Automated flow rate calculation based on digital analysis of flow convergence proximal to regurgitant orifice

AbstractObjectives. The purpose of the study was to develop and validate an automated method for calculating regurgitant flow rate using color Doppler echocardiography.Background. The proximal flow convergence method is a promising approach to quantitate valvular regurgitation noninvasively because it allows one to calculate regurgitant flow rate and regurgitant orifice area; however, defining the location of the regurgitant orifice is often difficult and can lead to significant error in the calculated flow rates. To overcome this problem we developed an automated algorithm to locate the orifice and calculate flow rate based on the digital Doppler velocity map.Methods. This algorithm compares the observed velocities with the anticipated relative velocities, cos ϑ/μt2. The orifice is localized as the point with maximal correlation between predicted and observed velocity, whereas flow rate is specified as the slope of the regression line. We validated this algorithm in an in vitro model for flow through circular orifices with planar surroundings and a porcine bioprosthesis.Results. For flow through circular orifices, flow rates calculated on individual Doppler maps and on an average of eight velocity maps showed excellent agreement with true flow, with r = 0.977 and ΔQ = −3.7 ± 15.8 cm3/s and r = 0.991 and ΔQ = −4.3 ± 8.5 cm3/s, respectively. Calculated flow rates through the bioprosthesis correlated well but underestimated true flow, with r = 0.97, ΔQ = −10.9 ± 12.5 cm3/s, suggesting flow convergence over an >2π. This systematic underestimation was corrected by assuming an effective convergence angle of 212 δ.Conclusions. This algorithm accurately locates the regurgitant orifice and calculates regurgitant flow rate for circular orifices with planar surroundings. Automated analysis of the proximal flow field is also applicable to more physiologic surfaces surrounding the regurgitant orifice; however, the convergence angle should be adjusted. This automated algorithm should make quantification of regurgitant flow rate and regurgitant orifice area more reproducible and readily available in clinical cardiology practice

"I am NN": A Reconstruction of Anscombe's "The First Person"

This paper develops a way of understanding G.E.M. Anscombe’s essay “The First Person”, at the heart of which are the following two ideas: first, that the point of her essay is to show that it is not possible for anyone to understand what they express with “I” as an Art des Gegebenseins—a way of thinking of an object that constitutes identifying knowledge of which object is being thought of; and second, that the argument through which her essay seeks to show this is itself first personal in character. Understanding Anscombe’s essay in this light has the merit of showing much of what it says to be correct. But it sets us the task of saying what it is that we understand ourselves to express with “I” if not an Art des Gegebenseins, and in particular what it is that we understand ourselves to express with sentences with “I” as subject that might seem to express identity-judgments, such as “I am NN”, and “I am this body”

'The nourishing soil of the soul': The role of horticultural therapy in promoting well-being in community-dwelling people with dementia.

Two-thirds of people with dementia reside in their own homes; however, support for community-dwelling people with dementia to continue to participate in everyday activities is often lacking, resulting in feelings of depression and isolation among people living with the condition. Engagement in outdoor activities such as gardening can potentially counteract these negative experiences by enabling people with dementia to interact with nature, helping to improve their physical and psychological well-being. Additionally, the collaborative nature of community gardening may encourage the development of a sense of community, thereby enhancing social integration. Despite increasing evidence supporting its therapeutic value for people with dementia in residential care, the benefits of horticultural therapy have yet to be transposed into a community setting. This paper will examine the theoretical support for the application of horticultural therapy in dementia care, before exploring the potential of horticultural therapy as a means of facilitating improved physical and psychological well-being and social integration for people living with dementia within the community

Landscape, Memory, and the Shifting Regional Geographies of Northwest Bosnia-Herzegovina

Writing and arguing with older discourses that have informed the subdiscipline of regional geography and setting them against new ways of conceiving of the region, this article considers the northwest of Bosnia-Herzegovina as a site that calls for a newly animated form of regional study. Of particular concern here is the role that memory and commemorative practices play in such a spatial schema. The monumental landscapes of the Tito regime and its collective commemoration of World War II sit alongside and are troubled by the more recent traumas and spaces of unmarked death associated with the ethnic war in Bosnia during the early 1990s. Read together, northwest Bosnia-Herzegovina functions as a vivid exemplar for understanding traumatic historical mourning as a phenomenological process that is inseparable from the wider geopolitical landscape

Simplicity in Visual Representation: A Semiotic Approach

Simplicity, as an ideal in the design of visual representations, has not received systematic attention. High-level guidelines are too general, and low-level guidelines too ad hoc, too numerous, and too often incompatible, to serve in a particular design situation. This paper reviews notions of visual simplicity in the literature within the analytical framework provided by Charles Morris' communication model, specifically, his trichotomy of communication levels—the syntactic, the semantic, and the pragmatic. Simplicity is ultimate ly shown to entail the adjudication of incompatibilities both within, and between, levels.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68281/2/10.1177_105065198700100103.pd