Biomedical subjects

David Joffe

Publications and source records attributed to David Joffe.

3 recordsLinked to original sources

PubMed2004

Sleepiness, sleep-disordered breathing, and accident risk factors in commercial vehicle drivers.

Sleep-disordered breathing and excessive sleepiness may be more common in commercial vehicle drivers than in the general population. The relative importance of factors causing excessive sleepiness and accidents in this population remains unclear. We measured the prevalence of excessive sleepiness and sleep-disordered breathing and assessed accident risk factors in 2,342 respondents to a questionnaire distributed to a random sample of 3,268 Australian commercial vehicle drivers and another 161 drivers among 244 invited to undergo polysomnography. More than half (59.6%) of drivers had sleep-disordered breathing and 15.8% had obstructive sleep apnea syndrome. Twenty-four percent of drivers had excessive sleepiness. Increasing sleepiness was related to an increased accident risk. The sleepiest 5% of drivers on the Epworth Sleepiness Scale and Functional Outcomes of Sleep Questionnaire had an increased risk of an accident (odds ratio [OR] 1.91, p = 0.02 and OR 2.23, p < 0.01, respectively) and multiple accidents (OR 2.67, p < 0.01 and OR 2.39, p = 0.01), adjusted for established risk factors. There was an increased accident risk with narcotic analgesic use (OR 2.40, p < 0.01) and antihistamine use (OR 3.44, p = 0.04). Chronic excessive sleepiness and sleep-disordered breathing are common in Australian commercial vehicle drivers. Accident risk was related to increasing chronic sleepiness and antihistamine and narcotic analgesic use.

Accident Prevention↗

PubMed2004

Low-resolution electromagnetic tomography neurofeedback.

Through continuous feedback of the electroencephalogram (EEG) humans can learn how to shape their brain electrical activity in a desired direction. The technique is known as EEG biofeedback, or neurofeedback, and has been used since the late 1960s in research and clinical applications. A major limitation of neurofeedback relates to the limited information provided by a single or small number of electrodes placed on the scalp. We establish a method for extracting and feeding back intracranial current density and we carry out an experimental study to ascertain the ability of the participants to drive their own EEG power in a desired direction. To derive current density within the brain volume, we used the low-resolution electromagnetic tomography (LORETA). Six undergraduate students (three males, three females) underwent tomographic neurofeedback (based on 19 electrodes placed according to the 10-20 system) to enhance the current density power ratio between the frequency bands beta (16-20 Hz) and alpha (8-10 Hz). According to LORETA modeling, the region of interest corresponded to the Anterior Cingulate (cognitive division). The protocol was designed to improve the performance of the subjects on the dimension of sustained attention. Two hypotheses were tested: 1) that the beta/alpha current density power ratio increased over sessions and 2) that by the end of the training subjects acquired the ability of increasing that ratio at will. Both hypotheses received substantial experimental support in this study. This is the first application of an EEG inverse solution to neurofeedback. Possible applications of the technique include the treatment of epileptic foci, the rehabilitation of specific brain regions damaged as a consequence of traumatic brain injury and, in general, the training of any spatial specific cortical electrical activity. These findings may also have relevant consequences for the development of brain-computer interfaces.

Adult↗

PubMed2002

Treadmill ambulation with partial body weight support for the treatment of low back and leg pain.

STUDY DESIGN: A single-subject experimental design using an A-B-A treatment protocol. OBJECTIVE: To determine whether walking on a treadmill with partial body weight support (PBWS) would be an effective adjunct treatment method to standard care for decreasing pain and increasing function in patients suffering from low back and leg pain. BACKGROUND: Mechanical low back pain (LBP) is commonly aggravated by activities that increase axial loading in the spine, such as sitting, standing, and walking. Patients with mechanical LBP usually describe relief with positions that unload the spine. One traction technique now being used in clinics to unload the spine is the PBWS system. The use of endurance exercise has also been found to be a consistent predictor of better outcomes in patients with LBP. Thus treatment that combines spinal unloading using PBWS and endurance exercise may be an effective intervention for patients with low back and leg pain. METHODS AND MEASURES: Eleven subjects participated in this study using an A-B-A design. Phase A was defined as the baseline condition and phase B was intervention with PBWS provided by a mechanical unloading system. The Roland-Morris Questionnaire (RMQ) and Visual Analog Scale (VAS) were utilized to collect data on functional status and perceived pain, respectively. Visual Analysis and 2 standard deviation band method (2SDBM) were used to analyze the data. RESULTS: Pain scores between baseline and PBWS treatment phases were significantly improved for 3 out of the 6 subjects who completed the study. RMQ baseline and treatment scores revealed that 5 out of 6 subjects had significant functional improvements in the PBWS treatment phase. CONCLUSION: The results suggest that ambulation with PBWS combined with the standard level of care for this population holds sufficient promise for pain relief and functional improvement to justify testing its efficacy in larger groups of subjects with these complaints.

Adult↗