Outline the sensitivity and filter settings that are recommended for the EEG, EOG, EMG, and EKG parameters. Include in your discussion the adjustments you would make for routine polysomnography in a s

Polysomnography Filters and Calibrations
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Filter Settings and Sensitivity
Filters used for the various polysomnographic processes require predefined filtering ranges to help define their maximum and minimum limits. The bandwidth of recorded parameters helps in selection of these filters. Usually, filters are set slightly above the bandwidth range to allow the sloppiness of the “frequency response curve” and ensure that all essential frequencies are preserved (Butkov, 2007, p. 264). A typical filter used for routine EEG should meet various specifications. First, it should make use of broad-pass analog filter settings for acquisition (scalp: 0.1-70 Hz, intracranial 0.1-100 Hz). Therefore, when recording an EEG that falls in the range of 0.5-25 Hz, the low-frequency filter should be set at 0.3 Hz while the high-frequency filter is set at 30 Hz or 35 Hz to allow full signal resolution at either end of the spectrum and cancel out undesirable frequencies outside the predefined range. Filter settings for EOG are similar to those of EEG, and they aid in the identification of both slow and rapid eye movements. The EMG operates with filter settings at a low frequency of 10 Hz and a high of 90-100 Hz. Sometimes, these frequencies exceed 100 Hz, but avoiding such high frequencies is important to prevent signal interference. EKG, or ECG, is recorded as a “single-channeled, modified lead II configuration,” whose main function is to detect heart rhythms and identify dysrhythmias.

Hence, filter settings of low frequencies at 1 Hz and high frequencies at 30-35 Hz adequately meet their intended purpose (Butkov, 2007).
Children hardly remain stable when a recording is being made; thus, electrode application should be handled with care. Electrodes should be attached to the child’s skin using paste or collodion depending on the lab’s preference. However, their positions and associated impedances should be closely monitored. Due to the fact that voltage of EEG is higher in children, and in reference to the six-year-old child, ideal reductions in sensitivity are recommended (to as low as 10 μVmm or 15 μV/mm) (Beck & Marcus, 2009). Adult EEG recordings’ sensitivity are at 5μV/mm. There are no clear criteria govern the filter settings of an elderly adult, in this case, a seventy-year-old adult. Therefore, considering that their voltage is lower than that of children and younger adults, then sensitivity should be set at <5μVmm.
Calibrations
Interface/Pulse Oximeter
Calibration of the pulse oximeter is an invasive process even though investigations into and standardization of less invasive processes are in progress. Individuals freely volunteer, and after the oximeter is attached to the volunteer, he or she breathes high and low volumes of oxygen saturations, and arterial blood samples are drawn at intervals. Measurements for oxygen-dense and less oxygen-dense blood samples are compared using the test oximeter, and while applying a relevant law, a correction calibration graph is developed. However, taking the health of the volunteers into account, oxygen saturation does not go below 75-80%.
CPAP
Titration process is used to calibrate the PAP device. Prior to this process, the individual is assessed, puts on the device, and sleeps. Upon recognizing an apnea episode, the therapist activates the CPAP. The CPAP pressure increases to the point where apnea episodes are erased, and this is usually at a pressure of between 7 and 12 cm H2O (Sills, 2016).
Ph Monitor
A pH electrode is immersed in water when not in use and its surface is touched gently to drive the pH meter to the zero potential. The meter is disconnected, then recharged slowly for one minute until equilibrium is attained.
References
Beck, S. E., & Marcus, C. L. (2009). Pediatric polysomnography. Sleep Medicine Clinics, 4(3), 393–406. Retrieved on 11 December 2016.
Butkov, N. (2007). Polysomnography recording systems. In N. Butkov, & T. L. Lee-Chiong (Eds.), Fundamentals of sleep technology. Philadelphia, PA: Wolters Kluwer. Retrieved on 12 December 2016.
Sills, J. R. (2016). The comprehensive respiratory therapist exam review (6th ed.). Missouri: Elsevier. Retrieved on 12 December 2016.