No abstract

Periodic leg movements during sleep (PLMs) are non-epileptiform, repetitive limb movements that are highly prevalent among the geriatric population. The mechanisms underlying these movements are poorly understood. In this study we evaluated PLMs of 24 aged volunteers. We hypothesized that the high prevalence of PLMs seen in the aged would be related to (a) lower creatinine clearance and (b) slowed velocities/delayed latencies in the nerve conduction studies of such individuals. Results did not support hypothesis (a) but offered some equivocal support for hypothesis (b), inasmuch as aged subjects with higher levels of PLMs had delayed motor and sensory latencies in the upper limbs (median n., ulnar n.). Results are discussed in terms of central vs peripheral mechanisms involved in the generation of PLMs in elderly persons.

An excitation method to reduce harmonic content in the third harmonic was verified utilizing SPICE modeling. The SPICE model incorporated a MOSFET model and the Leach model to form a multi-level switch-mode pulser circuit. The pulser circuit was driven with a Harmonic Reduction PWM excitation sequence and a stepped excitation sequence with a fundamental frequency of 2 Mhz. An FFT of the excitation sequences was compared to verify the performance of the MOSFETs with the excitation sequences. It was found that at the third harmonic, the harmonic content was reduced by 22.2 dB.