What is claimed is:
1. A pulse spectraphotometry system comprising:
a light source adapted to illuminate a tissue site with optical radiation having a plurality of wavelengths selected from at least one of a primary band and a secondary band, said tissue site having a modulated blood volume;
a detector configured to receive said optical radiation attenuated by said tissue site and to generate a detector output responsive to absorption of said optical radiation within said tissue site;
a normalizer operating on said detector output to generate a plurality of normalized plethysmographs corresponding to said plurality of wavelengths; and
a processor configured to calculate a ratio of fractional volumes of analytes in said blood volume based upon said normalized plethysmographs.
2. The pulse spectraphotometry system according to claim 1 wherein said primary band is in a range of about 1620 nm to about 1730 nm.
3. The pulse spectraphotometry system according to claim 2 wherein said primary band is in a range of about 1620 nm to about 1670 nm.
4. The pulse spectraphotometry system according to claim 3 wherein at least one of said wavelengths is selected in a range of about 1650 nm5 nm.
5. The pulse spectraphotometry system according to claim 1 wherein said secondary band is in a range of about 1000 nm to about 1380 nm.
6. The pulse spectraphotometry system according to claim 5 wherein at least one of said wavelengths is selected in a range of about 1032 nm5 nm.
7. The pulse spectraphotometry system according to claim 5 wherein at least one of said wavelengths is selected in a range of about 1097 nm5 nm.
8. The pulse spectraphotometry system according to claim 5 wherein at least one of said wavelengths is selected in a range of about 1375 nm5 nm.
9. The pulse spectraphotometry system according to claim 1 wherein said detector is configured to receive said optical radiation after reflection from said tissue site and said wavelengths are further selected from a tertiary band of said wavelengths in a range of about 2000 nm to about 2500 nm.
10. A pulse spectraphotometry method comprising the steps of:
illuminating a tissue site having a pulsatile blood flow with a narrowband optical radiation;
time division multiplexing said optical radiation over a plurality of wavelengths;
selecting at least a portion of said wavelengths within a range of about 1620 nm to about 1730 nm;
detecting an attenuated optical radiation from said tissue site as the result of said illuminating step; and
calculating a ratio of analytes in said blood flow based upon said attenuated optical radiation.
11. The pulse spectraphotometry method according to claim 10 wherein said selecting step comprises the substep of selecting at least one wavelength in a range of about 1620 nm to about 1670 nm.
12. The pulse spectraphotometry method according to claim 10 wherein said selecting step comprises a substep of selecting at least one wavelength in a range of about 1650 nm5 nm.
13. The pulse spectraphotometry method according to claim 10 comprising the further step of selecting a second portion of said wavelengths within a range of about 1000 nm to about 1380 nm.
14. The pulse spectraphotometry method according to claim 13 wherein said selecting a second portion step comprises a substep of selecting at least one wavelength in a range of about 1032 nm5 nm.
15. The pulse spectraphotometry method according to claim 13 wherein said selecting a second portion step comprises a substep of selecting at least one wavelength in a range of about 1097 nm5 nm.
16. The pulse spectraphotometry method according to claim 13 wherein said selecting a second portion step comprises a substep of selecting at least one wavelength in a range of about 1375 nm5 nm.
17. A pulse spectraphotometry system comprising:
an optical radiation means for illuminating a tissue site;
a filter means for determining a nominal wavelength of said optical radiation, said nominal wavelength selected from a range of about 1620 nm to about 1730 nm.
a detector means for receiving said optical radiation after transmission through or reflection from said tissue site and generating a corresponding plethysmograph signal; and
a processor means for calculating a ratio of analyte portions of pulsatile blood flow within said tissue site based upon said plethysmograph signal.
18. The pulse spectraphotometry system according to claim 17 wherein said nominal wavelength is selected from a range of about 1620 nm to about 1670 nm.
19. The pulse spectraphotometry system according to claim 18 wherein said nominal wavelength is selected from a range of about 1650 nm5 nm.
20. The pulse spectraphotometry system according to claim 17 wherein said nominal wavelength is selected from a range of about 1000 nm to about 1380 nm.
21. The pulse spectraphotometry system according to claim 20 wherein said nominal wavelength is selected from a range of about 1032 nm5 nm.
22. The pulse spectraphotometry system according to claim 20 wherein said nominal wavelength is selected from a range of about 1097 nm5 nm.
23. The pulse spectraphotometry system according to claim 20 wherein said nominal wavelength is selected from a range of about 1375 nm5 nm.
24. The pulse spectraphotometry system according to claim 17 wherein said nominal wavelength is selected from a range of about 2000 nm to about 2500 nm.
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. An audio signal processing apparatus characterized by comprising:
signal delay means for, upon receipt of a first signal that has been subjected to a predetermined processing stage in a first processing path for executing predetermined processing involved until an audio signal transmitted from a side of another party of communication is received and is emitted as sound from a speaker, delaying the first signal by a set delay time and outputting the first signal;
cancellation processing means for, by obtaining a signal output from the signal delay means as an input signal, executing a process for removing a signal component of the sound emitted from the speaker, which is regarded as having been picked up by a microphone, as a cancellation target, from a second signal that has been subjected to a predetermined processing stage in a second processing path for executing predetermined processing involved until sound picked up by the microphone is sent to the side of the other party of communication;
time difference determining means for determining a time difference until the first signal is emitted from the speaker, picked up by the microphone, and appears as a signal component that forms the second signal; and
delay time setting means for setting a delay time of the signal delay means on the basis of a time difference acquired by the time difference determining means,
wherein the signal delay means sets a delay time corresponding to a processing time required for signal processing of an image signal transmitted simultaneously with the audio signal transmitted from the side of the other party of communication.
2. The audio signal processing apparatus according to claim 1, characterized in that the cancellation processing means is configured to include
an adaptive filter that operates so as to minimize the signal component of the sound serving as the cancellation target, which is included in the second signal, on the basis of the input signal and a residual signal, and
the time difference determining means is configured to
obtain, as information about the time difference, a coefficient vector that is set in the adaptive filter when the cancellation processing means captures an input signal designed to bypass the signal delay means.
3. The audio signal processing apparatus according to claim 1, characterized in that the time difference determining means is configured to directly receive the first signal and the second signal and to obtain, as a time difference to be determined, a time difference between an input timing of the first signal and an input timing of the second signal.
4. A delay time setting method for an audio signal processing apparatus including a signal delay unit that receives a first signal that has been subjected to a predetermined processing stage in a first processing path for executing predetermined processing involved until an audio signal transmitted from a side of another party of communication is received and is emitted as sound from a speaker, delays the first signal by a set delay time, and outputs the first signal, and a cancellation processing unit that, by obtaining a signal output from the signal delay unit as an input signal, executes a process for removing a signal component of the sound emitted from the speaker, which is regarded as having been picked up by a microphone, as a cancellation target, from a second signal that has been subjected to a predetermined processing stage in a second processing path for executing predetermined processing involved until sound picked up by the microphone is sent to the side of the other party of communication, characterized by being configured to execute:
under a state where the speaker and the microphone are placed so that a physical distance of a path along which the sound emitted from the speaker is picked up by the microphone is shortened as much as possible,
a time difference determining procedure for determining a time difference until the first signal is emitted from the speaker, picked up by the microphone, and appears as a signal component that forms the second signal; and
a delay time setting procedure for setting a delay time of the signal delay unit on the basis of a time difference acquired in the time difference determining procedure.
5. The delay time setting method according to claim 4, characterized in that the cancellation processing unit includes
an adaptive filter that operates so as to minimize the signal component of the sound serving as the cancellation target, which is included in the second signal, on the basis of the input signal and a residual signal, and
the time difference determining procedure is configured to
obtain, as information about the time difference, a coefficient vector that is set in the adaptive filter when the cancellation processing unit captures an input signal designed to bypass the signal delay means.
6. The delay time setting method according to claim 4, characterized in that the time difference determining procedure is configured to directly receive the first signal and the second signal and to obtain, as a time difference to be determined, a time difference between an input timing of the first signal and an input timing of the second signal.