heart Development Versus Regeneration.

Science.gov (United States)

Ai, Shanshan; Yu, Xianhong; Li, Yumei; Peng, Yong; Li, Chen; Yue, Yanzhu; Tao, Ge; Li, Chuanyun; Pu, William T; He, Aibin

2017-07-07

Polycomb repressive complex 2 is a major epigenetic repressor that deposits methylation on histone H3 on lysine 27 (H3K27me) and controls differentiation and function of many cells, including cardiac myocytes. EZH1 and EZH2 are 2 alternative catalytic subunits with partial functional redundancy. The relative roles of EZH1 and EZH2 in heart development and regeneration are unknown. We compared the roles of EZH1 versus EZH2 in heart development and neonatal heart regeneration. Heart development was normal in Ezh1 -/- ( Ezh 1 knockout) and Ezh2 f/f ::cTNT -Cre ( Ezh 2 knockout) embryos. Ablation of both genes in Ezh1 -/- ::Ezh2 f/f ::cTNT -Cre embryos caused lethal heart malformations, including hypertrabeculation, compact myocardial hypoplasia, and ventricular septal defect. Epigenome and transcriptome profiling showed that derepressed genes were upregulated in a manner consistent with total EZH dose. In neonatal heart regeneration, Ezh1 was required, but Ezh2 was dispensable. This finding was further supported by rescue experiments: cardiac myocyte-restricted re-expression of EZH1 but not EZH2 restored neonatal heart regeneration in Ezh 1 knockout. In myocardial infarction performed outside of the neonatal regenerative window, EZH1 but not EZH2 likewise improved heart function and stimulated cardiac myocyte proliferation. Mechanistically, EZH1 occupied and activated genes related to cardiac growth. Our work unravels divergent mechanisms of EZH1 in heart development and regeneration, which will empower efforts to overcome epigenetic barriers to heart regeneration. © 2017 American Heart Association, Inc.

Evaluation of sympathetic nerve system activity with MIBG. Comparison with heart rate variability

International Nuclear Information System (INIS)

Kurata, Chinori; Wakabayashi, Yasushi; Shouda, Sakae; Mikami, Tadashi; Tawarahara, Kei; Sugiyama, Tsuyoshi; Nakano, Tomoyasu; Suzuki, Toshihiko.

1997-01-01

Authors attempted to elucidate the relations of plasma concentration of norepinephrine (pNE) and findings of heart rate variability and MIBG myocardial scintigraphy and evaluated cardiac autonomic nervous activity in chronic renal failure. Subjects were 211 patients with various heart diseases (coronary artery lesion, cardiomyopathy, hypertension, diabetes mellitus, renal failure and so on), 60 patients with artificial kidney due to chronic renal failure, 13 of whom were found to have coronary arterial disease by Tl myocardial scintigraphy, and 14 normal volunteers. ECG was recorded with the portable recorder for heart rate variability. Together with collection of blood for pNE measurement, myocardial scintigraphy was done at 15 and 150 min after intravenous administration of 111 MBq of MIBG for acquisition of early and delayed, respectively, images of the frontal breast. Accumulation at and elimination during the time points of MIBG were computed in cps unit. Variability of heart rate was found to have the correlation positive with MIBG delayed accumulation and negative with the elimination, and pNE, negative with heart rate variability and the delayed accumulation and positive with the elimination. Thus cardiac autonomic nervous abnormality was suggested to occur before uremic cardiomyopathy. (K.H.)

Negative transfer of heart rate control following biofeedback training: a partial replication.

Science.gov (United States)

Steptoe, A; Macready, D

1985-09-01

Ability to raise and lower heart rate (HR) on instruction was tested before and after unidirectional biofeedback training in two groups of 10 male volunteers. Instructional control was assessed in 2-min trials before training, and after 5 and 10 biofeedback trials of increasing (Group I) and decreasing (Group D) HR. The magnitude of HR elevations produced by Group D diminished following training, while modifications in Group I were unchanged. This negative transfer effect is discussed in relation to whether voluntary speeding and slowing HR reflect distinct capacities.

Heart allograft preservation : an arduous journey from the donor to the recipient

NARCIS (Netherlands)

Erasmus, Michiel; Neyrink, Arne; Sabatino, Mario; Potena, Luciano

Purpose of review The discrepancy between needs and availability of organs for heart transplantation may be partially reduced by improving the utilization of organs currently deemed unsuitable. Strategies to achieve this goal need optimization of the entire process of organ procurement,

Management of single-ventricle patients with Berlin Heart EXCOR Ventricular Assist Device: single-center experience.

Science.gov (United States)

Mackling, Tracey; Shah, Tejas; Dimas, Vivian; Guleserian, Kristine; Sharma, Mahesh; Forbess, Joseph; Ardura, Monica; Gross-Toalson, Jami; Lee, Ying; Journeycake, Janna; Barnes, Aliessa

2012-06-01

intubation, significant anasarca, and bleeding from the endotracheal tube. The family elected to withdraw support. Although both patients died prior to heart transplantation, a consistent specialized multidisciplinary team approach to the medical care of our VAD patients, consisting of cardiothoracic surgeons, heart transplant team, hematologists, pharmacists, infectious disease physicians, psychiatrists, specialty trained bedside nursing, and nurse practitioners, allowed us to manage these patients long term while awaiting heart transplantation. © 2012, Copyright the Authors. Artificial Organs © 2012, International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

Prosthetic reconstruction using gingiva-colored ceramic agent in fixed partial restoration in a 24-year old patient

Directory of Open Access Journals (Sweden)

Sadaqah NR

2012-11-01

Full Text Available Nasrin R Sadaqah,1 Jawad Ali Abu Tair21Department of Prosthodontics, 2Department of Oral and Maxillofacial Surgery, Faculty of Dentistry, Arab American University, Jenin, Palestinian TerritoryAbstract: Achieving an optimal esthetic result when replacing missing anterior teeth with a fixed partial denture can be a challenge. This is especially true when interdisciplinary treatment is needed and the patient refuses this for personal or financial reasons. Here we report a clinical case where a fixed partial denture was used to change the incisor relationship and to restore the normal tooth and gingival tissue shape, morphology, and relationship by including artificial gingiva within the fixed partial denture when the patient refused lengthy and costly multispecialty treatment options.Keywords: gingival porcelain, fixed partial denture, diagnostic waxup, provisional restoration

Novel therapeutic strategies targeting fibroblasts and fibrosis in heart disease

Science.gov (United States)

Gourdie, Robert G.; Dimmeler, Stefanie; Kohl, Peter

2016-01-01

Our understanding of cardiac fibroblast functions has moved beyond their roles in heart structure and extracellular matrix generation, and now includes contributions to paracrine, mechanical and electrical signalling during ontogenesis and normal cardiac activity. Fibroblasts have central roles in pathogenic remodelling during myocardial ischaemia, hypertension and heart failure. As key contributors to scar formation, they are crucial for tissue repair after interventions including surgery and ablation. Novel experimental approaches targeting cardiac fibroblasts are promising potential therapies for heart disease. Indeed, several existing drugs act, at least partially, through effects on cardiac connective tissue. This Review outlines the origins and roles of fibroblasts in cardiac development, homeostasis and disease; illustrates the involvement of fibroblasts in current and emerging clinical interventions; and identifies future targets for research and development. PMID:27339799

Myocardial Energetics and Heart Failure: a Review of Recent Therapeutic Trials.

Science.gov (United States)

Bhatt, Kunal N; Butler, Javed

2018-06-01

Several novel therapeutics being tested in patients with heart failure are based on myocardial energetics. This review will provide a summary of the recent trials in this area, including therapeutic options targeting various aspects of cellular and mitochondrial metabolism. Agents that improve the energetic balance in myocardial cells have the potential to improve clinical heart failure status. The most promising therapies currently under investigation in this arena include (1) elamipretide, a cardiolipin stabilizer; (2) repletion of iron deficiency with intravenous ferrous carboxymaltose; (3) coenzyme Q10; and (4) the partial adenosine receptor antagonists capadenoson and neladenosone. Myocardial energetics-based therapeutics are groundbreaking in that they utilize novel mechanisms of action to improve heart failure symptoms, without causing the adverse neurohormonal side effects associated with current guideline-based therapies. The drugs appear likely to be added to the heart failure therapy armamentarium as adjuncts to current regimens in the near future.

Aggressive behavior: an alternative model of resting heart rate and sensation seeking.

Science.gov (United States)

Wilson, Laura C; Scarpa, Angela

2014-01-01

Low resting heart rate is a well-replicated biological correlate of aggression, and sensation seeking is frequently cited as the underlying causal explanation. However, little empirical evidence supports this mediating relationship. Furthermore, the biosocial model of violence and social push theory suggest sensation seeking may moderate the relationship between heart rate and aggression. In a sample of 128 college students (82.0% White; 73.4% female), the current study tested a moderation model as an alternative relationship between resting heart rate and sensation seeking in regard to aggression. Overall, the findings partially supported an interaction effect, whereby the relationship between heart rate and aggression was moderated by sensation seeking. Specifically, the oft-noted relationship between low resting heart rate and increased aggression was found, but only for individuals with low levels of sensation seeking. If replication supports this finding, the results may better inform prevention and intervention work. © 2013 Wiley Periodicals, Inc.

INDICATIONS FOR IMPLANTATION OF A PERMANENT DRIVER’S TRANSPLANTED HEART RHYTHM AND CHOICE OF A TREATMENT ELEKTROKARDIOSTIMULYATION

Directory of Open Access Journals (Sweden)

S. J. Shemakin

2009-01-01

Full Text Available This report presents retrospective analysis of using artificial pacemaker in 16 heart transplanted patients because of developmented bradiarithmic disfunctions in the early and later posttransplanted periods. DDDR or SSIR regimens are recommended for persistened disfuncion of sinus node. DDDR regimen is recommened to prevent atrio-ventricular conduction. 

Chick embryo partial ischemia model: a new approach to study ischemia ex vivo.

Directory of Open Access Journals (Sweden)

Syamantak Majumder

Full Text Available BACKGROUND: Ischemia is a pathophysiological condition due to blockade in blood supply to a specific tissue thus damaging the physiological activity of the tissue. Different in vivo models are presently available to study ischemia in heart and other tissues. However, no ex vivo ischemia model has been available to date for routine ischemia research and for faster screening of anti-ischemia drugs. In the present study, we took the opportunity to develop an ex vivo model of partial ischemia using the vascular bed of 4(th day incubated chick embryo. METHODOLOGY/PRINCIPAL FINDINGS: Ischemia was created in chick embryo by ligating the right vitelline artery using sterile surgical suture. Hypoxia inducible factor- 1 alpha (HIF-1alpha, creatine phospho kinase-MB and reactive oxygen species in animal tissues and cells were measured to confirm ischemia in chick embryo. Additionally, ranolazine, N-acetyl cysteine and trimetazidine were administered as an anti-ischemic drug to validate the present model. Results from the present study depicted that blocking blood flow elevates HIF-1alpha, lipid peroxidation, peroxynitrite level in ischemic vessels while ranolazine administration partially attenuates ischemia driven HIF-1alpha expression. Endothelial cell incubated on ischemic blood vessels elucidated a higher level of HIF-1alpha expression with time while ranolazine treatment reduced HIF-1alpha in ischemic cells. Incubation of caprine heart strip on chick embryo ischemia model depicted an elevated creatine phospho kinase-MB activity under ischemic condition while histology of the treated heart sections evoked edema and disruption of myofibril structures. CONCLUSIONS/SIGNIFICANCE: The present study concluded that chick embryo partial ischemia model can be used as a novel ex vivo model of ischemia. Therefore, the present model can be used parallel with the known in vivo ischemia models in understanding the mechanistic insight of ischemia development and in

Appropriate control time constant in relation to characteristics of the baroreflex vascular system in 1/R control of the total artificial heart.

Science.gov (United States)

Mizuta, Sora; Saito, Itsuro; Isoyama, Takashi; Hara, Shintaro; Yurimoto, Terumi; Li, Xinyang; Murakami, Haruka; Ono, Toshiya; Mabuchi, Kunihiko; Abe, Yusuke

2017-09-01

1/R control is a physiological control method of the total artificial heart (TAH) with which long-term survival was obtained with animal experiments. However, 1/R control occasionally diverged in the undulation pump TAH (UPTAH) animal experiment. To improve the control stability of the 1/R control, appropriate control time constant in relation to characteristics of the baroreflex vascular system was investigated with frequency analysis and numerical simulation. In the frequency analysis, data of five goats in which the UPTAH was implanted were analyzed with first Fourier transform technique to examine the vasomotion frequency. The numerical simulation was carried out repeatedly changing baroreflex parameters and control time constant using the elements-expanded Windkessel model. Results of the frequency analysis showed that the 1/R control tended to diverge when very low frequency band that was an indication of the vasomotion frequency was relative high. In numerical simulation, divergence of the 1/R control could be reproduced and the boundary curves between the divergence and convergence of the 1/R control varied depending on the control time constant. These results suggested that the 1/R control tended to be unstable when the TAH recipient had high reflex speed in the baroreflex vascular system. Therefore, the control time constant should be adjusted appropriately with the individual vasomotion frequency.

Probability of detection of clinical seizures using heart rate changes.

Science.gov (United States)

Osorio, Ivan; Manly, B F J

2015-08-01

Heart rate-based seizure detection is a viable complement or alternative to ECoG/EEG. This study investigates the role of various biological factors on the probability of clinical seizure detection using heart rate. Regression models were applied to 266 clinical seizures recorded from 72 subjects to investigate if factors such as age, gender, years with epilepsy, etiology, seizure site origin, seizure class, and data collection centers, among others, shape the probability of EKG-based seizure detection. Clinical seizure detection probability based on heart rate changes, is significantly (pprobability of detecting clinical seizures (>0.8 in the majority of subjects) using heart rate is highest for complex partial seizures, increases with a patient's years with epilepsy, is lower for females than for males and is unrelated to the side of hemisphere origin. Clinical seizure detection probability using heart rate is multi-factorially dependent and sufficiently high (>0.8) in most cases to be clinically useful. Knowledge of the role that these factors play in shaping said probability will enhance its applicability and usefulness. Heart rate is a reliable and practical signal for extra-cerebral detection of clinical seizures originating from or spreading to central autonomic network structures. Copyright © 2015 British Epilepsy Association. Published by Elsevier Ltd. All rights reserved.

Valvular Heart Disease in Heart Failure

Directory of Open Access Journals (Sweden)

Giuseppe MC Rosano

2017-01-01

Full Text Available Structural valvular heart disease may be the cause of heart failure or may worsen the clinical status of patients with heart failure. Heart failure may also develop in patients treated with valve surgery. Patients with heart failure with valvular heart disease are at increased risk of events including sudden cardiac death. Before considering intervention (surgical or percutaneous all patients should receive appropriate medical and device therapy taking into account that vasodilators must be used with caution in patients with severe aortic stenosis. Numerous percutaneous and/or hybrid procedures have been introduced in the past few years and they are changing the management of valvular heart disease. In patients with heart failure and valvular heart disease, either primary or functional, the whole process of decision-making should be staged through a comprehensive evaluation of the risk– benefit ratio of different treatment strategies and should be made by a multidisciplinary ‘heart team’ with a particular expertise in valvular heart disease. The heart team should include heart failure cardiologists, cardiac surgeons/structural valve interventionists, imaging specialists, anaesthetists, geriatricians and intensive care specialists. This article will review recent developments and distill practical guidance in the management of this important heart failure co-morbidity.

Active inhibitor-1 maintains protein hyper-phosphorylation in aging hearts and halts remodeling in failing hearts.

Science.gov (United States)

Pritchard, Tracy J; Kawase, Yoshiaki; Haghighi, Kobra; Anjak, Ahmad; Cai, Wenfeng; Jiang, Min; Nicolaou, Persoulla; Pylar, George; Karakikes, Ioannis; Rapti, Kleopatra; Rubinstein, Jack; Hajjar, Roger J; Kranias, Evangelia G

2013-01-01

Impaired sarcoplasmic reticulum calcium cycling and depressed contractility are key characteristics in heart failure. Defects in sarcoplasmic reticulum function are characterized by decreased SERCA2a Ca-transport that is partially attributable to dephosphorylation of its regulator phospholamban by increased protein phosphatase 1 activity. Inhibition of protein phosphatase 1 through activation of its endogenous inhibitor-1 has been shown to enhance cardiac Ca-handling and contractility as well as protect from pathological stress remodeling in young mice. In this study, we assessed the long-term effects of inducible expression of constitutively active inhibitor-1 in the adult heart and followed function and remodeling through the aging process, up to 20 months. Mice with inhibitor-1 had normal survival and similar function to WTs. There was no overt remodeling as evidenced by measures of left ventricular end-systolic and diastolic diameters and posterior wall dimensions, heart weight to tibia length ratio, and histology. Higher phosphorylation of phospholamban at both Ser16 and Thr17 was maintained in aged hearts with active inhibitor-1, potentially offsetting the effects of elevated Ser2815-phosphorylation in ryanodine receptor, as there were no increases in arrhythmias under stress conditions in 20-month old mice. Furthermore, long-term expression of active inhibitor-1 via recombinant adeno-associated virus type 9 gene transfer in rats with pressure-overload induced heart failure improved function and prevented remodeling, associated with increased phosphorylation of phospholamban at Ser16 and Thr17. Thus, chronic inhibition of protein phosphatase 1, through increases in active inhibitor-1, does not accelerate age-related cardiomyopathy and gene transfer of this molecule in vivo improves function and halts remodeling in the long term.

Coronary Heart Disease and Emotional Intelligence.

Science.gov (United States)

Vlachaki, Chrisanthy; Maridaki Kassotaki, Katerina

2013-09-23

Coronary Heart Disease (CHD) is associated with emotions, especially negative ones, namely anxiety and depression. Emotional Intelligence (EI) is a psychological model that consists of a variety of emotional skills. The aim of the present study was to examine the relation between different dimensions of Emotional Intelligence and coronary heart disease. A total of 300 participants were studied during a 3-year period in an attempt to partially replicate and further expand a previous study conducted in Greece among CHD patients, which indicated a strong association between certain dimensions of Emotional Intelligence and the incidence of CHD. All participants completed a self-report questionnaire, assessing several aspects of Emotional Intelligence. The results showed that there is a link between the regulation of emotions and the occurrence of CHD. The evidence reported in the present study makes stronger the claim that EI plays a significant role in the occurrence of CHD.

Heart Health - Brave Heart

Science.gov (United States)

... Bar Home Current Issue Past Issues Cover Story Heart Health Brave Heart Past Issues / Winter 2009 Table of Contents For ... you can have a good life after a heart attack." Lifestyle Changes Surviving—and thriving—after such ...

Artificial intelligence

CERN Document Server

Ennals, J R

1987-01-01

Artificial Intelligence: State of the Art Report is a two-part report consisting of the invited papers and the analysis. The editor first gives an introduction to the invited papers before presenting each paper and the analysis, and then concludes with the list of references related to the study. The invited papers explore the various aspects of artificial intelligence. The analysis part assesses the major advances in artificial intelligence and provides a balanced analysis of the state of the art in this field. The Bibliography compiles the most important published material on the subject of

An artificial vector model for generating abnormal electrocardiographic rhythms

International Nuclear Information System (INIS)

Clifford, Gari D; Nemati, Shamim; Sameni, Reza

2010-01-01

We present generalizations of our previously published artificial models for generating multi-channel ECG to provide simulations of abnormal cardiac rhythms. Using a three-dimensional vectorcardiogram (VCG) formulation, we generate the normal cardiac dipole for a patient using a sum of Gaussian kernels, fitted to real VCG recordings. Abnormal beats are specified either as perturbations to the normal dipole or as new dipole trajectories. Switching between normal and abnormal beat types is achieved using a first-order Markov chain. Probability transitions can be learned from real data or modeled by coupling to heart rate and sympathovagal balance. Natural morphology changes from beat-to-beat are incorporated by varying the angular frequency of the dipole as a function of the inter-beat (RR) interval. The RR interval time series is generated using our previously described model whereby time- and frequency-domain heart rate (HR) and heart rate variability characteristics can be specified. QT-HR hysteresis is simulated by coupling the Gaussian kernels associated with the T-wave in the model with a nonlinear factor related to the local HR (determined from the last n RR intervals). Morphology changes due to respiration are simulated by introducing a rotation matrix couple to the respiratory frequency. We demonstrate an example of the use of this model by simulating HR-dependent T-wave alternans (TWA) with and without phase-switching due to ectopy. Application of our model also reveals previously unreported effects of common TWA estimation methods

Partial LVAD restores ventricular outputs and normalizes LV but not RV stress distributions in the acutely failing heart in silico

OpenAIRE

Sack, Kevin L.; Baillargeon, Brian; Acevedo-Bolton, Gabriel; Genet, Martin; Rebelo, Nuno; Kuhl, Ellen; Klein, Liviu; Weiselthaler, Georg M.; Burkhoff, Daniel; Franz, Thomas; Guccione, Julius M.

2016-01-01

Purpose: Heart failure is a worldwide epidemic that is unlikely to change as the population ages and life expectancy increases. We sought to detail significant recent improvements to the Dassault Systèmes Living Heart Model (LHM) and use the LHM to compute left ventricular (LV) and right ventricular (RV) myofiber stress distributions under the following 4 conditions: (1) normal cardiac function; (2) acute left heart failure (ALHF); (3) ALHF treated using an LV assist device (LVAD) flow rate o...

Biomass hydrolysis inhibition at high hydrogen partial pressure in solid-state anaerobic digestion.

Science.gov (United States)

Cazier, E A; Trably, E; Steyer, J P; Escudie, R

2015-08-01

In solid-state anaerobic digestion, so-called ss-AD, biogas production is inhibited at high total solids contents. Such inhibition is likely caused by a slow diffusion of dissolved reaction intermediates that locally accumulate. In this study, we investigated the effect of H2 and CO2 partial pressure on ss-AD. Partial pressure of H2 and/or CO2 was artificially fixed, from 0 to 1 557mbars for H2 and from 0 to 427mbars for CO2. High partial pressure of H2 showed a significant effect on methanogenesis, while CO2 had no impact. At high [Formula: see text] , the overall substrate degradation decreased with no accumulation of metabolites from acidogenic bacteria, indicating that the hydrolytic activity was specifically impacted. Interestingly, such inhibition did not occur when CO2 was added with H2. This result suggests that CO2 gas transfer is probably a key factor in ss-AD from biomass. Copyright © 2015 Elsevier Ltd. All rights reserved.

The modulatory effects of noradrenaline on vagal control of heart rate in the dogfish, Squalus acanthias.

Science.gov (United States)

Agnisola, Claudio; Randall, David J; Taylor, Edwin W

2003-01-01

The possible interactions between inhibitory vagal control of the heart and circulating levels of catecholamines in dogfish (Squalus acanthias) were studied using an in situ preparation of the heart, which retained intact its innervation from centrally cut vagus nerves. The response to peripheral vagal stimulation typically consisted of an initial cardiac arrest, followed by an escape beat, leading to renewed beating at a mean heart rate lower than the prestimulation rate (partial recovery). Cessation of vagal stimulation led to a transient increase in heart rate, above the prestimulation rate. This whole response was completely abolished by 10(-4) M atropine (a muscarinic cholinergic antagonist). The degree of vagal inhibition was evaluated in terms of both the initial, maximal cardiac interval and the mean heart rate during partial recovery, both expressed as a percentage of the prestimulation heart rate. The mean prestimulation heart rate of this preparation (36+/-4 beats min(-1)) was not affected by noradrenaline but was significantly reduced by 10(-4) M nadolol (a beta-adrenergic receptor antagonist), suggesting the existence of a resting adrenergic tone arising from endogenous catecholamines. The degree of vagal inhibition of heart rate varied with the rate of stimulation and was increased by the presence of 10(-8) M noradrenaline (the normal in vivo level in routinely active fish), while 10(-7) M noradrenaline (the in vivo level measured in disturbed or deeply hypoxic fish) reduced the cardiac response to vagal stimulation. In the presence of 10(-7) M noradrenaline, 10(-4) M nadolol further reduced the vagal response, while 10(-4) M nadolol + 10(-4) M phentolamine had no effect, indicating a complex interaction between adrenoreceptors, possibly involving presynaptic modulation of vagal inhibition.

The future of the artificial kidney: moving towards wearable and miniaturized devices.

Science.gov (United States)

Ronco, C; Davenport, A; Gura, V

2011-01-01

New directions in dialysis research include cheaper treatments, home based therapies and simpler methods of blood purification. These objectives may be probably obtained with innovations in the field of artificial kidney through the utilization of new disciplines such as miniaturization, microfluidics, nanotechnology. This research may lead to a new era of dialysis in which the new challenges are transportability, wearability and why not the possibility to develop implantable devices. Although we are not there yet, a new series of papers have recently been published disclosing interesting and promising results on the application of wearable ultrafiltration systems (WUF) and wearable artificial kidneys (WAK). Some of them use extracorporeal blood cleansing as a method of blood purification while others use peritoneal dialysis as a treatment modality (ViWAK and AWAK.) A special mention deserves the wearable/portable ultrafiltration system for the therapy of overhydration and congestive heart failure (WAKMAN). This system will allow dehospitalization and treatment of patients with less comorbidity and improved tolerance. On the way to the wearable artificial kidney, new discoveries have been made such as a complete system for hemofiltration in newborns (CARPEDIEM). The neonate in fact is the typical patient who may benefit from miniaturization of the dialysis circuit. This review analyzes the rationale for such endeavour and the challenges to overcome in order to make possible a true ambulatory dialysis treatment. Some initial results with these new devices are presented. We would like to stimulate a collaborative effort to make a quantum leap in technology making the wearable artificial kidney a reality rather than a dream. 

Entertainment Capture through Heart Rate Activity in Physical Interactive Playgrounds

DEFF Research Database (Denmark)

Yannakakis, Georgios; Hallam, John; Lund, Henrik Hautop

2008-01-01

children’s physiological signals, an estimator of the degree to which games provided by the playground engage the players. For this purpose children’s heart rate (HR) signals, and their expressed preferences of how much “fun” particular game variants are, are obtained from experiments using games...... that predict reported entertainment preferences given HR features. These models are expressed as artificial neural networks and are demonstrated and evaluated on two Playware games and two control tasks requiring physical activity. The best network is able to correctly match expressed preferences in 64...

Association between resting heart rate and N-terminal pro-brain natriuretic peptide in a community-based population study in Beijing

Directory of Open Access Journals (Sweden)

Cao R

2014-12-01

Full Text Available Ruihua Cao, Yongyi Bai, Ruyi Xu, Ping Ye Department of Geriatric Cardiology, Chinese PLA General Hospital, Beijing, People’s Republic of China Background: N-terminal pro-brain natriuretic peptide (NT-proBNP is associated with an increased risk of cardiac insufficiency, which possibly leads to heart failure. However, the relationship between resting heart rate and NT-proBNP is unclear.Objective: This study focuses on this relativity between resting heart rate and plasma NT-proBNP levels in a surveyed community-based population.Methods: We evaluated the relativity between resting heart rate and plasma levels of NT-proBNP in 1,567 participants (mean age 61.0 years, range 21–96 years from a community-based population in Beijing, People’s Republic of China.Results: In patients with high resting heart rate (≥75 beats/min, NT-proBNP was higher than in those having low resting heart rate (<75 beats/min. In multiple linear stepwise regression analysis, plasma NT-proBNP was associated with resting heart rate (partial correlation coefficient, 0.82; 95% confidence interval, 0.18–1.51; P=0.011. A subsequent subgroup analysis revealed that the association between resting heart rate and plasma NT-proBNP was strengthened in subjects over 60 years old (partial correlation coefficient 1.28; 95% confidence interval, 0.49–2.36; P=0.031; while the relativity between resting heart rate and plasma NT-proBNP was not emerged in the younger subgroup (<60 years old.Conclusions: Resting heart rate was associated with plasma NT-proBNP in the elderly, which indicated a relationship between resting heart rate and cardiac function damage. Keywords: resting heart rate, N-terminal pro-brain natriuretic peptide, epidemiology, cardiac function, relationship

The HEART mobile phone trial: The partial mediating effects of self-efficacy on physical activity among cardiac patients

Directory of Open Access Journals (Sweden)

Ralph eMaddison

2014-05-01

Full Text Available Background: The ubiquitous use of mobile phones provides an ideal opportunity to deliver interventions to increase physical activity levels. Understanding potential mediators of such interventions is needed to increase their effectiveness. A recent randomized controlled trial of a mobile phone and Internet (mHealth intervention was conducted in New Zealand to determine the effectiveness on exercise capacity and physical activity levels in addition to current cardiac rehabilitation (CR services for people (n=171 with ischaemic heart disease (IHD. Significant intervention effect was observed for self-reported leisure time physical activity and walking, but not peak oxygen uptake (PVO2 at 24 weeks. There was also significant improvement in self-efficacy.Objective: To evaluate the mediating effect of self-efficacy on physical activity levels in an mHealth delivered exercise CR programme. Methods: Treatment evaluations were performed on the principle of intention to treat (ITT. Adjusted regression analyses were conducted to evaluate the main treatment effect on leisure time physical activity and walking at 24 weeks, with and without change in self-efficacy as the mediator of interest. Results: Change in self-efficacy at 24 weeks significantly mediated the treatment effect on leisure time physical activity by 13%, but only partially mediated the effect on walking by 4% at 24 weeks. Conclusion: An mHealth intervention involving text messaging and Internet support had a positive treatment effect on leisure time physical activity and walking at 24 weeks, and this effect was likely mediated through changes in self-efficacy. Future trials should examine other potential mediators related to this type of intervention.

Time-variant partial directed coherence in analysis of the cardiovascular system. A methodological study

International Nuclear Information System (INIS)

Milde, T; Schwab, K; Walther, M; Eiselt, M; Witte, H; Schelenz, C; Voss, A

2011-01-01

Time-variant partial directed coherence (tvPDC) is used for the first time in a multivariate analysis of heart rate variability (HRV), respiratory movements (RMs) and (systolic) arterial blood pressure. It is shown that respiration-related HRV components which also occur at other frequencies besides the RM frequency (= respiratory sinus arrhythmia, RSA) can be identified. These additional components are known to be an effect of the 'half-the-mean-heart-rate-dilemma' ('cardiac aliasing' CA). These CA components may contaminate the entire frequency range of HRV and can lead to misinterpretation of the RSA analysis. TvPDC analysis of simulated and clinical data (full-term neonates and sedated patients) reveals these contamination effects and, in addition, the respiration-related CA components can be separated from the RSA component and the Traube–Hering–Mayer wave. It can be concluded that tvPDC can be beneficially applied to avoid misinterpretations in HRV analyses as well as to quantify partial correlative interaction properties between RM and RSA

Artificial Leaf Based on Artificial Photosynthesis for Solar Fuel Production

Science.gov (United States)

2017-06-30

collect light energy and separate charge for developing new types of nanobiodevices to construct ”artificial leaf” from solar to fuel. or Concept of...AFRL-AFOSR-JP-TR-2017-0054 Artificial Leaf Based on Artificial Photosynthesis for Solar Fuel Production Mamoru Nango NAGOYA INSTITUTE OF TECHNOLOGY...display a currently valid OMB control number. PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ORGANIZATION. 1. REPORT DATE (DD-MM-YYYY)      30-06-2017 2

Mercury Exposure and Heart Diseases

Science.gov (United States)

Genchi, Giuseppe; Sinicropi, Maria Stefania; Carocci, Alessia; Lauria, Graziantonio; Catalano, Alessia

2017-01-01

Environmental contamination has exposed humans to various metal agents, including mercury. It has been determined that mercury is not only harmful to the health of vulnerable populations such as pregnant women and children, but is also toxic to ordinary adults in various ways. For many years, mercury was used in a wide variety of human activities. Nowadays, the exposure to this metal from both natural and artificial sources is significantly increasing. Recent studies suggest that chronic exposure, even to low concentration levels of mercury, can cause cardiovascular, reproductive, and developmental toxicity, neurotoxicity, nephrotoxicity, immunotoxicity, and carcinogenicity. Possible biological effects of mercury, including the relationship between mercury toxicity and diseases of the cardiovascular system, such as hypertension, coronary heart disease, and myocardial infarction, are being studied. As heart rhythm and function are under autonomic nervous system control, it has been hypothesized that the neurotoxic effects of mercury might also impact cardiac autonomic function. Mercury exposure could have a long-lasting effect on cardiac parasympathetic activity and some evidence has shown that mercury exposure might affect heart rate variability, particularly early exposures in children. The mechanism by which mercury produces toxic effects on the cardiovascular system is not fully elucidated, but this mechanism is believed to involve an increase in oxidative stress. The exposure to mercury increases the production of free radicals, potentially because of the role of mercury in the Fenton reaction and a reduction in the activity of antioxidant enzymes, such as glutathione peroxidase. In this review we report an overview on the toxicity of mercury and focus our attention on the toxic effects on the cardiovascular system. PMID:28085104

Mercury Exposure and Heart Diseases.

Science.gov (United States)

Genchi, Giuseppe; Sinicropi, Maria Stefania; Carocci, Alessia; Lauria, Graziantonio; Catalano, Alessia

2017-01-12

Environmental contamination has exposed humans to various metal agents, including mercury. It has been determined that mercury is not only harmful to the health of vulnerable populations such as pregnant women and children, but is also toxic to ordinary adults in various ways. For many years, mercury was used in a wide variety of human activities. Nowadays, the exposure to this metal from both natural and artificial sources is significantly increasing. Recent studies suggest that chronic exposure, even to low concentration levels of mercury, can cause cardiovascular, reproductive, and developmental toxicity, neurotoxicity, nephrotoxicity, immunotoxicity, and carcinogenicity. Possible biological effects of mercury, including the relationship between mercury toxicity and diseases of the cardiovascular system, such as hypertension, coronary heart disease, and myocardial infarction, are being studied. As heart rhythm and function are under autonomic nervous system control, it has been hypothesized that the neurotoxic effects of mercury might also impact cardiac autonomic function. Mercury exposure could have a long-lasting effect on cardiac parasympathetic activity and some evidence has shown that mercury exposure might affect heart rate variability, particularly early exposures in children. The mechanism by which mercury produces toxic effects on the cardiovascular system is not fully elucidated, but this mechanism is believed to involve an increase in oxidative stress. The exposure to mercury increases the production of free radicals, potentially because of the role of mercury in the Fenton reaction and a reduction in the activity of antioxidant enzymes, such as glutathione peroxidase. In this review we report an overview on the toxicity of mercury and focus our attention on the toxic effects on the cardiovascular system.

Mercury Exposure and Heart Diseases

Directory of Open Access Journals (Sweden)

Giuseppe Genchi

2017-01-01

Full Text Available Environmental contamination has exposed humans to various metal agents, including mercury. It has been determined that mercury is not only harmful to the health of vulnerable populations such as pregnant women and children, but is also toxic to ordinary adults in various ways. For many years, mercury was used in a wide variety of human activities. Nowadays, the exposure to this metal from both natural and artificial sources is significantly increasing. Recent studies suggest that chronic exposure, even to low concentration levels of mercury, can cause cardiovascular, reproductive, and developmental toxicity, neurotoxicity, nephrotoxicity, immunotoxicity, and carcinogenicity. Possible biological effects of mercury, including the relationship between mercury toxicity and diseases of the cardiovascular system, such as hypertension, coronary heart disease, and myocardial infarction, are being studied. As heart rhythm and function are under autonomic nervous system control, it has been hypothesized that the neurotoxic effects of mercury might also impact cardiac autonomic function. Mercury exposure could have a long-lasting effect on cardiac parasympathetic activity and some evidence has shown that mercury exposure might affect heart rate variability, particularly early exposures in children. The mechanism by which mercury produces toxic effects on the cardiovascular system is not fully elucidated, but this mechanism is believed to involve an increase in oxidative stress. The exposure to mercury increases the production of free radicals, potentially because of the role of mercury in the Fenton reaction and a reduction in the activity of antioxidant enzymes, such as glutathione peroxidase. In this review we report an overview on the toxicity of mercury and focus our attention on the toxic effects on the cardiovascular system.

Cardioscopic tricuspid valve repair in a beating ovine heart.

Science.gov (United States)

Umakanthan, Ramanan; Ghanta, Ravi K; Rangaraj, Aravind T; Lee, Lawrence S; Laurence, Rita G; Fox, John A; Mihaljevic, Tomislav; Bolman, Ralph M; Cohn, Lawrence H; Chen, Frederick Y

2009-04-01

Open heart surgery is commonly associated with cardiopulmonary bypass and cardioplegic arrest. The attendant risks of cardiopulmonary bypass may be prohibitive in high-risk patients. We present a novel endoscopic technique of performing tricuspid valve repair without cardiopulmonary bypass in a beating ovine heart. Six sheep underwent sternotomy and creation of a right heart shunt to eliminate right atrial and right ventricular blood for clear visualization. The superior vena cava, inferior vena cava, pulmonary artery, and coronary sinus were cannulated, and the blood flow from these vessels was shunted into the pulmonary artery via a roller pump. The posterior leaflet of the tricuspid valve was partially excised to create tricuspid regurgitation, which was confirmed by Doppler echocardiography. A 7.0-mm fiberoptic videoscope was inserted into the right atrium to visualize the tricuspid valve. Under cardioscopic vision, an endoscopic needle driver was inserted into the right atrium, and a concentric stitch was placed along the posterior annulus to bicuspidize the tricuspid valve. Doppler echocardiography confirmed reduction of tricuspid regurgitation. All animals successfully underwent and tolerated the surgical procedure. The right heart shunt generated a bloodless field, facilitating cardioscopic tricuspid valve visualization. The endoscopic stitch resulted in annular plication and functional tricuspid valve bicuspidization, significantly reducing the degree of tricuspid regurgitation. Cardioscopy enables less invasive, beating-heart tricuspid valve surgery in an ovine model. This technique may be useful in performing right heart surgery without cardiopulmonary bypass in high-risk patients.

[PULMONARY COMPLICATIONS IN CHILDREN, OPERATED ON FOR INBORN HEART FAILURES IN THE ARTIFICIAL BLOOD CIRCULATION ENVIRONMENT].

Science.gov (United States)

Moshkivska, L V; Nastenko, E A; Golovenko, O S; Lazoryshynets, V V

2015-11-01

The risk factors of pulmonary complications occurrence were analyzed in children, operated on for inborn heart failures in atrificial blood circulation environment. Pulmonary complications rate and the risk factors of their occurrence were analyzed.

Artificially lengthened and constricted vocal tract in vocal training methods.

Science.gov (United States)

Bele, Irene Velsvik

2005-01-01

It is common practice in vocal training to make use of vocal exercise techniques that involve partial occlusion of the vocal tract. Various techniques are used; some of them form an occlusion within the front part of the oral cavity or at the lips. Another vocal exercise technique involves lengthening the vocal tract; for example, the method of phonation into small tubes. This essay presents some studies made on the effects of various vocal training methods that involve an artificially lengthened and constricted vocal tract. The influence of sufficient acoustic impedance on vocal fold vibration and economical voice production is presented.

Generative Artificial Intelligence : Philosophy and Theory of Artificial Intelligence

NARCIS (Netherlands)

van der Zant, Tijn; Kouw, Matthijs; Schomaker, Lambertus; Mueller, Vincent C.

2013-01-01

The closed systems of contemporary Artificial Intelligence do not seem to lead to intelligent machines in the near future. What is needed are open-ended systems with non-linear properties in order to create interesting properties for the scaffolding of an artificial mind. Using post-structuralistic

Evolution and development of ventricular septation in the amniote heart.

Directory of Open Access Journals (Sweden)

Robert E Poelmann

Full Text Available During cardiogenesis the epicardium, covering the surface of the myocardial tube, has been ascribed several functions essential for normal heart development of vertebrates from lampreys to mammals. We investigated a novel function of the epicardium in ventricular development in species with partial and complete septation. These species include reptiles, birds and mammals. Adult turtles, lizards and snakes have a complex ventricle with three cava, partially separated by the horizontal and vertical septa. The crocodilians, birds and mammals with origins some 100 million years apart, however, have a left and right ventricle that are completely separated, being a clear example of convergent evolution. In specific embryonic stages these species show similarities in development, prompting us to investigate the mechanisms underlying epicardial involvement. The primitive ventricle of early embryos becomes septated by folding and fusion of the anterior ventricular wall, trapping epicardium in its core. This folding septum develops as the horizontal septum in reptiles and the anterior part of the interventricular septum in the other taxa. The mechanism of folding is confirmed using DiI tattoos of the ventricular surface. Trapping of epicardium-derived cells is studied by transplanting embryonic quail pro-epicardial organ into chicken hosts. The effect of decreased epicardium involvement is studied in knock-out mice, and pro-epicardium ablated chicken, resulting in diminished and even absent septum formation. Proper folding followed by diminished ventricular fusion may explain the deep interventricular cleft observed in elephants. The vertical septum, although indistinct in most reptiles except in crocodilians and pythonidsis apparently homologous to the inlet septum. Eventually the various septal components merge to form the completely septated heart. In our attempt to discover homologies between the various septum components we aim to elucidate the

Care to patient in heart arrest at the intensive care unit

Directory of Open Access Journals (Sweden)

Luiza Taciana Rodrigues de Moura

2012-06-01

Full Text Available Care to heart arrest patient should be performed in a systematic way, based on basic protocol as well as advanced life support. The objective of this study is to assess the knowledge of the nursing staff of an intensive care unit in relation to the recognition of heart arrest and the establishment of resuscitation according to the protocols above. It is a descriptive and quantitative study which was conducted from April to June 2011. Of the 33 professionals who participated in the study, 54.5% had not undergone previous training on the theme, 93.9% partially agreed the rates of heart arrest, and only 15.2 % got all the maneuvers in ventilating intubated patient. The low hit total demonstrates the need to update the nursing staff, with periodical theoretical-practical training, and systematic assessments of the performance of the team.

Artificial life and Piaget.

Science.gov (United States)

Mueller, Ulrich; Grobman, K H.

2003-04-01

Artificial life provides important theoretical and methodological tools for the investigation of Piaget's developmental theory. This new method uses artificial neural networks to simulate living phenomena in a computer. A recent study by Parisi and Schlesinger suggests that artificial life might reinvigorate the Piagetian framework. We contrast artificial life with traditional cognitivist approaches, discuss the role of innateness in development, and examine the relation between physiological and psychological explanations of intelligent behaviour.

Magnetic resonance imaging in patients with heart valve prostheses

International Nuclear Information System (INIS)

Bachmann, R.; Juengehuelsing, M.; Schicha, H.; Deutsch, H.J.; Sechtem, U.; Hilger, H.H.

1991-01-01

Artifical valve prostheses are often regarded as a contraindication for magnetic resonance imaging (MRI), although preliminary in vitro studies suggested, that patients with these metallic implants might safely undergo MR examination. This study reports on the experience with a group of 89 patients with 100 heart valve prostheses who were examined by spin-echo MR and gradient-echo MR. MR examination was performed in all patients without complications. The spin-echo sequence showed advantages in the depiction of anatomical structures like paravalvular abcesses. Anatomical structures adjacent to the artificial valve were clearly visivle and the metal components of the valves showes no or only small artifacts. Artifacts were accentuated when using gradient-echo sequences. Gradient-echo sequences provided valuable information regarding the presence of valvular insufficiency. Physiological valvular regurgitation was easy to differentiate from pathological paravalvular or transvalvular regurgitation. These results demonstrate that patients with artificial valve prostheses can be imaged by MR without risk and that prosthesis-induced artifacts do no interfere with image interpretation. (orig.) [de

Description, evaluation and clinical decision making according to various fetal heart rate patterns. Inter-observer and regional variability

DEFF Research Database (Denmark)

Lidegaard, O; Bøttcher, L M; Weber, Tom

1992-01-01

departments, especially between departments far apart. It is concluded that we still need a scientific clarification of which specific heart rate changes are the best predictors of fetal stress. Artificial intelligence programs for interpreting fetal cardiotocograms and ECG signals constitute one promising......At 10 Danish obstetrical departments, 116 residents (42 senior and 74 junior) participated in a study to assess inter-observer and regional variability in the description and evaluation of and clinical decision regarding 11 fetal heart rate patterns. The 11 traces included normal as well...... as pathological patterns, and normal as well as clinically asphyxiated babies. Five antepartum and six intrapartum patterns were included. A total of 1,276 descriptions and evaluations were obtained. The degree of agreement in description of fetal heart rate changes was high regarding the baseline...

Artificial sweeteners

DEFF Research Database (Denmark)

Raben, Anne Birgitte; Richelsen, Bjørn

2012-01-01

Artificial sweeteners can be a helpful tool to reduce energy intake and body weight and thereby risk for diabetes and cardiovascular diseases (CVD). Considering the prevailing diabesity (obesity and diabetes) epidemic, this can, therefore, be an important alternative to natural, calorie-containin......Artificial sweeteners can be a helpful tool to reduce energy intake and body weight and thereby risk for diabetes and cardiovascular diseases (CVD). Considering the prevailing diabesity (obesity and diabetes) epidemic, this can, therefore, be an important alternative to natural, calorie......-containing sweeteners. The purpose of this review is to summarize the current evidence on the effect of artificial sweeteners on body weight, appetite, and risk markers for diabetes and CVD in humans....

Artificial cognition architectures

CERN Document Server

Crowder, James A; Friess, Shelli A

2013-01-01

The goal of this book is to establish the foundation, principles, theory, and concepts that are the backbone of real, autonomous Artificial Intelligence. Presented here are some basic human intelligence concepts framed for Artificial Intelligence systems. These include concepts like Metacognition and Metamemory, along with architectural constructs for Artificial Intelligence versions of human brain functions like the prefrontal cortex. Also presented are possible hardware and software architectures that lend themselves to learning, reasoning, and self-evolution

MR imaging of congenital heart diseases in adolescents and adults

International Nuclear Information System (INIS)

Choe, Yeon Hyeon; Kang, I Seok; Park, Seung Woo; Lee, Heung Jae

2001-01-01

Echocardiography and catheterization angiography suffer certain limitations in the evaluation of congenital heart diseases in adults, though these are overcome by MRI, in which a wide field-of view, unlimited multiplanar imaging capability and three-dimensional contrast-enhanced MR angiography techniques are used. In adults, recently introduced fast imaging techniques provide cardiac MR images of sufficient quality and with less artifacts. Ventricular volume, ejection fraction, and vascular flow measurements, including pressure gradients and pulmonary-to-systemic flow ratio, can be calculated or obtained using fast cine MRI, phase-contrast MR flow-velocity mapping, and semiautomatic analysis software. MRI is superior to echocardiography in diagnosing partial anomalous pulmonary venous connection, unroofed coronary sinus, anomalies of the pulmonary arteries, aorta and systemic veins, complex heart diseases, and postsurgical sequelae. Biventricular function is reliably evaluated with cine MRI after repair of tetralogy of Fallot, and Senning's and Mustard's operations. MRI has an important and growing role in the morphologic and functional assessment of congenital heart diseases in adolescents and adults

Antithrombotic therapy in atrial fibrillation associated with valvular heart disease: a joint consensus document from the European Heart Rhythm Association (EHRA) and European Society of Cardiology Working Group on Thrombosis, endorsed by the ESC Working Group on Valvular Heart Disease, Cardiac Arrhythmia Society of Southern Africa (CASSA), Heart Rhythm Society (HRS), Asia Pacific Heart Rhythm Society (APHRS), South African Heart (SA Heart) Association and Sociedad Latinoamericana de Estimulación Cardíaca y Electrofisiología (SOLEACE).

Science.gov (United States)

Lip, Gregory Y H; Collet, Jean Philippe; Caterina, Raffaele de; Fauchier, Laurent; Lane, Deirdre A; Larsen, Torben B; Marin, Francisco; Morais, Joao; Narasimhan, Calambur; Olshansky, Brian; Pierard, Luc; Potpara, Tatjana; Sarrafzadegan, Nizal; Sliwa, Karen; Varela, Gonzalo; Vilahur, Gemma; Weiss, Thomas; Boriani, Giuseppe; Rocca, Bianca

2017-11-01

Atrial fibrillation (AF) is a major worldwide public health problem, and AF in association with valvular heart disease (VHD) is also common. However, management strategies for this group of patients have been less informed by randomized trials, which have largely focused on 'non-valvular AF' patients. Thrombo-embolic risk also varies according to valve lesion and may also be associated with CHA2DS2VASc score risk factor components, rather than only the valve disease being causal. Given marked heterogeneity in the definition of valvular and non-valvular AF and variable management strategies, including non-vitamin K antagonist oral anticoagulants (NOACs) in patients with VHD other than prosthetic heart valves or haemodynamically significant mitral valve disease, there is a need to provide expert recommendations for professionals participating in the care of patients presenting with AF and associated VHD. To address this topic, a Task Force was convened by the European Heart Rhythm Association (EHRA) and European Society of Cardiology (ESC) Working Group on Thrombosis, with representation from the ESC Working Group on Valvular Heart Disease, Heart Rhythm Society (HRS), Asia Pacific Heart Rhythm Society (APHRS), South African Heart (SA Heart) Association and Sociedad Latinoamericana de Estimulación Cardíaca y Electrofisiología (SOLEACE) with the remit to comprehensively review the published evidence, and to publish a joint consensus document on the management of patients with AF and associated VHD, with up-to-date consensus recommendations for clinical practice for different forms of VHD. This consensus document proposes that the term 'valvular AF' is outdated and given that any definition ultimately relates to the evaluated practical use of oral anticoagulation (OAC) type, we propose a functional Evaluated Heartvalves, Rheumatic or Artificial (EHRA) categorization in relation to the type of OAC use in patients with AF, as follows: (i) EHRA Type 1 VHD, which refers

Artificial Disc Replacement

Science.gov (United States)

... Spondylolisthesis BLOG FIND A SPECIALIST Treatments Artificial Disc Replacement (ADR) Patient Education Committee Jamie Baisden The disc ... Disc An artificial disc (also called a disc replacement, disc prosthesis or spine arthroplasty device) is a ...

Preattentive processing of heart cues and the perception of heart symptoms in congenital heart disease.

Science.gov (United States)

Karsdorp, Petra A; Kindt, Merel; Everaerd, Walter; Mulder, Barbara J M

2007-08-01

The present study was aimed at clarifying whether preattentive processing of heart cues results in biased perception of heart sensations in patients with congenital heart disease (ConHD) who are also highly trait anxious. Twenty-six patients with ConHD and 22 healthy participants categorized heart-related (heart rate) or neutral sensations (constant vibration) as either heart or neutral. Both sensations were evoked using a bass speaker that was attached on the chest of the participant. Before each physical sensation, a subliminal heart-related or neutral prime was presented. Biased perception of heart-sensations would become evident by a delayed categorization of the heart-related sensations. In line with the prediction, a combination of high trait anxiety and ConHD resulted in slower responses after a heart-related sensation that was preceded by a subliminal heart cue. Preattentive processing of harmless heart cues may easily elicit overperception of heart symptoms in highly trait anxious patients with ConHD.

Computer Aided Automatic Control - CAAC artificial intelligence block

Energy Technology Data Exchange (ETDEWEB)

Balate, J.; Chramcov, B.; Princ, M. [Brno Univ. of Technology (Czech Republic). Faculty of Technology in Zlin

2000-07-01

The aim of the plan to build up the system CAAC - Computer Aided Automatic Control is to create modular setup of partial computing programs including theory of automatic control, algorithms of programs for processing signals and programs of control algorithms. To approach its informative contents to students and professional public the CAAC system utilizes Internet services http in the form of WWW pages. The CAAC system is being processed at the Institute of Automation and Control Technique of the Faculty of Technology in Zlin of the Brno University of Technology and is determined particularly for pedagogic purposes. Recently also the methods of artificial intelligence have been included to the open CAAC system and that is comprised in this article. (orig.)

Design of a heart rate controller for treadmill exercise using a recurrent fuzzy neural network.

Science.gov (United States)

Lu, Chun-Hao; Wang, Wei-Cheng; Tai, Cheng-Chi; Chen, Tien-Chi

2016-05-01

In this study, we developed a computer controlled treadmill system using a recurrent fuzzy neural network heart rate controller (RFNNHRC). Treadmill speeds and inclines were controlled by corresponding control servo motors. The RFNNHRC was used to generate the control signals to automatically control treadmill speed and incline to minimize the user heart rate deviations from a preset profile. The RFNNHRC combines a fuzzy reasoning capability to accommodate uncertain information and an artificial recurrent neural network learning process that corrects for treadmill system nonlinearities and uncertainties. Treadmill speeds and inclines are controlled by the RFNNHRC to achieve minimal heart rate deviation from a pre-set profile using adjustable parameters and an on-line learning algorithm that provides robust performance against parameter variations. The on-line learning algorithm of RFNNHRC was developed and implemented using a dsPIC 30F4011 DSP. Application of the proposed control scheme to heart rate responses of runners resulted in smaller fluctuations than those produced by using proportional integra control, and treadmill speeds and inclines were smoother. The present experiments demonstrate improved heart rate tracking performance with the proposed control scheme. The RFNNHRC scheme with adjustable parameters and an on-line learning algorithm was applied to a computer controlled treadmill system with heart rate control during treadmill exercise. Novel RFNNHRC structure and controller stability analyses were introduced. The RFNNHRC were tuned using a Lyapunov function to ensure system stability. The superior heart rate control with the proposed RFNNHRC scheme was demonstrated with various pre-set heart rates. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Artificial life and life artificialization in Tron

Directory of Open Access Journals (Sweden)

Carolina Dantas Figueiredo

2012-12-01

Full Text Available Cinema constantly shows the struggle between the men and artificial intelligences. Fiction, and more specifically fiction films, lends itself to explore possibilities asking “what if?”. “What if”, in this case, is related to the eventual rebellion of artificial intelligences, theme explored in the movies Tron (1982 and Tron Legacy (2010 trat portray the conflict between programs and users. The present paper examines these films, observing particularly the possibility programs empowering. Finally, is briefly mentioned the concept of cyborg as a possibility of response to human concerns.

Experimental study on the effect of an artificial cardiac valve on the left ventricular flow

Science.gov (United States)

Wang, JiangSheng; Gao, Qi; Wei, RunJie; Wang, JinJun

2017-09-01

The use of artificial valves to replace diseased human heart valves is currently the main solution to address the malfunctioning of these valves. However, the effect of artificial valves on the ventricular flow still needs to be understood in flow physics. The left ventricular flow downstream of a St. Jude Medical (SJM) bileaflet mechanical heart valve (BMHV), which is a widely implanted mechanical bileaflet valve, is investigated with time-resolved particle image velocimetry in the current work. A tilting-disk valve is installed on the aortic orifice to guarantee unidirectional flow. Several post-processing tools are applied to provide combined analyses of the physics involved in the ventricular flow. The triple jet pattern that is closely related to the characteristics of the bileaflet valve is discussed in detail from both Eulerian and Lagrangian views. The effects of large-scale vortices on the transportation of blood are revealed by the combined analysis of the tracking of Lagrangian coherent structures, the Eulerian monitoring of the shear stresses, and virtual dye visualization. It is found that the utilization of the SJM BMHV complicates the ventricular flow and could reduce the efficiency of blood transportation. In addition, the kinematics of the bileaflets is presented to explore the effects of flow structures on their motion. These combined analyses could elucidate the properties of SJM BMHV. Furthermore, they could provide new insights into the understanding of other complex blood flows.

Imaging technique and current status of valvular heart disease using cardiac MRI

International Nuclear Information System (INIS)

Lotz, J.; Sohns, J.M.

2013-01-01

The main indications for cardiac magnetic resonance imaging (MRI) in the evaluation of valvular heart disease are pathologies of the aortic and pulmonary valve. For mitral and tricuspid valve pathologies MRI is not the first line modality as these are usually well visualized by echocardiography. The advantages of MRI in valvular heart disease are a high reliability in the evaluation of ventricular volumes and function as well as the assessment of the perivalvular arterial or atrial structures. This reliability and the limitless access to any imaging plane partially compensates for the lower temporal and spatial resolution in comparison to echocardiography. In patients with congenital heart disease, cardiac MRI is established as a valuable diagnostic tool in daily clinical management, especially for the evaluation of pulmonary valve defects. Nevertheless, echocardiography remains the first-line diagnostic imaging tool for the foreseeable future. (orig.) [de

High-Speed Single Quantum Dot Imaging of Artificial Lipids in Live Cells Reveal Partial Hop Diffusion

DEFF Research Database (Denmark)

Lagerholm, B. Christoffer; Clausen, Mathias P.; Christensen, Eva Arnspang

2010-01-01

-81). These findings have yet to be independently confirmed. In this work, we show that high-speed single particle tracking with quantum dots(QDs)and using a standard wide-field fluorescence microscope and an EMCCD is possible at image acquisition rates of up to ~2000 Hz with an image integration time of ~0.5 msec....... The spatial precision in these experiments is ~40 nm (as determined from the standard deviation of repeated position measurements of an immobile QD on a cell). Using this system, we further show that an artificial lipid, biotin-cap-DPPE, inserted in a mouse embryo fibroblast (MEF), labeled with sAv-QD655...

Physiopathological approach to infective endocarditis in chronic hemodialysis patients: left heart versus right heart involvement.

Science.gov (United States)

Bentata, Yassamine

2017-11-01

Infectious endocarditis (IE), a complication that is both cardiac and infectious, occurs frequently and is associated with a heavy burden of morbidity and mortality in chronic hemodialysis patients (CHD). About 2-6% of chronic hemodialysis patients develop IE and the incidence is 50-60 times higher among CHD patients than in the general population. The left heart is the most frequent location of IE in CHD and the different published series report a prevalence of left valve involvement varying from 80% to 100%. Valvular and perivalvular abnormalities, alteration of the immune system, and bacteremia associated with repeated manipulation of the vascular access, particularly central venous catheters, comprise the main factors explaining the left heart IE in CHD patients. While left-sided IE develops in altered valves in a high-pressure system, right-sided IE on the contrary, generally develops in healthy valves in a low-pressure system. Right-sided IE is rare, with its incidence varying from 0% to 26% depending on the study, and the tricuspid valve is the main location. Might the massive influx of pathogenic and virulent germs via the central venous catheter to the right heart, with the tricuspid being the first contact valve, have a role in the physiopathology of IE in CHD, thus facilitating bacterial adhesion? While the physiopathology of left-sided IE entails multiple and convincing mechanisms, it is not the case for right-sided IE, for which the physiopathological mechanism is only partially understood and remains shrouded in mystery.

The effect of rigor mortis on the passage of erythrocytes and fluid through the myocardium of isolated dog hearts.

Science.gov (United States)

Nevalainen, T J; Gavin, J B; Seelye, R N; Whitehouse, S; Donnell, M

1978-07-01

The effect of normal and artificially induced rigor mortis on the vascular passage of erythrocytes and fluid through isolated dog hearts was studied. Increased rigidity of 6-mm thick transmural sections through the centre of the posterior papillary muscle was used as an indication of rigor. The perfusibility of the myocardium was tested by injecting 10 ml of 1% sodium fluorescein in Hanks solution into the circumflex branch of the left coronary artery. In prerigor hearts (20 minute incubation) fluorescein perfused the myocardium evenly whether or not it was preceded by an injection of 10 ml of heparinized dog blood. Rigor mortis developed in all hearts after 90 minutes incubation or within 20 minutes of perfusing the heart with 50 ml of 5 mM iodoacetate in Hanks solution. Fluorescein injected into hearts in rigor did not enter the posterior papillary muscle and adjacent subendocardium whether or not it was preceded by heparinized blood. Thus the vascular occlusion caused by rigor in the dog heart appears to be so effective that it prevents flow into the subendocardium of small soluble ions such as fluorescein.

Gerbode defect and multivalvular dysfunction: Complex complications in adult congenital heart disease.

Science.gov (United States)

Ruivo, Catarina; Guardado, Joana; Montenegro Sá, Fernando; Saraiva, Fátima; Antunes, Alexandre; Correia, Joana; Morais, João

2017-07-01

We report a clinical case of a 40-year-old male with surgically corrected congenital heart disease (CHD) 10 years earlier: closure of ostium primum, mitral annuloplasty, and aortic valve and root surgery. The patient was admitted with acute heart failure. Transesophageal echocardiography (TEE) revealed a dysmorphic and severely incompetent aortic valve, a partial tear of the mitral valve cleft repair and annuloplasty ring dehiscence. A true left ventricular-to-right atrial shunt confirmed a direct Gerbode defect. The authors aim to discuss the diagnostic challenge of adult CHD, namely the key role of TEE on septal defects and valve regurgitations description. © 2017, Wiley Periodicals, Inc.

Bleeding with the artificial heart: Gastrointestinal hemorrhage in CF-LVAD patients.

Science.gov (United States)

Gurvits, Grigoriy E; Fradkov, Elena

2017-06-14

Continuous-flow left ventricular assist devices (CF-LVADs) have significantly improved outcomes for patients with end-stage heart failure when used as a bridge to cardiac transplantation or, more recently, as destination therapy. However, its implantations carries a risk of complications including infection, device malfunction, arrhythmias, right ventricular failure, thromboembolic disease, postoperative and nonsurgical bleeding. A significant number of left ventricular assist devices (LVAD) recipients may experience recurrent gastrointestinal hemorrhage, mainly due to combination of antiplatelet and vitamin K antagonist therapy, activation of fibrinolytic pathway, acquired von Willebrand factor deficiency, and tendency to develop small intestinal angiodysplasias due to increased rotary speed of the pump. Gastrointestinal bleeding in LVAD patients remains a source of increased morbidity including the need for blood transfusions, extended hospital stays, multiple readmissions, and overall mortality. Management of gastrointestinal bleeding in LVAD patients involves multidisciplinary approach in stabilizing the patients, addressing risk factors and performing structured endoluminal evaluation with focus on upper gastrointestinal tract including jejunum to find and eradicate culprit lesion. Medical and procedural intervention is largely successful and universal bleeding cessation occurs in transplanted patients.

Heart transplantation in adults with congenital heart disease.

Science.gov (United States)

Houyel, Lucile; To-Dumortier, Ngoc-Tram; Lepers, Yannick; Petit, Jérôme; Roussin, Régine; Ly, Mohamed; Lebret, Emmanuel; Fadel, Elie; Hörer, Jürgen; Hascoët, Sébastien

2017-05-01

With the advances in congenital cardiac surgery and postoperative care, an increasing number of children with complex congenital heart disease now reach adulthood. There are already more adults than children living with a congenital heart defect, including patients with complex congenital heart defects. Among these adults with congenital heart disease, a significant number will develop ventricular dysfunction over time. Heart failure accounts for 26-42% of deaths in adults with congenital heart defects. Heart transplantation, or heart-lung transplantation in Eisenmenger syndrome, then becomes the ultimate therapeutic possibility for these patients. This population is deemed to be at high risk of mortality after heart transplantation, although their long-term survival is similar to that of patients transplanted for other reasons. Indeed, heart transplantation in adults with congenital heart disease is often challenging, because of several potential problems: complex cardiac and vascular anatomy, multiple previous palliative and corrective surgeries, and effects on other organs (kidney, liver, lungs) of long-standing cardiac dysfunction or cyanosis, with frequent elevation of pulmonary vascular resistance. In this review, we focus on the specific problems relating to heart and heart-lung transplantation in this population, revisit the indications/contraindications, and update the long-term outcomes. Copyright © 2017. Published by Elsevier Masson SAS.

Women's Heart Disease: Heart Attack Symptoms

Science.gov (United States)

... of this page please turn JavaScript on. Feature: Women's Heart Disease Heart Attack Symptoms Past Issues / Winter ... most common heart attack symptom in men and women is chest pain or discomfort. However, women also ...

Using Artificial Intelligence to Reduce the Risk of Nonadherence in Patients on Anticoagulation Therapy.

Science.gov (United States)

Labovitz, Daniel L; Shafner, Laura; Reyes Gil, Morayma; Virmani, Deepti; Hanina, Adam

2017-05-01

This study evaluated the use of an artificial intelligence platform on mobile devices in measuring and increasing medication adherence in stroke patients on anticoagulation therapy. The introduction of direct oral anticoagulants, while reducing the need for monitoring, have also placed pressure on patients to self-manage. Suboptimal adherence goes undetected as routine laboratory tests are not reliable indicators of adherence, placing patients at increased risk of stroke and bleeding. A randomized, parallel-group, 12-week study was conducted in adults (n=28) with recently diagnosed ischemic stroke receiving any anticoagulation. Patients were randomized to daily monitoring by the artificial intelligence platform (intervention) or to no daily monitoring (control). The artificial intelligence application visually identified the patient, the medication, and the confirmed ingestion. Adherence was measured by pill counts and plasma sampling in both groups. For all patients (n=28), mean (SD) age was 57 years (13.2 years) and 53.6% were women. Mean (SD) cumulative adherence based on the artificial intelligence platform was 90.5% (7.5%). Plasma drug concentration levels indicated that adherence was 100% (15 of 15) and 50% (6 of 12) in the intervention and control groups, respectively. Patients, some with little experience using a smartphone, successfully used the technology and demonstrated a 50% improvement in adherence based on plasma drug concentration levels. For patients receiving direct oral anticoagulants, absolute improvement increased to 67%. Real-time monitoring has the potential to increase adherence and change behavior, particularly in patients on direct oral anticoagulant therapy. URL: http://www.clinicaltrials.gov. Unique identifier: NCT02599259. © 2017 American Heart Association, Inc.

Detection of improvement in the masticatory function from old to new removable partial dentures using mixing ability test.

Science.gov (United States)

Asakawa, A; Fueki, K; Ohyama, T

2005-09-01

The aim of this study was to determine the sensitivity of the Mixing Ability Test to detect improvement of masticatory function in subjects on transition from old to new removable partial dentures. Thirty-two subjects (seven males, 25 females, mean age 65.0 years) with distal extension partially edentulous area in mandible and/or maxilla participated in the study. The following reasons were presented for replacing the old removable partial dentures with new ones: fracture and/or poor fitness of retainers, extraction of abutment teeth, poor fitness of denture base, severe wear of artificial teeth and request for metal base dentures. Masticatory function with old and new removable partial dentures after an adaptation period (mean 27.4 weeks) was evaluated by the Mixing Ability Test. Subjects were asked to masticate five two-coloured wax cubes with each removable partial denture. Mixing Ability Index was obtained from the colour mixture and shape of the masticated cubes. Wilcoxon signed-rank test was used to test the difference of Mixing Ability Indexes between old and new removable partial dentures. The mixing ability indexes with new removable partial dentures (mean+/- s.d.: 0.70+/- 0.68) was significantly higher (Premovable partial dentures (-0.11+/-1.13). The results suggest that the Mixing Ability Test was capable of detecting improvement in masticatory function with new removable partial dentures.

Prediction of air-to-blood partition coefficients of volatile organic compounds using genetic algorithm and artificial neural network

International Nuclear Information System (INIS)

Konoz, Elahe; Golmohammadi, Hassan

2008-01-01

An artificial neural network (ANN) was constructed and trained for the prediction of air-to-blood partition coefficients of volatile organic compounds. The inputs of this neural network are theoretically derived descriptors that were chosen by genetic algorithm (GA) and multiple linear regression (MLR) features selection techniques. These descriptors are: R maximal autocorrelation of lag 1 weighted by atomic Sanderson electronegativities (R1E+), electron density on the most negative atom in molecule (EDNA), maximum partial charge for C atom (MXPCC), surface weighted charge partial surface area (WNSA1), fractional charge partial surface area (FNSA2) and atomic charge weighted partial positive surface area (PPSA3). The standard errors of training, test and validation sets for the ANN model are 0.095, 0.148 and 0.120, respectively. Result obtained showed that nonlinear model can simulate the relationship between structural descriptors and the partition coefficients of the molecules in data set accurately

Chemical analysis of multicomponent aqueous solutions using a system of nonselective sensor and artificial neural networks

International Nuclear Information System (INIS)

Vlasov, Yu.G.; Legin, A.V.; Rudnitskaya, A.M.; Amiko, A.D.; Natale, K.D.

1997-01-01

With the aim of creating a multisensor system for determining heavy-metal cations (Cu 2+ , Pb 2+ , Cd 2+ , and Zn 2+ ) and inorganic anions (Cl - , F - , and SO 4 2- ), measurements in mixed solutions were carried out with the use of an array of sensors based on chalcogenide glass electrodes, and the possibility of using various methods of mathematical processing of the resulting intricate signals was studied. Three methods of data processing were used: multilinear regression, partial least squares, and artificial neural networks. It was found that the multisensor system proposed were suitable for determining all of the analytes with an accuracy of 1-10%. Because the responses of sensors in solutions of complex composition deviated from linearity, the lowest determination errors were obtained with the use of an artificial neural network. As to the method of data securing (nonselective response of a sensor array) and processing (artificial neural network), the multisensor system developed may be considered a prototype of a device of the electronic tongue type

Artificial Intelligence in Astronomy

Science.gov (United States)

Devinney, E. J.; Prša, A.; Guinan, E. F.; Degeorge, M.

2010-12-01

From the perspective (and bias) as Eclipsing Binary researchers, we give a brief overview of the development of Artificial Intelligence (AI) applications, describe major application areas of AI in astronomy, and illustrate the power of an AI approach in an application developed under the EBAI (Eclipsing Binaries via Artificial Intelligence) project, which employs Artificial Neural Network technology for estimating light curve solution parameters of eclipsing binary systems.

Partial purification and properties of an AMP-specific soluble 5'-nucleotidase from pigeon heart.

OpenAIRE

Skladanowski, A C; Newby, A C

1990-01-01

A soluble 5'-nucleotidase was purified 200-fold from pigeon heart. The enzyme (1) had an apparent molecular mass close to 150 kDa, (2) had a neutral pH optimum and hydrolysed a wide range of nucleoside 5'-monophosphates with a 15-fold preference for AMP over IMP, (3) at near-physiological concentrations of AMP was activated by ADP but not by ATP, (4) was inhibited by high Mg2+ concentration and high ionic strength, (5) was weakly inhibited by p-nitrophenol phosphate and Pi, and (6) was non-co...

[Preparation of nano-nacre artificial bone].

Science.gov (United States)

Chen, Jian-ting; Tang, Yong-zhi; Zhang, Jian-gang; Wang, Jian-jun; Xiao, Ying

2008-12-01

To assess the improvements in the properties of nano-nacre artificial bone prepared on the basis of nacre/polylactide acid composite artificial bone and its potential for clinical use. The compound of nano-scale nacre powder and poly-D, L-lactide acid (PDLLA) was used to prepare the cylindrical hollow artificial bone, whose properties including raw material powder scale, pore size, porosity and biomechanical characteristics were compared with another artificial bone made of micron-scale nacre powder and PDLLA. Scanning electron microscope showed that the average particle size of the nano-nacre powder was 50.4-/+12.4 nm, and the average pore size of the artificial bone prepared using nano-nacre powder was 215.7-/+77.5 microm, as compared with the particle size of the micron-scale nacre powder of 5.0-/+3.0 microm and the pore size of the resultant artificial bone of 205.1-/+72.0 microm. The porosities of nano-nacre artificial bone and the micron-nacre artificial bone were (65.4-/+2.9)% and (53.4-/+2.2)%, respectively, and the two artificial bones had comparable compressive strength and Young's modulus, but the flexural strength of the nano-nacre artificial bone was lower than that of the micro-nacre artificial bone. The nano-nacre artificial bone allows better biodegradability and possesses appropriate pore size, porosity and biomechanical properties for use as a promising material in bone tissue engineering.

Heart murmurs

Science.gov (United States)

Chest sounds - murmurs; Heart sounds - abnormal; Murmur - innocent; Innocent murmur; Systolic heart murmur; Diastolic heart murmur ... The heart has 4 chambers: Two upper chambers (atria) Two lower chambers (ventricles) The heart has valves that close ...

Executive dysfunction is independently associated with reduced functional independence in heart failure.

Science.gov (United States)

Alosco, Michael L; Spitznagel, Mary Beth; Raz, Naftali; Cohen, Ronald; Sweet, Lawrence H; Colbert, Lisa H; Josephson, Richard; van Dulmen, Manfred; Hughes, Joel; Rosneck, Jim; Gunstad, John

2014-03-01

To examine the independent association between executive function with instrumental activities of daily living and health behaviours in older adults with heart failure. Executive function is an important contributor to functional independence as it consists of cognitive processes needed for decision-making, planning, organising and behavioural monitoring. Impairment in this domain is common in heart failure patients and associated with reduced performance of instrumental activities of daily living in many medical and neurological populations. However, the contribution of executive functions to functional independence and healthy lifestyle choices in heart failure patients has not been fully examined. Cross-sectional analyses. One hundred and seventy-five heart failure patients completed a neuropsychological battery and echocardiogram. Participants also completed the Lawton-Brody Instrumental Activities of Daily Living Scale and reported current cigarette use. Hierarchical regressions revealed that reduced executive function was independently associated with worse instrumental activity of daily living performance with a specific association for decreased ability to manage medications. Partial correlations showed that executive dysfunction was associated with current cigarette use. Our findings suggest that executive dysfunction is associated with poorer functional independence and contributes to unhealthy behaviours in heart failure. Future studies should examine whether heart failure patients benefit from formal organisation schema (i.e. pill organisers) to maintain independence. Screening of executive function in heart failure patients may provide key insight into their ability to perform daily tasks, including the management of treatment recommendations. © 2013 John Wiley & Sons Ltd.

Prospective Heart Tracking for Whole-heart Magnetic Resonance Angiography

Science.gov (United States)

Moghari, Mehdi H.; Geva, Tal; Powell, Andrew J.

2015-01-01

Purpose To develop a prospective respiratory-gating technique (Heart-NAV) for use with contrast-enhanced 3D inversion recovery (IR) whole-heart magnetic resonance angiography (MRA) acquisitions that directly tracks heart motion without creating image inflow artifact. Methods With Heart-NAV, 1 of the startup pulses for the whole-heart steady-state free precession MRA sequence is used to collect the centerline of k-space, and its 1-dimensional reconstruction is fed into the standard diaphragm-navigator (NAV) signal analysis process to prospectively gate and track respiratory-induced heart displacement. Ten healthy volunteers underwent non-contrast whole-heart MRA acquisitions using the conventional diaphragm-NAV and Heart-NAV with 5 and 10 mm acceptance windows in a 1.5T scanner. Five patients underwent contrast-enhanced IR whole-heart MRA using a diaphragm-NAV and Heart-NAV with a 5 mm acceptance window. Results For non-contrast whole-heart MRA with both the 5 and 10 mm acceptance windows, Heart-NAV yielded coronary artery vessel sharpness and subjective visual scores that were not significantly different than those using a conventional diaphragm-NAV. Scan time for Heart-NAV was 10% shorter (p<0.05). In patients undergoing contrast-enhanced IR whole-heart MRA, inflow artifact was seen with the diaphragm-NAV but not with Heart-NAV. Conclusion Compared to a conventional diaphragm-NAV, Heart-NAV achieves similar image quality in a slightly shorter scan time and eliminates inflow artifact. PMID:26843458

Artificial Intelligence Study (AIS).

Science.gov (United States)

1987-02-01

ARTIFICIAL INTELLIGNECE HARDWARE ....... 2-50 AI Architecture ................................... 2-49 AI Hardware ....................................... 2...ftf1 829 ARTIFICIAL INTELLIGENCE STUDY (RIS)(U) MAY CONCEPTS 1/3 A~NLYSIS AGENCY BETHESA RD R B NOJESKI FED 6? CM-RP-97-1 NCASIFIED /01/6 M |K 1.0...p/ - - ., e -- CAA- RP- 87-1 SAOFŔ)11 I ARTIFICIAL INTELLIGENCE STUDY (AIS) tNo DTICFEBRUARY 1987 LECT 00 I PREPARED BY RESEARCH AND ANALYSIS

[Effect of artificial mountain climate on the functional state of higher regions of the central nervous system in man].

Science.gov (United States)

Berezovskiĭ, V A; Levashov, M I

2009-01-01

The study included 97 patients with vegetative vascular dystonia and chronic non-specific pulmonary diseases exposed to artificial high-altitude climate in an Orotron climatic chamber during 2 weeks. Atmospheric conditions maintained in the chamber had the following parameters: partial pressure of oxygen--147-160 gPa, relative humidity--60-70%, air temperature--16-18 degrees C, light aeroion content--up to 6000 cub.cm. It was shown that the exposure to artificial mountain climatic conditions enhanced functional mobility of nervous processes and decreased the length of the sensorimotor reactions of the patients. Individual differences in the change of parameters being measured depended on the degree of initial functional flexibility of nervous processes.

Development of a partial least squares-artificial neural network (PLS-ANN) hybrid model for the prediction of consumer liking scores of ready-to-drink green tea beverages.

Science.gov (United States)

Yu, Peigen; Low, Mei Yin; Zhou, Weibiao

2018-01-01

In order to develop products that would be preferred by consumers, the effects of the chemical compositions of ready-to-drink green tea beverages on consumer liking were studied through regression analyses. Green tea model systems were prepared by dosing solutions of 0.1% green tea extract with differing concentrations of eight flavour keys deemed to be important for green tea aroma and taste, based on a D-optimal experimental design, before undergoing commercial sterilisation. Sensory evaluation of the green tea model system was carried out using an untrained consumer panel to obtain hedonic liking scores of the samples. Regression models were subsequently trained to objectively predict the consumer liking scores of the green tea model systems. A linear partial least squares (PLS) regression model was developed to describe the effects of the eight flavour keys on consumer liking, with a coefficient of determination (R 2 ) of 0.733, and a root-mean-square error (RMSE) of 3.53%. The PLS model was further augmented with an artificial neural network (ANN) to establish a PLS-ANN hybrid model. The established hybrid model was found to give a better prediction of consumer liking scores, based on its R 2 (0.875) and RMSE (2.41%). Copyright © 2017 Elsevier Ltd. All rights reserved.

MR imaging of congenital heart diseases in adolescents and adults

Energy Technology Data Exchange (ETDEWEB)

Choe, Yeon Hyeon; Kang, I Seok; Park, Seung Woo; Lee, Heung Jae [Sungkwunkwan University School of Medicine, Seoul (Korea, Republic of)

2001-09-01

Echocardiography and catheterization angiography suffer certain limitations in the evaluation of congenital heart diseases in adults, though these are overcome by MRI, in which a wide field-of view, unlimited multiplanar imaging capability and three-dimensional contrast-enhanced MR angiography techniques are used. In adults, recently introduced fast imaging techniques provide cardiac MR images of sufficient quality and with less artifacts. Ventricular volume, ejection fraction, and vascular flow measurements, including pressure gradients and pulmonary-to-systemic flow ratio, can be calculated or obtained using fast cine MRI, phase-contrast MR flow-velocity mapping, and semiautomatic analysis software. MRI is superior to echocardiography in diagnosing partial anomalous pulmonary venous connection, unroofed coronary sinus, anomalies of the pulmonary arteries, aorta and systemic veins, complex heart diseases, and postsurgical sequelae. Biventricular function is reliably evaluated with cine MRI after repair of tetralogy of Fallot, and Senning's and Mustard's operations. MRI has an important and growing role in the morphologic and functional assessment of congenital heart diseases in adolescents and adults.

Microwave measurements of water vapor partial pressure at high temperatures

International Nuclear Information System (INIS)

Latorre, V.R.

1991-01-01

One of the desired parameters in the Yucca Mountain Project is the capillary pressure of the rock comprising the repository. This parameter is related to the partial pressure of water vapor in the air when in equilibrium with the rock mass. Although there are a number of devices that will measure the relative humidity (directly related to the water vapor partial pressure), they generally will fail at temperatures on the order of 150C. Since thee author has observed borehole temperatures considerably in excess of this value in G-Tunnel at the Nevada Test Site (NTS), a different scheme is required to obtain the desired partial pressure data at higher temperatures. This chapter presents a microwave technique that has been developed to measure water vapor partial pressure in boreholes at temperatures up to 250C. The heart of the system is a microwave coaxial resonator whose resonant frequency is inversely proportional to the square root of the real part of the complex dielectric constant of the medium (air) filling the resonator. The real part of the dielectric constant of air is approximately equal to the square of the refractive index which, in turn, is proportional to the partial pressure of the water vapor in the air. Thus, a microwave resonant cavity can be used to measure changes in the relative humidity or partial pressure of water vapor in the air. Since this type of device is constructed of metal, it is able to withstand very high temperatures. The actual limitation is the temperature limit of the dielectric material in the cable connecting the resonator to its driving and monitoring equipment-an automatic network analyzer in our case. In the following sections, the theory of operation, design, construction, calibration and installation of the microwave diagnostics system is presented. The results and conclusions are also presented, along with suggestions for future work

Influence of Nanosilica Filler Content in LDPE Composites on Partial Discharge Characteristics

Institute of Scientific and Technical Information of China (English)

Z. Abdul-Malek; A.M. Azzin; Y.Z. Ariel; Aulia; K.Y. Lau; M. Jaafar

2011-01-01

Partial discharges （PDs） due to artificial void in samples of LDPE nanocomposite sheet have been investiga- ted in this work. PDs may cause the degradation of insulating materials and may affect the lifetime of high-voltage ap- paratus. An experimental work using sphere ball-plane electrode system （CIGRE Method II） and a 1.0 mm LDPE composite sheet was carried out. Different weight percentages of nanosilica （0%, 2%, 4%, 6% and 8%） were used. PD experimental results, such as PD magnitude and PD number （both PD pulse polarities）, as functions of the ap- plied stress duration at a specified applied voltage were compared. The surface morphology of specimens was also presented and this conforms to the PD findings. The experimental results show that the PD characteristics of the LDPE generally improve with the introduction of nanosilica, the composite with the highest content of filler, namely the 8% （wt） nanosilica sample has the least partial discharge activities.

Quo Vadis, Artificial Intelligence?

OpenAIRE

Berrar, Daniel; Sato, Naoyuki; Schuster, Alfons

2010-01-01

Since its conception in the mid 1950s, artificial intelligence with its great ambition to understand and emulate intelligence in natural and artificial environments alike is now a truly multidisciplinary field that reaches out and is inspired by a great diversity of other fields. Rapid advances in research and technology in various fields have created environments into which artificial intelligence could embed itself naturally and comfortably. Neuroscience with its desire to understand nervou...

Inteligencia artificial en vehiculo

OpenAIRE

Amador Díaz, Pedro

2012-01-01

Desarrollo de un robot seguidor de líneas, en el que se implementan diversas soluciones de las áreas de sistemas embebidos e inteligencia artificial. Desenvolupament d'un robot seguidor de línies, en el qual s'implementen diverses solucions de les àrees de sistemes encastats i intel·ligència artificial. Follower robot development of lines, in which various solutions are implemented in the areas of artificial intelligence embedded systems.

Hardness of enamel exposed to Coca-Cola and artificial saliva.

Science.gov (United States)

Devlin, H; Bassiouny, M A; Boston, D

2006-01-01

The purpose of this study was to determine the rate of change in indentation hardness of enamel in permanent teeth exposed to Coca-Cola. In a further experiment, the ability of a commercially available artificial saliva to remineralize enamel treated with Coca-Cola was tested. Ten enamel specimens were randomly chosen to be treated with Coca-Cola (experimental groups) and seven with water (control group). The fluids were applied for 1, 2, 3 h and overnight (15 h), washed off with a few drops of water and the moist enamel indentation hardness tested after each interval. With Coca-Cola treatment, the mean enamel hardness was 92.6% (s.d. = 7.9) of the original baseline hardness after 1 h, 93.25% (s.d. = 10.15) after 2 h, 85.7% (s.d. = 12.03) after 3 h and 80.3% after 15 h. The mean indentation hardness of control specimens treated with water was 108.7% (s.d. = 16.09) of the original hardness after 1 h, 99.09% (s.d. = 18.98) after 2 h, 98.97% (s.d. =11.24) after 3 h and 98.42% (s.d. = 22.78) after 15 h. In a separate experiment, the hardness of 9 enamel specimens was tested, as previously described, before and after treatment with Coca-Cola overnight and again after application of artificial saliva for 3 min. Coca-Cola reduced the mean indentation hardness of enamel in the teeth, but the hardness was partially restored with artificial saliva (Salivart) and increased by 18% from the demineralized enamel hardness.

Heart Failure

Science.gov (United States)

Heart failure is a condition in which the heart can't pump enough blood to meet the body's needs. Heart failure does not mean that your heart has stopped ... and shortness of breath Common causes of heart failure are coronary artery disease, high blood pressure and ...

Criminal Aspects of Artificial Abortion

OpenAIRE

Hartmanová, Leona

2016-01-01

Criminal Aspects of Artificial Abortion This diploma thesis deals with the issue of artificial abortion, especially its criminal aspects. Legal aspects are not the most important aspects of artificial abortion. Social, ethical or ideological aspects are of the same importance but this diploma thesis cannot analyse all of them. The main issue with artificial abortion is whether it is possible to force a pregnant woman to carry a child and give birth to a child when she cannot or does not want ...

Heart MRI

Science.gov (United States)

Magnetic resonance imaging - cardiac; Magnetic resonance imaging - heart; Nuclear magnetic resonance - cardiac; NMR - cardiac; MRI of the heart; Cardiomyopathy - MRI; Heart failure - MRI; Congenital heart disease - MRI

Use of waste brick as a partial replacement of cement in mortar.

Science.gov (United States)

Naceri, Abdelghani; Hamina, Makhloufi Chikouche

2009-08-01

The aim of this study is to investigate the use of waste brick as a partial replacement for cement in the production of cement mortar. Clinker was replaced by waste brick in different proportions (0%, 5%, 10%, 15% and 20%) by weight for cement. The physico-chemical properties of cement at anhydrous state and the hydrated state, thus the mechanical strengths (flexural and compressive strengths after 7, 28 and 90 days) for the mortar were studied. The microstructure of the mortar was investigated using scanning electron microscopy (SEM), the mineralogical composition (mineral phases) of the artificial pozzolan was investigated by the X-ray diffraction (XRD) and the particle size distributions was obtained from laser granulometry (LG) of cements powders used in this study. The results obtained show that the addition of artificial pozzolan improves the grinding time and setting times of the cement, thus the mechanical characteristics of mortar. A substitution of cement by 10% of waste brick increased mechanical strengths of mortar. The results of the investigation confirmed the potential use of this waste material to produce pozzolanic cement.

Use of waste brick as a partial replacement of cement in mortar

International Nuclear Information System (INIS)

Naceri, Abdelghani; Hamina, Makhloufi Chikouche

2009-01-01

The aim of this study is to investigate the use of waste brick as a partial replacement for cement in the production of cement mortar. Clinker was replaced by waste brick in different proportions (0%, 5%, 10%, 15% and 20%) by weight for cement. The physico-chemical properties of cement at anhydrous state and the hydrated state, thus the mechanical strengths (flexural and compressive strengths after 7, 28 and 90 days) for the mortar were studied. The microstructure of the mortar was investigated using scanning electron microscopy (SEM), the mineralogical composition (mineral phases) of the artificial pozzolan was investigated by the X-ray diffraction (XRD) and the particle size distributions was obtained from laser granulometry (LG) of cements powders used in this study. The results obtained show that the addition of artificial pozzolan improves the grinding time and setting times of the cement, thus the mechanical characteristics of mortar. A substitution of cement by 10% of waste brick increased mechanical strengths of mortar. The results of the investigation confirmed the potential use of this waste material to produce pozzolanic cement.

Experimental studies on cytogenetic dosimetry for in vitro simulated and in vivo partial body exposure

International Nuclear Information System (INIS)

Han Baoguang; Chen Di; Jin Cuizhen; Liu Xiulin; Luo Yisheng

1993-01-01

The feasibility was examined of the contaminated Poisson distribution method as applied to dose estimation of in vitro simulated and in vivo partial body exposure of New Zealand rabbits. For this purpose, the preparatory experiments were conducted. Aberration yields were obtained for mixed cultures prepared from normal and irradiated peripheral lymphocytes with volume ratio 3 to 7 and for pure cultures of irradiated cells. Comparison of the dicentric yields from these two types of cultures indicated that the probability of cultured irradiated cells entering M 1 phase was exponentially decreased as the absorbed dose increased with a D 37 value of 2.41 Gy. Analysis of the dicentric yields obtained from pure cultures demonstrated that the dose-response relationship of dicentric yields was represented by a linear-quadratic model. Partial body exposures with irradiated fractions ranging from 90% to 30% were simulated by irradiating rabbit blood in vitro with 5 Gy 60 Co γ rays. The contaminated Poisson distribution method was utilized to derive the fraction of irradiated blood in the mixed culture and its absorbed dose. The results showed the estimations are in good agreement with true values. Moreover, the same results were arrived at for in vivo partial body irradiation in spite of many complicated factors inhered. Two groups of rabbits were irradiated in vivo on right halves along their backbones at 3.6 Gy and 5.0 Gy respectively. Heart blood was sampled 24 hours later. The result analysed by the same method approximated the true values. Before the in vivo irradiation, heart blood was sampled and irradiated in vitro to simulate half body and whole body exposure, which provided self-control for its in vivo data. These offered further proof for the previous results of in vitro simulated partial body exposure

Aplicaciones de la dermis artificial para la prevención y tratamiento de cicatrices hipertróficas y contracturas Artificial dermis aplications to prevent and treat hypertrofyc scars and skin retractions

Directory of Open Access Journals (Sweden)

I. Ferreiro González

2012-03-01

hypertrophic scars and contractures. The following variables were evaluated: haematoma, infection and total or partial loss of artificial dermis. The scar quality was reviewed during the postoperative period, using the Vancouver Scar Scale (VSS. Patients´ satisfaction was measured using a 0-10 score survey. None of the areas treated with artificial dermis showed adverse scarring and in patients with prior hypertrophic scars no recurrence was found. We also observed that in acute burns, the areas treated with artificial dermis developed much better scar quality compared with those areas treated with split skin grafts. We achieved satisfactory coverage in areas with tendon exposure. Artificial dermis can be selectively applied to special areas during acute burn injury to prevent scar hypertrophy and contracture. It can also be used as coverage for normally non-graftable structures less than 3 cm where skin flaps are usually required. During the chronic stage, artificial dermis can be useful to treat contractures, as well as hypertrophic scars.

Heart Health - Heart Disease: Symptoms, Diagnosis, Treatment

Science.gov (United States)

... Bar Home Current Issue Past Issues Cover Story Heart Health Heart Disease: Symptoms, Diagnosis, Treatment Past Issues / Winter 2009 ... of this page please turn Javascript on. Most heart attacks happen when a clot in the coronary ...

Heart Health: The Heart Truth Campaign 2009

Science.gov (United States)

... Bar Home Current Issue Past Issues Cover Story Heart Health The Heart Truth Campaign 2009 Past Issues / Winter 2009 Table ... one of the celebrities supporting this year's The Heart Truth campaign. Both R&B singer Ashanti (center) ...

Women's Heart Disease: Heart Disease Risk Factors

Science.gov (United States)

... this page please turn JavaScript on. Feature: Women's Heart Disease Heart Disease Risk Factors Past Issues / Winter 2014 Table ... or habits may raise your risk for coronary heart disease (CHD). These conditions are known as risk ...

Nondestructive evaluation of braided carbon fiber composites with artificial defect using HTS-SQUID gradiometer

International Nuclear Information System (INIS)

Shinyama, Y.; Yamaji, T.; Hatsukade, Y.; Takai, Y.; Aly-Hassan, M.S.; Nakai, A.; Hamada, H.; Tanaka, S.

2011-01-01

We applied a current-injection-based NDE method using a HTS-SQUID gradiometer to a braided CFRP with artificial cracks. Current distributions in the braided CFRP were estimated from measured field gradient distributions. A small crack, in which a few carbon-fiber bundles were cut, was well detected from the current distributions. A cross-section of the CFRP showed that a density of the bundles at edges is higher than the other part. The experimental results demonstrated the capability of the method to detect sub-mm cracks. Braided carbon fiber reinforced plastics (CFRPs) are one of multifunctional materials with superior properties such as mechanical strength to normal CFRPs since the braided CFRPs have continuous fiber bundles. In this paper, we applied the current-injection-based nondestructive evaluation (NDE) method using a HTS-SQUID gradiometer to the braided CFRP for the detection of the breakage of the bundles. We prepared planar braided CFRP samples with and without artificial cracks of 1 and 2 mm lengths, and measured the current density distribution above the samples using the NDE method. In the measurement results, not only a few completely-cut bundles but also the additional partially-cut bundles were detected from decrease in the measured current density along the cut bundle around the cracks. From these results, we showed that it is possible to inspect a few partially-cut bundles in the braided CFRPs by the NDE method.

Artificial Hydration and Nutrition

Science.gov (United States)

... Crisis Situations Pets and Animals myhealthfinder Food and Nutrition Healthy Food Choices Weight Loss and Diet Plans ... Your Health Resources Healthcare Management Artificial Hydration and Nutrition Artificial Hydration and Nutrition Share Print Patients who ...

Artificial Evolution for the Detection of Group Identities in Complex Artificial Societies

DEFF Research Database (Denmark)

Grappiolo, Corrado; Togelius, Julian; Yannakakis, Georgios N.

2013-01-01

This paper aims at detecting the presence of group structures in complex artificial societies by solely observing and analysing the interactions occurring among the artificial agents. Our approach combines: (1) an unsupervised method for clustering interactions into two possible classes, namely in...

Artificial intelligence

International Nuclear Information System (INIS)

Perret-Galix, D.

1992-01-01

A vivid example of the growing need for frontier physics experiments to make use of frontier technology is in the field of artificial intelligence and related themes. This was reflected in the second international workshop on 'Software Engineering, Artificial Intelligence and Expert Systems in High Energy and Nuclear Physics' which took place from 13-18 January at France Telecom's Agelonde site at La Londe des Maures, Provence. It was the second in a series, the first having been held at Lyon in 1990

Prone Accelerated Partial Breast Irradiation After Breast-Conserving Surgery: Compliance to the Dosimetry Requirements of RTOG-0413

Energy Technology Data Exchange (ETDEWEB)

Wen Bixiu [Department of Radiation Oncology, New York University Medical Center, New York, New York (United States); Department of Radiation Oncology, The First Affiliated Hospital, Sun Yat-Sen University, Guangzhou 510080 (China); Hsu, Howard; Formenti-Ujlaki, George F.; Lymberis, Stella; Magnolfi, Chiara; Zhao Xuan; Chang Jenghwa; DeWyngaert, J. Keith; Jozsef, Gabor [Department of Radiation Oncology, New York University Medical Center, New York, New York (United States); Formenti, Silvia C., E-mail: silvia.formenti@nyumc.org [Department of Radiation Oncology, New York University Medical Center, New York, New York (United States)

2012-11-15

Purpose: The dosimetric results from our institution's trials of prone accelerated partial breast irradiation are compared with the dosimetric requirements of RTOG-0413. Methods and Materials: Trial 1 and Trial 2 are 2 consecutive trials of prone-accelerated partial breast irradiation. Eligible for both trials were stage I breast cancer patients with negative margins after breast-conserving surgery. The planning target tumor volume (PTV) was created by extending the surgical cavity 2.0 cm for Trial 1 and 1.5 cm for Trial 2, respectively. Contralateral breast, heart, lungs, and thyroid were contoured. Thirty Gray was delivered in five daily fractions of 6 Gy by a three-dimensional conformal radiation therapy technique in Trial 1 and were by image-guided radiation therapy/intensity-modulated radiation therapy in Trial 2. Dosimetric results from the trials are reported and compared with RTOG 0413 requirements. Results: One hundred forty-six consecutive plans were analyzed: 67 left and 79 right breast cancers. The plans from the trials complied with the required >90% of prescribed dose covering 90% of PTV{sub E}VAL (=generated from the PTV by cropping 0.5 cm from the skin edge and excluding the chest wall): V90% was 98.1 {+-} 3.0% (with V100% and V95%, 89.4 {+-} 12.8%, 96.4 {+-} 5.1%, respectively). No significant difference between laterality was found (Student's t test). The dose constraints criteria of the RTOG-0413 protocol for ipsilateral and contralateral lung (V30 <15% and Dmax <3%), heart (V5 <40%), and thyroid (Dmax <3%) were satisfied because the plans showed an average V5% of 0.6% (range, 0-13.4) for heart, an average V30% of 0.6% (range, 0-9.1%) for ipsilateral lung, and <2% maximum dose to the thyroid. However, our partial breast irradiation plans demonstrated a higher dose to contralateral breast than that defined by RTOG constraints, with a median value of maximum doses of 4.1% (1.2 Gy), possibly as a result of contouring differences

Clinical observation on the treatment of acute liver failure by combined non-biological artificial liver.

Science.gov (United States)

Li, Maoqin; Sun, Jingxi; Li, Jiaqiong; Shi, Zaixiang; Xu, Jiyuan; Lu, Bo; Cheng, Shuli; Xu, Yanjun; Wang, Xiaomeng; Zhang, Xianjiang

2016-12-01

The clinical efficacy and safety of different combinations of non-bio artificial liver in the treatment of acute liver failure was examined. A total of 61 cases were selected under blood purification treatment from the patients with severe acute liver failure admitted to the severe disease department of the hospital from December, 2010 to December, 2015. Three types of artificial liver combinations were observed, i.e., plasma exchange plus hemoperfusion plus continuous venovenous hemodiafiltration (PE+HP+CVVHDF), PE+CVVHDF and HP+CVVHDF. The heart rate (HR), mean arterial pressure (MAP), respiratory index (PaO 2 /FiO 2 ), liver and kidney function indicator, as well as platelet and coagulation function were compared. A comparison before and after the treatment using the three methods, showed improvement in the HRs, MAPs, PaO 2 /FiO 2 , total bilirubins (TBIL) and alanine aminotransferases (ALT) (Prate of 62.3% (38/61), and a viral survival rate of 35.0% (7/20); with the non-viral survival rate being 75.6% (31/41). In conclusion, following the treatment of three types of artificial livers, the function was improved to varying degrees, with the PE+HP+CVVHDF and the PE+CVVHDF method being better. By contrast, after the treatment of non-viral liver failure, the survival rate was significantly higher than the patients with viral liver failure.

Characterizing potential heart agents with an isolated perfused heart system

International Nuclear Information System (INIS)

Pendleton, D.B.; Sands, H.; Gallagher, B.M.; Camin, L.L.

1984-01-01

The authors have used an isolated perfused heart system for characterizing potential myocardial perfusion radiopharamaceuticals. Rabbit or guinea pig (GP) hearts are removed and perfused through the aorta with a blood-free buffer. Heart rate and ventricular pressure are monitored as indices of viability. Tc-99m-MAA is 96-100% retained in these hearts, and Tc-99m human serum albumin shows less than 5% extraction. Tl-201 is 30-40% extracted. It is known that in-vivo, Tc-99m(dmpe)/sub 2/Cl/sub 2//sup +/ is taken up by rabbit heart but not by GP or human heart. Analogous results are obtained with the isolated perfused heart model, where the complex is extracted well by the isolated rabbit heart (24%) but not by the GP heart (<5%). Values are unchanged if human, rabbit or GP blood is mixed and co-injected with the complex. Tc-99m)dmpe)/sub 3//sup +/ is also taken up by rabbit but not by GP hearts in-vivo. However, isolated perfused hearts of both species extract this complex well (45-52%). Heart uptake is diminished to <7% if the complex is pre-equilibrated with human blood. GP blood produces a moderate inhibition (in GP hearts only) and rabbit blood has no effect. This suggests that a human or GP blood factor may have a significant effect on heart uptake of this complex. Tc-99m(CN-t-butyl)/sub 6//sup +/ is taken up well by both rabbit and GP hearts in-vivo, and is extracted 100% by both isolated perfused hearts. Heart retention remains high (73-75%) in the presence of human blood

Morphological characteristic of surgically removed cardiac myxomas: 25-YEAR EXPERIENCE IN V.I. SHUMAKOV FEDERAL RESEARCH CENTER OF TRANSPLANTOLOGY AND ARTIFICIAL ORGANS

Directory of Open Access Journals (Sweden)

I. M. Iljinsky

2017-01-01

Full Text Available Analysis of intracardiac space-occupying lesions, surgically removed at V.I. Shumakov Federal Research Center of Transplantology and Artificial Organs over 25 years (in the period from 1992 until 2016 was carried out. During that period 134 patients underwent surgery. Preoperative clinical diagnosis before surgery was heart myxoma. From 134 patients, only in 115 (85.8% patients the removed intracardiac lesions were myxomas: left atrium – 103 (89.7% patients, right atrium – 10 (8.7%, right ventricle – 2 (1.8% and mitral valve – 1 (0.8% patient. 9 patients had thrombi in the heart, 10 patients had not myxomas, but other benign and malignant heart tumors. This article presents macroscopic, histolological and ultrastructural characteristic of cardiac myxomas. Recurrence of the left atrium myxoma occurred in 2 patients. They were re-operated in four and six years after the first removal of myxoma. 2 patients died during hospital period. One patient with atherosclerosis of the coronary arteries as a concurrent disease died of embolization of the stent coronary artery with myxoma particles with the development of acute heart failure. Death of the 2nd patient was not directly related to the surgery, and was due to the acute heart failure as well in connection with the presence of concurrent disease, coronary heart disease.

Heart Diseases

Science.gov (United States)

... you're like most people, you think that heart disease is a problem for others. But heart disease is the number one killer in the ... of disability. There are many different forms of heart disease. The most common cause of heart disease ...

Heart Transplantation

Science.gov (United States)

A heart transplant removes a damaged or diseased heart and replaces it with a healthy one. The healthy heart comes from a donor who has died. It is the last resort for people with heart failure when all other treatments have failed. The ...

2013 update on congenital heart disease, clinical cardiology, heart failure, and heart transplant.

Science.gov (United States)

Subirana, M Teresa; Barón-Esquivias, Gonzalo; Manito, Nicolás; Oliver, José M; Ripoll, Tomás; Lambert, Jose Luis; Zunzunegui, José L; Bover, Ramon; García-Pinilla, José Manuel

2014-03-01

This article presents the most relevant developments in 2013 in 3 key areas of cardiology: congenital heart disease, clinical cardiology, and heart failure and transplant. Within the area of congenital heart disease, we reviewed contributions related to sudden death in adult congenital heart disease, the importance of specific echocardiographic parameters in assessing the systemic right ventricle, problems in patients with repaired tetralogy of Fallot and indication for pulmonary valve replacement, and confirmation of the role of specific factors in the selection of candidates for Fontan surgery. The most recent publications in clinical cardiology include a study by a European working group on correct diagnostic work-up in cardiomyopathies, studies on the cost-effectiveness of percutaneous aortic valve implantation, a consensus document on the management of type B aortic dissection, and guidelines on aortic valve and ascending aortic disease. The most noteworthy developments in heart failure and transplantation include new American guidelines on heart failure, therapeutic advances in acute heart failure (serelaxin), the management of comorbidities such as iron deficiency, risk assessment using new biomarkers, and advances in ventricular assist devices. Copyright © 2013 Sociedad Española de Cardiología. Published by Elsevier Espana. All rights reserved.

Pediatric heart surgery

Science.gov (United States)

Heart surgery - pediatric; Heart surgery for children; Acquired heart disease; Heart valve surgery - children ... There are many kinds of heart defects. Some are minor, and others are more serious. Defects can occur inside the heart or in the large blood vessels ...

Off-pump transapical implantation of artificial neo-chordae to correct mitral regurgitation: the TACT Trial (Transapical Artificial Chordae Tendinae) proof of concept.

Science.gov (United States)

Seeburger, Joerg; Rinaldi, Mauro; Nielsen, Sten Lyager; Salizzoni, Stefano; Lange, Ruediger; Schoenburg, Markus; Alfieri, Ottavio; Borger, Michael Andrew; Mohr, Friedrich Wilhelm; Aidietis, Audrius

2014-03-11

The goal of this study was to evaluate the safety and performance of the NeoChord DS1000 system (NeoChord, Inc., Minneapolis, Minnesota). There is an increasing interest in transcatheter mitral valve (MV) treatment. The NeoChord DS 1000 system enables off-pump beating heart transapical MV repair with implantation of artificial neo-chordae. Patients with severe mitral regurgitation (MR) due to isolated posterior prolapse were included in this TACT (Transapical Artificial Chordae Tendinae) trial. All patients were scheduled for off-pump transapical implantation of neo-chordae. Thirty patients at 7 centers were enrolled. Major adverse events included 1 death due to post-cardiotomy syndrome and concomitant sepsis and 1 minor stroke with the patient fully recovered at the 30-day follow-up visit. Additional patients experienced procedural major adverse events related to a reoperation or conversion to standard of care. Acute procedural success (placement of at least 1 neo-chord and reduction of MR from 3+ or 4+ to ≤2+) was achieved in 26 patients (86.7%). In 4 patients neo-chordae were not placed for technical and/or patient-specific reasons. These patients underwent intraoperative (3 patients) or post-operative (1 patient) standard MV repair. At 30 days, 17 patients maintained an MR grade ≤2+. Four patients who developed recurrent MR were successfully treated with open MV repair during 30-day follow-up. Results improved with experience: durable reduction in MR to ≤2+ at 30 days was achieved in 5 (33.3%) of the first 15 patients and 12 (85.7%) of the last 14 patients. Off-pump transapical implantation of artificial chordae to correct MR is technically safe and feasible; however, it yields further potential for improvement of efficacy and durability. (Safety and Performance Study of the NeoChord Device [TACT]; NCT01777815). Copyright © 2014 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Mitigation of near-band balanced steady-state free precession through-plane flow artifacts using partial dephasing.

Science.gov (United States)

Datta, Anjali; Cheng, Joseph Y; Hargreaves, Brian A; Baron, Corey A; Nishimura, Dwight G

2018-06-01

To mitigate artifacts from through-plane flow at the locations of steady-state stopbands in balanced steady-state free precession (SSFP) using partial dephasing. A 60° range in the phase accrual during a TR was created over the voxel by slightly unbalancing the slice-select dephaser. The spectral profiles of SSFP with partial dephasing for various constant flow rates and during pulsatile flow were simulated to determine if partial dephasing decreases through-plane flow artifacts originating near SSFP dark bands while maintaining on-resonant signal. Simulations were then validated in a flow phantom. Lastly, phase-cycled SSFP cardiac cine images were acquired with and without partial dephasing in six subjects. Partial dephasing decreased the strength and non-linearity of the dependence of the signal at the stopbands on the through-plane flow rate. It thus mitigated hyper-enhancement from out-of-slice signal contributions and transient-related artifacts caused by variable flow both in the phantom and in vivo. In six volunteers, partial dephasing noticeably decreased artifacts in all of the phase-cycled cardiac cine datasets. Partial dephasing can mitigate the flow artifacts seen at the stopbands in balanced SSFP while maintaining the sequence's desired signal. By mitigating hyper-enhancement and transient-related artifacts originating from the stopbands, partial dephasing facilitates robust multiple-acquisition phase-cycled SSFP in the heart. Magn Reson Med 79:2944-2953, 2018. © 2017 International Society for Magnetic Resonance in Medicine. © 2017 International Society for Magnetic Resonance in Medicine.

Evidence of the Role of Physical Activity and Cardiorespiratory Fitness in the Prevention of Coronary Heart Disease.

Science.gov (United States)

Leon, Arthur S.; Norstrom, Jane

1995-01-01

This paper presents epidemiologic evidence on the contributions of physical inactivity and reduced cardiorespiratory fitness to risk of coronary heart disease (CHD). The types and dose of physical activity to reduce risk of CHD and plausible biologic mechanisms for the partial protective effect are reviewed. (Author/SM)

Soft computing in artificial intelligence

CERN Document Server

Matson, Eric

2014-01-01

This book explores the concept of artificial intelligence based on knowledge-based algorithms. Given the current hardware and software technologies and artificial intelligence theories, we can think of how efficient to provide a solution, how best to implement a model and how successful to achieve it. This edition provides readers with the most recent progress and novel solutions in artificial intelligence. This book aims at presenting the research results and solutions of applications in relevance with artificial intelligence technologies. We propose to researchers and practitioners some methods to advance the intelligent systems and apply artificial intelligence to specific or general purpose. This book consists of 13 contributions that feature fuzzy (r, s)-minimal pre- and β-open sets, handling big coocurrence matrices, Xie-Beni-type fuzzy cluster validation, fuzzy c-regression models, combination of genetic algorithm and ant colony optimization, building expert system, fuzzy logic and neural network, ind...

Partial discharge characteristics and mechanism in voids at impulse voltages

International Nuclear Information System (INIS)

Zhao, X F; Guo, Z F; Wang, Y Y; Li, J H; Li, Y M; Yao, X

2011-01-01

Partial discharge (PD) characteristics and mechanism in artificial cavities in an epoxy plate have been investigated for different void dimensions and impulse voltage waveforms. A differential measurement system was developed in order to detect PD current pulses effectively. Experimental results showed that the 50% probability PD inception voltage (PDIV 50 ) increases initially as the cavity diameter decreases at constant depth for double exponential impulses as well as oscillating impulses, but after aging, it becomes independent of the cavity diameter. Moreover, some distinctive characteristics of PD (e.g. main discharge and reverse discharge during the rise and fall phases of the applied voltage) were also investigated. The differences of the PD propagation and the mechanism between double exponential impulses and oscillating impulse were discussed

Seasonal variation of plankton communities influenced by environmental factors in an artificial lake

Science.gov (United States)

Li, Xuemei; Yu, Yuhe; Zhang, Tanglin; Feng, Weisong; Ao, Hongyi; Yan, Qingyun

2012-05-01

We evaluated the seasonal variation in plankton community composition in an artificial lake. We conducted microscopic analysis and denaturing gradient gel electrophoresis (DGGE) of PCR-amplified partial 16S rRNA and 18S rRNA genes to characterize the plankton community. The clustering of unweighted pair group method with arithmetic mean (UPGMA) was then used to investigate the similarity of these plankton communities. DGGE fingerprinting revealed that samples collected at the different sites within a season shared high similarity and were generally grouped together. In contrast, we did not observe any seasonal variation based on microscopic analysis. Redundancy analysis (RDA) of the plankton operational taxonomic units (OTUs) in relation to environmental factors revealed that transparency was negatively correlated with the first axis ( R=-0.931), and temperature and total phosphorus (TP) were positively correlated with the first axis ( R=0.736 and R=0.660, respectively). In conclusion, plankton communities in the artificial lake exhibited significant seasonal variation. Transparency, phosphorus and temperature appear to be the major factors driving the differences in plankton composition.

Can We Predict Plan Quality for External Beam Partial Breast Irradiation: Results of a Multicenter Feasibility Study (Trans Tasman Radiation Oncology Group Study 06.02)

Energy Technology Data Exchange (ETDEWEB)

Kron, Tomas, E-mail: Tomas.Kron@petermac.org [Peter MacCallum Cancer Centre, Departments of Radiation Oncology, Physical Sciences and Radiation Therapy, Melbourne, Victoria (Australia); Sir Peter MacCallum Department of Oncology, University of Melbourne, Melbourne, Victoria (Australia); School of Science, Engineering and Technology, Royal Melbourne Institute of Technology University, Melbourne, Victoria (Australia); Willis, David; Link, Emma [Peter MacCallum Cancer Centre, Departments of Radiation Oncology, Physical Sciences and Radiation Therapy, Melbourne, Victoria (Australia); Lehman, Margot [Princess Alexandra Hospital, Department of Radiation Oncology, Brisbane, Queensland (Australia); Campbell, Gillian [Auckland City Hospital, Department of Radiation Oncology, Auckland (New Zealand); O' Brien, Peter [Newcastle Calvary Mater Hospital, Department of Radiation Oncology, Newcastle, NSW (Australia); Chua, Boon [Peter MacCallum Cancer Centre, Departments of Radiation Oncology, Physical Sciences and Radiation Therapy, Melbourne, Victoria (Australia); Sir Peter MacCallum Department of Oncology, University of Melbourne, Melbourne, Victoria (Australia)

2013-11-15

Purpose: Partial breast irradiation (PBI) after lumpectomy may be an option for selected patients with early breast cancer. A feasibility study of accelerated PBI delivered using external beam 3-dimensional conformal radiation therapy (RT) was undertaken at 8 Australasian centers. The present study evaluated the impact of patient, tumor, and RT technique-related factors on the quality of RT plans as determined by the dose–volume parameters of organs at risk. Methods and Materials: Forty-eight patients were enrolled in the study. All RT plans were centrally reviewed using predefined dosimetric criteria before commencement and after completion of protocol therapy. The RT plans of 47 patients met the dose–volume constraints, and all 47 patients received PBI to a prescribed dose of 38.5 Gy in 10 fractions. The RT plan quality was determined by volumes of the ipsilateral whole breast, lung, and heart that received 50% and 95%; 30%; and 5% of the prescribed dose, respectively. Patient, tumor, and RT technique-related factors were investigated for association with the parameters of RT plan quality. Results: The ratio of the planning target volume to the ipsilateral whole-breast volume was significantly associated with the ipsilateral breast doses on multiple variable analyses. The distance of the postlumpectomy surgical cavity from the heart and lung were predictive for heart and lung doses, respectively. A distance between surgical cavity and heart of >4 cm typically resulted in <1% of the heart volume receiving 5 Gy or less. It was more difficult to meet the heart dose constraint for left-sided and medially located tumors. Conclusions: Partial breast irradiation using 3-dimensional conformal RT was feasible within the study constraints. The ratio of planning target volume to ipsilateral whole-breast volume and the distance of surgical cavity from the heart were significant predictors of the quality of treatment plan for external beam PBI.

Can We Predict Plan Quality for External Beam Partial Breast Irradiation: Results of a Multicenter Feasibility Study (Trans Tasman Radiation Oncology Group Study 06.02)

International Nuclear Information System (INIS)

Kron, Tomas; Willis, David; Link, Emma; Lehman, Margot; Campbell, Gillian; O'Brien, Peter; Chua, Boon

2013-01-01

Purpose: Partial breast irradiation (PBI) after lumpectomy may be an option for selected patients with early breast cancer. A feasibility study of accelerated PBI delivered using external beam 3-dimensional conformal radiation therapy (RT) was undertaken at 8 Australasian centers. The present study evaluated the impact of patient, tumor, and RT technique-related factors on the quality of RT plans as determined by the dose–volume parameters of organs at risk. Methods and Materials: Forty-eight patients were enrolled in the study. All RT plans were centrally reviewed using predefined dosimetric criteria before commencement and after completion of protocol therapy. The RT plans of 47 patients met the dose–volume constraints, and all 47 patients received PBI to a prescribed dose of 38.5 Gy in 10 fractions. The RT plan quality was determined by volumes of the ipsilateral whole breast, lung, and heart that received 50% and 95%; 30%; and 5% of the prescribed dose, respectively. Patient, tumor, and RT technique-related factors were investigated for association with the parameters of RT plan quality. Results: The ratio of the planning target volume to the ipsilateral whole-breast volume was significantly associated with the ipsilateral breast doses on multiple variable analyses. The distance of the postlumpectomy surgical cavity from the heart and lung were predictive for heart and lung doses, respectively. A distance between surgical cavity and heart of >4 cm typically resulted in <1% of the heart volume receiving 5 Gy or less. It was more difficult to meet the heart dose constraint for left-sided and medially located tumors. Conclusions: Partial breast irradiation using 3-dimensional conformal RT was feasible within the study constraints. The ratio of planning target volume to ipsilateral whole-breast volume and the distance of surgical cavity from the heart were significant predictors of the quality of treatment plan for external beam PBI

Artificial Intelligence

CERN Document Server

Warwick, Kevin

2011-01-01

if AI is outside your field, or you know something of the subject and would like to know more then Artificial Intelligence: The Basics is a brilliant primer.' - Nick Smith, Engineering and Technology Magazine November 2011 Artificial Intelligence: The Basics is a concise and cutting-edge introduction to the fast moving world of AI. The author Kevin Warwick, a pioneer in the field, examines issues of what it means to be man or machine and looks at advances in robotics which have blurred the boundaries. Topics covered include: how intelligence can be defined whether machines can 'think' sensory

Healthy Body, Happy Heart: Improve Your Heart Health

Science.gov (United States)

... November 2017 Print this issue Healthy Body, Happy Heart Improve Your Heart Health En español Send us your comments Every moment of the day, your heart is pumping blood throughout your body. In silent ...

Charlas sobre inteligencia artificial

OpenAIRE

Álvarez Sánchez, José Ramón; Ferrández Vicente, José Manuel; Paz López, Félix de la

2014-01-01

Serie: Informática en Radio 3 La Inteligencia Artificial es una de las ciencias que causa mayor impacto en la sociedad, mucho más si tenemos en cuenta que cambiará el futuro de la humanidad. En España existen actualmente un nutrido grupo de equipos de investigación relacionados con las tecnologías de computación natural-artificial que aúnan sus esfuerzos a través de la RTNAC la Red Temática en Tecnologías de Computación Natural-Artificial . La UNED participa en todas sus actividades desde ...

Artificial Intelligence Project

Science.gov (United States)

1990-01-01

Symposium on Aritificial Intelligence and Software Engineering Working Notes, March 1989. Blumenthal, Brad, "An Architecture for Automating...Artificial Intelligence Project Final Technical Report ARO Contract: DAAG29-84-K-OGO Artificial Intelligence LaboratO"ry The University of Texas at...Austin N>.. ~ ~ JA 1/I 1991 n~~~ Austin, Texas 78712 ________k A,.tificial Intelligence Project i Final Technical Report ARO Contract: DAAG29-84-K-0060

Cast Partial Denture versus Acrylic Partial Denture for Replacement of Missing Teeth in Partially Edentulous Patients

Directory of Open Access Journals (Sweden)

Pramita Suwal

2017-03-01

Full Text Available Aim: To compare the effects of cast partial denture with conventional all acrylic denture in respect to retention, stability, masticatory efficiency, comfort and periodontal health of abutments. Methods: 50 adult partially edentulous patient seeking for replacement of missing teeth having Kennedy class I and II arches with or without modification areas were selected for the study. Group-A was treated with cast partial denture and Group-B with acrylic partial denture. Data collected during follow-up visit of 3 months, 6 months, and 1 year by evaluating retention, stability, masticatory efficiency, comfort, periodontal health of abutment. Results: Chi-square test was applied to find out differences between the groups at 95% confidence interval where p = 0.05. One year comparison shows that cast partial denture maintained retention and stability better than acrylic partial denture (p< 0.05. The masticatory efficiency was significantly compromising from 3rd month to 1 year in all acrylic partial denture groups (p< 0.05. The comfort of patient with cast partial denture was maintained better during the observation period (p< 0.05. Periodontal health of abutment was gradually deteriorated in all acrylic denture group (p

Participation in Heart-Healthy Behaviors: A Secondary Analysis of the American Heart Association Go Red Heart Match Data.

Science.gov (United States)

Arslanian-Engoren, Cynthia; Eastwood, Jo-Ann; De Jong, Marla J; Berra, Kathy

2015-01-01

The American Heart Association created Go Red Heart Match, a free and secure online program that enables women to connect with each other to fight heart disease either personally or as a caregiver for someone with heart disease. Through these connections, participants have an opportunity to develop a personal, private, and supportive relationship with other women; share common experiences; and motivate and encourage each other to follow a heart-healthy lifestyle. The aims of this study were to describe the demographic characteristics of the Go Red Heart Match responders and to determine whether participation in the program prompted participants to engage in heart-healthy behaviors. A secondary analysis of data collected as part of a needs assessment survey from the American Heart Association Go Red Heart Match was conducted. A total of 117 (35%) of the 334 invited women completed the survey. Most responders were female, married, and college educated. A total of 105 (90%) responders were diagnosed with a type of heart disease or stroke and 77 (73%) responders had undergone treatment. As a result of participating in the program, 75% of the responders reported the following improvements in heart-healthy behaviors: eating a more heart-healthy diet (54%), exercising more frequently (53%), losing weight (47%), and quitting smoking (10%). Responders who had a diagnosis of heart attack (n = 48) were more likely (P = .003) to quit smoking than were those with other diagnoses (n = 69). Notably, 48% of responders reported encouraging someone else in their life to speak to their doctor about their risk for heart disease. Most women who participated in Heart Match reported engaging in new heart-healthy behaviors. The findings support expanding the existing program in a more diverse population as a potentially important way to reach women and encourage cardiovascular disease risk reduction for those with heart disease and stroke.

Rearing the southern green stink bug using an artificial dry diet and an artificial plant Criação do percevejo-verde usando dieta artificial seca e planta artificial

Directory of Open Access Journals (Sweden)

ANTÔNIO RICARDO PANIZZI

2000-09-01

Full Text Available Laboratory and greenhouse studies were conducted with an artificial dry diet to rear nymphs, and with an artificial plant as substrate for egg laying by the southern green stink bug, Nezara viridula (L.. The artificial diet was composed of: soybean protein (15 g; potato starch (7.5 g; dextrose (7.5 g; sucrose (2.5 g; cellulose (12.5 g; vitamin mixture (niacinamide 1 g, calcium pantothenate 1 g, thiamine 0.25 g, riboflavin 0.5 g, pyridoxine 0.25 g, folic acid 0.25 g, biotin 0.02 mL, vitamin B12 1 g - added to 1,000 mL of distilled water (5.0 mL; soybean oil (20 mL; wheat germ (17.9 g; and water (30 mL. Nymphs showed normal feeding behavior when fed on the artificial diet. Nymphal development time was longer than or similar to that of nymphs fed on soybean pods. Total nymphal mortality was low (ca. 30%, both for nymphs reared on the artificial diet, and for nymphs fed on soybean pods. At adult emergence, fresh body weights were significantly (PForam conduzidos estudos em laboratório e em casa de vegetação, com uma dieta artificial seca para a criação de ninfas e com um modelo de planta artificial como substrato para a colocação de ovos por adultos do percevejo-verde, Nezara viridula (L.. Os componentes da dieta artificial foram: proteína de soja (15 g; fécula de batata (7,5 g; dextrose (7,5 g; sacarose (2,5 g; celulose (12,5 g; mistura vitamínica (niacinamida 1 g, pantotenato de cálcio 1 g, tiamina 0,25 g, riboflavina 0,5 g, piridoxina 0,25 g, ácido fólico 0,25 g, biotina 0,02 mL, vitamina B12 1 g, adicionada em 1.000 mL de água destilada (5,0 mL; óleo de soja (20 mL; germe de trigo (17,9 g; e água (30 mL. As ninfas alimentaram-se normalmente da dieta, embora o tempo de desenvolvimento tenha sido em um caso, maior, e em outro, semelhante, ao das ninfas que se alimentaram de vagens da soja. A mortalidade total das ninfas foi baixa (ca. 30%, tanto na dieta como na vagem de soja. Na emergência, os adultos apresentaram peso fresco

Beyond AI: Artificial Dreams Conference

CERN Document Server

Zackova, Eva; Kelemen, Jozef; Beyond Artificial Intelligence : The Disappearing Human-Machine Divide

2015-01-01

This book is an edited collection of chapters based on the papers presented at the conference “Beyond AI: Artificial Dreams” held in Pilsen in November 2012. The aim of the conference was to question deep-rooted ideas of artificial intelligence and cast critical reflection on methods standing at its foundations.  Artificial Dreams epitomize our controversial quest for non-biological intelligence, and therefore the contributors of this book tried to fully exploit such a controversy in their respective chapters, which resulted in an interdisciplinary dialogue between experts from engineering, natural sciences and humanities.   While pursuing the Artificial Dreams, it has become clear that it is still more and more difficult to draw a clear divide between human and machine. And therefore this book tries to portrait such an image of what lies beyond artificial intelligence: we can see the disappearing human-machine divide, a very important phenomenon of nowadays technological society, the phenomenon which i...

Enlarged Heart

Science.gov (United States)

... rheumatic fever, a heart defect, infections (infectious endocarditis), connective tissue disorders, certain medications or radiation treatments for cancer, your heart may enlarge. Disease of the heart ...

Mild Oxidative Damage in the Diabetic Rat Heart Is Attenuated by Glyoxalase-1 Overexpression

Directory of Open Access Journals (Sweden)

Casper G. Schalkwijk

2013-07-01

Full Text Available Diabetes significantly increases the risk of heart failure. The increase in advanced glycation endproducts (AGEs and oxidative stress have been associated with diabetic cardiomyopathy. We recently demonstrated that there is a direct link between AGEs and oxidative stress. Therefore, the aim of the current study was to investigate if a reduction of AGEs by overexpression of the glycation precursor detoxifying enzyme glyoxalase-I (GLO-I can prevent diabetes-induced oxidative damage, inflammation and fibrosis in the heart. Diabetes was induced in wild-type and GLO-I transgenic rats by streptozotocin. After 24-weeks of diabetes, cardiac function was monitored with ultrasound under isoflurane anesthesia. Blood was drawn and heart tissue was collected for further analysis. Analysis with UPLC-MSMS showed that the AGE Nε-(1-carboxymethyllysine and its precursor 3-deoxyglucosone were significantly elevated in the diabetic hearts. Markers of oxidative damage, inflammation, and fibrosis were mildly up-regulated in the heart of the diabetic rats and were attenuated by GLO-I overexpression. In this model of diabetes, these processes were not accompanied by significant changes in systolic heart function, i.e., stroke volume, fractional shortening and ejection fraction. This study shows that 24-weeks of diabetes in rats induce early signs of mild cardiac alterations as indicated by an increase of oxidative stress, inflammation and fibrosis which are mediated, at least partially, by glycation.

Artificial Photosynthesis: Beyond Mimicking Nature

International Nuclear Information System (INIS)

Dau, Holger; Fujita, Etsuko; Sun, Licheng

2017-01-01

In this Editorial, Guest Editors Holger Dau, Etsuko Fujita, and Licheng Sun introduce the Special Issue of ChemSusChem on “Artificial Photosynthesis for Sustainable Fuels”. Here, they discuss the need for non-fossil based fuels, introduce both biological and artificial photosynthesis, and outline various important concepts in artificial photosynthesis, including molecular and solid-state catalysts for water oxidation and hydrogen evolution, catalytic CO 2 reduction, and photoelectrochemical systems.

Parallel artificial liquid membrane extraction

DEFF Research Database (Denmark)

Gjelstad, Astrid; Rasmussen, Knut Einar; Parmer, Marthe Petrine

2013-01-01

This paper reports development of a new approach towards analytical liquid-liquid-liquid membrane extraction termed parallel artificial liquid membrane extraction. A donor plate and acceptor plate create a sandwich, in which each sample (human plasma) and acceptor solution is separated by an arti......This paper reports development of a new approach towards analytical liquid-liquid-liquid membrane extraction termed parallel artificial liquid membrane extraction. A donor plate and acceptor plate create a sandwich, in which each sample (human plasma) and acceptor solution is separated...... by an artificial liquid membrane. Parallel artificial liquid membrane extraction is a modification of hollow-fiber liquid-phase microextraction, where the hollow fibers are replaced by flat membranes in a 96-well plate format....

Women's Heart Disease: Join the Heart Truth Community

Science.gov (United States)

... this page please turn JavaScript on. Feature: Women's Heart Disease Join The Heart Truth Community Past Issues / Winter 2014 Table of Contents National Symbol The centerpiece of The Heart Truth ® is The Red Dress ® which was introduced ...

Keeping the heart in balance: the functional interactions of myoglobin with nitrogen oxides

DEFF Research Database (Denmark)

Flögel, Ulrich; Fago, Angela; Rassaf, Tienush

2010-01-01

in the heart. By a dynamic cycle, in which a decrease in tissue O2 tension drives the conversion of Mb from being a NO scavenger under normoxia to a NO producer during hypoxia, mitochondrial respiration is reversibly adapted to the intracellular O2 tension. Therefore, Mb may act as an important O2 sensor...... through which NO can regulate muscle energetics and function. As Mb is widespread throughout the fauna, the diverse oxygen-dependent interactions between Mb and nitrogen oxides may not only be of relevance for mammals but also for other vertebrates as evidenced by comparable phenotypes of ‘artificial...

Technical Note: Evaluation of a 160-mm/256-row CT scanner for whole-heart quantitative myocardial perfusion imaging

Energy Technology Data Exchange (ETDEWEB)

So, Aaron, E-mail: aso@robarts.ca [Imaging Program, Lawson Health Research Institute, London, Ontario N6A 4V2 (Canada); Imai, Yasuhiro; Nett, Brian; Jackson, John; Nett, Liz; Hsieh, Jiang [CT Engineering, GE Healthcare, Waukesha, Wisconsin 53188 (United States); Wisenberg, Gerald; Teefy, Patrick; Yadegari, Andrew [Cardiology, University Hospital, London Health Sciences Centre, London, Ontario N6A 5A5 (Canada); Islam, Ali [Radiology, St. Joseph’s Hospital London, Ontario N6A 4V2 (Canada); Lee, Ting-Yim [Imaging Program, Lawson Health Research Institute, London, Ontario N6A 4V2, Canada and Imaging Research Laboratories, Robarts Research Institute, London, Ontario N6A 5K8 (Canada)

2016-08-15

Purpose: The authors investigated the performance of a recently introduced 160-mm/256-row CT system for low dose quantitative myocardial perfusion (MP) imaging of the whole heart. This platform is equipped with a gantry capable of rotating at 280 ms per full cycle, a second generation of adaptive statistical iterative reconstruction (ASiR-V) to correct for image noise arising from low tube voltage potential/tube current dynamic scanning, and image reconstruction algorithms to tackle beam-hardening, cone-beam, and partial-scan effects. Methods: Phantom studies were performed to investigate the effectiveness of image noise and artifact reduction with a GE Healthcare Revolution CT system for three acquisition protocols used in quantitative CT MP imaging: 100, 120, and 140 kVp/25 mAs. The heart chambers of an anthropomorphic chest phantom were filled with iodinated contrast solution at different concentrations (contrast levels) to simulate the circulation of contrast through the heart in quantitative CT MP imaging. To evaluate beam-hardening correction, the phantom was scanned at each contrast level to measure the changes in CT number (in Hounsfield unit or HU) in the water-filled region surrounding the heart chambers with respect to baseline. To evaluate cone-beam artifact correction, differences in mean water HU between the central and peripheral slices were compared. Partial-scan artifact correction was evaluated from the fluctuation of mean water HU in successive partial scans. To evaluate image noise reduction, a small hollow region adjacent to the heart chambers was filled with diluted contrast, and contrast-to-noise ratio in the region before and after noise correction with ASiR-V was compared. The quality of MP maps acquired with the CT system was also evaluated in porcine CT MP studies. Myocardial infarct was induced in a farm pig from a transient occlusion of the distal left anterior descending (LAD) artery with a catheter-based interventional procedure. MP