231 research outputs found

    Exploring the interactions between radiation therapists and cancer patients : an ethnographic study

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    Radiation therapists are responsible for the planning and delivery of radiation therapy treatment for patients diagnosed with cancer as prescribed by radiation oncologists. Treatment courses with a curative intent usually involve daily interaction between radiation therapists and the patient for six to eight weeks. Evidence in the literature suggests that patients with a diagnosis of cancer can experience levels of anxiety and depression, and radiation therapy can also invoke fear and anxiety. Psychosocial support of the patient has been found to enhance the treatment experience and the efficacy of the treatment. Radiation therapists need to communicate with patients and may have a role to play in reducing patient anxiety and distress. The aims of this study were to gain an understanding of the underlying beliefs, values, practices and systems that form the current culture of radiation therapists and how it might be affecting the extent of supportive care that their patients receive.An ethnographic approach enabled the gathering of rich descriptive data through observations and interviews conducted in two radiation therapy centres between May-November 2009. Participants were radiation therapists, patients, nurses and administration staff. Four group interviews with radiation therapists were conducted between April-June 2010. Data was analysed by familiarisation with the raw data, charting themes using coding and identifying subthemes, and interpretation using mind mapping diagrams, consultation with supervisors and presentations to peers. Extensive reflective journaling was also used to assist data analysis.Radiation therapistsā€™ interactions with patients are complicated by a combination of radiation therapistsā€™ cultural aspects, radiation therapistsā€™ perceptions of supportive patient care, and the environment where the interactions occur. This study disclosed new understandings and highlighted the complexities of four main cultural concepts. These concepts consist of: a disease focus, technology motivated, task and teamwork behaviour and a heightened awareness of time and space.Interactions between radiation therapists and patients were identified as (a) structured consisting of information provision and instruction giving, and (b) unstructured (i.e. informal talk). The findings of the study indicated the lack of appropriate space or available space within treatment areas restricted radiation therapists interacting in-depth or in meaningful interactions with patients. The amounts of time radiation therapists had available for interactions were limited because their role within the treatment area required greater amounts of time undertaking technical tasks. There was also pressure to keep to time with an emphasis on efficient throughput of patients. However, patients found interacting with radiation therapists helpful in reducing anxiety and normalising the process but required information to be individualised to cater for individual needs.This study provides an understanding of the cultural and environmental factors underpinning the radiation therapist/ patient relationship. The findings suggest the need for Australian radiation therapistsā€™ to reassess their current approaches to supportive patient care. This study highlighted the need for radiation therapy education and training to be inclusive of communication skills and their use within different clinical spaces. The findings of the study suggest the need to develop a structured approach to supportive patient care by radiation therapists and to the future professional role development of radiation therapists in supportive patient care

    Effects of Middle-Ear Disorders on Power Reflectance Measured in Cadaveric Ear Canals

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    Objective: Reflectance measured in the ear canal offers a noninvasive method to monitor the acoustic properties of the middle ear, and few systematic measurements exist on the effects of various middleear disorders on the reflectance. This work uses a human cadaver-ear preparation and a mathematical middle-ear model to both measure and predict how power reflectance R is affected by the middle-ear disorders of static middle-ear pressures, middle-ear fluid, fixed stapes, disarticulated incudostapedial joint, and tympanic-membrane perforations. Design: R was calculated from ear-canal pressure measurements made on human-cadaver ears in the normal condition and five states: (1) positive and negative pressure in the middle-ear cavity, (2) fluidfilled middle ear, (3) stapes fixed with dental cement, (4) incudostapedial joint disarticulated, and (5) tympanic-membrane perforations. The middle-ear model of Kringlebotn (1988) was modified to represent the middle-ear disorders. Model predictions are compared with measurements. Results: For a given disorder, the general trends of the measurements and model were similar. The changes from normal in R, induced by the simulated disorder, generally depend on frequency and the extent of the disorder (except for the disarticulation). Systematic changes in middle-ear static pressure (up to Ā±300 daPa) resulted in systematic increases in R. These affects were most pronounced for frequencies up to 1000 to 2000 Hz. Above about 2000 Hz there were some asymmetries in behavior between negative and positive pressures. Results with fluid in the middle-ear air space were highly dependent on the percentage of the air space that was filled. Changes in R were minimal when a smaller fraction of the air space was filled with fluid, and as the air space was filled with more saline, R increased at most frequencies. Fixation of the stapes generally resulted in a relatively small low-frequency increase in R. Disarticulation of the incus with the stapes led to a consistent lowfrequency decrease in R with a distinctive minimum below 1000 Hz. Perforations of the tympanic membrane resulted in a decrease in R for frequencies up to about 2000 Hz; at these lower frequencies, smaller perforations led to larger changes from normal when compared with larger perforations. Conclusions: These preliminary measurements help assess the utility of power reflectance as a diagnostic tool for middle-ear disorders. In particular, the measurements document (1) the frequency ranges for which the changes are largest and (2) the extent of the changes from normal for a spectrum of middle-ear disorders

    Middle-Ear Function with Tympanic-Membrane Perforations. II. A Simple Model.

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    A quantitative model of the human middle ear with a tympanic-membrane ~TM! perforation is developed. The model is constrained by several types of acoustic measurements made on human cadaver ears, which indicate that perforation-induced changes in transmission result primarily from changes in driving pressure across the TM and that perforation-induced change in the structure of the TM and its coupling to the ossicles contributes a substantially smaller component. The model represents the effect of a perforation on the pressure difference across the TM by inclusion of a path for sound coupling through the perforation from the ear canal to the middle-ear cavity. The model implies that hearing loss with perforations depends primarily on three quantities: the perforation diameter, sound frequency, and the volume of air in the middle-ear cavity. For the conditions that produce the largest hearing loss ~low frequency and large perforation!, the model yields a simple dependence of loss on frequency, perforation diameter, and middle-ear cavity volume. Predictions from this model may be useful to clinicians in determining whether, in particular cases, hearing losses are explainable by the observed perforations or if additional pathology must be involved

    Non-Ossicular Signal Transmission in Human Middle Ears: Experimental Assessment of the Acoustic Route with Perforated Tympanic Membranes

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    Direct acoustic stimulation of the cochlea by the sound-pressure difference between the oval and round windows (called the acoustic route ) has been thought to contribute to hearing in some pathological conditions, along with the normally dominant ossicular route. To determine the efficacy of this acoustic route and its constituent mechanisms in human ears, sound pressures were measured at three locations in cadaveric temporal bones [with intact and perforated tympanic membranes (TMs)]: (1) in the external ear canal lateral to the TM, PTM; (2) in the tympanic cavity lateral to the oval window, POW; and (3) near the round window, PRW. Sound transmission via the acoustic route is described by two concatenated processes: (1) coupling of sound pressure from ear canal to middle-ear cavity, H PCAV ā‰” PCAV PTM, where PCAV represents the middle-ear cavity pressure, and (2) sound-pressure difference between the windows, HWPD ā‰” (POW - PRW) PCAV. Results show that: H PCAV depends on perforation size but not perforation location; HWPD depends on neither perforation size nor location. The results (1) provide a description of the window pressures based on measurements, (2) refute the common otological view that TM perforation location affects the relative phase of the pressures at the oval and round windows, and (3) show with an intact ossicular chain that acoustic-route transmission is substantially below ossicular-route transmission except for low frequencies with large perforations. Thus, hearing loss from TM perforations results primarily from reduction in sound coupling via the ossicular route. Some features of the frequency dependence of H PCAV and HWPD can be interpreted in terms of a structure-based lumped-element acoustic model of the perforation and middle-ear cavities

    Middle-Ear Function with Tympanic-Membrane Perforations. I. Measurements and Mechanisms

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    Sound transmission through ears with tympanic-membrane ~TM! perforations is not well understood. Here, measurements on human-cadaver ears are reported that describe sound transmission through the middle ear with experimentally produced perforations, which range from 0.5 to 5.0 mm in diameter. Three response variables were measured with acoustic stimulation at the TM: stapes velocity, middle-ear cavity sound pressure, and acoustic impedance at the TM. The stapes-velocity measurements show that perforations cause frequency-dependent losses; at low frequencies losses are largest and increase as perforation size increases. Measurements of middle-ear cavity pressure coupled with the stapes-velocity measurements indicate that the dominant mechanism for loss with TM perforations is reduction in pressure difference across the TM; changes in TM-to-ossicular coupling generally contribute less than 5 dB to the loss. Measurements of middle-ear input impedance indicate that for low frequencies, the input impedance with a perforation approximates the impedance of the middle-ear cavity; as the perforation size increases, the similarity to the cavityā€™s impedance extends to higher frequencies. The collection of results suggests that the effects of perforations can be represented by the path for air-volume flow from the ear canal to the middle-ear cavity. The quantitative description of perforation-induced losses may help clinicians determine, in an ear with a perforation, whether poor hearing results only from the perforation or whether other pathology should be expected

    Determinants of Hearing Loss in Perforations of the Tympanic Membrane

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    Background: Although tympanic membrane perforations are common, there have been few systematic studies of the structural features determining the magnitude of the resulting conductive hearing loss. Our recent experimental and modeling studies predicted that the conductive hearing loss will increase with increasing perforation size, be independent of perforation location (contrary to popular otologic belief), and increase with decreasing size of the middle-ear and mastoid air space (an idea new to otology). Objective: To test our predictions regarding determinants of conductive hearing loss in tympanic membrane perforations against clinical data gathered from patients. Study Design: Prospective clinical study. Setting: Tertiary referral center. Inclusion Criteria: Patients with tympanic membrane perforations without other middle-ear disease. Main Outcome Measures: Size and location of perforation; air-bone gap at 250, 500, 1,000, 2,000, and 4,000 Hz; and tympanometric estimate of volume of the middle-ear air spaces. Results: Isolated tympanic membrane perforations in 62 ears from 56 patients met inclusion criteria. Air-bone gaps were largest at the lower frequencies and decreased as frequency increased. Air-bone gaps increased with perforation size at each frequency. Ears with small middle-ear volumes, ā‰¤4.3 ml (n = 23), had significantly larger air-bone gaps than ears with large middle-ear volumes, \u3e4.3 ml (n = 39), except at 2,000 Hz. The mean air-bone gaps in ears with small volumes were 10 to 20 dB larger than in ears with large volumes. Perforations in anterior versus posterior quadrants showed no significant differences in air-bone gaps at any frequency, although anterior perforations had, on average, air-bone gaps that were smaller by 1 to 8 dB at lower frequencies. Conclusion: The conductive hearing loss resulting from a tympanic membrane perforation is frequency-dependent, with the largest losses occurring at the lowest sound frequencies; increases as size of the perforation increases; varies inversely with volume of the middle-ear and mastoid air space (losses are larger in ears with small volumes); and does not vary appreciably with location of the perforation. Effects of location, if any, are small

    Supporting and preparing patients for radiotherapy: Patientsā€™ and radiation therapistsā€™ perspectives on their one-to-one consultations

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    OBJECTIVE: Patients are often anxious and lack knowledge of radiotherapy prior to commencing treatment. Evidence-based interventions are required to reduce patient anxiety and increase patient preparation before treatment. This study is part of a larger project examining the effectiveness of an innovative preparatory intervention "RT Prepare," to reduce patient psychological distress prior to treatment for breast cancer. This study aimed to explore patients' and RTs' perceptions about the "RT Prepare" intervention and was conducted to assist with refinement of the intervention for future implementation. METHODS: Semi-structured interviews were conducted with patients and radiation therapists (RTs) to elicit their perspectives on the "RT Prepare" intervention. Thematic analysis was used to analyse the data. RESULTS: Telephone interviews were conducted with 21 patients who had received the intervention and 15 RTs who had delivered the intervention. Patients and RTs described the intervention positively and highlighted that it was beneficial for preparing patients for treatment planning and treatment. The overarching themes were communication skills; preparation; information provision and dedicated space and time. CONCLUSION: RT Prepare was well received by patients and RTs. Practice implications Based on the results of this study and our quantitative findings, implementation of the intervention would be beneficial for both patients and RTs

    Algae as nutritional and functional food sources: revisiting our understanding.

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    Global demand for macroalgal and microalgal foods is growing, and algae are increasingly being consumed for functional benefits beyond the traditional considerations of nutrition and health. There is substantial evidence for the health benefits of algal-derived food products, but there remain considerable challenges in quantifying these benefits, as well as possible adverse effects. First, there is a limited understanding of nutritional composition across algal species, geographical regions, and seasons, all of which can substantially affect their dietary value. The second issue is quantifying which fractions of algal foods are bioavailable to humans, and which factors influence how food constituents are released, ranging from food preparation through genetic differentiation in the gut microbiome. Third is understanding how algal nutritional and functional constituents interact in human metabolism. Superimposed considerations are the effects of harvesting, storage, and food processing techniques that can dramatically influence the potential nutritive value of algal-derived foods. We highlight this rapidly advancing area of algal science with a particular focus on the key research required to assess better the health benefits of an alga or algal product. There are rich opportunities for phycologists in this emerging field, requiring exciting new experimental and collaborative approaches.AGS & KEH thank the Biotechnology and Biological Sciences Research Council (BBSRC BB/1013164/1) of the UK for funding. The University of Dundee is a registered Scottish charity, No. SC015096. PP is supported by IDEALG in the frame of the stimuli program entitled ā€œInvestissements dā€™avenir, Biotechnologies-Bioressourcesā€ (ANR-10-BTBR-04-02). The open access fee was supported by NSF-OCE-1435021 (MLW), DIC project 1823-06 (MEC), Maine Sea Grant (NOAA) 5405971 (SHB), NSF #11A-1355457 to Maine EPSCoR at the University of Maine (SHB), and the listed funding to AGS and PP

    Algae as nutritional and functional food sources: revisiting our understanding.

    Get PDF
    Global demand for macroalgal and microalgal foods is growing, and algae are increasingly being consumed for functional benefits beyond the traditional considerations of nutrition and health. There is substantial evidence for the health benefits of algal-derived food products, but there remain considerable challenges in quantifying these benefits, as well as possible adverse effects. First, there is a limited understanding of nutritional composition across algal species, geographical regions, and seasons, all of which can substantially affect their dietary value. The second issue is quantifying which fractions of algal foods are bioavailable to humans, and which factors influence how food constituents are released, ranging from food preparation through genetic differentiation in the gut microbiome. Third is understanding how algal nutritional and functional constituents interact in human metabolism. Superimposed considerations are the effects of harvesting, storage, and food processing techniques that can dramatically influence the potential nutritive value of algal-derived foods. We highlight this rapidly advancing area of algal science with a particular focus on the key research required to assess better the health benefits of an alga or algal product. There are rich opportunities for phycologists in this emerging field, requiring exciting new experimental and collaborative approaches.AGS & KEH thank the Biotechnology and Biological Sciences Research Council (BBSRC BB/1013164/1) of the UK for funding. The University of Dundee is a registered Scottish charity, No. SC015096. PP is supported by IDEALG in the frame of the stimuli program entitled ā€œInvestissements dā€™avenir, Biotechnologies-Bioressourcesā€ (ANR-10-BTBR-04-02). The open access fee was supported by NSF-OCE-1435021 (MLW), DIC project 1823-06 (MEC), Maine Sea Grant (NOAA) 5405971 (SHB), NSF #11A-1355457 to Maine EPSCoR at the University of Maine (SHB), and the listed funding to AGS and PP
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