Biological optical measuring instrument
First Claim
1. A biomedical optical measurement apparatus comprising:
- a light source means for generating an inspection light containing multiple lights modulated at a given number of different frequencies,a light-receiving means for receiving the light generated at said light source means and passed through an object to be examined and for outputting synthesized signals made of a given number of electric signals each having a different frequency and an intensity corresponding to the received light, anda detection means for detecting a signal with the same frequency as a frequency of a reference signal having a frequency corresponding to frequencies of modulated multiple lights in the synthesized signals, whereinsaid detection means comprises;
an analog-digital conversion means for outputting digitized synthesized signal data by converting said synthesized signals having different frequencies to a digital signal,a storage means for storing digitized data of a number of reference signals, where the number of reference signals is equal to the number of the synthesized signals output from the light-receiving means,a delaying means for delaying said reference signals data read out from the storage means based on phase differences between said synthesized signals data output from said analog-digital conversion means and said reference signals data read out from the storage means,a digital multiplication means for multiplying said synthesized signals data output from said analog-digital conversion means by said reference signals data delayed by the delaying means and for outputting the product of multiplication, anda digital band-limitation means for taking out DC data from the output from said digital multiplication means.
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Accused Products
Abstract
A biomedical optical measurement apparatus comprising a light source unit for generating an inspection light containing multiple lights modulated at different frequencies, a light-receiving unit for receiving the light generated at said light source unit and passing through an object to be examined and for outputting the electric signals with the intensity corresponding to the received inspection light, and a detection means for detecting a signal with the same frequency of the reference signal in the output from said light-receiving unit. The detection means comprises an analog-digital conversion means for outputting digitized data by converting an input signal to a digital signal, a storage means for storing digitized data of multiple reference signals, a digital multiplication means for multiplying digitized data of input signals outputted from the analog-digital converting means by the digitized data of the reference signals read out from the storage means and for outputting the product of multiplication, and a digital band-limitation means for taking out DC data from the output from the digital multiplication means. Reference signal generating circuits of a number equal to that of frequencies of detected signals, which has been necessary for the conventional instrument, can be replaced by a single memory means and the configuration of the instrument can be simplified. Changes in frequency can be easily coped with by only re-writing the data of the storing means.
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Citations
14 Claims
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1. A biomedical optical measurement apparatus comprising:
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a light source means for generating an inspection light containing multiple lights modulated at a given number of different frequencies, a light-receiving means for receiving the light generated at said light source means and passed through an object to be examined and for outputting synthesized signals made of a given number of electric signals each having a different frequency and an intensity corresponding to the received light, and a detection means for detecting a signal with the same frequency as a frequency of a reference signal having a frequency corresponding to frequencies of modulated multiple lights in the synthesized signals, wherein said detection means comprises; an analog-digital conversion means for outputting digitized synthesized signal data by converting said synthesized signals having different frequencies to a digital signal, a storage means for storing digitized data of a number of reference signals, where the number of reference signals is equal to the number of the synthesized signals output from the light-receiving means, a delaying means for delaying said reference signals data read out from the storage means based on phase differences between said synthesized signals data output from said analog-digital conversion means and said reference signals data read out from the storage means, a digital multiplication means for multiplying said synthesized signals data output from said analog-digital conversion means by said reference signals data delayed by the delaying means and for outputting the product of multiplication, and a digital band-limitation means for taking out DC data from the output from said digital multiplication means. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A biomedical optical measurement apparatus comprising:
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a light source means for generating multiple inspection lights modulated at different frequencies in a time-sharing manner, a light-receiving means for sequentially receiving the inspection light generated at said light source means and passed through an object to be examined and for outputting synthesized signals made of electric signals having different frequencies with an intensity corresponding to the received inspection light, and a detection means for detecting signals with the same frequency corresponding to frequencies of modulated multiple lights in the synthesized signals;
whereinsaid detection means further comprises; an analog-digital conversion means for outputting digitized synthesized signals data by converting said synthesized signals having different frequencies to a digital signal, a clock means for generating a timing signal so that said analog-digital converting means can begin analog-digital conversion at a specified sampling timing, a function generating means for generating functions which become “
0 ”
or “
close to 0 ”
near the sampling time of said synthesized signals,a delaying means for delaying said functions based on phase differences between said synthesized signals data output from said analog-digital conversion means and said timing signal of said clock means, and a digital multiplying means for multiplying digitized synthesized signals outputted from said analog-digital converting means by the function of said function generating means and for outputting the product of multiplication. - View Dependent Claims (12)
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13. A detection circuit for a biomedical optical measurement apparatus comprising;
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an analog-digital converting means for performing analog-digital conversion of input signals and for outputting digitized data of the input signal, a function generator for generating one or more functions to be selected from trigonometric function, Gaussian function, Hamming and Hanning window functions, a delaying means for delaying said functions based on phase differences between said digitized data output from said analog-digital conversion means and said functions generated from said function generator, and a multiplying means for multiplying output from said analog-digital converting means by the function generated from said function generator. - View Dependent Claims (14)
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Specification