1. A system for delivering a flow of breathing gas to an airway of a patient, the system comprising:
a gas flow generator configured to generate a flow of gas;
a patient circuit coupled to the gas flow generator configured to communicate the flow of gas to an airway of a patient;
a sensor configured to generate output signals related to a characteristic associated with the flow of gas;
a controller configured to selectively control the flow of gas to the airway of the patient from the gas flow generator via the patient circuit by operating in:
1) a first pressure mode responsive to the characteristic being below a first threshold, wherein the first mode comprises providing higher pressure to the patient during inspiration and lower pressure to the patient during expiration; and
2) a second pressure mode responsive to the characteristic being above a second threshold, wherein the second pressure mode comprises providing lower pressure to the patient during inspiration and higher pressure to the patient during expiration.
2. The system of claim 1, wherein the controller is configured to detect a predetermined breathing characteristic of the patient based on the characteristic associated with the flow of gas, wherein the controller operates in the second mode responsive to detection of the predetermined breathing characteristic and the characteristic associated with the flow of gas being above the second threshold.
3. The system of claim 2, wherein the characteristic associated with the flow of gas is a sleep disorder breathing event.
4. The system of claim 3, wherein the controllers alters the first threshold and the second threshold based on a determination that the patient is experiencing a sleep disordered breathing event.
5. The system of claim 3, wherein the sleep disorder breathing event is Cheynes-Stokes Respiration, hypopnea, or apnea.
6. The system of claim 1, wherein the characteristic is Cheynes Stokes Respiration, further comprising an oxygen saturation monitor adapted to output a signal indicative of an oxygen saturation of the patient, and wherein the controller determines whether the patient is experiencing Cheynes-Stokes Respiration based, at least in part, on an output of the oxygen saturation monitor.
7. The system of claim 1, wherein the characteristic is a flow rate.
8. The system of claim 1, wherein the controller operates in the second pressure mode, and wherein the pressure provided to the patient during expiration or the pressure provided to the patient during inspiration is at or below atmospheric pressure.
9. The system of claim 1, wherein the controller operates in the second pressure mode, and wherein both the pressure provided to the patient during expiration and the pressure provided to the patient during inspiration are above atmospheric pressure.
10. The system of claim 1, wherein the first threshold is the same as the second threshold.
11. The system of claim 1, wherein the characteristic is a Maximum Average Inspiratory Flow (Qave(max)), wherein the controller compares the Qave(max) to the first threshold and the second threshold, and wherein the controller controls the system based on a result of this comparison.
12. The system of claim 1, wherein the characteristic is a tidal volume, and wherein the controller compares the tidal volume to the first threshold and the second threshold, and wherein the controller controls the system based on a result of this comparison.
13. The system of claim 1, wherein the characteristic is a minute ventilation, wherein the controller compares the minute ventilation to the first threshold and the second threshold, and wherein the controller controls the system based on a result of this comparison.
14. A method of ventilating a patient, comprising:
delivering a flow of gas to the airway of a patient from a source of breathing gas via a patient circuit;
measuring a characteristic associated with the flow of gas;
determining a first characteristic based on the measured characteristic; and
controlling delivery of the flow of gas to the patient by:
1) providing the flow of gas according to a first pressure mode responsive to the characteristic being below a first threshold, wherein the first mode comprises providing higher pressure to the patient during inspiration and lower pressure to the patient during expiration, and
2) providing the flow of gas according to a second pressure mode responsive to the characteristic being above a second threshold, wherein the second pressure mode comprises providing lower pressure to the patient during inspiration and higher pressure to the patient during expiration.
15. The method of claim 14, wherein controlling the delivery of the flow of gas to the patient comprises detecting a predetermined breathing characteristic of the patient based on the measured characteristic, and the controller provides negative pressure support to the patient if the predetermined breathing characteristic is detected and the first characteristic is above the second target.
16. The method of claim 15, wherein the predetermined breathing characteristic is a sleep disorder breathing event.
17. The method of claim 16, wherein controlling the delivery of the flow of gas to the patient comprises altering the first target and the second target based on a determination that the patient is experiencing a sleep disordered breathing event.
18. The method of claim 16, wherein the sleep disorder breathing event is Cheynes-Stokes Respiration, hypopnea, or apnea.
19. The method of claim 15, wherein the predetermine breathing characteristic is Cheynes Stokes Respiration, and further comprising monitoring an oxygen saturation of the patient and determining whether the patient is experiencing Cheynes-Stokes Respiration based, at least in part, on the monitored oxygen saturation.
20. The method of claim 14, wherein when negative pressure support is provided to the patient, one of the pressure provided to the patient during expiration and the pressure provided to the patient during inspiration is at or below atmospheric pressure.
21. The method of claim 14, wherein when negative pressure support is provided to the patient, both the pressure provided to the patient during expiration and the pressure provided to the patient during inspiration are above atmospheric pressure.
22. The method of claim 14, wherein the second target is the same as the first target.
23. The method of claim 14, wherein the first characteristic is a Maximum Average Inspiratory Flow (Qave(max)), wherein controlling the delivery of the flow of gas to the patient comprises comparing the Qave(max) to the first target and the second target.
24. The method of claim 14, wherein the first characteristic is a tidal volume, wherein controlling the delivery of the flow of gas to the patient comprises comparing the tidal volume to the first target and the second target.
25. The method of claim 14, wherein the first characteristic is a minute ventilation, wherein controlling the delivery of the flow of gas to the patient comprises comparing the minute ventilation to the first target and the second target.
26. A system for ventilating a patient, comprising:
means to generate a flow of gas:
means for delivering a flow of gas to the airway of a patient from a source of breathing gas via a patient circuit;
means to generate output signals related to a characteristic associated with the flow of gas;
and
means to selectively control delivery of the flow of gas to the patient by:
1) operating in a first pressure mode responsive to the characteristic being below a first threshold, wherein the first mode comprises providing higher pressure to the patient during inspiration and lower pressure to the patient during expiration; and
2) operating in a second pressure mode responsive to the characteristic being above a second threshold, wherein the second pressure mode comprises providing lower pressure to the patient during inspiration and higher pressure to the patient during expiration.
27. The system of claim 26, wherein the means to selectively control delivery of the flow of gas to the patient is configured to detect a predetermined breathing characteristic of the patient based on the characteristic associated with the flow of gas, wherein the controller operates in the second mode responsive to detection of the predetermined breathing characteristic and the characteristic associated with the flow of gas being above the second threshold.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A noise reduction apparatus comprising:
a speech segment determiner configured to detect a speech segment of a voice sound based on a first sound pick-up signal obtained based on the voice sound;
a voice direction detector configured to determine a voice incoming direction of the voice sound using the first sound pick-up signal and a second sound pick-up signal obtained based on a picked-up sound; and
a noise reduction processor configured to perform a noise reduction process to reduce a noise component carried by the first sound pick-up signal by using the second sound pick-up signal,
wherein a noise reduction amount adjusted in accordance with the voice incoming direction is used in the noise reduction process.
2. The noise reduction apparatus according to claim 1, wherein the noise reduction processor includes:
an adaptive filter configured to generate a noise-presumed signal corresponding to the noise component carried by the first sound pick-up signal by using the second sound pick-up signal;
an adaptive coefficient adjuster configured to adjust adaptive coefficients of the adaptive filter based on a result of an arithmetic operation between the first and second sound pick-up signals;
a noise reduction-amount adjuster configured to adjust the noise-presumed signal in accordance with the voice incoming direction; and
an arithmetic unit configured to reduce the noise component carried by the first sound pick-up signal by using the noise-presumed signal adjusted by the noise reduction-amount adjuster and the first sound pick-up signal.
3. The noise reduction apparatus according to claim 1, wherein the voice direction detector determines the voice incoming direction of the voice based on a phase difference between the first and sound pick-up signals.
4. The noise reduction apparatus according to claim 3, wherein the voice direction detector calculates the phase difference based on a cross-correlation value obtained by using a first group of sampled signals each corresponding to the first sound pick-up signal and a second group of sampled signals each corresponding to the second sound pick-up signal, either one of the first and second groups being used as reference signals and the other of the first and second groups being used as comparison signals.
5. The noise reduction apparatus according to claim 3, wherein the noise reduction processor reduces the noise reduction amount when at least either one of a first case and a second case is established, the first case being a case in which the phase difference is within a predetermined range and the second case being a case in which a phase of the first sound pick-up signal is more delayed than a phase of the second sound pick-up signal.
6. The noise reduction apparatus according to claim 1, wherein the voice direction detector detects the voice incoming direction based on a power difference between magnitudes of the first and second sound pick-up signals.
7. The noise reduction apparatus according to claim 6, wherein the noise reduction processor reduces the noise reduction amount when at least either one of a first case and a second case is established, the first case being a case in which the power difference is within a predetermined range and the second case being a case in which the magnitude of the first sound pick-up signal is smaller than the magnitude of the second sound pick-up signal.
8. The noise reduction apparatus according to claim 1, wherein the voice direction detector detects the voice incoming direction based on a phase difference between the first and second sound pick-up signals and a power difference between magnitudes of the first and second sound pick-up signals.
9. The noise reduction apparatus according to claim 1, wherein the noise reduction-amount adjuster adjusts the noise-presumed signal by multiplying the noise-presumed signal by a noise reduction-amount adjustment value in a range from 0 to 1 in accordance with the voice incoming direction.
10. The noise reduction apparatus according to claim 9, wherein the noise reduction-amount adjuster restricts rapid change in the noise-presumed signal when adjusting the noise-presumed signal.
11. The noise reduction apparatus according to claim 1, wherein the speech segment determiner determines the speech segment when a feature value that indicates a feature of a voice component carried by the first sound pick-up signal is equal to or larger than a specific threshold value.
12. The noise reduction apparatus according to claim 1, wherein the speech segment determiner detects the speech segment when a signal-to-noise ratio between a peak level of a vowel-sound frequency component of a voice component carried by the first sound pick-up signal and a noise level set in each frequency band is at least a specific ratio for at least a specific number of peaks.
13. The noise reduction apparatus according to claim 1, wherein the speech segment determiner detects the speech segment when a spectral pattern of a consonant of a voice component carried by the first sound pick-up signal in each specific frequency band rises as the specific frequency band rises.
14. An audio input apparatus comprising:
a first face and an opposite second face that is apart from the first face with a specific distance;
a first microphone and a second microphone provided on the first face and the second face, respectively;
a speech segment determiner configured to detect a speech segment of a voice sound based on a first sound pick-up signal obtained based on the voice sound picked up by the first microphone;
a voice direction detector configured to determine a voice incoming direction of the voice sound using the first sound pick-up signal and a second sound pick-up signal obtained based on a sound picked up by the second microphone; and
a noise reduction processor configured to perform a noise reduction process to reduce a noise component carried by the first sound pick-up signal by using the second sound pick-up signal,
wherein a noise reduction amount adjusted in accordance with the voice incoming direction is used in the noise reduction process.
15. A wireless communication apparatus comprising:
a first face and an opposite second face that is apart from the first face with a specific distance;
a first microphone and a second microphone provided on the first face and the second face, respectively;
a speech segment determiner configured to detect a speech segment of a voice sound based on a first sound pick-up signal obtained based on the voice sound picked up by the first microphone;
a voice direction detector configured to determine a voice incoming direction of the voice sound using the first sound pick-up signal and a second sound pick-up signal obtained based on a sound picked up by the second microphone; and
a noise reduction processor configured to perform a noise reduction process to reduce a noise component carried by the first sound pick-up signal by using the second sound pick-up signal,
wherein a noise reduction amount adjusted in accordance with the voice incoming direction is used in the noise reduction process.
16. A noise reduction method comprising the steps of:
detecting a speech segment of a voice sound based on a first sound pick-up signal obtained based on the voice sound;
determining a voice incoming direction of the voice sound using the first sound pick-up signal and a second sound pick-up signal obtained based on a picked-up sound; and
performing a noise reduction process to reduce a noise component carried by the first sound pick-up signal by using the second sound pick-up signal, wherein a noise reduction amount adjusted in accordance with the voice incoming direction is used in the noise reduction process.