Studies in health technology and informatics
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Stud Health Technol Inform · Jan 2001
Experimental and theoretical analysis of wavelet-based denoising filter for echocardiographic images.
One of the most significant features of diagnostic echocardiographic images is to reduce speckle noise and make better image quality. In this paper we proposed a simple and effective filter design for image denoising and contrast enhancement based on multiscale wavelet denoising method. Wavelet threshold algorithms replace wavelet coefficients with small magnitude by zero and keep or shrink the other coefficients. ⋯ High spectral content tends to over-estimate the noise standard deviation estimation performed at the finest level of the DWT. As a result, a lower threshold parameter is required to get the optimal S/MSE. The standard WCS theory predicts a threshold that depends on the number of signal samples only.
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Stud Health Technol Inform · Jan 2001
Measurement of in-vivo local shear modulus by combining multiple phase offsets mr elastography.
To provide realistic surgical simulation, haptic feedback is important. In the existing surgical simulators, the fidelity of the deformation and haptic feedback is limited because they are based on the subjective evaluation of the expert-user and not on an objective model-based evaluation. To obtain elastic modulus of in-vivo human tissues, magnetic resonance elastography (MRE) was developed. ⋯ To confirm the reliability of this method, a computer simulation and phantom study were performed. The shear modulus measured with various elastic objects was well consistent with the value obtained by MRE and the mechanical method. The shear moduli of excised porcine liver and in-vivo human calf muscle were also analyzed by this method. on the subjective evaluation of an expert-user and not on objective model-based methods.
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Training medics, medical students, nurses, and residents to perform trauma care skills presents many obstacles. These include: emergent nature of the procedures, instructor time, availability of clinical material, and anatomic knowledge. Virtual Reality simulators address each of these obstacles. ⋯ Commercial VR simulators to teach trauma skills include: CathSim Intravenous Simulator (HT Medical), UltraSim Ultrasound Simulator (MedSim), Limb Trauma Simulator (Musculographics/BDI), and the Human Patient Simulator (MedSim). Additionally, we have developed two additional simulators based on the HT CathSim; these are the pericardiocentesis simulator and the diagnostic peritoneal lavage simulator. Future applications include virtual environment triage simulation and surgical airway simulators.
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Implementing telehealth applications represents a substantial investment of resources, which is one reason why success is of great interest. Many research and evaluation studies have investigated measures of successful telehealth systems. However, the term "telehealth" represents a wide range of variables including clinical application, characteristics of the information being transmitted, temporal relationships of data transfer and the organizational context. ⋯ Less is known about the relationship among these variables and whether the findings around one variable are generalizable to other settings or applications. For example, organizational support may be essential for successful provider-patient interactions via videoconference, which result in higher quality of life. A conceptual framework would assist in accumulating this type of evidence and supporting more advanced research efforts.