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Biomedical subjects

E Borg

Publications and source records attributed to E Borg.

At least 19 recordsLinked to original sources

A comparison between three rating scales for perceived exertion and two different work tests.

In the present article, three scales developed by Borg are compared on bicycle ergometer work. In the first study, comparing the Borg Ratings of Perceived Exertion (RPE) and Category scales with Ratio properties (CR10) scales, 40 healthy subjects (12 men and eight women for each scale) with a mean age of about 30 years (SD approximately 6) participated. A work-test protocol with step-wise increase of work loads every minute was used (20 W increase for men and 15 W for women). Ratings and heart rates (HRs) were recorded every minute and blood lactates every third minute. Data obtained with the RPE scale were described with linear regressions, with individual correlations of about 0.98. Data obtained with the CR10 scale could also be described by linear regressions, but when described by power functions gave exponents of about 1.2 (SD approximately 0.4) (with one additional constant included in the power function). This was significantly lower than the exponent of between 1.5 and 1.9 that has previously been observed. Mean individual correlations were 0.98. Blood lactate concentration grew with monotonously increasing functions that could be described by power functions with a mean exponent of about 2.6 (SD approximately 0.6) (with two additional constants included in the power functions). In the second study, where also the more recently developed Borg CR100 scale (centiMax) was included, 24 healthy subjects (12 men and 12 women) with a mean age of about 29 years (SD approximately 3) participated in a work test with a step-wise increase of work loads (25 W) every third minute. Ratings and HRs were recorded. RPE values were described by linear regressions with individual correlations of about 0.97. Data from the two CR scales were described by power functions with mean exponents of about 1.4 (SD approximately 0.5) (with a-values in the power functions). Mean individual correlations were about 0.98. In both studies, a tendency for a deviation from linearity between RPE values and HRs was observed. The obtained deviations from what has previously been obtained for work of longer duration (4-6 min) points to a need for standardization of work-test protocols and to the advantage of using CR scales.

Adult↗

Long-term effects of integrated rehabilitation in patients with advanced angina pectoris: a nonrandomized comparative study.

OBJECTIVES: An evaluation of Integrative Rehabilitation (IR) of patients with angina pectoris with respect to death rate, the need for invasive treatment, and cost effectiveness. DESIGN: A report from a clinical database. Death rates were compared to those of the general Danish population matched for age, gender, and observation period, as well as with data from the literature concerning medical and invasive treatments. SETTING: The treatment was carried out as an ambulatory treatment in a private clinic. SUBJECTS: One hundred and sixty-eight (168) patients with angina pectoris, of whom 103 were candidates for invasive treatment and 65 for whom this had been rejected. INTERVENTIONS: Integrated rehabilitation consists of acupuncture, a self-care program including acupressure, Chinese health philosophy, stress management techniques, and lifestyle adjustments. OUTCOME MEASURES: Death rate from any cause, the need for invasive treatment, and health care expenses. RESULTS: The 3-year accumulated risk of death was 2.0% (95% confidence limits: 0.0%-4.7%) for the 103 candidates for invasive treatment, 6.4% for the general Danish population, 5.4% (4.7%-6.1%), and 8.4% (7.7%-9.1%) for patients who underwent percutaneous transluminal balloon angioplasty and coronary artery bypass grafting, respectively, in New York. For the 65 inoperable patients the risk of death due to heart disease was 7.7% (3.9%-11.5%), compared to 16% (10%-34%) and 25% (18%-36%) for American patients, who were treated with laser revascularization or medication, respectively. Of the 103 candidates for invasive treatment, only 19 (18%) still required surgery. Cost savings over 3 years were US 36,000 dollars and US 22,000 dollars for surgical and nonsurgical patients, respectively. These were mainly achieved by the reduction in the use of invasive treatment and a 95% reduction in in-hospital days. CONCLUSIONS: Integrated rehabilitation was found to be cost effective, and added years to the lives of patients with severe angina pectoris. The results invite further testing in a randomized trial.

Acupressure↗

Signal-to-noise ratios of 6 intraoral digital sensors.

OBJECTIVE: The objective of this study was to compare the signal-to-noise ratios (SNRs) of 6 intraoral direct digital sensors. The sensors were Visualix 1, Visualix 2, DenOptix, Computed Dental Radiography (CDR), CDR APS, and Digora. STUDY DESIGN: The sensors were exposed by using a dental x-ray machine operating at 50 kV, 8 mA and various exposure times. The phantom used was a hole measuring 1 mm in diameter and 1.25 mm in depth, drilled in a 10-mm-thick aluminum block. Digital images were transferred as 8-bit tagged image file format files and analyzed by using a personal computer. RESULTS AND CONCLUSIONS: SNR values increased up to a maximum value at a certain exposure level and then, depending on the system, either decreased or maintained a high level with increased exposure. The Digora system produced the highest SNR values over a large exposure range, whereas the Visualix 2 and DenOptix systems produced the lowest SNR values. The 2 CDR sensors produced rather high SNRs but over a very small exposure range.

Algorithms↗

Long-term objective and subjective audiologic consequences of closed head injury.

During a period of 5 years, a total of 47 patients, 16-60 years of age, with major closed head injury (CHI) were admitted to 2 Swedish medical centres. Seven to 11 years after injury, 25 of them (mean age 40.8 years; range 25-59 years) were evaluated using peripheral and central auditory tests, and most of them also completed 2 questionnaires concerning self-assessed hearing ability and quality of life. Twenty-two patients did not participate in the long-term follow-up tests: 15 were excluded for medical reasons and 4 did not wish to participate; an additional 2 were impossible to trace and 1 had died. As many as 68% of patients (17/25) demonstrated abnormalities on 1 or more of the audiometric tests, 14 on pure-tone audiometry (p < 0.02) and/or central audiometric tests (3 on central tests only and 2 on pure-tone audiometry only). Four out of six patients with available early post-traumatic audiograms showed a significant progressive deterioration. As a group, their assessments of hearing ability and quality of life were equal to or better than those of the controls. These results may indicate that a higher priority should be given to obtaining an early audiologic evaluation of every CHI patient than is the rule today. The impact of post-traumatic progress and central lesions on social hearing at an advanced age is highlighted.

Acoustic Impedance Tests↗

A review and evaluation of research on the deaf-blind from perceptual, communicative, social and rehabilitative perspectives.

This paper reviews research on deaf-blind individuals, primarily from behavioral and communicative points of view. Inclusion in the population of deaf-blind is qualified by describing a variety of subgroups and genetically based syndromes associated with deaf-blindness. Sensory assessment procedures--based primarily on residual capacities--are appraised. Consequences for everyday life are described briefly. Non-sensory, alternative classificatory schemes and procedures are presented and the results from behavior modification procedures used for correcting maladaptive behaviors are summarized. Methods for communicating tactilely are described and evaluated. Attention is also drawn to some suggestions regarding learning of alphabetic codes and sign acquisition. Finally, suggestions for future research are proposed.

Activities of Daily Living↗

Reliability and responsiveness of three different pain assessments.

The visual analogue scale (VAS) and ordered categorical scales, i.e. numeric rating scales (NRS), are commonly used in the assessment of pain. However, these scales are bounded by fixed endpoints and thus the range of measurement is limited. The disparity in repeated assessments of perceived pain intensity with the VAS, NRS, and electrical stimulation applied as a matching stimulus was studied in 69 patients (48 women and 21 men, 19-72 years) with chronic nociceptive or neurogenic pain. Responsiveness with transcutaneous electrical nerve stimulation (TENS) using the same measurement procedures was evaluated in the same patients. Comparison of results from the three pain assessments showed that the painmatcher is at least as reliable and responsive as VAS and NRS. None of the three measurements showed evidence for systematic disagreement and had only significant random individual disagreement. They also showed evidence for responsiveness.

Adult↗

Magnetic resonance imaging of the membranous labyrinth during in vivo gadolinium (Gd-DTPA-BMA) uptake in the normal and lesioned cochlea.

MRI with a T1 contrast agent was used to investigate the normal and noise-damaged cochlea. The time course and distribution of the in vivo uptake of the gadodiamide chelate bound paramagnetic Gd ion (GdDTPA-BMA) throughout the membranous labyrinth of normal and impulse noise-damaged guinea pig cochleae were measured by MRI at 4.7T. Simultaneous signal enhancement of the basal, medial and apical scala tympani (ST) and scala vestibuli (SV) was observed within 10 min following i.v. injection, reaching maximum levels at around 100 min. ANOVA and post hoc paired t-tests showed statistically significant differences in the levels and rates of Gd uptake-enhancement between the scalae. The ST revealed the most rapid and extensive enhancement throughout the period of active Gd uptake, while the SV showed comparatively slower and less enhancement, and the intact scala media (SM) indicated insignificant enhancement. The in vivo Gd penetration and enhancement of the membranous SM increased significantly in the noise-damaged cochlea, suggesting lesioning of the cochlear membranes.

Acoustic Stimulation↗

[Future cure of hearing disorders? Gene therapy and stem cell implantation are possible new therapeutic alternatives].

Hearing loss is a very common disorder; nearly 10 per cent of the population is affected. Recently, a few findings such as the roles of neurotrophins, nitric oxide, reactive oxygen species and glutamate receptors in the peripheral hearing system have been highlighted. In this review, focus is set on possible mechanisms of peripheral hearing disorders, and on recent advances to prevent and treat hearing loss. Clinically useful treatment strategies, especially gene therapy and the use of embryonic stem cells, are particularly stressed.

Animals↗

Image plate systems differ in physical performance.

OBJECTIVE: The purpose of this study was to compare 2 storage phosphor image plate systems, the Digora and the DenOptix, with respect to physical performance. STUDY DESIGN: The 2 systems were tested both with and without use of their default settings through physical and psychophysical measurements. A homogeneous 10-mm-thick aluminum block, a 10-mm-thick aluminum block with a pattern of holes varying in diameter and depth, and a resolving power target were used as test phantoms. The image plates were exposed at 50 kV and 8 mA with a focus-sensor distance of 30 cm and exposure times ranging from 10 to 3,200 ms. Measurements of large area transfer function, gray level variations, perceptibility, contrast resolution, exposure range, and modulation transfer function were performed. RESULTS: When the two systems were used at their default settings, the DenOptix had a better dose response, a higher contrast index, and a higher modulation transfer function (MTF) than the Digora; however, the DenOptix also had higher noise than the Digora at lower exposures. CONCLUSIONS: When image enhancement algorithms were applied with the Digora system, performance similar to that of the DenOptix could be obtained.

Algorithms↗

Subjective image quality of solid-state and photostimulable phosphor systems for digital intra-oral radiography.

OBJECTIVES: To compare subjectively the image quality of intra-oral radiographs from six digital systems. METHODS: Two generations of two different solid-state detectors; Visualix-1 and -2 (Gendex Dental Systems, Milan, Italy), Computed Dental Radiography (CDR) and CDR Active Pixel Sensor (APS) (Schick Technologies Inc., Long Island City, NY, USA), and two photostimulable phosphor (PSP) systems; Digora (Soredex, Orion Corporation, Helsinki, Finland) and DenOptix (Gendex Dental Systems, Milan, Italy) were compared. Tooth-containing specimens from different areas of dried mandibles were radiographed at exposures between 91-9400 microGy. Images were transferred to a personal computer, displayed in random order and evaluated in their original form and after applying a histogram equalisation algorithm. Eight observers graded subjective image quality using a 5-point scale. RESULTS: Both CDR systems scored highest for image quality but within the narrowest exposure range. The Visualix images received the lowest scores. The PSP systems produced acceptable image quality at both lower and higher exposures than the solid-state systems. Enhanced images were generally considered to be inferior to the original images, except for those produced by the four solid-state systems at very low exposures. CONCLUSIONS: (i) the PSP systems provided a clinically acceptable image quality over a wide exposure range; (ii) the CDR systems had the best image quality but over the narrowest exposure ranges; (iii) the Visualix systems had the lowest image quality; and (iv) histogram equalisation did not generally improve image quality.

Algorithms↗

Digitisation and display of intra-oral films.

AIM: To determine the optimal parameters for the digitisation and display of intra-oral radiographs. MATERIALS AND METHODS: Six intra-oral radiographs (EP size 2 dental film, Eastman Kodak Co., Rochester, NY, USA) were digitised using an Arcus II image scanner (Agfa-Gevaert N. V., Mortsel, Belgium). Each film was digitised at 8 bits, with and without a film mask, using three scanner resolutions (200, 400 and 600 p.p.i.), resulting in six versions of each radiograph. Seven experienced observers were asked to evaluate the quality of the resulting images as they were displayed on a Nokia 445Xi monitor (Nokia Display Products, Helsinki, Finland). Monitor settings were varied by changing the colour palette and screen resolution. RESULTS: Digital images of masked films had a statistically significant (t-test with alpha 2 tail < or = 0.05) higher quality than those scanned without a mask. The best image quality was obtained at a resolution of 400 p.p.i. Display options were optimum with 256 colours and a screen size of 1152 x 864 pixels. CONCLUSIONS: Better results were obtained when intra-oral radiographs were digitised with a mask at a resolution of 200 or 400 p.p.i. and displayed using 256 colours and the largest screen size possible. Further studies are needed to extend these results to other makes and models of scanner and monitor.

Algorithms↗

Analysis of magnetic resonance imaging acoustic noise generated by a 4.7 T experimental system.

High intensity acoustic noise is an undesirable side-effect in magnetic resonance imaging (MRI) that can cause discomfort and hearing loss in patients and may be an impediment in functional MRI (fMRI) studies of the auditory system. Experimental MRI systems with high magnetic field strengths may generate acoustic noise of higher sound pressure levels (SPLs) than conventional 1.0 and 1.5 T clinical systems. We measured the SPL and spectral content of the acoustic noise generated by the Bruker Biospect 47/40 4.7 T experimental MRI system during scanning sequences commonly used in animal testing. Each sequence generated acoustic noise of high SPL, rapid pulse rates, amplitude-modulated pulse envelopes and multi-peaked spectra. The rapid acquisition with enhancement sequence with a 0.25 mm slice thickness generated SPLs of up to 129 dB peak SPL and 130 dB (A). Fourier analysis of the spectral content of the acoustic noise generated by each MRI sequence showed a wide band of acoustic energy with spectral peaks from 0.2-5 kHz. The intense MRI acoustic impulse noise generated by the 4.7 T system may cause masking of stimuli used in fMRI of the auditory cortex, reduce the hearing acuity of experimental animals and present a risk for unprotected human ears.

Acoustics↗

Ecological aspects of auditory rehabilitation.

Speech and language communication represents an important aspect of interaction between humans and their social environment. In this respect, communication can be analysed in analogy with ecological systems. A conceptual framework based on this analogy has been presented recently and is further developed in this paper. In particular, the consequences for design and accomplishment of auditory rehabilitation are discussed in relation to our own studies. The ecological model contains three levels of interpersonal interaction: signal, message and behaviour, as well as an interaction with the social and physical background. Sensory information is treated in afferent neural systems, processed in language centres and expressed via the vocal system. The communication situation is evaluated and compared with the internal reference "preferendum". The discrepancy between this internal template, a self-image and the perceived reality gives rise to a feedback signal that acts on the components of the communication process within the individual and in the environment, on the one hand, and on the preferendum, on the other. The role of language training, speaking behaviour, meta-communication, e.g. reporting lack of understanding or acknowledging understood messages, are made apparent through an application of the model to rehabilitation.

Communication↗

Visual cognitive tests, central auditory function and auditory communication.

A cognitive, text-based test battery, presented as text on a computer screen (TIPS), was used to assess properties of central cognitive processing relevant for visual and audiovisual speech comprehension. TIPS was compared and contrasted with another, purely auditory, battery, ACE, aimed at assessing afferent (A), central (C) and efferent (E) auditory communicative functions. The results show that there is no overlap with the 'A' component, but some overlap between TIPS parameters and the 'C' component, especially when the auditory-language tests are used in the C estimate. However, the TIPS parameters show high correlations with the 'E' component (i.e. measuring output and phonological parameters), suggesting that the efferent component may be composed of an interesting central feature. TIPS parameters do not fare as well in the predictions of the auditory ecological test performances, but the ACE parameters do, especially when organized according to a cognitive complexity parameter. In order to optimize the conceptual and practical benefit of the TIPS and ACE concepts, TIPS needs to be adapted auditorily and ACE tests need to be audiovisual. These developments will become important for ecological audiology.

Adult↗

Marginal bone level around implants assessed in digital and film radiographs: in vivo study in the dog.

BACKGROUND: One of the objectives of postoperative radiographic examinations of implants is to evaluate the marginal bone height and its changes over time. PURPOSE: The purpose of this study was to assess the influence of digital image processing on measurements of the marginal bone level around implants. MATERIAL AND METHODS: Implants in beagle dogs, used to study the development of peri-implantitis and subsequent healing following treatment, were monitored with conventional radiography and a digital image plate system. Five observers measured the distance between a reference point and the bone level. Measurements in conventional radiographs were made with the use of an x-ray viewer (2x) and a magnifying lens (7x). For the digital images, the system's built-in measuring function was used together with five image processing techniques: edge enhancement (matrixes set on 5 and 25), inverted grey scale, single color highlight, and color intensity mapping together with the brightness and contrast control. From the time of maximum breakdown and the end of the experiment, histologic values were available. RESULTS: Differences between techniques and observers increased toward the end of the healing period. Measurements made at maximum breakdown did not differ significantly from the histologic value. Measurements made after healing all methods, except that using edge enhancement and a 25 x 25 kernel, differed significantly from the histologic value by underestimating the bone level. CONCLUSIONS: Measurements of bone level around implants from digital radiographs are as accurate and precise as those from film images. In particular cases, the use of specific image processing algorithms may improve both accuracy and precision. After healing, the histologic specimens showed an incomplete bone fill in the crater with a remaining thin layer of connective tissue in contact with the fixture, and in such situations, the morphology of the bone will give a more complicated diagnostic task.

Algorithms↗

Audiometric characterization of a family with digenic autosomal, dominant, progressive sensorineural hearing loss.

In this study, a non-syndromic progressive bilateral high frequency hearing loss is described in a family with 141 identified members. Recent genetic analyses indicated a digenic inheritance with linkage to the gene loci DFNA2 and DFNA12. The affected family members who shared haplotypes at both loci (type I) showed an early postlingual onset and a more rapid rate of progress compared with those with one either of the two disease associated haplotypes (type II). The audiometric pattern was cochlear without a vestibular involvement. Auditory brainstem response audiometry and magnetic resonance imaging indicated normal retrocochlear features. The otoacoustic emissions were affected for both type I and type II, whereas the acoustic stapedius reflex thresholds were normal in most cases. It is concluded that both types had an outer hair cell/micro-mechanical abnormality, but that the DFNA 2 type might have an additional dysfunction at the level of the inner hair cells. It is furthermore pointed out that the application of refined audiometric techniques as well as a further development of new techniques is needed in order to characterize the phenotypes of the rapidly expanding number of genetically defined inner ear abnormalities.

Adult↗

Magnetic resonance imaging of the cochlea, spiral ganglia and eighth nerve of the guinea pig.

The membranous labyrinth of the guinea pig cochlea and retrocochlear neural structures were investigated by magnetic resonance imaging (MRI) using an experimental system with a field strength of 4.7T and a single turn surface coil 25 mm in diameter, or standard resonators of 34 or 70 mm in diameter and gradient field strengths of 950 mTm and 200 mTm. High-resolution 2-D and 3-D images of 0.3-1.0 mm slice thickness were acquired by a rapid acquisition with relaxation enhancement (RARE) sequence and a standard multi-echo technique. Structural and dimensional aspects of the cochlea were resolved in vitro and in vivo down to <50 microm, showing the scala vestibule, scala media, scala tympani, spiral ganglia and the cochlear (eighth) nerve. In vivo perfusions with the gadodiamide (GdDTPA-BMA) chelate-bound paramagnetic gadolinium ion resulted in dynamic temporal enhancement of the scala vestibule and scala tympani, but did not penetrate the scala media.

Animals↗