|
PatentVote.com: Vote on your favourite invention!
|
|
 |
Title: Photoelectric physiological measuring apparatus
Claims: I claim: 1. An apparatus for the non-invasive measurement of physiological data obtainable from monitoring blood flow in the circulatory ststem comprising: a. a pulsating light source adapted to be placed in non-invasive adjacent relationship to at least a portion of said circulatory system; b. light receiving means for receiving light signals from said light source after reflection from said circulatory system, and for generating electrical signals representative of said received light signals; c. a demodulating circuit means, connected to said light receiving means, for demodulating said electrical signals to amplitude modulate said pulsating light representations, and having an output terminal for transmitting said demodulating signals; d. circuit means, connected to said output terminal, for providing at least one of the electrical functions: i. averaging over a predetermined time interval, ii. detecting peak signal magnitudes, and iii. passing signals over a predetermined frequency band; and e. display means, connected to said circuit means, for providing a visual display of said electrical functions. 2. The apparatus of claim 1, further comprising a common housing wherein said pulsating light source and said light receiving means are mounted. 3. The apparatus of claim 2 wherein said pulsating light source further comprises a plurality of light emitting elements mounted in a symmetrical relationship about said light receiving means in said housing. 4. The apparatus of claim 3 wherein said pulsating light source further comprises three light-emitting diodes and said light receiving means further comprises a photocell. 5. The apparatus of claim 2 wherein said circuit means providing the electrical function of averaging over a predetermined time further comprises an integrating circuit means having the capability of averaging over at least 50 seconds. 6. The apparatus of claim 2 wherein said circuit means for providing the electrical function of passing signals over a predetermined frequency band further comprises a band pass filter circuit means for passing signals in the frequency range 3.75 - 6.75 Hz. 7. The apparatus of claim 2 wherein said circuit means for providing the electrical function of detecting peak signal magnitude further comprises a trigger circuit adjustable for detecting signal magnitudes representative of heart beats. 8. The apparatus of claim 2 further comprising a pulse amplitude circuit, connected to said output terminal, said pulse amplitude circuit having an integrating means for storing a voltage representative of said demodulated signals peak amplitudes; and display means for providing a visual display of the value of said stored voltage. 9. The apparatus of claim 8, further comprising a means for selectively discharging said integrating means, said discharging means comprising a timing circuit activated by said circuit means for detecting peak signal magnitude. 10. The apparatus of claim 9 wherein said timing circuit activation interval is predetermined and fixed. 11. The apparatus of claim 10 wherein said integrating means is discharged by said discharging means at a rate corresponding to the heartbeat rate. 12. An apparatus for the non-invasive measurement of physiological data obtainable from monitoring blood flow in the circulatory system, comprising: a. a housing including a pulsating light source adapted to be placed in non-invasive relationship and adjacent to at least a portion of the circulatory system; b. a light receiving means, located in said housing in fixed relationship to said pulsating light source, for receiving light signals reflected from said circulatory system portion, and for generating electrical signals representative of said received light signals; c. demodulating circuit means, connected to said light receiving means, for developing an envelope signal tracking said electrical signals' peak amplitudes; d. an averaging circuit connected to said demodulating circuit means, said averaging circuit having means for developing a voltage representative of said envelope signal average value over a time period of at least about 50 seconds; and e. an indicator connected to said averaging circuit, said indicator having a visual display means for displaying said average voltage signal. 13. The apparatus of claim 12 wherein said pulsating light source further comprises a plurality of light emitting elements mounted in a symmetrical relationship about said light receiving means in said housing. 14. The apparatus of claim 13 wherein said pulsating light source further comprises three light-emitting diodes and said light receiving means further comprises a photocell. 15. The apparatus of claim 14 wherein said pulsating light source frequency of pulsation is about 1000 Hz. 16. The apparatus of claim 15 wherein said pulsating light source has a duty cycle of about 10%, and a light wavelength of about 9000 A. 17. The apparatus of claim 16 wherein said averaging circuit further comprises an integrating capacitor circuit having a discharge time constant of about 50 seconds and a charge time constant of about 1 second. 18. The apparatus of claim 17 wherein said indicator further comprises a voltage meter of the D'Arsonval type. 19. An apparatus for the non-invasive measurement of physiological data obtainable from monitoring blood flow in the circulatory system, comprising: a. a housing including a pulsating light source adapted to be placed in non-invasive relationship and adjacent to at least a portion of the circulatory system; b. a light receiving means, located in said housing in fixed relationship to said pulsating light source, for receiving light signals reflected from said circulatory system portion, and for generating electrical signals representative of said received light signals; c. demodulating circuit means, connected to said light receiving means, for developing an envelope signal tracking said electrical signals' peak amplitudes; d. a band pass circuit connected to said demodulating circuit means, said band pass circuit having means for passing signals in the frequency range 3.75 - 6.75 Hz; and e. an indicator connected to said band pass circuit, said indicator having a visual display means for displaying signals passed. 20. The apparatus of claim 19 wherein said pulsating light source further comprises a plurality of light emitting elements mounted in a symmetrical relationship about said light receiving means in said housing. 21. The apparatus of claim 20 wherein said pulsating light source further comprises three light-emitting diodes and said light receiving means further comprises a photocell. 22. The apparatus of claim 21 wherein said pulsating light source frequency of pulsation is about 1000 Hz. 23. The apparatus of claim 22 wherein said pulsating light source has a duty cycle of about 10%, and a light wavelength of about 9000 A. 24. An apparatus for the non-invasive measurement of physiological data obtainable from monitoring blood flow in the circulatory system, comprising: a. a housing including a pulsating light source adapted to be placed in non-invasive relationship and adjacent to at least a portion of the circulatory system; b. a light receiving means, located in fixed relationship to said pulsating light source, for receiving light signals reflected from said circulatory system portion, and for generating electrical signals representative of said received light signals; c. demodulating circuit means, connected to said light receiving means for developing an envelope signal tracking said electrical signals' peak amplitudes; d. an amplitude indicating circuit connected to said demodulating circuit means, said amplitude indicating circuit having means for developing a voltage representative of the average value of said envelope signals' peak amplitudes; e. an indicator connected to said amplitude indicating circuit, said indicator having a visual display means for displaying said developed voltage signal. 25. The apparatus of claim 24 further comprising a peak detector circuit connected to said demodulating circuit means and to said amplitude indicating circuit, said peak detector circuit having means for detecting peak envelope signal voltages and for disabling said amplitude indicating circuit for a predetermined time interval after each peak voltage detection. 26. The apparatus of claim 25 wherein said pulsating light source further comprises a plurality of light emitting elements mounted in a symmetrical relationship about said light receiving means in said housing. 27. The apparatus of claim 26 wherein said pulsating light source further comprises three light-emitting diodes and said light receiving means further comprises a photocell. 28. The apparatus of claim 27 wherein said pulsating light source frequency of pulsation is about 1000 Hz. 29. The apparatus of claim 28 wherein said pulsating light source has a duty cycle of about 10%, and a light wavelength of about 9000 A. Other info: Inventors: Heule, James E. (Minneapolis, MN, US) Application Number: 510006 Filing Date: 1974-09-27 Publication_date: 1976-09-14 Assignee: Audronics, Inc. (Minneapolis, MN) Primary Class(es): 600/479 Other Classes: US Patent Ref:
Other Refs:
Cohen, "Led Skin Reflectance Oximeter", Med. and Biol. Eng., vol. 10, pp. 385-391, 1972. | |