Mark J. O'Malley

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A method for the automatic processing of the electrocardiogram (ECG) for the detection of obstructive apnoea is presented. The method screens nighttime single-lead ECG recordings for the presence of major sleep apnoea and provides a minute-by-minute analysis of disordered breathing. A large independently validated database of 70 ECG recordings acquired from(More)
The timing of heel strike (HS) and toe off (TO), the events that mark the transitions between stance and swing phase of gait, is essential when analysing gait. Force plate recordings are routinely used to identify these events. Additional instrumentation, such as force sensitive resistors, can also been used. These approaches, however, include restrictions(More)
The purpose of this study was to examine the effect of joint angle on the relationship between force and electromyogram (EMG) amplitude and median frequency, in the biceps, brachioradialis and triceps muscles. Surface EMG were measured at eight elbow angles, during isometric flexion and extension at force levels from 10% to 100% of maximum voluntary(More)
We have developed a gait nomogram based on dynamic similarity to characterize and compare neuromuscular function. We used temporal-distance data based on 669 normal participants (age range 5 to 98 years), and 78 children and young adults with spastic diplegia (43 males, 35 females; mean age 10 y 8 mo, standard deviation 3 y 11 mo, range 5 to 20 y), all of(More)
Changes in surface electromyographic (EMG) amplitude during sustained, fatiguing contractions are commonly attributed to variations in muscle fiber conduction velocity (MFCV), motor unit firing rates, transmembrane action potentials and the synchronization or recruitment of motor units. However, the relative contribution of each factor remains unclear.(More)
When two fundamental gait parameters--step length and step frequency--are scaled non-dimensionally, thereby accounting for increases in a child's physical size, ontogenetic changes in the locomotor control strategy are revealed. We believe dimensionless velocity beta, the product of dimensionless step length and frequency, serves as a measure of neural(More)
Joint centre displacement may occur following total elbow replacement due to aseptic loosening or surgical misalignment, and has been linked to implant failure. In this study, the effects of joint centre displacement were examined using a neuromusculoskeletal model of the elbow joint. Isometric contractions were simulated at a range of joint angles during(More)
Activation of the genioglossus (GG) muscles is necessary to maintain the patency of the upper airway. In the condition of obstructive sleep apnea (OSA) this mechanism fails and the possible role of fatigue in its pathogenesis is still not fully understood. In this paper, a new electrode design for recording the genioglossus surface electromyogram (sEMG) is(More)