Technology applications

A summary of NASA Technology Utilization programs for the period of 1 December 1971 through 31 May 1972 is presented. An abbreviated description of the overall Technology Utilization Applications Program is provided as a background for the specific applications examples. Subjects discussed are in the broad headings of: (1) cancer, (2) cardiovascular disease, (2) medical instrumentation, (4) urinary system disorders, (5) rehabilitation medicine, (6) air and water pollution, (7) housing and urban construction, (8) fire safety, (9) law enforcement and criminalistics, (10) transportation, and (11) mine safety

Comparison of heart measurements in thoracic radiographs before and after the treatment of pulmonary edema in dogs with degenerative mitral valve disease : a retrospective study of 18 clinical cases

Dissertação de Mestrado Integrado em Medicina VeterináriaThe Degenerative Mitral Valve Disease (DMVD) has the highest prevalence of all canine heart diseases accounting for 75-80% of the cases of dogs with cardiac disease. DMVD is characterized by having an evolutive nature. As the disease progresses the microscopic and macroscopic alterations of the mitral valve’s apparatus become more severe and gradually start preventing the valve’s normal function. One of the complications that may occur is the development of pulmonary edema. Overt pulmonary edema occurs when the capacity of the pulmonary lymphatic system is exceeded, leading to an increase in the extravascular water content of the lungs. The etiology and consequently the cure for DMVD are not currently known, hence the importance of understanding and developing tools that allow the monitoring of the disease. Even though the best way to assess and confirm the diagnosis of DMVD is through echocardiography, this exam requires additional expertise to be performed and interpreted, as well as substantial financial costs to the owner. Simultaneously, radiography of the thorax is widely available and cost-effective, which justifies the interest in studying the evolution of the radiographic measures Vertebral Heart Score (VHS) and Vertebral Left Atrium Size (VLAS) in dogs with DMVD. This retrospective study aims to compare heart measurements in thoracic radiographs before and after the treatment of pulmonary edema in 18 dogs with DMVD that were submitted to consultation in a french veterinary referral center. The main conclusion of this study is that the size of the left atrium and the cardiac silhouette decreases after the resolution of cardiogenic pulmonary edema when compared to the dimensions during its occurrence. Furthermore, this decrease in the left atrium’s size is detectable using the VLAS method, which confirms its value in monitoring the progression of the disease. Consequently, it is possible for those who do not have access to an echocardiographic exam, to use the VLAS method to follow the evolution of the left atrium’s size throughout the progression of DMVD. It was also verified that VLAS measurements have a positive correlation with echocardiographic measures of the left atrium, implying that when one increases the other does so as well, and vice-versa.RESUMO - Comparação de medições cardíacas em radiografias torácicas antes e depois do tratamento de edema pulmonar em animais com Doença Degenerativa da Válvula Mitral: um estudo retrospetivo de 18 casos clínicos - A Doença Degenerativa da Válvula Mitral (DDVM) tem a prevalência mais alta de todas as doenças cardíacas caninas, representando 75-80% dos casos destes doentes. A DDVM é caracterizada pela sua natureza evolutiva. Assim à medida que a doença progride, as alterações microscópicas e macroscópicas da válvula mitral tornam-se mais graves e começam gradualmente a impedir o seu normal funcionamento. Uma das complicações que pode ocorrer é o desenvolvimento de edema pulmonar que sucede quando a capacidade do sistema linfático do pulmão é excedida, levando, por isso, à acumulação de conteúdo aquoso no compartimento extravascular dos mesmos. A etiologia e consequentemente a cura da DDVM não são atualmente conhecidas, dai a importância em perceber e desenvolver ferramentas que permitam a monitorização da doença. Embora a melhor maneira de determinar e confirmar o diagnóstico de DDVM seja através de uma ecocardiografia, este exame de diagnóstico representa um investimento para o proprietário, necessita de material caro e exige um nível de competência mais elevado para o realizar e interpretar. Simultaneamente, a realização de radiografias do tórax é uma técnica amplamente disponível e económica, o que justifica o interesse em estudar a evolução das medidas radiográficas Vertebral Heart Score (VHS) e Vertebral Left Atrium Size (VLAS) em cães com DDVM. O objetivo deste estudo retrospetivo prende-se com a comparação de medidas cardíacas, em radiografias da cavidade torácica, antes e depois do tratamento de edema pulmonar em 18 cães com DDVM que foram apresentados em consulta num centro hospitalar veterinário de referência francês. A principal conclusão deste estudo indica que o tamanho do átrio esquerdo e da silhueta cardíaca diminui depois da resolução do edema pulmonar de origem cardíaca, quando comparado com as dimensões durante a sua ocorrência. Adicionalmente, esta diminuição de tamanho do átrio esquerdo é detetável utilizando o método VLAS, o que confirma o seu valor na monitorização da progressão da doença. Consequentemente, é possível para aqueles que não têm acesso a um exame ecocardiográfico, utilizarem o método VLAS para seguir a evolução do tamanho do átrio esquerdo durante a progressão da DDVM. Também se verificou que as medições VLAS têm uma correlação positiva com as medidas ecocardiográficas do átrio esquerdo, o que implica que quando uma medida aumenta a outra aumenta também, e vice-versa.N/

Southwest Research Institute assistance to NASA in biomedical areas of the technology utilization program Final report, 1 Feb. 1969 - 24 Aug. 1970

Research progress in technology transfer by NASA Biomedical Application Tea

Remote measurements of heart valve sounds for health assessment and biometric identification

Heart failure will contribute to the death of one in three people who read this thesis; and one in three of those who don't. Although in order to diagnose patients’ heart condition cardiologists have access to electrocardiograms, chest X-rays, ultrasound imaging, MRI, Doppler techniques, angiography, and transesophageal echocardiography, these diagnostic techniques require a cardiologist’s visit, are expensive, the examination time is long and so are the waiting lists. Furthermore abnormal events might be sporadic and thus constant monitoring would be needed to avoid fatalities. Therefore in this thesis we propose a cost effective device which can constantly monitor the heart condition based on the principles of phonocardiography, which is a cost-effective method which records heart sounds. Manual auscultation is not widely used to diagnose because it requires considerable training, it relies on the hearing abilities of the clinician and specificity and sensitivity for manual auscultation are low since results are qualitative and not reproducible. However we propose a cheap laser-based device which is contactless and can constantly monitor patients’ heart sounds with a better SNR than the digital stethoscope. We also propose a Machine Learning (ML) aided software trained on data acquired with our device which can classify healthy from unhealthy heart sounds and can perform biometric authentication. This device might allow development of gadgets for remote monitoring of cardiovascular health in different settings

Development of a digital ascultometer for the diagnosis of heart murmurs

В процессе исследования был создан макет цифрового аускультометра проведена аускультация звуков сердца и легких на полученном устройстве. В результате изучения характеристик цифрового аускультометра, устройство показал эффективность в диагностике сердца и легких: четко распознает звуки разного диапазона спектров частотIn the process of research it was created a layout of digital audio. As a result of studying the characteristics of a digital audio device, the device showed effectiveness in the diagnosis of the heart and lungs: clearly recognizable sounds of different frequency ranges

DEVELOPMENT OF A REPEATABLE DIP MOULDING PROCESS FOR MANUFACTURING POLYMER ARTIFICIAL HEART VALVES

Published ThesisPolyurethane heart valves have been widely studied as possible replacements for mechanical and biological heart valves. To function optimally, these valves have to be free from calcification, require no anticoagulation, function silently and have longevities exceeding those of biological heart valves. The potential widespread use of such valves certainly exists and modern materials and fabrication methods place it within reach. However, polymer heart valves that are available at present are unaffordable for large parts of the population. Therefore, the development of an inexpensive routine production technique for manufacturing of polyurethane heart valves will greatly benefit a very large number of patients in developing and emerging countries. Polyurethane heart valves show favourable physical properties and flow dynamics compared to human heart valves; however, the successful outcome of producing a polyurethane heart valve with the required flexibility, durability and hemodynamic function is often difficult to predict. The design of the mould, the selection of the material and the fabrication method used are key factors that influence the achievement of an acceptable heart valve for use in the human body. In this study, a repeatable, semi-automated dip moulding process for producing tri-leaflet polyurethane heart valves was developed. An experimental facility was designed and established, as well as an experimental dip-moulding mould, which allowed the selection of an appropriate set of dip-moulding process parameters and mould properties for the routine production of polyurethane valve leaflets with the required physical and mechanical properties. The results obtained from the experimental facility were evaluated with regard to compliance of the relevant properties, namely leaflet thickness, surface topography and mechanical strength, with the requirements of polymer heart valves. Additive manufacturing of Ti6Al4V (ELI) was used for producing the heart valve frame, sewing ring and mould. By applying the experimentally developed dip-moulding process and using the mould assembly, the valve leaflets were moulded directly onto the valve frame. The first prototype polyurethane heart valves were tested in the pulse duplicator machine of the Robert WM Frater Cardiovascular Research Centre of the University of the Free State. The valves displayed good opening and closing performance, mimicking the behaviour of natural heart valves during the pulse duplicator tests. Although these prototype valves did not meet all the minimum specifications of the ISO 5840 standard, it was clearly demonstrated that with further design improvements it would be possible to produce tri-leaflet valves through dip moulding, which would provide an attractive alternative to the tissue and mechanical heart valves currently used

DIGITAL ANALYSIS OF CARDIAC ACOUSTIC SIGNALS IN CHILDREN

DIGITAL ANALYSIS OF CARDIAC ACOUSTIC SIGNALS IN CHILDREN Milad El-Segaier, MD Division of Paediatric Cardiology, Department of Paediatrics, Lund University Hospital, Lund, Sweden SUMMARY Despite tremendous development in cardiac imaging, use of the stethoscope and cardiac auscultation remains the primary diagnostic tool in evaluation of cardiac pathology. With the advent of miniaturized and powerful technology for data acquisition, display and digital signal processing, the possibilities for detecting cardiac pathology by signal analysis have increased. The objective of this study was to develop a simple, cost-effective diagnostic tool for analysis of cardiac acoustic signals. Heart sounds and murmurs were recorded in 360 children with a single-channel device and in 15 children with a multiple-channel device. Time intervals between acoustic signals were measured. Short-time Fourier transform (STFT) analysis was used to present the acoustic signals to a digital algorithm for detection of heart sounds, define systole and diastole and analyse the spectrum of a cardiac murmur. A statistical model for distinguishing physiological murmurs from pathological findings was developed using logistic regression analysis. The receiver operating characteristic (ROC) curve was used to evaluate the discriminating ability of the developed model. The sensitivities and specificities of the model were calculated at different cut-off points. Signal deconvolution using blind source separation (BSS) analysis was performed for separation of signals from different sources. The first and second heart sounds (S1 and S2) were detected with high accuracy (100% for the S1 and 97% for the S2) independently of heart rates and presence of a murmur. The systole and diastole were defined, but only systolic murmur was analysed in this work. The developed statistical model showed excellent prediction ability (area under the curve, AUC = 0.995) in distinguishing a physiological murmur from a pathological one with high sensitivity and specificity (98%). In further analyses deconvolution of the signals was successfully performed using blind separation analysis. This yielded two spatially independent sources, heart sounds (S1 and S2) in one component, and a murmur in another. The study supports the view that a cost-effective diagnostic device would be useful in primary health care. It would diminish the need for referring children with cardiac murmur to cardiac specialists and the load on the health care system. Likewise, it would help to minimize the psychological stress experienced by the children and their parents at an early stage of the medical care

LVAD Occlusion Condition Monitoring Using Boost Classification Trees

Cardiac related diseases are a serious health risk for adults. Consequently, therapies exist to treat these aliments such as heart transplant and medication. Heart transplant remains the gold standard for treating severe heart failure, however left ventricular assistive devices, a cardiac blood pump, are become a viable long term treatment. Unfortunately, with the benefits of these devices come risks of clot formation. These occlusions can cause strokes, further cardiac damage, or even death. Therefore, it is critical that these occlusions be detected as early as possible. This work presents an expanded method to non-invasively monitor the condition of a Thoratec HeartMate II ventricular assist device through the application of a boosted classification tree. In addition, both inflow and outflow blockages measured at aorta and pump locations were experimentally tested on a cardiac phantom. The proposed method presents a potential outpatient diagnostic method that may assist experienced cardiologists in their treatment of LVAD patients

In-Suit Doppler Technology Assessment

The objective of this program was to perform a technology assessment survey of non-invasive air embolism detection utilizing Doppler ultrasound methodologies. The primary application of this technology will be a continuous monitor for astronauts while performing extravehicular activities (EVA's). The technology assessment was to include: (1) development of a full understanding of all relevant background research; and (2) a survey of the medical ultrasound marketplace for expertise, information, and technical capability relevant to this development. Upon completion of the assessment, LSR was to provide an overview of technological approaches and R&D/manufacturing organizations