Raymond L. H. Murphy

Bio: Raymond L. H. Murphy is an academic researcher from Harvard University. The author has contributed to research in topics: Crackles & Auscultation. The author has an hindex of 21, co-authored 38 publications receiving 1175 citations.

Visual Lung-Sound Characterization by Time-Expanded Wave-Form Analysis

Abstract: To characterize lung sounds objectively, we examined, by means of time-amplitude plots, selected tape recordings of auscultatory phenomena considered by six observers to be typical of those in a standard classification. Normal lung sounds could not consistently be visually distinguished from adventitious sounds at conventional chart recorder speeds of 100 mm per second or less, but the differentiation was easily achieved when the time scale of the plots was raised to 800 mm per second. When discontinuous sounds (rales, crackles or crepitations) were heard clinically, the time-expanded wave forms showed intermittent "discontinuous" deflections usually less than 10 msec in duration. When continuous sounds (rhonchi or wheezes) were heard, the deflections were usually more than 250 msec. Time-expanded wave-form analysis provides reproducible visual displays that allow documentation of the differentiating features of lung sounds and enhances the diagnostic utility of the sounds. (N Engl J Med 296:968–...

Sound transmission in the lung as a function of lung volume

Abstract: We were interested in how the transmission of sound through the lung was affected by varying air content in intact humans as a method of monitoring tissue properties noninvasively. To study this, w...

In defense of the stethoscope.

Abstract: The stethoscope is widely considered to be an unreliable instrument. Many studies document the significant observer variability in its use. Numerous other diagnostic tools are available that are generally regarded to provide more reliable diagnostic information. Some even argue that teaching of the ancient art should be de-emphasized in medical schools. Yet auscultation with an acoustic stethoscope can provide important, even life-saving, information. The purpose of this article is to present evidence that supports the use of the stethoscope in clinical medicine. The argument for the stethoscope will be made by presenting relevant investigations, including clinical studies acknowledged to meet the criteria of evidence-based medicine. It will focus on studies that have employed computerized acoustic technology to correlate lung sounds with disease states. This technology has advanced in recent years, which has stimulated a resurgence of interest in auscultation. Numerous studies have been done that utilized objective methods that circumvented the problem of observer variability. There is now a good deal of scientific evidence to support the hypothesis that lung sounds contain information that is clinically useful. This technology also allows this information to be collected more efficiently than previously possible. Advances in educational technology have made it possible to impart information on auscultation much more easily than was possible in the past. Contrary to predictions, the stethoscope is not likely to be relegated to the museum shelf in the near future. Computer technology is making it an even more useful clinical instrument.

Accuracy of Dermatologic Diagnosis by Television

Abstract: Comparisons of diagnoses made by black and white television viewing of slides of dermatologic lesions to those made by directly viewing of the same color slides revealed that in 85% to 89% of cases the dermatologists were as accurate by television as on direct examination. Color television improved accuracy only slightly, but was more acceptable to the dermatologists as less time was required to reach a diagnosis. Considerable work must be done to improve facility of dermatologic inspection by television. Focusing, zoom control, camera positioning, and lighting require particular attention. This study demonstrated that dermatologists can diagnose color slides by black and white television more accurately than nondermatologists viewing direct projections of the same color slides.

Mechanisms in the pathogenesis of asbestosis and silicosis.

Abstract: Interstitial pulmonary fibrosis caused by the inhalation of asbestos fibers or silica particles continues to be an important cause of interstitial lung disease. Although more stringent control of asbestos in the workplace and decreasing industrial use has contributed to declines in the prevalence of asbestosis in the United States (1), new cases continue to be identified. Similarly, silicosis is seen among sandblasters, underground miners, foundry and quarry workers, and in other dust-exposed trades (2). Both diseases, which may have relatively long latency periods, are observed in the clinic today, usually as a result of high occupational exposures in the past, and they are problematic in that treatment with corticosteroids and immunosuppressants, the usual approaches to therapy for fibrotic lung disease, is ineffective (3). Asbestos and silica are complex, naturally occurring minerals that are chemically and physically distinct. Moreover, the pathology of asbestosis and silcosis is dissimilar. However, the pathogenesis of these lesions and the major changes in pulmonary architecture, namely, the laying down of collagen in an interstitial location, appear to be similar to many of the features seen in idiopathic pulmonary fibrosis (IPF). Like IPF and representative animal models of IPF such as bleomycin instillation (4), both asbestosis and silicosis are characterized by a persistent inflammatory response and generation of proinflammatory and profibrotic mediators. Although asbestosis and silicosis have been studied intensely by basic and clinical research scientists, little is known about the crucial cellular mechanisms that initiate and drive the processes of inflammation and fibrogenesis. Many laboratories have developed animal and in vitro models of asbestosis and silicosis to elucidate the cellular events and properties of minerals important in disease causation. Others have explored confounding factors contributing to particulate-induced cell injury as well as cellular and molecular defense mechanisms in response to these minerals. This information has been used to modulate inflammation and fibrosis in expermental animal models in attempts to develop more effective treatment regimens for pulmonary fibroses. This review will briefly address the clinical and pathologic features of asbestosis and silicosis, and consider the mineralogic features of asbestos and silica that may be important in disease causation along with confounding factors such as coexposures to smoking and/or other mineral dusts. The relationship of particle number, type, and size to disease patterns will be reviewed. We will then summarize data published within the past 5 yr on cellular and molecular mechanisms of asbestosis and silicosis and preventive approaches to these diseases in experimental animal models. Lastly, we emphasize in our SUMMARY AND CONCLUSIONS the common mediators and cell types affected in the pathogenesis of both mineral-related and other forms of pulmonary fibrosis and plausible interrelationships between the development of fibrosis and lung cancer, a disease linked to occupational exposures to asbestos and possibly to exposures to silica (1, 5).

Telemedicine Technology and Clinical Applications

Abstract: TELEMEDICINE can be broadly defined as the use of telecommunications technologies to provide medical information and services. Although this definition includes medical uses of the telephone, facsimile, and distance education,telemedicineis increasingly being used as shorthand for remote electronic clinical consultation. Interest in the field has increased dramatically in the 1990s. State and federal allocations for telemedicine and related technologies are likely to exceed $100 million in fiscal 1994-1995.1At least 13 federal agencies, including the US Department of Commerce, Health Care Financing Administration (HCFA), Office of Rural Health Policy, and US Department of Defense, have begun telemedicine research and demonstration programs. Many states are using their own resources to build state-of-the-art telemedicine systems, some with capital investments exceeding $50 million. Faith in this technology is not universal, however. Depending on one's viewpoint, telemedicine may be seen as a valuable tool for providing badly needed specialty care services

Sensory Irritation by Airborne Chemicals

Abstract: (1973). Sensory Irritation by Airborne Chemicals. CRC Critical Reviews in Toxicology: Vol. 2, No. 3, pp. 299-363.