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At least 1,495 records · Page 83Linked to original sources
PubMed2001

Preliminary comparison of treatments of shoulder injuries using the FitLinxx computer feedback system and standard physical therapy.

Men and women suffering from various shoulder injuries (n = 28) were recruited to test the efficacy of a computer feedback system during physical therapy. Measures of physiological progress were statistically equivalent between the Standard Treatment and FitLinxx supported groups. Although compliance was uniformly high between groups, the FitLinxx-supported patients were more likely to continue exercise after termination of treatment. Considerably less total professional time was required for FitLinxx-supported therapy. Suggestions were made to replicate and extend the present preliminary findings.

Adult↗
PubMed2003

Determination of the two-dimensional detective quantum efficiency of a computed radiography system.

Based on a recently described method for determining the two-dimensional presampling modulation transfer function (MTF), the aperture mask method, a method for determining the two-dimensional detective quantum efficiency (DQE) of a digital radiographic system was developed. The method was applied to a new computed radiography (CR) system and comparisons with one-dimensional determinations of the presampling MTF and the DQE were performed. The aperture mask method was shown to agree with the conventional tilted slit method for determining the presampling MTF along the axes. For the particular CR system studied, the mean of one-dimensional determinations of the DQE in orthogonal directions led to a representative measure of the average DQE behavior of the system up to the Nyquist frequency along the axes, but a deviation was observed above this frequency. In conclusion, the method developed for determining the two-dimensional DQE can be used to determine the imaging properties of a digital radiographic detector system over almost the entire frequency domain, the exception being the lowest frequencies (< or = 0.1 mm(-1)) at which the validity and the reliability of the method are low.

Algorithms↗
PubMed2006

Could a computer-based system including a prevalence function support emergency medical systems and improve the allocation of life support level?

OBJECTIVES: To evaluate whether a computer-based decision support system could be useful for the emergency medical system when identifying patients with acute myocardial infarction (AMI) or life-threatening conditions and thereby improve the allocation of life support level. METHODS: Patients in the Municipality of Göteborg who dialled the dispatch centre due to chest pain during a period of 3 months. To analyse the relationship between patient characteristics (according to a case record form used during an interview) and the response variables (AMI or life-threatening condition), multivariate logistic regression was used. For each patient, the probability of AMI/life-threatening condition was estimated by the model. We used these probabilities retrospectively to allocate advanced life support or basic life support. This model allocation was then compared with the true allocation made by the dispatchers. RESULTS: The sensitivity, that is, the percentage of AMI patients allocated to advanced life support, was 85.7% in relation to the true allocation made by the dispatchers. The corresponding sensitivity regarding allocation made by the model was 92.4% (P=0.17). The specificity was also slightly higher for the model allocation than the dispatcher allocation. Among the 15 patients with AMI who were allocated to basic life support by the dispatchers, nine died (eight during and one after hospitalization). Among the eight patients with AMI allocated to basic life support by the model, only one patient died (in hospital) (P=0.02). CONCLUSION: A computer-based decision support system including a prevalence function could be a valuable tool for allocating the level of life support. The case record form, however, used for the interview can be refined and a model based on a larger sample and confirmed in a prospective study is recommended.

Advanced Cardiac Life Support↗
PubMed1996

Laboratory computer availability: a College of American Pathologists Q-probes study of computer downtime in 422 institutions.

OBJECTIVE: To determine the frequency, duration, and impact of computer downtime on laboratory operations. METHODS: Four hundred twenty-two laboratories monitored the frequency of computer system downtime and other computer malfunctions over a period of 30 days. Participants classified each instance of unavailability according to its cause, duration, and consequences. In all, data from 11 967 instances were submitted for analysis. RESULTS: During the 30-day study period, the participating institutions experienced a median of eight episodes in which all or a primary computer function was unavailable. The cumulative median duration of downtime during these 30 days was 14.3 hours. The most unfortunate 10% of participants reported having 44 or more episodes in which all or a primary computer function was lost during the 30 days, for a cumulative duration of 77.7 or more hours of system unavailability. Computer installations that served two or more full-service laboratories were significantly more likely to experience unscheduled loss of all or a primary computer function than were sites that served only one laboratory, and unscheduled events were more likely to be of longer duration. Participants reported that 1.3% of downtime events required the use of staff overtime to perform required work. Overtime was more likely with longer-than-average periods of downtime and losses that had not been scheduled. Of all the downtime instances, 0.2% led to the release of inaccurate results, and 0.1% led to an adverse clinical outcome. These events were associated with software failure, unscheduled downtime, a site's overall frequency of downtime, particular software vendors, and not having installed a software patch in the previous 1000 days. CONCLUSIONS: The frequency of laboratory computer downtime varies widely among institutions and is occasionally associated with adverse clinical outcomes or additional staff expense.

Chi-Square Distribution↗
PubMed1993

Variable compensation chest radiography performed with a computed radiography system: design considerations and initial clinical experience.

The authors describe a variable compensation (VC) technique in which an x-ray equalizer and a computed radiography system are used. The VC technique allows retrospective alteration of equalized chest appearance with maintenance of improved signal-to-noise ratio in dense regions. Two imaging plates are used: one upstream of the patient to record the incident beam profile and one down-stream to record the equalized image. Subtraction of a weighted version of the upstream image from the down-stream image permits alteration of the appearance of the VC image, from the extremes of stimulated-unequalized to highly equalized. VC image appearance was optimized with a real-time workstation. The quality of VC images obtained in 33 patients was evaluated by three chest radiologists. Mediastinal appearance was better on VC equalized images than on conventional screen-film images. The stimulation of the appearance of a conventional radiograph with VC proved useful in interpretation of lung appearances on equalized radiographs.

Aged↗
PubMedDate not supplied

The effect of incomplete knowledge on the diagnoses of a computer consultant system.

The knowledge bases (KBs) of diagnostic decision support systems are often incomplete, and gaps in the KB could potentially lead systems to reach diagnoses that are implausible to physicians. To investigate this possibility we studied Iliad (Version 2.01), a computer consultant system that generates differential diagnosis across the domain of internal medicine. Data from the history, physical examination, and laboratory findings of 50 grand-rounds cases were entered into Iliad by a computer consultant aware of the diagnosis but blinded to its presence or absence in Iliad's KB. Two experienced internists were asked to diagnose these cases before and after seeing the results of the computer consultation, and to assess the plausibility of the computer's diagnoses. Twenty-eight of the 50 cases (56.0%) were diseases contained in Iliad's KB. After seeing Iliad's diagnoses for cases in the KB, physicians assigned to their correct diagnoses a higher mean ranked position (1.5 versus 2.0, p less than 0.008) and a higher mean probability (84.0% versus 77.6%, p less than 0.008) compared with their pre-Iliad values, whereas for cases not in the KB, mean position and probability for correct diagnoses did not change. Physician diagnostic accuracy did not change after consultation on cases included or not included in the KB. After adjusting for case difficulty, mean plausibility of Iliad's diagnoses was judged significantly higher (on a seven-point scale) for cases in the KB than for cases not in the KB (4.2 versus 3.2, p less than 0.02).(ABSTRACT TRUNCATED AT 250 WORDS)

Artificial Intelligence↗
PubMed1975

Automatic measurement of random interpotenial intervals in single fibre electromyography.

The paper describes computer-aided measurement of interpotential intervals in single fibre eletromyography (SFEMG), a diagnostic and research method in clinical medicine. The method is based on analysis of consecutive intervals in pairs of single muscle fibre action potentials. The most important parameter obtained is the mean value of absolute differences of consecutive interpotential intervals, which reflects the reliability of impulse conduction along the terminal branches of motor axons and across the neuromuscular junction. The interface units, in combination with amplifers, binary counters and pulse amplitude-to-pulse width converters, allow not only direct analogue-to-digital conversion but also recognition of potentials. This enables the computer system to make decisions. The results are computed in less than 1 sec after analysis, and are immediately displayed in a graphic and alpha-numberical form on a screen at the measurement site. This provides an immediate visual feedback for the investigator thus both increasing the diagnostic efficacy and reducing the discomfort to the patient. Simultaneous printout by a teletype is used for documentation. The computer system consists of an HP 2116C computer with standard periphery and the program has been written in FORTRAN IV language with subroutines in FORTRAN IV and ASSEMBLER languages.

Action Potentials↗
PubMed1977

[A system of computer pre-treatment of electrocardiographic data].

A system of analogue pretreatment aimed at analysis of the arrhythmias in real time is presented. It is based on the separate detection of the P wave and the QRS complex, and on the use of a bipolar electrically conducting catheter introduced into the auricle of the right atrium. Such an arrangement is relatively insensitive to adventitous activity, both in the high and low frequency range, and provides on four separate channels impulses representing the P wave, the QRS complex, wide QRS complexes and premature QRS waves. In all cases, the atrial channel transmits all synchronised signals originating from atrial activity without any loss of information. This apparatus has been tried out with various arrhythmias and, if integrated, into a system of automatic detection, it should bring about a considerable saving in time and memory storage space.

Cardiac Complexes, Premature↗
PubMed1986

Computers in clinical laboratory management in Singapore.

In 1974, an off-line mini-computer system was introduced in the Clinical Biochemistry Laboratories of the Government Department of Pathology in Singapore. With the resiting of the 24-hour emergency biochemistry laboratory on the same floor as the Haematology Department within the new Singapore General Hospital, an on-line computer system was installed in 1983 to serve both the emergency biochemistry and haematology laboratories. An almost identical on-line system was also purchased in 1984 to replace the aged off-line system at the Department of Pathology. A description of the new computer systems based on Eclipse S/140 computers and Medical Information Technology (Meditech) software using Meditech Interpretive Information System (MIIS) language will be given. The specific features required and the selection criteria for the on-line systems are also discussed. The systems are used for the acquisition and processing of all patient and test data of the laboratories, direct capture of data from automated instruments, generation of work schedules and laboratory reports, compilation of work done, workload and revenue statistics and a variety of other reports. Patient cumulative records and quality control statistics are available on a real-time basis, thus greatly facilitating enquiries on patient results and monitoring of analytical performance. Prior experience with an off-line system and careful planning have been helpful in greatly shortening the preparatory period required for the smooth implementation of the on-line systems. Use of the systems has significantly improved laboratory management and has resulted in improved quality, and higher efficiency and productivity.

Chemistry, Clinical↗
PubMed1993

An overview of human-computer interaction.

This article presents an overview of the field of human-computer interaction. This branch of computer science concerns the design, implementation and analysis of interactive computer systems. We show that this field is multidisciplinary in essence, involving social scientists as well as computer scientists, experts of application domains, graphics designers, etc. Once the fundamental aspects of human-computer interaction are presented, we take a practical approach in order to introduce the methods, tools and techniques that are available today for the design and implementation of interactive computer systems. Finally, we present the main directions of research in this domain.

Computer Simulation↗
PubMed2006

PelvicSim--a computational-experimental system for biomechanical evaluation of female pelvic floor organ disorders and associated minimally invasive interventions.

In this paper we describe the prototype of a new computational simulation system, PelvicSim. This system is being developed to simulate the in vivo biomechanics of the female pelvic floor organ system with the intent to provide clinical researchers, medical device designers with a virtual environment to understand the various biomechanical pathologies occurring in the pelvic floor. This information can then be used to develop new reconstructive surgical techniques, or design non surgical/surgical devices for the treatment of urinary incontinence and pelvic organ prolapse. In this paper, we provide the initial results from the development of the PelvicSim modules which combine in vivo sensing experiments, Ultrasound and MRI imaging datasets, and an inverse finite element modeling technology based on hyperviscoelastic constitutive modeling of the pelvic floor organs and tissues.

Biomechanical Phenomena↗
PubMed1985

Effect of computer use in the consultation on the delivery of care.

The effects of the use of a computer on the delivery of care in consultations in general practice were examined. In this trial a computer system provided for the review and update of patients' medical histories, notes on doctor-patient contacts, and information on repeat prescribing. Thirty consultations in which the computer system was used and 30 consultations in which no computer was used were matched individually for the doctor consulted, the sex and age of the patient, and the presenting problem(s). Six independent general practitioners blind rated each consultation for the standard of care attained. A minor negative effect of computer use on the doctors' clinical performance was found. We suggest, however, that this small effect would disappear if a computer system was used routinely.

Computers↗
PubMed2002

An experimental comparison of detector performance for computed radiography systems.

The intrinsic resolution, noise, and signal-to-noise transfer characteristics of five commercial digital computed radiography (CR) systems were compared using identical experimental methods. The reader/screen combinations evaluated were Agfa ADC-Compact/MD-10, Agfa ADC-Compact/MD-30, Agfa ADC-Solo/MD-10, Agfa ADC-Solo/MD-30, Lumisys CR-2000/MD-10, Fuji FCR-9501 (HQ)/ST-Va, Kodak CR-400/GP-25, and Kodak CR-400/HR. Measurements were made at 70 and 115 kVp with 19 mm added aluminum filtration. The presampled modulation transfer functions (MTFs) of the systems were measured using an edge method. The noise power spectra (NPS) were determined by 2D Fourier analysis of uniformly exposed radiographs. The frequency-dependent detective quantum efficiencies (DQEs) were computed from the MTF, NPS, exposure measurements, and computational estimates of the ideal signal-to-noise ratios. Using 70 kVp and 0.1-0.12 mm pixel sizes, spatial frequencies of 2.1, 2.0, 2.2, 1.9, 2.0, 2.0, 2.3, 2.3, and 3.5 cycles/mm were measured at 0.2 MTF for the eight reader/screen combinations, respectively. Using 70 kVp, 7.74 x 10(-8) C/kg (0.3 mR), and 0.1-0.12 mm pixel sizes, DQE(0.15) values of 20.3%, 22.9%, 24.6%, 28.6%, 22.2%, 30.0%, 29.5%, and 17.3% were obtained for the eight combinations, respectively. The corresponding values at 115 kVp were 15.9%, 18.5%, 21.5%, 21.8%, 15.3%, 23.1%, 22.3%, and 13.8%, respectively. The findings of the study demonstrate the pixel size, orientation, beam quality, screen, and reader dependencies of image quality in CR systems. The physical performance of the systems having standard-resolution screens demonstrated similar resolution performance but more notable variations in DQE. The one high-resolution screen tested had reduced DQE and increased MTF at high frequencies.

Evaluation Studies as Topic↗
PubMed1995

The usage of infrared, ultraviolet and image computer transformation system in human cerebral angiologic examinations.

The usage of infrared, ultraviolet, luminescence both in infrared and ultraviolet for anatomical purposes was studied and the films were transformed with image computer analysis system. Infrared turned out to be exceptionally useful for examination of deep structures. Ultraviolet and especially luminescence in ultraviolet enables tracing the elements placed on the surface. Image computer transformation makes possible the spatial assessment of selected details and it broadens the exploratory possibilities.

Brain↗
PubMed1998

Computer analysis system of blood oxygen saturation in an animal hypoxia model.

An experimental animal hypoxia model has been developed. It consists of two sensors (an in vitro and in vivo model), an experimental device and a computer signal processing system. This method can easily be applied to determine and analyse blood oxygen saturation at various hypoxia levels. It can also be used to evaluate the accuracy of pulse oximetry over a wide range of oxyhemoglobin desaturation levels. The DC and AC components of recorded red and infra-red signals, the dual-wavelength ratio R12 and the reading of a pulse oximeter (SpO2) can be automatically calculated and displayed on a computer screen. Preliminary results of the animal hypoxia test indicate that the measurements made by the instrument correlate well with the oxygen saturation readings of the automatic blood gas analyser AVL945. The computer analysis system is suitable for repeated estimations in the animal model.

Animals↗