Aerospace Medicine and Biology: A continuing bibliography with indexes (supplement 156)

This bibliography lists 170 reports, articles, and other documents introduced into the NASA scientific and technical information system in June 1976

Cardiovascular instrumentation for spaceflight

The observation mechanisms dealing with pressure, flow, morphology, temperature, etc. are discussed. The approach taken in the performance of this study was to (1) review ground and space-flight data on cardiovascular function, including earlier related ground-based and space-flight animal studies, Mercury, Gemini, Apollo, Skylab, and recent bed-rest studies, (2) review cardiovascular measurement parameters required to assess individual performance and physiological alternations during space flight, (3) perform an instrumentation survey including a literature search as well as personal contact with the applicable investigators, (4) assess instrumentation applicability with respect to the established criteria, and (5) recommend future research and development activity. It is concluded that, for the most part, the required instrumentation technology is available but that mission-peculiar criteria will require modifications to adapt the applicable instrumentation to a space-flight configuration

Aerospace medicine and biology: A continuing bibliography with indexes, supplement 218, April 1981

This bibliography lists 161 reports, articles, and other documents introduced into the NASA scientific and technical information system in March 1981

Future of Tele-echocardiography

Telemedicine is defined as the ‘delivery of health care and sharing of medical knowledge over a distance using telecommunication systems’. Echocardiography is often used to diagnose and exclude important cardiac diagnoses in adults and children. Evolving telemedicine technology has boosted access to echocardiography and has created a network that offers many possibilities for clinical, research and teaching activities.The two primary modes of telemedicine practise are ‘ store and forward’ and ‘real time’ videoconferencing. Using these technologies, relevant, up-to-date scientific information is instantly available for analysis and interaction. Studies have also shown these to be accurate, cost effective, improves patient care, enhances echocardiography quality and sonographer proficiency and promotes practice expansion.The growing use of technology such as smart phones, laptops and computer tablets as well as newer technologies like cloud computing, picture archiving computer systems(PACS) and the standardization of medical images(DICOM) has fuelled the now accelerating specific demands for tele-echocardiography. However, all these are not without challenges and obstacles. Some of these include lack of standardization of telemedicine components, confusing medico-legal and licensure issues, privacy/confidentiality, poor reimbursement, training issues as well as attitude and acceptance.These issues need to be addressed by all those involved in medical practice. Clinicians must work with sonographers, medical IT experts, hospital management and hospital physicists as well as manufacturers and insurance companies to ensure that the new system is integrated as an extra function within ultrasound consoles. National and international societies such as the European Society of Cardiology (ESC) and the American College of Cardiology (ACC) could play a role in bringing everyone together and define the necessary training programmes. In conclusion, the revolution in digital technology is rapidly changing the world of telecommunications. Tele-echocardiography has a bright future to become an integrated part of our clinical available echocardiographic tool set – in a matter of tim

Comparison of heart valve flow dynamics assessment between echocardiography and pulse duplication

Published ThesisHeart valve surgery and valvular heart disease still pose a significant threat to patients worldwide. The aortic valve doesn't remain healthy and has largely been the focus of innovation and the development of replacement heart valves. Improving the ability of blood to flow througha prosthetic valve while minimizing the load on the heart is regarded as one of the performance objectives of prosthetic heart valves. In order to meet valvular performance objectives and to assess whether potential prosthetic heart valves meets hydrodynamic performance, testing simulated under in vivo flow conditions is necessary. Pulse duplication is widely accepted as a valid method to determine the performance of heart valves during their development. Few specialised centres exist to perform pulse duplication tests accurately and in accordance to the required ISO and FDA standards for cardiovascular implants. Real-time patient data of prosthetic heart valves is however not obtained with pulse duplication but with echocardiography. Modern day pulse duplicators come equipped with viewing chambers that can allow for echocardiographic measurements. Therefore, the aim of this study was to perform pulse duplication and echocardiography simultaneously on five different prosthetic heart valves using a commercial ViVitro pulse duplicator system. METHODS A hydrodynamic evaluation was performed on five prosthetic heart valves (i) Medtronic-Hall mechanical valve (tilting disc), (ii) Carbomedics mechanical valve (bileaflet), (iii) Glycar mechanical valve (Glycar), (iv) Edwards Perimount (tissue valve), (v) ViVitro reference (ViVitro) using pulse duplication and echocardiography. All the valves were inserted in the aortic position of the pulse duplicator and echocardiographic measurements was performed simultaneously. Each of the valves were tested at 5 different testing conditions by varying the stroke volume and beats per minute. The study concludes with a comparison between the pulse duplicator data and the echocardiography data acquired. RESULTS Pulse duplication: -The Glycar valve had the largest pressure drop across the valve at the lowest CO (3.6 L/min) of 17.15 mmHg, although it increased steadily at a slower rate than the other four valves. The Glycar and tissue valve had the highest EOA of 1.885 cm2 and 1.884 cm2 respectively at a peak CO of 9.6 L/min. The bi-leaflet valve had the highest EOA of 2.002 cm2 (CO 3.6 L/min), however the EOA deteriorated as the CO increased resulting in an EOA of 1.572 cm2 at a CO of 9.6L/min. The tissue valve had the largest RF for all testing conditions, ranging from 16.3% (CO 8.0 L/min) to 25.6% (4.9 L/min) where the bi-leaflet valve had the lowest (0.72% - 3.42%). Echocardiography: -The Glycar valve had the lowest overall pressure drop for all CO. The pulse duplicator pressure drop results were more consistent than three echocardiography results measured on the pulse duplicator. The bileaflet and Glycar valves EOA showed better consistency across the CO range than the ViVitro, tissue and tilting disk valves. The data showed that no definite correlation between all the valves exists between echocardiography and pulse duplication for EOA. However, a correlation for pressure drop between the pulse duplicator and echocardiographic data was demonstrated for both the tissue and bi-leaflet valve

Second-opinion stress tele-echocardiography for the Adonhers (Aged donor heart rescue by stress echo) project

<p>Abstract</p> <p>Background</p> <p>To resolve the current shortage of donor hearts, we established the Adonhers protocol. An upward shift of the donor age cut-off limit (from the present 55 to 65 years) is acceptable if a stress echo screening on the candidate donor heart is normal. This study aimed to verify feasibility of a "second opinion" of digitally transferred images of stress echo results to minimize technical variability in selection of aged donor hearts for heart transplant.</p> <p>Methods</p> <p>The informatics infrastructure was created for a core lab reading with a second opinion from the Pisa stress echo lab. To test the system, simulation standard stress echo cineloops were sent digitally from 5 peripheral labs to the central core lab.</p> <p>Starting January 2009, real marginal donor stress echos were sent via internet to the central core echo lab, Pisa, for a second opinion before heart transplant.</p> <p>Results</p> <p>In the simulation protocol, 30 dipyridamole stress echocardiograms were sent from the five peripheral echo labs to the central core lab in Pisa. Both the echo images and reports were correctly uploaded in the web system and sent to the core echo lab; the second opinion evaluation was obtained in all cases (100% feasibility). In the transplant protocol, eight donor cases were sent to the Pisa core lab for the second opinion protocol, and six of them were transplanted in marginal recipients.</p> <p>Conclusions</p> <p>Second-Opinion Stress Tele-Echocardiography can effectively be performed in a network aimed to safely expand the heart donor pool for heart transplant.</p