PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Surgery, Computer-Assisted”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 163 records · Page 9Linked to original sources
PubMed1992

Staircase assessment of the magnitude and time-course of 50% nitrous-oxide analgesia.

The analgesic effect of 50% nitrous oxide and oxygen on thermal pain sensations was evaluated in a placebo-controlled, double-blind crossover design. In a session immediately before oral surgery, 20 patients used a seven-point verbal scale to rate the intensity of pain sensations evoked by three-second thermal stimuli delivered to 14 sites on the volar forearm at 20-second intervals by a 1-cm-diameter contact thermode. Subjects rated 36 stimuli while breathing room air and then two additional sets of 36 stimuli while inhaling 50% nitrous oxide and oxygen during one set and oxygen placebo during the other. Each of these two stimulus sets was preceded by a two-minute induction of the agent, and the sets were separated by a three-minute washout period. Order of administration was randomized and counterbalanced. Stimulus temperatures were adjusted continuously by an interactive computer program so that response could be maintained at predetermined levels. This method resulted in a continuous measure of analgesia in units of stimulus intensity. Results showed that, in comparison with placebo, nitrous oxide significantly increased the stimulus temperatures (mean = 0.42 degrees C) required to make the same response [F (11,209) = 6.76, p less than 0.0001], indicating analgesia. This increase was one-third to one-half that observed with clinical doses of intravenous fentanyl. Analgesic effects were apparent at three min and wanted 10 min after termination of nitrous-oxide inhalation. These times closely correlated with previous measures of alveolar concentration, further supporting the fast but modest analgesic action of nitrous oxide.

Anesthesia, Dental↗
PubMed1992

A computerized intensive care unit order-writing protocol.

OBJECTIVE: To present a computerized intensive care unit order-writing protocol. DESIGN: Descriptive report. SETTING: Eight-bed surgical intensive care unit, Department of Surgery, Department of Veterans Affairs Medical Center, Bronx, NY. METHODS: IBM-based, computer network program that provides user-friendly, logical, and comprehensive organ-system order sequences for patient management. RESULTS: Since July 1988, an order program that stresses (1) improved and more efficient patient care, (2) the use of program-integrated automatic safety features, (3) the substitution of computer entry for handwriting, and (4) the assurance that physicians deliver obligatory care in a logical organ-system-based progression has been implemented. CONCLUSIONS: The order protocol system presented is simple to introduce and operate, has minimal training and technical requirements, and is demonstrably reliable.

Computer Security↗
PubMed1992

Management of unruptured intracranial arteriovenous malformations: a decision analysis.

The management of unruptured intracranial arteriovenous malformations (AVMs) is controversial. Some authorities favor elective excision of the AVM before it bleeds, whereas others advise nonintervention unless the AVM bleeds, at which time surgical excision is performed in those who survive. A Markov model was developed that stimulates a clinical trial in which cohorts of patients with unruptured AVMs were assigned to either elective excision of their AVMs or conservative treatment (unless the AVM bled). Incremental utilities for both strategies were calculated at the end of each year after the beginning of the trial and are expressed as quality and risk-adjusted life years. The process was continued until all members of the cohorts had died. The mean quality and risk-adjusted life expectancy for members of a cohort was calculated by dividing the total number of quality and risk-adjusted life years the cohort had accumulated by the size of the cohort. If the baseline values for surgical complications were used in the computation, the quality and risk-adjusted life expectancy for the surgical cohorts was at least 1 quality and risk-adjusted life year greater than for nonsurgical cohorts up to age 44. If a more favorable complication rate were used, elective surgery could benefit selected patients in their early 60s when the location and configuration of the AVM was favorable. Elective surgical resection is justified in many instances before rupture, particularly in young patients who have intracranial AVMs that have a favorable location, size, and venous drainage.

Cerebral Hemorrhage↗
PubMed1992

Evaluation of congenital heart disease with MR imaging: current and coming attractions.

Nearly 10 years of experience in the use of MR imaging for the diagnosis of congenital heart disease has accumulated. Although MR imaging is superior to other techniques in showing certain structures and abnormalities such as small central pulmonary arteries in tetralogy of Fallot, aortic coarctations, and venous connections in heterotaxia syndromes, it remains an ancillary tool to echocardiography and cardiac catheterization. In this review, we examine present limitations and advantages of conventional MR in the evaluation of congenital anomalies of the heart and great vessels and explore future developments that might bring MR imaging into the diagnostic mainstream. Key improvements now in development are ultrafast MR systems for acquisition of multiple real-time MR images (in 30 msec or less) and on-line three-dimensional computer reconstruction of the heart and great vessels. Improved display and understanding of complex anatomy, as well as more extensive functional analysis of hearts before and after surgery, should be the benefits of such developments.

Adolescent↗
PubMed1992

Measurement of tumor resection volumes from computerized images. Technical note.

The authors describe a method for quantitation of the area and volume of the resection cavity in patients who have undergone surgery for brain tumors. Using a slide scanner and Image 1.27, a public domain program for the Apple Macintosh II computer, computerized tomography scans and magnetic resonance images can be digitized and analyzed for a particular region of interest, such as the area and volume of tumor on preoperative and postresection scans. Phantom scans were used to analyze the accuracy of the program and the program users. User error was estimated at 2%, program error was 4.5%. This methodology is proposed as a means of retrospectively calculating the extent of tumor resection.

Humans↗
PubMedDate not supplied

Refractive error changes following strabismus surgery.

Several uncontrolled, retrospective studies have suggested that permanent changes in refractive error can be seen following strabismus surgery. We prospectively enrolled 68 patients undergoing strabismus surgery for evaluation of pre- and postoperative cycloplegic refraction. In addition, the adult patients had computerized corneal topography recorded using the Corneal Modeling System, (Computed Anatomy, Inc, New York, NY). Pre- and postoperative refractions were compared using spherical equivalent and meridional equivalent (90- and 180-degree meridian). We found no significant change in the spherical equivalent between the pre- and postoperative measurements. However, a significant increase in the astigmatic power at 180 degrees (meridional equivalent at 180 degrees) was detected in both pediatric and adult patients. We did not observe any qualitative change in the corneal topography pre- and postoperatively. The change in astigmatic power at 180 degrees is equivalent to additional plus-cylinder correction at 90 degrees and was persistent throughout the 4-month postoperative period.

Adolescent↗
PubMedDate not supplied

Knowledge-based multi-modality three-dimensional image analysis of the brain.

With the recent advances in medical imaging, three-dimensional anatomical and metabolic images of the brain are now available through MR/CT and PET/SPECT imaging modalities. Computerized multi-modality three-dimensional brain image registration and analysis can provide important correlated information for improving diagnosis and studying the pathology of disease. Such analysis may also provide help in planning brain surgery. Further, an anatomical model based quantification and analysis of internal structure can be used to develop a computerized anatomical atlas. Conventional anatomical atlases provide rigid spatial distribution of internal structures extracted from a single subject. The proposed computerized anatomical atlas provides probabilistic spatial distributions which can be easily updated to incorporate the variability of brain structures of subjects selected from pre-defined groups. This paper first presents a review of the current trends in knowledge-based segmentation, labeling, and analysis of MR brain images and then describes the Principal Axes Transformation based registration of three-dimensional MR brain images to develop composite models of selected internal brain structures. The composite models can be used as a computerized anatomical atlas in model-based segmentation and labeling of MR brain images. Three-dimensional labeled MR images of the brain can also be registered and correlated with PET images for analyzing the metabolic activity in the anatomically selected volume of interest. On the other hand, a volume of interest can be selected using the metabolic information and then analyzed for correlated anatomical information using the registered MR-PET images.

Algorithms↗
PubMed1992

[Three-dimensional computerized tomography in trauma surgery. A case presentation].

Three-dimensional images of bone structures can easily be reconstructed from computed tomography data. The technique and the advantages of contemplating reconstructions of bone defects in different directions are described. A special software programme allows to combine all data which are given by the standard CT. The slice diameter is two millimetres. The reconstruction shows bone surfaces in all required views. In traumatic and orthopaedic surgery 3-D-CT is useful in the analysis, detection and preoperative planning of comminuted bone injuries of the spine, pelvis, knee, shoulder and the calcaneus. With this technique it is possible to see the bone in its topographic constellation, to observe fractures in unusual directions and to identify fragments from each other. The surgeon gets a lot of additional information which is helpful to decide on the incision, the reduction and the fixation of fragments. Undesirable effects during operation are reduced, which leads to a more accurate treatment and subsequent better results.

Accidents↗
PubMed1992

Expert computer program for the management of laser surgery.

Since 1960 when the first laser was produced, different types of lasers were developed and over one hundred of them are actually used in medicine. These facts makes very difficult for a surgeon to optimally utilize different types of laser in varying surgical circumstances, unless a laser expert is actually participating in the procedure. As this presence is impractical, if not impossible in every case, we are offering a computer program which presents information in a flexible and friendly way; it is self perfecting and greatly expandable.

Humans↗
PubMedDate not supplied

Computer assisted instruction for preoperative and postoperative patient education in joint replacement surgery.

This article describes a comprehensive system for preoperative and postoperative patient education. The system offers a cost-effective method of instruction which encourages patient interaction and practice with decision making. The system was designed for patients undergoing total joint replacement surgery and includes two preoperative lessons, and a third lesson presented postoperatively at the bedside. The computer lessons were developed using data collected by a patient assessment instrument, and collaboratively with input from a nurse clinical specialist, orthopedic surgeon, physical therapist, and computer programmer. In this project, several advantages for using computer assisted instruction for preoperative and postoperative patient education were identified.

Computer-Assisted Instruction↗
PubMed1992

Electronic imaging of the human body.

The Human Engineering Division of the Armstrong Laboratory (USAF); the Mallinckrodt Institute of Radiology; the Washington University School of Medicine; and the Lister-Hill National Center for Biomedical Communication, National Library of Medicine are sponsoring a working group on electronic imaging of the human body. Electronic imaging of the surface of the human body has been pursued and developed by a number of disciplines including radiology, forensics, surgery, engineering, medical education, and anthropometry. The applications range from reconstructive surgery to computer-aided design (CAD) of protective equipment. Although these areas appear unrelated, they have a great deal of commonality. All the organizations working in this area are faced with the challenges of collecting, reducing, and formatting the data in an efficient and standard manner; storing this data in a computerized database to make it readily accessible; and developing software applications that can visualize, manipulate, and analyze the data. This working group is being established to encourage effective use of the resources of all the various groups and disciplines involved in electronic imaging of the human body surface by providing a forum for discussing progress and challenges with these types of data.

Computer Simulation↗
PubMed1992

An analysis of vitreous tamponade effect in encircling surgery by means of finite element method.

The vitreous tamponade effect in encircling surgery was investigated by means of a finite element method. We performed the simulated encircling surgery on a computer program, which could have alternative band positions, i.e. anterior or posterior band position. Computed results revealed that the band position has a great influence on the vitreous stress distribution, and that the anterior band position is more advantageous than the posterior band position with regard to the vitreous tamponade effect. To our knowledge, this is the first numerical experiment to demonstrate the advantage of the anterior band position in encircling surgery.

Computer Simulation↗
PubMed1992

Digital imaging, image processing, and three-dimensional computer graphics for radiology.

The acquisition of medical images and their display, manipulation, and applications have advanced significantly in the recent past. MR imaging using ultrafast echo planar and fast gradient-echo techniques have expanded application in cardiovascular studies, as well as in the brain and spinal cord. Spiral CT has the potential to revolutionize a well-established modality, subject to several important limitations. The postprocessing of medical sectional images from MR imaging, CT, ultrasound, positron emission tomography, and single-photon emission CT has rapidly grown in importance. We have seen the emergence of renewed and expanded applications of these images, suitably processed, in directing planning and performance of therapeutic procedures on patients through stereotactic techniques, intravascular ultrasound, robot surgery, and integrated displays. This more central role of three-dimensional imaging to medical care is new and will continue to grow. Research applications have recently appeared in neuromorphometry, multimodality registration, functional neuroimaging, quantitative coronary angiography, and saturation MR techniques for myocardial tissue tagging.

Computer Graphics↗
PubMedDate not supplied

On the computer-aided and optimal design of keratorefractive surgery.

BACKGROUND: Several recent papers have discussed the use of engineering-based computer methods for the analysis of keratorefractive surgical procedures. What has been lacking is a broader view of the role of engineering analysis in keratorefractive surgery. This article demonstrates how these various analysis methods can be coupled to provide a comprehensive methodology for the design of refractive surgical procedures. METHODS: A structural model of the eye, based on a linearly elastic, transversely isotropic finite element formulation is coupled to a full-eye optical model. The optical errors due to refractive keratotomy are estimated by ray tracing through the optical model and measuring the position of the resulting focal plane relative to the retina. Computer-based optimization methods are employed to determine the surgical parameters necessary to correct myopia for a given set of surgical design goals. RESULTS: Results based on a hypothetical eye demonstrate agreement with clinical trends. Radial keratotomies are designed that eliminate refractive error while minimizing invasiveness in one case and maximizing the optical zone size in another. It is also shown that there is significant potential to customize this process on a patient-by-patient basis using clinically measured data. CONCLUSIONS: We present an overview of the research necessary to bring this approach to fruition. While only a first step, the methodology presented in this article has the potential to increase the predictability of keratorefractive surgery by substantially increasing both the quality and the quantity of the information available to the refractive surgeon preoperatively.

Biomechanical Phenomena↗
PubMed1992

Computer-controlled sodium nitroprusside infusions in patients after cardiac surgery.

Postoperative hypertension, a common occurrence after cardiac surgery, is frequently controlled by sodium nitroprusside infusions. Computer-controlled administration of this drug has been shown to be superior to manually controlled systems for maintaining the patient's blood pressure within an optimal range. The impact of this technology on patients, nurses, and hospitals is discussed.

Cardiac Surgical Procedures↗
PubMed1992

Linear accelerator radiosurgery at the University of Florida.

The University of Florida radiosurgical project began in 1986 with the following design criteria: the most accurate radiosurgical device possible, state-of-the-art computer hardware and software for dose planning, and a number of collimators sufficient to treat any lesion homogeneously. In this article we have reviewed how these goals have been met. Physical aspects of this device (accuracy, dose gradient, and dose-planning speed) as well as clinical results compare favorably with any other radiosurgical experience. We believe that LINAC radiosurgical systems are advantageous in terms of cost, variety of collimator sizes available, and currently available sophistication of computerized dose planning. In the near future, the development of conformal treatment may significantly change the entire field of radiosurgery by offering heretofore unobtainable dose plans for irregularly shaped lesions. In addition, LINAC systems may be adapted for stereotactically focused fractionated radiation therapy and for radiosurgical treatment of lesions elsewhere in the body. Accuracy and computer sophistication notwithstanding, we cannot emphasize strongly enough our belief that the least important determinant of radiosurgical results is the machine used to deliver the radiation. It is absolutely vital that all groups undertaking radiosurgery include neurosurgeons, radiation physicists, and radiation therapists who have spent considerable time studying and learning the myriad details necessary to produce consistently good results. All radiosurgical patients must be followed up carefully and studied so that we can learn how to better apply this technique. Only patients who are not candidates for conventional surgery should be treated radiosurgically, at least until much more is known about long-term success and complication rates. A patient never should be treated radiosurgically simply because the referring or treating neurosurgeon is uncomfortable with proven conventional procedures. All groups performing radiosurgery should strive to adhere to the highest possible standards. We are all responsible for verifying the adequacy of our radiosurgical systems. We are all responsible for selecting our patients well, treating them with a team approach that applies the latest available knowledge of our field, following up closely, and reporting our results honestly and thoroughly so that all can benefit. We owe this, at least, to our patients and to neurosurgery.

Adult↗
PubMed1978

Enlarged acid-base and blood gas calculations by electronical data computing in the blood gas laboratory.

A rapid anaysis of parameters of the acid-base equilibrium and blood gases during open heart surgery and emergency therapy is absolutely necessary. Computing of the several parameters of the acid-base status by slide rules or nomograms is time consuming and can be shortened by computer applications. The central blood gas laboratory consists of a blood gas analyzer for PO2, PCO2 and pH, an electronic desktop calculator, a four color X-Y-plotter and two data lines to the cardiac surgery unit and to the intensive care unit. The time needed for computing and feedback of the parameters could be decreased to one quarter. In addition to numerical data printout, a graphical representation of the several parameters is possible on a X-Y-plotter and includes the Rahn-Fenn-O2-CO2-Diagram with venous admixture, ventilation perfusion ratio, alveolar dead space ventilation and the standard and actual oxygen dissociation curve as well as the pH/HCO3- Acid-Base nomogram. Furthermore, a computer diagnosis of the actual disturbances can be plotted.

Acid-Base Equilibrium↗