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PubMedDate not supplied

Computer-generated correspondence for patients attending an open-access chest pain clinic.

AIM: To determine whether general practitioners (GPs) prefer structured computer-generated or standard dictated outpatient clinic letters. DESIGN: Questionnaire survey of all GPs referring patients to an open-access chest pain clinic at a district general hospital in London. The GPs were asked to compare three twinned examples of structured computer-generated and unstructured dictated letters. RESULTS: Of 93 respondents (response rate 77.5%), 75 (80.6%) preferred the computer-generated letter and 16 (17.2%) preferred the dictated letter (p < 0.0005). The preferred features of the computer-generated letter were its clear presentation, subheadings, and concise information. The computer-generated letter scored significantly higher than the dictated letter: for clarity, mean 8.2 vs 6.5 (p < 0.0005); content, mean 8.5 vs 6.9 (p < 0.0005); and readability, mean 8.2 vs 6.8 (p < 0.0005). The GPs in the survey considered a mean delay of 3.4 days to be acceptable for receiving the letter from the chest pain clinic. CONCLUSION: GPs prefer structured computer-generated letters to unstructured dictated letters for patients referred to an open-access chest pain clinic. Computer-generated correspondence allows rapid feedback of information to the referring GP, one of the key requirements of open-access clinics.

Ambulatory Care Facilities↗
PubMed2005

Computing intraoperative dosimetry for prostate brachytherapy using TRUS and fluoroscopy.

RATIONALE AND OBJECTIVES: There is a need to provide real-time dosimetric feedback during prostate brachytherapy based on the location of the implanted seeds. The objective of our approach is to develop a system to accurately locate seeds with minimal impact on the current protocol for prostate brachytherapy and without additional imaging equipment. MATERIALS AND METHODS: A new approach for intraoperatively computing dosimetry for prostate brachytherapy is presented. The approach uses transrectal ultrasound (TRUS) and fluoroscopic images. A fluoroscopic image of the TRUS probe is required to register the fluoroscopic and ultrasound images. The C-arm is not moved during the procedure and all images are acquired from the same C-arm angles. A needle path is interpolated for each needle based on the location of the needle tip in TRUS images and the known entry point of the needle. Throughout the procedure, fluoroscopic images are acquired to determine the coronal plane coordinates of the seeds and the remaining coordinate of each seed is computed from the needle path. For accurate results, intraoperative seed motion tracking is advised and a method to achieve such tracking is also presented. RESULTS: Experimentally, the TRUS and fluoroscopic images are registered with a mean and maximum error of 1.3 mm and 5.8 mm, respectively. In a phantom, 12 seeds are located using our approach and compared with the known locations, with a mean error in the x, y, and z direction of 0.96 mm, 0.33, and 0.68 mm, respectively, and a corresponding maximum error of 1.85 mm, 0.56 mm, and 1.63 mm. Experimental results show motion tracking in the y-direction with submillimeter accuracy. The feasibility of our approach is tested on five cases of clinical data using a semiautomated version of our system and the resulting dosimetry is compared with that found using postoperative computed tomography images. The D90 and V100 metrics computed using our approach and the computed tomography images differ by a maximum of 16.6% and 1.7%, respectively. CONCLUSIONS: TRUS can be combined with single pose fluoroscopic images to compute delivered dose intraoperatively for prostate brachytherapy. Phantom results demonstrate the accuracy of the method and preliminary clinical results show its potential.

Brachytherapy↗
PubMed2005

Toward a theory of evolutionary computation.

We outline a theory of evolutionary computation using a formal model of evolutionary computation--the Evolutionary Turing Machine--which is introduced as the extension of the Turing Machine model. Evolutionary Turing Machines provide a better and a more complete model for evolutionary computing than conventional Turing Machines, algorithms, and Markov chains. The convergence and convergence rate are defined and investigated in terms of this new model. The sufficient conditions needed for the completeness and optimality of evolutionary search are investigated. In particular, the notion of the total optimality as an instance of the multiobjective optimization of the Universal Evolutionary Turing Machine is introduced. This provides an automatic way to deal with the intractability of evolutionary search by optimizing the quality of solutions and search costs simultaneously. Based on a new model a very flexible classification of optimization problem hardness for the evolutionary techniques is proposed. The expressiveness of evolutionary computation is investigated. We show that the problem of the best evolutionary algorithm is undecidable independently of whether the fitness function is time dependent or fixed. It is demonstrated that the evolutionary computation paradigm is more expressive than Turing Machines, and thus the conventional computer science based on them. We show that an Evolutionary Turing Machine is able to solve nonalgorithmically the halting problem of the Universal Turing Machine and, asymptotically, the best evolutionary algorithm problem. In other words, the best evolutionary algorithm does not exist, but it can be potentially indefinitely approximated using evolutionary techniques.

Algorithms↗
PubMed1998

Computers in community-based drug and alcohol clinical settings: are they acceptable to respondents?

The use of computer technology is not new in the delivery of health services. Previous studies have assessed the reliability and validity of computerised surveys, relative to pen and paper versions or interviews or the acceptability of computers in a range of treatment settings. Generally, these studies have reported that the reliability, validity and acceptability of computer surveys is at least comparable to more traditional survey methods. This study provides evidence for the appropriateness of using computers in community-based drug and alcohol clinical settings, reporting a high level of computer acceptability among clients. The advantages of utilising computers in clinical settings, for researchers and clinicians, are discussed.

Adult↗
PubMedDate not supplied

Segmentation of gated Tl-SPECT images and computation of ejection fraction: a different approach.

BACKGROUND: We describe a set of image processing algorithms and mathematical models that can be advantageously used in schemes for the segmentation of thallium-201-single photon emission computed tomography (SPECT) images and for computation of left ventricular ejection fraction (EF). METHODS: The system consists of two independent blocs for image segmentation and computation of function. The former is based on a multiresolution elliptical coordinate transformation and dynamic contour tracking. Computation of EF is formulated on the basis of both the endocardial and epicardial contours, and we compare this formulation with that using only the endocardial border for images with low signal-to-noise ratios. The accuracy of border detection was validated against manual border tracing on FDG-PET images, simulated Tl-201-SPECT images where the true underlying borders were known, and actual Tl-201-SPECT images. Finally, we compared EFs computed for FDG-PET, technetium-99m-SPECT and Tl-201-SPECT with those obtained from planar gated blood pool imaging. RESULTS: The automatically obtained results always were within the manual uncertainty range. Agreement between myocardial volumes from positron emission tomography and automatically obtained values from the simulated Tl-201-SPECT images was excellent (r = 0.95, n = 32). Agreement between EFs from planar gated blood pool imaging and the other image modalities was good (FDG-PET: y = 5.89 + 1.21x, r = 0.92, see = 6.24, n = 19, Tc-99m-SPECT: y = -3.86 + 1.06x, r = 0.88, see = 7.78, n = 9, Tl-201-SPECT: y = 17.8 + 0.81x, r = 0.77, see = 7.44, n = 26). For noisy input data the combined use of information from epicardial and endocardial contours gives more accurate EF values than the traditional formula on the basis of the endocardial contour only. CONCLUSIONS: Alternate approaches for segmentation and computation of function have been presented and validated. They might also be advantageously incorporated into other existing techniques.

Algorithms↗
PubMed2002

Dermoscopic diagnosis by a trained clinician vs. a clinician with minimal dermoscopy training vs. computer-aided diagnosis of 341 pigmented skin lesions: a comparative study.

BACKGROUND: In the last few years digital dermoscopy has been introduced as an additional tool to improve the clinical diagnosis of pigmented skin lesions. OBJECTIVE: To evaluate the validity of digital dermoscopy by comparing the diagnoses of a dermatologist experienced in dermoscopy (5 years of experience) with those of a clinician with minimal training in this field, and then comparing these results with those obtained using computer-aided diagnoses. METHODS: Three hundred and forty-one pigmented melanocytic and non-melanocytic skin lesions were included. All lesions were surgically excised and histopathologically examined. Digital dermoscopic images of all lesions were framed and analysed using software based on a trained artificial neural network. Cohen's kappa statistic was calculated to assess the validity with regard to the correct diagnoses of melanoma and non-melanoma. RESULTS: Sensitivity was high for the experienced dermatologist and the computer (92%) and lower for the inexperienced clinician (69%). Specificity of the diagnosis by the experienced dermatologist was higher (99%) than that of the inexperienced clinician (94%) and the computer assessment (74%). Notably, computer analysis gave a higher number of false positives (26%) compared with the experienced dermatologist (0.6%) and the inexperienced clinician (5.5%). CONCLUSIONS: Our results indicate that analysis either by a trained dermatologist or an artificial neural network-trained computer can improve the diagnostic accuracy of melanoma compared with that of an inexperienced clinician and that the computer diagnosis might represent a useful tool for the screening of melanoma, particularly at centres not experienced in dermoscopy.

Adolescent↗
PubMed1991

Use of computer graphics simulation for teaching of flexible sigmoidoscopy.

The concept of simulation training in endoscopy is now well-established. The systems currently under development employ either computer graphics simulation or interactive video technology; each has its strengths and weaknesses. A flexible sigmoidoscopy training device has been designed which uses graphic routines--such as object oriented programming and double buffering--in entirely new ways. These programming techniques compensate for the limitations of currently available desk-top microcomputers. By boosting existing computer 'horsepower' with next generation coprocessors and sophisticated graphics tools such as intensity interpolation (Gouraud shading), the realism of computer simulation of flexible sigmoidoscopy is being greatly enhanced. The computer program has teaching and scoring capabilities, making it a truly interactive system. Use has been made of this ability to record, grade and store each trainee encounter in computer memory as part of a multi-center, prospective trial of simulation training being conducted currently in the USA. A new input device, a dummy endoscope, has been designed that allows application of variable resistance to the insertion tube. This greatly enhances tactile feedback, such as resistance during looping. If carefully designed trials show that computer simulation is an attractive and effective training tool, it is expected that this technology will evolve rapidly and be made widely available to trainee endoscopists.

Computer Graphics↗
PubMed2006

Noise simulation in cone beam CT imaging with parallel computing.

We developed a computer noise simulation model for cone beam computed tomography imaging using a general purpose PC cluster. This model uses a mono-energetic x-ray approximation and allows us to investigate three primary performance components, specifically quantum noise, detector blurring and additive system noise. A parallel random number generator based on the Weyl sequence was implemented in the noise simulation and a visualization technique was accordingly developed to validate the quality of the parallel random number generator. In our computer simulation model, three-dimensional (3D) phantoms were mathematically modelled and used to create 450 analytical projections, which were then sampled into digital image data. Quantum noise was simulated and added to the analytical projection image data, which were then filtered to incorporate flat panel detector blurring. Additive system noise was generated and added to form the final projection images. The Feldkamp algorithm was implemented and used to reconstruct the 3D images of the phantoms. A 24 dual-Xeon PC cluster was used to compute the projections and reconstructed images in parallel with each CPU processing 10 projection views for a total of 450 views. Based on this computer simulation system, simulated cone beam CT images were generated for various phantoms and technique settings. Noise power spectra for the flat panel x-ray detector and reconstructed images were then computed to characterize the noise properties. As an example among the potential applications of our noise simulation model, we showed that images of low contrast objects can be produced and used for image quality evaluation.

Algorithms↗
PubMed2004

Computer use among community-based primary care physician preceptors.

PURPOSE: Use of the Internet to access biomedical information in patient care has important implications in medical education. Little is known about how community-based clinical teachers use computers in their offices and what factors, such as age, may influence use. METHOD: A total of 178 active community-based primary care preceptors were mailed a 15-item questionnaire about their computer equipment; Internet use; and specific applications in patient care, patients' education, medical students' or residents' education, or accessing other clinical and/or research information. Data analysis used descriptive statistics, chi-square for comparisons of categorical data and analysis of variance (ANOVA) mixed model for comparisons of continuous variables. All tests were two-tailed with alpha set at.05 to determine statistical significance. RESULTS: In all, 129 preceptors responded (73%). Office computer availability was high (92%). The Internet as a clinical information resource was used most frequently (98%) and MD Consult and Medline-EBM were used less frequently (20% and 21%, respectively). No statistical differences were found in routine use by age of preceptor; frequency of use did differ. Preceptors 60 years or older were four times more likely to use the Internet to assist in students' and residents' education (p =.02) and at least twice as likely to use full text Medline articles for patient care decisions (p =.05) than their younger colleagues. Decreased computer use was related to lack of time (45%) or other logistical reasons (40%), such as the computer's distance from the patient care areas or slow connections. CONCLUSIONS: Rates of computer access and Internet connectivity were high among community-based preceptors of all ages. Uses of specific online clinical and/or educational resources varied by preceptors' age with more rather than less use among older preceptors, an unexpected finding.

Adult↗
PubMed1989

Liver-tumor boundary detection: human observer vs computer edge detection.

As a preliminary step in computing tumor volume, we developed a computer edge detection program to define the liver-tumor interface in computed tomography (CT) images. Computer program performance was tested using CT images from a lucite liver/tumor phantom; from normal livers containing computer-generated pseudotumors of known size, object contrast, and liver-tumor edge gradients; and from 12 abdominal livers containing 19 focal tumors, eight with well-defined and 11 with ill-defined borders. Calculated sizes of the tumor phantom and pseudo-tumors were compared with measured volumes and predetermined cross-sectional areas, respectively. In the absence of a truth standard for the size of the focal hepatic tumors, computer-calculated cross-sectional areas of the tumors were compared with the measurements made by an experienced interpreter of CT images using the trackball cursor at the CT console. The console measurements were made five times on separate days during a one-week period. The variability in the measured areas of these tumors averaged 7.1% for the well-defined tumors and 14.0% for the poorly defined tumors (P = 0.05). The edge-linking algorithm systematically overestimated the volumes of individual slices of the hemispherical tumors in the lucite phantom. Nevertheless, because of algorithm failure in the slices containing the poles of the hemispheres, errors in total tumor volumes were -2.1% for the 5.1 cm radius tumor, +1.2% for the 2.7 cm radius tumor, and +15% for the 1.8 cm radius tumor. The edge-linking algorithm was reasonably successful in calculating areas of pseudotumors with object contrast of 3.0% or greater and steep edge gradients.(ABSTRACT TRUNCATED AT 250 WORDS)

Humans↗
PubMed1994

Method for preparing an exact-size model using helical volume scan computed tomography.

Helical volume scan computed tomography is a recently developed technology by means of which detailed data for most facial bone areas can be accumulated in a very short period, i.e., about 30 seconds, a much shorter time than required with conventional computed tomography. From a clinical standpoint, this is extremely important. In this report we discuss the principles of a method for preparing actual-size models by laser lithographic procedures based on data obtained by helical volume scan computed tomography. With these procedures, it is possible to obtain a good reproduction with high accuracy, on the order of 0.5 mm, not only of the outer morphologic structure of the cranial and maxillofacial bones but also of portions of the inner structure of cavities such as the cranium and paranasal sinuses. The difference between the original and model was under 3 percent, as confirmed by constructing a model of the dry skull with helical volume scan computed tomography. Therefore, production of exact-size models using helical volume scan computed tomography data represents an important technological development, breaking through previous limits imposed by conventional simulations prepared with three-dimensional images using CRT. With the combined use of laser lithographics and helical volume scan computed tomography, operative methods for craniomaxillofacial surgery should improve significantly in the near future.

Adult↗
PubMedDate not supplied

Computer use in an urban university hospital: technology ahead of literacy.

The linkage of patient safety and care quality to the implementation of computerized information systems assumes that clinical staff are skilled with computers. Nurses and nursing support staff increasingly require computers to carry out their work. Minimum computer competencies for nurses have been identified. The determination of whether the current nursing workforce has acquired these competencies remains uncertain. We administered a self-assessment survey to nurses and nursing support staff to determine proficiency with computer skills they might perform at work. Respondents reported inadequacies in basic and work-related computer skills. More than 28% scored themselves as having fair or poor proficiency on all skills, and more than 50% as fair or poor on five of 11 skills. Respondents over age 50 and those graduating before 1984 tended to score proficiency lower. Our study suggests that many nurses and nursing support staff may not have the minimum computer competencies to effectively and efficiently perform their work.

Adult↗
PubMed2002

Computation of the mid-sagittal plane in 3-D brain images.

We present a new method to automatically compute, reorient, and recenter the mid-sagittal plane in anatomical and functional three-dimensional (3-D) brain images. This iterative approach is composed of two steps. At first, given an initial guess of the mid-sagittal plane (generally, the central plane of the image grid), the computation of local similarity measures between the two sides of the head allows to identify homologous anatomical structures or functional areas, by way of a block matching procedure. The output is a set of point-to-point correspondences: the centers of homologous blocks. Subsequently, we define the mid-sagittal plane as the one best superposing the points on one side and their counterparts on the other side by reflective symmetry. Practically, the computation of the parameters characterizing the plane is performed by a least trimmed squares estimation. Then, the estimated plane is aligned with the center of the image grid, and the whole process is iterated until convergence. The robust estimation technique we use allows normal or abnormal asymmetrical structures or areas to be treated as outliers, and the plane to be mainly computed from the underlying gross symmetry of the brain. The algorithm is fast and accurate, even for strongly tilted heads, and even in presence of high acquisition noise and bias field, as shown on a large set of synthetic data. The algorithm has also been visually evaluated on a large set of real magnetic resonance (MR) images. We present a few results on isotropic as well as anisotropic anatomical (MR and computed tomography) and functional (single photon emission computed tomography and positron emission tomography) real images, for normal and pathological subjects.

Algorithms↗
PubMed2004

Doctors' experience with handheld computers in clinical practice: qualitative study.

OBJECTIVE: To examine doctors' perspectives about their experiences with handheld computers in clinical practice. DESIGN: Qualitative study of eight focus groups consisting of doctors with diverse training and practice patterns. SETTING: Six practice settings across the United States and two additional focus group sessions held at a national meeting of general internists. PARTICIPANTS: 54 doctors who did or did not use handheld computers. RESULTS: Doctors who used handheld computers in clinical practice seemed generally satisfied with them and reported diverse patterns of use. Users perceived that the devices helped them increase productivity and improve patient care. Barriers to use concerned the device itself and personal and perceptual constraints, with perceptual factors such as comfort with technology, preference for paper, and the impression that the devices are not easy to use somewhat difficult to overcome. Participants suggested that organisations can help promote handheld computers by providing advice on purchase, usage, training, and user support. Participants expressed concern about reliability and security of the device but were particularly concerned about dependency on the device and over-reliance as a substitute for clinical thinking. CONCLUSIONS: Doctors expect handheld computers to become more useful, and most seem interested in leveraging (getting the most value from) their use. Key opportunities with handheld computers included their use as a stepping stone to build doctors' comfort with other information technology and ehealth initiatives and providing point of care support that helps improve patient care.

Attitude of Health Personnel↗
PubMed2003

Remote computing environment compensating for brain shift.

OBJECTIVE: Anatomical and functional image data become invalid during an operation due to brain shift. Compensation is achieved by using intraoperative imaging to update anatomical information. To accelerate the registration and visualization of pre- and intraoperative image data, the presented work focuses on remote computing capabilities. The underlying framework efficiently combines local desktop computers and remote high-end graphics workstations exploiting expensive hardware. METHODS: By performing all computations on the remote computer, the MR volumes are rigidly aligned via voxel-based registration. Using graphics hardware for acceleration, all interpolation operations are performed with 3D texture-mapping hardware. A new approach then transforms functional markers from preoperative measurements to the intraoperative situation using an automatic tracking algorithm to identify corresponding sulci. Communicating Java viewers are suggested for analyzing the results interactively on a local computer, with all calculations being performed exclusively on the remote computer. RESULTS: The suggested approach was successfully applied in 5 cases using MR data containing functional markers of MEG and fMRI measurements identifying eloquent brain areas. Remote large-scale graphics hardware was thereby efficiently made available for fast registration and interactive direct volume rendering in neurosurgery. CONCLUSION: Overall, the presented framework demonstrates efficient access of expensive high-end hardware remotely controlled by thin clients, and further emphasizes the need to compensate for brain shift in functional neuronavigation.

Brain↗
PubMedDate not supplied

Changing how and what children learn in school with computer-based technologies.

Schools today face ever-increasing demands in their attempts to ensure that students are well equipped to enter the workforce and navigate a complex world. Research indicates that computer technology can help support learning, and that it is especially useful in developing the higher-order skills of critical thinking, analysis, and scientific inquiry. But the mere presence of computers in the classroom does not ensure their effective use. Some computer applications have been shown to be more successful than others, and many factors influence how well even the most promising applications are implemented. This article explores the various ways computer technology can be used to improve how and what children learn in the classroom. Several examples of computer-based applications are highlighted to illustrate ways technology can enhance how children learn by supporting four fundamental characteristics of learning: (1) active engagement, (2) participation in groups, (3) frequent interaction and feedback, and (4) connections to real-world contexts. Additional examples illustrate ways technology can expand what children learn by helping them to understand core concepts in subjects like math, science, and literacy. Research indicates, however, that the use of technology as an effective learning tool is more likely to take place when embedded in a broader education reform movement that includes improvements in teacher training, curriculum, student assessment, and a school's capacity for change. To help inform decisions about the future role of computers in the classroom, the authors conclude that further research is needed to identify the uses that most effectively support learning and the conditions required for successful implementation.

Adolescent↗
PubMedDate not supplied

Introduction of handheld computing to a family practice residency program.

BACKGROUND: Handheld computers are valuable practice tools. It is important for residency programs to introduce their trainees and faculty to this technology. This article describes a formal strategy to introduce handheld computing to a family practice residency program. METHODS: Objectives were selected for the handheld computer training program that reflected skills physicians would find useful in practice. TRGpro handheld computers preloaded with a suite of medical reference programs, a medical calculator, and a database program were supplied to participants. Training consisted of four 1-hour modules each with a written evaluation quiz. Participants completed a self-assessment questionnaire after the program to determine their ability to meet each objective. RESULTS: Sixty of the 62 participants successfully completed the training program. The mean composite score on quizzes was 36 of 40 (90%), with no significant differences by level of residency training. The mean self-ratings of participants across all objectives was 3.31 of 4.00. Third-year residents had higher mean self-ratings than others (mean of group, 3.62). Participants were very comfortable with practical skills, such as using drug reference software, and less comfortable with theory, such as knowing the different types of handheld computers available. CONCLUSION: Structured training is a successful strategy for introducing handheld computing to a residency program.

Attitude to Computers↗
PubMed2004

Computers in patient education and monitoring.

Computing technologies offer much promise in the field of medicine. Every discipline in medicine has been affected by the proliferation of computerized technology. Clinicians face challenges in balancing constraints of time and personnel resources when caring for and educating patients. The potential value of computer technology is tremendous and expectations run high among providers and patients. Computers can help patients to synthesize knowledge from information and to retain information about diseases. Computer and communication technologies can extend the caregiver's reach with remote patient monitoring. Health care providers' roles are changing because of the availability of health information on the Internet. Computer-based patient education can help improve the patient's awareness and understanding of his or her disease(s), which can help make the patient more of a partner in the patient-physician relationship. Currently, there are some limitations to and issues about using computers for patient education and monitoring, but I expect those limitations and issues to be substantially mitigated in the future.

Computer-Assisted Instruction↗