ResScan 3.7 Terms & Definitions

Usage = the time that a patient receives therapy from the device
Used days > X hours Y minutes = total number of days where daily usage exceeded the compliance threshold
% Used days > X hours Y minutes = calculates the percentage of used days out of the total number of days selected
Total hours used = total patient usage of a selected time range
Events = apneas, hypopneas, AHI
Apnea = temporary absence or cessation of breathing. An apnea is scored when there is reduction in breathing by 75% of the baseline breathing for at least 10 seconds
Hypopnea = an episode of shallow or slow breathing during sleep. A hypopnea is scored when there is a reduction in breathing by 50% of the baseline for 10 seconds or more. The event is scored after 10 seconds of the hypopnea.
AHI = apnea/hypopnea index = is calculated by adding together the total number of apnea and hypopnea events over a period of time. For statistics it is the total number of events divided by total daily usage. For graphs the AHI is incremented at the occurence of every event and reset every hour
Leak = an estimate of the total rate of air escaping due to mouth and mask leaks. It is derived by analyzing the inspriatory and expiratory air flows together with the expected mask vent flows. High or changing leak rates may affect the accuracy of other measurements
Tidal volume = the volume of air inspired or expired in one respiratory cycle (breath)
Respiratory rate = the frequency of breathing, expressed as the number of breaths per minute
Minute ventilation = the volume of air breathed in (or out) w/in any 60 second period
Flattening = a measurement of partial upper airway obstruction. This measurement is based on the shape of the inspiratory flow-time curve. A flat shape suggests upper airway obstruction.
Snore = Snore index is the measure of the amplitude of pressure wave generated by a patient's snoring
% Spontaneous cycled breaths = Spont C = the percentage of patient breaths that were spontaneously cycled (termination of IPAP and changing to EPAP)
% Spontaneous triggered breaths = Spont T = the percentage of patient breaths that were spontaneously triggered (initiation of IPAP).
Oxygen desaturation index = the mean value of the number of drops in oxygen saturation per hour
Flow = an estimate of the air flow entering the lungs. It is derived by taking the total flow and then removing the leak and the mask vent flow components.
95th percentile = the value exceeded during the selected range for 5% of the time
Median = the median value recorded during the selected range
Maximum = the maximum value recording during the selected range

ResScan 3.10 Terms & Definitions

Compliance

Usage = the time that a patient receives therapy from the device.

Used Days > X hours Y minutes = the total number of days where Daily Usage exceeded the compliance threshold (X hours Y minutes).

% Used Days > X hours Y minutes = % Used Days calculates the percentage of Used Days out of the total number of days selected.

Total Hours Used = the total patient Usage over a selected time range.

Events

Apnea = the temporary absence or cessation of breathing. An apnea is scored when there is reduction in breathing by 75% of the baseline breathing for at least 10 seconds.

Obstructive Apnea = when there is a physical closing of the upper airway. Central Apnea = when the upper airway remains open.

Unknown Apnea = when accurate determination of whether the apnea is obstructive or central is not possible, due to the leak at any time during the apnea being higher than 30 L/min.

Hypopnea = episode of shallow or slow breathing during sleep. A hypopnea is scored when there is a reduction in breathing by 50% of baseline breathing for 10 seconds or more. The event is scored after 10 seconds of the hypopnea.

AHI = Apnea-Hypopnea Index (AHI) = calculated by adding together the total number of apnea and hypopnea events over a period of time. For statistics, it is the total number of events divided by total Daily Usage. For graphs, the AHI count is incremented at the occurrence of every event and reset every hour.

Key Respiratory Parameters

Leak = an estimate of the total rate of air escaping due to mouth and mask leaks. It is derived by analyzing the inspiratory and expiratory airflows, together with the expected mask vent flows. High or changing leak rates may affect the accuracy of other measurements.

Tidal Volume = the volume of air inspired or expired in one respiratory cycle (breath).

Respiratory Rate = the frequency of breathing, expressed as the number of breaths per minute.

Minute Ventilation = the volume of air breathed in (or out) within any 60 second period.

Flattening = a measurement of partial upper airway obstruction. This measurement is based on the shape of the inspiratory flow-time curve. A flat shape suggests upper airway obstruction.

Snore index = the measure of the amplitude of pressure wave generated by a patient's snoring.

% Spontaneous Triggered Breaths = the percentage of patient breaths that were spontaneously triggered (initiation of IPAP).

% Spontaneous Cycled Breaths = the percentage of patient breaths that were spontaneously cycled (termination of IPAP and changing to EPAP).

Oxygen Desaturation Index = the mean value of the number of drops in oxygen saturation per hour. Flow = an estimate of the airflow entering the lungs.It is derived by taking the total flow and then removing the leak and mask vent flow components.

Flow Limitation = a measurement of partial upper airway obstruction.

Statistics

95th Percentile = the value exceeded during the selected range for 5% of the time.

Median = the median value recorded during the selected range.

Maximum = the maximum value recorded during the selected range.