Search results for "Medical physics"
showing 10 items of 579 documents
From heart-rate data to training quantification: a comparison of 3 methods of training-intensity analysis.
2014
Purpose:The authors directly compared 3 frequently used methods of heart-rate-based training-intensity-distribution (TID) quantification in a large sample of training sessions performed by elite endurance athletes.Methods:Twenty-nine elite cross-country skiers (16 male, 13 female; 25 ± 4 y; 70 ± 11 kg; 76 ± 7 mL · min−1 · kg−1 VO2max) conducted 570 training sessions during a ~14-d altitude-training camp. Three analysis methods were used: time in zone (TIZ), session goal (SG), and a hybrid session-goal/time-in-zone (SG/TIZ) approach. The proportion of training in zone 1, zone 2, and zone 3 was quantified using total training time or frequency of sessions, and simple conversion factors across…
Evaluation of urodynamic studies by computer
1978
In an attempt to simplify urodynamic evaluation, the data obtained from cystometry, urethral profile and flowmetry were analysed using the ICS recommendations for standardization and terminology. All studies were compiled from check lists feasible for computation. The aim was to establish standards and "typical" changes for the normal bladder and pathological states to enable automatic readout of computed data. The results did, in fact, show "typical" changes but failed to establish standard measurements suitable for completely computed diagnoses.
Clinical evaluation of a wireless ECG sensor system for arrhythmia diagnostic purposes
2013
Accepted version of an article in the journal: Medical Engineering and Physics. Also available from the publisher at: http://dx.doi.org/10.1016/j.medengphy.2013.03.002 In a clinical study, a novel wireless electrocardiogram (ECG) recorder has been evaluated with regard to its ability to perform arrhythmia diagnostics. As the ECG recorder will detect a "non-standard" ECG signal, it has been necessary to compare those signals to "standard" ECG recording signals in order to evaluate the arrhythmia detection ability of the new system. Simultaneous recording of ECG signals from both the new wireless ECG recorder and a conventional Holter recorder was compared by two independent cardiology specia…
Evaluating tear clearance rate with optical coherence tomography
2017
Purpose: To assess the early-phase of tear clearance rate (TCR) with anterior segment optical coherence tomography (OCT) and to determine the association between TCR and other clinical measures of the tear film in a group of young subjects with different levels of tear film quality. Methods: TCR was classified as the percentage decrease of the inferior tear meniscus height 30s after instillation of 5uL 0.9% saline solution. Fifty subjects (32F and 18M) aged (mean +/- standard deviation) 25.5 +/- 4.3 years volunteered for the study. It consisted of a review of medical history, Ocular Surface Disease Index (OSDI) questionnaire, tear film osmolarity measurements, slit lamp examination and TCR …
Covariation of spectral and nonlinear EEG measures with alpha biofeedback.
2002
Item does not contain fulltext This study investigated how different spectral and nonlinear EEG measures covaried with alpha power during auditory alpha biofeedback training, performed by 13 healthy subjects. We found a significant positive correlation of alpha power with the largest Lyapunov-exponent, pointing to an increased dynamical instability of the EEG accompanying alpha enhancement. Alpha power amplification, moreover, was significantly correlated with a decrease of spectral entropy within the alpha range. This outcome reflects a sharpening of the alpha peak during biofeedback training. The fact that the sharpening effect clearly preceded the increase of alpha amplitude could be exp…
Nuclear magnetic resonance imaging of airways in humans with use of hyperpolarized3He
1996
The nuclear spin polarization of noble gases can be enhanced strongly by laser optical pumping followed by electron-nuclear polarization transfer. Direct optical pumping of metastable 3He atoms has been shown to produce enormous polarization on the order of 0.4-0.6. This is about 105 times larger than the polarization of water protons at thermal equilibrium used in conventional MRI. We demonstrate that hyperpolarized 3 He gas can be applied to nuclear magnetic resonance imaging of organs with air-filled spaces in humans. In vivo 3 He MR experiments were performed in a whole-body MR scanner with a superconducting magnet ramped down to 0.8 T. Anatomical details of the upper respiratory tract …
The effect of exposure to radiofrequency fields on cancer risk in the general and working population: A protocol for a systematic review of human obs…
2021
Highlights • RF-EMF was classified by IARC as possibly carcinogenic to humans (2B) in May 2011 • A systematic review of all subject-relevant epidemiological studies is now needed. • A detailed protocol ensures the review's transparency, utility and credibility. • Original study validity will be evaluated with a customized OHAT risk of bias tool. • Internal coherence and external plausibility will inform conclusions.
CT exposure in adult and paediatric patients: a review of the mechanisms of damage, relative dose and consequent possible risks.
2014
An increase has been observed not only in the absolute number of CT examinations but also in the length of coverage and number of scanning phases, with the result that exposure to ionising radiation from CT is becoming an increasingly serious problem. The extent of the problem is not entirely known and cannot be adequately addressed without proper knowledge of all the phases that leads to the effective dose calculation. In light of the growing awareness of the issue of ionising radiation dose and the possible risk for the individual and the population, there is a need for radiologists, medical physicists and radiographers to play an active role in dose management. In this review, the author…
Electronic Patient-Reported Outcome Measures Evaluating Cancer Symptoms: A Systematic Review.
2021
Abstract Objectives This systematic review aims to evaluate the psychometric properties and the methodologic quality of studies describing smartphone-, tablet- or computer-based questionnaires for Patient-Reported Outcome Measures (PROM) evaluating symptoms in oncology and hematology patients. Data Sources A literature search was conducted in PubMed, Scopus, Cochrane, Cinahl, Cuiden, Lilacs, and PsycINFO. Criteria for inclusion were (i) primary studies evaluating scales for symptoms assessment, (ii) developed in adult population (>18 years) with an oncology or hematology malignancy diagnosis, (iii) validations tested via phone or computer, and (iv) describing at least one psychometric prope…