Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Biomedical Engineering”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

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

At least 523 records · Page 29Linked to original sources
PubMed2000

Biophysical injury mechanisms in electrical shock trauma.

Electrical shock trauma tends to produce a very complex pattern of injury, mainly because of the multiple modes of frequency-dependent tissue-field interactions. Historically, Joule heating was thought to be the only cause of electrical injuries to tissue by commercial-frequency electrical shocks. In the last 15 years, biomedical engineering research has improved the understanding of the underlying biophysical injury mechanisms. Besides thermal burns secondary to Joule heating, permeabilization of cell membranes and direct electroconformational denaturation of macromolecules such as proteins have also been identified as tissue-damage mechanisms. This review summarizes the physics of tissue injury caused by contact with commercial-frequency power lines, as well as exposure to lightning and radio frequency (RF), microwave, and ionizing radiation. In addition, we describe the anatomic patterns of the resultant tissue injury from these modes of electromagnetic exposures.

Animals↗
PubMed2000

What is life, and what is a machine? The ontology of bioengineering.

In his Keynote address to the First Conference at Clemson University on Ethical Issues in Biomedical Engineering, George Bugliarello suggested that a most important ethical issue for bioengineering "is the positioning of the bio-machine interface." "Where," he asked, "should the biological organism end and the machine begin?" Central to this question of the limits of life and engineering is the more fundamental question of how life differs and how it is similar to a machine. This paper argues that until very recently, science, by its very nature, has treated life as if it were a machine, or has treated the parts of living systems as if they were machines. The distinctive feature of a machine is that its behavior is linear and hence predictable. On the other hand, living organisms may not be linear, but rather nonlinear systems. Thus, the interface between organism and machine may be conceived as the interface between nonlinear and linear systems.

Biomedical Engineering↗
PubMed1989

The postgraduate medical informatics programme at the University of Cape Town.

The Medical Informatics education programme at the University of Cape Town was developed as part of the postgraduate education programme run by the Department of Biomedical Engineering. The aim of the programme is twofold: a) To give students a broad background in Medical Informatics, to enable them to participate in the development, planning and management of information systems to support health care in South Africa, and b) To enable them to do a research project in a specialised area, thus learning research techniques, and contributing to the development of Medical Informatics as a discipline. Students benefit from participating in a postgraduate programme in a multidisciplinary department, which is firmly linked to the health care environment. A more specialised Medical Informatics programme is planned, but the multidisciplinary nature of work in this field will continue to be emphasised.

Biomedical Engineering↗
PubMed1982

Bioengineering aspects of heart valve replacement.

Biomedical engineering inputs have been important in the design, development and testing of substitute heart valves as well as in the pre- and post-operative management of patients with cardiac valve disease. This paper is a review of heart valve replacement whose goal is the enhancement of future bioengineering contributions. We review the approach to the patient with valvular heart disease, and the sources of early and late postoperative pathology with emphasis on complications of the prostheses used. Major significant problem areas relate to the noninvasive evaluation of cardiovascular function (both before and after surgery), device design, hemodynamics, and the need for thromboresistant and durable materials.

Biomedical Engineering↗
PubMedDate not supplied

Medical imaging equipment service in Kaiser Permanente, Northern California.

As the largest department in Biomedical Engineering, Medical Imaging Services (MIS) provides comprehensive equipment service for all imaging modalities in Kaiser Permanente, Northern California Region. MIS is customer-focused and committed to exploring better ways to deliver service, control costs and implement business strategies to meet customers' changing needs. Service extends beyond conventional preventive/corrective maintenance to include technology assessment, regulatory compliance, education and training, and managed vendor relationships. Program enhancements include film processor and solutions service, a second-source parts program, and a machine shop. In recent years, operations expanded to the Kaiser Permanente Northwest Region. Significant savings are available to any healthcare organization willing to embrace a new, expanded view of equipment management.

Biomedical Engineering↗
PubMed1999

Care and feeding of a staff for filmless radiology.

Texas Children's Hospital, a definitive care pediatric hospital located in the Texas Medical Center, has been constructing a large-scale picture archival and communications system (PACS) including ultrasound (US), computed tomography (CT), magnetic resonance (MR), and computed radiography (CR). Developing staffing adequate to meet the demands of filmless radiology operations has been a continuous challenge. Overall guidance for the PACS effort is provided by a hospital-level PACS Committee, a department-level PACS Steering Committee, and an Operations Committee. Operational Subcommittees have been formed to address service-specific implementation, such as the Emergency Center Operations Subcommittee. These committees include membership by those affected by the change, as well as those effecting the change. Initially, personnel resources for PACS were provided through additional duties of existing imaging service personnel. As the PACS effort became more complex, full-time positions were created, including a PACS Coordinator, a PACS Analyst, and a Digital Imaging Assistant. Each position requires a job description, qualifications, and personnel development plans that are difficult to anticipate in an evolving PACS implementation. These positions have been augmented by temporary full-time assignments, position reclassifications, and cross-training of other imaging personnel. Imaging personnel are assisted by other hospital personnel from Biomedical Engineering and Information Services. Ultimately, the PACS staff grows to include all those who must operate the PACS equipment in the normal course of their duties. The effectiveness of the PACS staff is limited by their level of their expertise. This report discusses our methods to obtain training from outside our institution and to develop, conduct, and document standardized in-house training. We describe some of the products of this work, including policies and procedures, clinical competency criteria, PACS inservice topics, and an informal PACS newsletter. As the PACS system software and hardware changes, and as our implementation grows, these products must to be revised and training must be repeated.

Biomedical Engineering↗
PubMed2006

Tutorial on multivariate autoregressive modelling.

In the present paper, the theoretical background of multivariate autoregressive modelling (MAR) is explained. The motivation for MAR modelling is the need to study the linear relationships between signals. In biomedical engineering, MAR modelling is used especially in the analysis of cardiovascular dynamics and electroencephalographic signals, because it allows determination of physiologically relevant connections between the measured signals. In a MAR model, the value of each variable at each time instance is predicted from the values of the same series and those of all other time series. The number of past values used is called the model order. Because of the inter-signal connections, a MAR model can describe causality, delays, closed-loop effects and simultaneous phenomena. To provide a better insight into the subject matter, MAR modelling is here illustrated with a model between systolic blood pressure, RR interval and instantaneous lung volume.

Biomedical Engineering↗
PubMed2002

Twenty-eight years of clinical experience with implantable neuroprostheses for various applications.

Since 1973, the author has been implanting neural stimulators and later drug pumps to restore or improve motor function and modulate pain, spasticity, and seizures in patients with spinal cord and brain injury, cerebral palsy, stroke, and multiple sclerosis. During these 28 years, many physicians, biomedical engineers, and manufactures have realized worthwhile successes. Many lessons have been learned to improve operative techniques to ensure safety, low infection, and improved results for implant patients. The relationships between manufacturers and physicians have varied. Problems arise with patents, royalties, confidentiality, publishing, and liability insurance. There has been a need to patent ideas and intellectual properties; however, some of the patented concepts have been published previously but missed by the patent author and patent office. This has led to vigorous legal battles, consuming money with time delays, or resulting in surrendering worthwhile projects. There is a need for a responsible, independent appeals board to review these disputed patent claims. Then their findings should be admissible at the Patent Office and if necessary in court.

Biomedical Engineering↗
PubMed1997

Ultrasonic wave propagation in porous media: determination of acoustic parameters and high frequency limit of the classical models.

Results on the ultrasonic wave propagation in porous materials are presented with emphasis on the measurement of acoustic parameters and on the discrepancy between experimental results and theoretical predictions for the attenuation at high frequencies. This discrepancy can be observed in Biomedical Engineering where the propagation in different sorts of bones is studied as well as in the fields of Geophysics and Material Science. In the present study, the slow wave propagation in polyurethane foams saturated by different gases is investigated in a frequency range of [70-800 kHz]. Methods are presented to determine the tortuosity and the viscous and thermal characteristic lengths. The experimental results, obtained using standard ultrasonic and vacuum equipments, show that an excess attenuation occurs when the wavelength is not sufficiently large compared to the lateral dimensions of the fibers. This effect constitutes a limit of the classical models of equivalent phases. It is evaluated with the help of a model of ultrasonic scattering. A numerical simulation of osteoporosis using Biot's model is also presented.

Acoustics↗
PubMed1997

Use of the virtual instrumentation laboratory for the assessment of human factors in surgery and anesthesia.

There is a growing consensus that human factors issues for anesthesiologists, surgeons, and other operating room personnel require serious attention. We have established a program of collaboration between the University of California Davis Medical Center Departments of Anesthesiology and Surgery and the California State University Sacramento Biomedical Engineering Program to address ergonomic problems in anesthesiology and surgery using a Virtual Instrumentation Laboratory. A 17-workstation Virtual Instrument Laboratory using LabVIEW software on Power Macintosh platforms permits rapid prototyping of medical monitor displays as well as rapid development of data acquisition and processing circuits for physiologic data collection. The Virtual Instrument Lab has been used for three Master's thesis projects and a BME course titled Human Factors in the Design of Medical and Assistive Technology. Course projects have included: 1) The design of novel physiologic data displays for potential use in anesthesia workstations, and 2) The measurement of surface electromyographic signals and heart rate variability to investigate the physical and mental workload of performing laparoscopic surgery. The Virtual Instrument Lab allows BME students to investigate relatively complex human factors issues in anesthesiology and surgery in a short time span.

Anesthesiology↗
PubMed1996

Development of a home ankle exerciser.

A portable, lightweight home ankle exerciser was designed and built by the Biomedical Engineering Department of University Hospital in London, Ontario, Canada. The ankle exerciser incorporates several unique features that overcomes the drawbacks of exercise equipment presently available. For optimal muscle strengthening, the resistance offered by the device matches the strength curve of the ankle muscles. The magnitude of the resistance can be widely varied to accommodate any subject. Resistance is generated by a slip clutch rather than by springs or weights which can be cumbersome and potentially dangerous. One of the considerations in the design of the ankle exerciser was to monitor subject compliance with the exercise regimen. This is accomplished with a battery-operated monitoring unit mounted on the device. The exerciser is instrumented with a battery-powered torque transducer and digital display unit that enables the subject and assessor to monitor the exercise resistance level at a glance.

Adult↗
PubMed1984

Statistical clustering procedures applied to low-cost speech recognition.

A new generation of low-cost speech recognition devices are appearing, which offer much promise for useful applications in biomedical engineering. These devices are statistical pattern recognizers. Input utterances are classified by comparison with a set of templates derived during 'speaker training'. For useful application of these devices, recognition accuracy must be high and speaker training must not be unacceptably complicated or tedious. This paper investigates techniques which consider the statistical nature of the input utterances, used to improve recognition accuracy. Word classification based on the Mahalonobis distance metric, and using templates derived from cluster analysis of the training inputs, was found to give results superior to the other strategies studied. This classifier was unsuitable for implementation in a real-time, low-cost system but the principle of clustering was successfully applied to produce an adaptive system which tracked changes in the user's voice. This allowed training to be drastically simplified by updating templates during normal operation. The adaptive system achieved 98.8% recognition accuracy on a 32 word vocabulary compared to 94.8% without adaptation.

Biomedical Engineering↗
PubMed2001

Plasma lithography--thin-film patterning of polymeric biomaterials by RF plasma polymerization I: Surface preparation and analysis.

Plasma lithography, combining plasma deposition with photolithography, is described as a versatile method to manufacture all-polymeric substrates with thin-film patterns for applications in biomedical engineering. Patterns of a hydrophobic fluorocarbon plasma polymer with feature sizes between 5 and 100 microm were deposited on a base substrate in a lift-off process: an intermediate tetraglyme plasma polymer layer provides non-fouling properties to the base substrate. Careful analysis of critical process parameters identified the narrow window of process conditions that led to the formation of functional surface patterns. High pattern fidelity, aspect ratios, and resolution of the patterns are demonstrated by atomic force microscopy. Electron spectroscopy for chemical analysis (ESCA) and secondary ion mass spectroscopy (SIMS) were used to characterize the surfaces, showing good retention of the original chemical structure of the pattern components throughout the process. SIMS imaging was used for specific chemical imaging of the components. Potential applications for the patterned polymer films, e.g., for studying cell behavior in vitro in dependence of shape and size of adhering cells, are discussed.

Biocompatible Materials↗
PubMed1975

Locomotion studies as an aid in clinical assessment of childhood gait.

A clinical locomotion laboratory has been developed to provide quantitative information in the management of gait disorders. The biomedical engineering development of this system identified two major clinical constraints: (a) the need for instrumentation that would not alter the natural gait of the patient and (b) the need for data-processing techniques that would permit analysis and correlation of the large volume of electromyographic (EMg) and kinematic information. The net result has been a unit that incorporates a multichannel telemetry system to capture the EMG and foot-switch information and a television computer system to handle the kinematic information. Gait studies on children with hemiparesis, muscular dystrophy and cerebral palsy have yielded quantitative EMG and kinematic information on the pathomechanics of ambulation in these disorders. Because the information obtained is quantitative, an accurate measure of improvement (or lack of it) after treatment can be documented. Therefore, the locomotion laboratory may have an important role in the preoperative and postoperative evaluation of children whose abnormal gait may require surgical corrective procedures or rehabilitative treatment including the use of prostheses or orthoses.

Adolescent↗
PubMed2005

Template-based finite-element mesh generation from medical images.

The finite-element (FE) method is commonly used in biomedical engineering to simulate the behaviour of biological structures because of its ability to model complex shapes in a subject-specific manner. However, generating FE meshes from medical images remains a bottleneck. We present a template-based technique for semi-automatically generating FE meshes which is applicable to prospective studies of individual patients in which FE meshes must be generated from scans of the same structure taken at different points in time to study the effects of disease progression/regression. In this "template-based" meshing approach, the baseline FE (tetrahedral) volume mesh is first manually aligned with the follow-up images. The triangulated surface of the mesh is then automatically deformed to fit the imaged organ boundary. The deformed surface nodes are then smoothed using a Laplacian smoothing algorithm to correct triangle (surface nodes) distortion and thus preserve triangle quality. Finally, the internal mesh nodes are smoothed to correct distorted tetrahedral elements and thus preserve tetrahedral element quality. This template-based approach is shown to be as accurate and precise as the previous technique used by our group, while preserving element quality and volume.

Algorithms↗
PubMed2000

Beyond a code of ethics for bioengineers: the role of ethics in an integrated compliance program.

Developing a code of ethics for biomedical engineering professionals is a very important first step in clarifying their professional obligations and in helping to establish and maintain their professional autonomy. However, it is only that--a first step. Unless ways can be found to bring the principles contained in this code to bear on the everyday decision making of these professionals, this code will have little practical influence. One effective way to bring a code of ethics to bear on decision making is to integrate it into organizational compliance programs. Such programs often have company-specific codes of ethics attached to them, and these company-specific codes can either include the principles contained in the professional code of ethics or reference the code by title. After defining what I take to be the challenge of compliance, I consider four (4) roles that codes of ethics and ethics generally can play in helping to create and sustain programs at the organizational level that integrate ethics and compliance and thereby aim to make a practical difference in the everyday decision making of bioengineering professionals. These four roles include: framing the program, grounding the standards, achieving critical distance, and creating and sustaining an ethical organizational culture.

Biomedical Engineering↗
PubMed2006

The DaVinci Group: a second modern Ophthalmotrope.

A group of undergraduate students at the University of Connecticut Biomedical Engineering Program has formed a "club" in order to more fully understand and educate themselves in modeling anatomical processes. This group is called the DaVinci Robot or DaVinci Group. Experiments to mechanically model the six extraocular muscles of the eye have been performed, each meeting little success. While researching methods that would lead to better success, the concept of the Ophthalmotrope was discovered. The Ophthalmotrope is a mechanical visual aide used in teaching the function of the extraocular muscles, prevalent in the mid 1800's. The Group decided to study this device and ultimately decided to build one. The paper presented here discusses our third experiment, currently under investigation, that is, to build an Opthalmotrope. Difficulties with this task are lack of any information with regard to how to construct this device. Presented are descriptions of the Group's initial experiments and research conducted into the construction of the Ophthalmotrpe. In the main body of the presented paper is a description of how the DaVinci Group Ophthalmotrope is constructed. Concluding is a discussion of the progress of the construction of the Ophthalmotrope along with a brief listing of research conducted in order to build the device.

Biomedical Engineering↗
PubMedDate not supplied

Cost-effective quality assurance of rented medical equipment.

The Biomedical Engineering Department (BME) at the University Medical Center, Tucson, Arizona, noted a sharp increase in the use of rented medical equipment. To increase efficiency, control costs, and provide effective quality assurance for rented equipment, a Medical Equipment Rental Vendor (MERV) program was formulated. The program increases efficiency by placing the burden of verifying safety and performance on the MERVs. Performance requirements were developed for the MERVs. The vendors who agreed to the requirements were compiled into a list of preferred vendors to be the primary suppliers of rental medical equipment to UMC. These preferred vendors were given preapproval from BME to deliver equipment directly to the requesting clinical department. All other vendors must continue to submit their equipment to BME for inspection. Policies were written to outline the responsibilities of the clinical departments and BME relative to the MERVs. Frequency of sampling, means of documentation, and assurance of user training were included. Response from the vendors and clinical departments has been positive. Communication between the vendors, clinical departments, and BME has improved through the development and implementation of this program. Vendor and equipment quality have been maintained or improved since compliance with the performance requirements is necessary to maintain preferred vendor status.

Arizona↗