Analysis of Time and Frequency Response for Single/Multi-Tone Stimulus Harmonic Phase-Reference Based on Prime Number Algorithm

We present a spectrally-dense phase-reference and its calibration for nonlinear vector network analyzers (NVNAs) using a step recovery diode (SRD) comb-generator with a multi-tone stimulus. Frequency selection for multi-tone stimulus based on prime number algorithms was used with the Digital Real-Time Oscilloscope (DRTO) to avoid the sub-Nyquist spurs components and to increase the effective sampling rate so that the waveform can be observed in greater detail. The measured results were calibrated to minimize drift and jitter and achieved excellent agreement between the prime number and the exact frequency strategies except at the sub-Nyquist frequencies. The analysis indicates that the prime number selected frequencies show significantly improved performance by avoiding the DRTO distortion components. We have verified the validity of the method described in this paper by experimental measurement results.

Electrodermal hyporeactivity evaluation for detecting suicidal propensity in depressed patients

IntroductionSince 1987 several publications have focused on electrodermal reactivity in groups with different suicidal behaviors, but with varying results. However, using an untraditional statistical approach with clinical application in focus revealed between themselves confirming results of a strong relationship between electrodermal hyporeactivity and suicide.ObjectivesThe objectives were to investigate how this research tool can be implemented for detecting suicide risk in depressed patients.AimsThe aims were to find a base for the objective test of electrodermal reactivity to be used as support in suicidal risk assessments in depressed patients.MethodsMore than ten published studies on electrodermal hyporeactivity and suicide were reviewed subsequent to the application of an untraditional statistical approach. Gender, age,subdiagnoses and depressive depth were considered. All subjects were tested in a habituation experiment of the electrodermal response to a moderately strong tone stimulus.ResultsThe percentage of electrodermally hyporeactive depressed patients who later committed suicide was 86–97%. The percentage of electrodermally reactive patients that did not commit suicide was 96–98%. Hyporeactivity seems to be stable in at least 1–2 years in remission.ConclusionsIt was considered favorable to test for hyporeactivity as early as possible, i.e. already in the primary care. That enables right treatment of right patients very early. The number of referrals to psychiatric specialists could be expected to decrease. Possible causes of hyporeactivity begin to be revealed, giving ideas of several treatment approaches.Disclosure of interestThe author has not supplied his declaration of competing interest.