Prenatal non-invasive detection of meconium stained amniotic fluid

• US 5,172,693 A
• Filed: 01/16/1990
• Issued: 12/22/1992
• Est. Priority Date: 01/16/1990
• Status: Expired due to Term

• Current Assignee: Doody, Michael C.
• Original Assignee: Doody, Michael C.
• Inventors: Doody, Michael C.
• Primary Examiner(s): Cohen, Lee S.
• Assistant Examiner(s): Pfaffle, K. M.
• Application Number:
  US07/465,510
• Time in Patent Office: 1,071 Days
• Field of Search: 128/633, 128/634, 128/637, 128/662.06, 128/664, 128/665, 128/775
• US Class Current: 600/317
• CPC Class Codes: A61B 5/0071 by measuring fluorescence emission
• CPC Class Codes: A61B 5/0084 for introduction into the body, e.g. by catheters A61B5/1459 takes precedence
• CPC Class Codes: A61B 5/14507 specially adapted for measuring characteristics of body fluids other than blood devices for taking samples of body liquids A61B10/0045
• CPC Class Codes: A61B 5/4362 Assessing foetal parameters

Abstract

This invention describes a process for the diagnosis of meconium stained amniotic fluid. Meconium staining is often the result of ongoing or transient fetal distress or prolonged gestation. This process involves the non-invasive illumination of the amnion with light of a specific wavelength and detecting the fluorescence of certain biological pigments contained within the meconium. The process uses a source of light and a means of selecting the desired wavelength of light, directing the light to the target area, retrieving the fluorescence, converting the fluorescent emission to an electrical signal, amplifying the signal and analyzing the signal with a data processing unit.

Claims

1. A process for a non-invasive in vivo detection of a meconium state pregnancy in a gravid female by detection of fluorescent pigments within meconium stained amniotic fluid, said process comprising steps:

A. spectrally isolating excitation wavelengths characteristic of said pigments;

B. passing said isolated excitation wavelengths into said amniotic fluid for exciting said fluorescent pigments contained within said meconium;

C. detecting fluorescence emitted by said excited pigments contained within said meconium;

D. spectrally isolating emission wavelengths characteristic of the fluorescence emitted by said pigments contained in the meconium and

E. amplifying and analyzing spectra of said detected fluorescence.

2. The process of claim 1 wherein said excitation wavelengths are passed into said amniotic fluid transcutaneously.

3. The process of claim 1 wherein said excitation wavelengths are passed into said amniotic fluid transabdominally.

4. The process of claim 1 wherein said excitation wavelengths are passed into said amniotic fluid transvaginally.

5. The process of claim 1 wherein said excitation wavelengths are passed into said amniotic fluid transcervically.

6. The process of claim 1 wherein said excitation wavelengths are passed into said amniotic fluid transamniotically.

7. The process of claim 1 wherein said excitation wavelength is in a range of about 300 to about 525 nm.

8. The process of claim 1 wherein said excitation wavelength is spectrally isolated by means of a monochromatic laser.

9. The process of claim 1 wherein said emission wavelength is in a range of about 460 to about 610 nm.

10. A process for a non-invasive in vivo detection of a meconium state pregnancy in a gravid female by detection of bilirubin and its metabolites within meconium stained amniotic fluid, said process comprising steps:

A. spectrally isolating excitation wavelengths characteristic of said bilirubin in a range of about 300 to about 525 nm by means of a monochromatic argon laser;

B. passing said isolated excitation wavelengths transcervically into said amniotic fluid for exciting fluorescent pigments contained within said bilirubin by said meconium;

C. detecting fluorescence emitted by said excited pigments contained within said meconium;

spectrally isolating emission wavelengths in a range of about 460 to about 610 nm characteristic of said fluorescence emitted by said bilirubin contained in said meconium by means of a filter and

E. amplifying and analyzing spectra of said detected fluorescence.

11. The process of claim 10 wherein said excitation wavelengths are passed into said amniotic fluid transcutaneously.

12. The process of claim 10 wherein said excitation wavelengths are passed into said amniotic fluid transabdominally.

13. The process of claim 10 wherein said excitation wavelengths are passed into said amniotic fluid transvaginally.

14. The process of claim 10 wherein said excitation wavelengths are passed into said amniotic fluid transamniotically.

15. A process utilizing fluorescent spectroscopy for non-invasively detecting a prenatal meconium state pregnancy in the gravid female by in vivo detection of fluorescent pigments in amniotic fluid wherein said pigments are bilirubin and its metabolites, said process comprising steps:

A. illuminating amniotic fluid with monochromatic light at a wavelength required for excitation of said fluorescent pigments contained within meconium thereby causing said pigments to fluoresce and emit photons;

B. detecting said emitted photons emitted by said excited pigments contained within said meconium thereby generating a signal representative of said emitted photons; and

C. amplifying and analyzing said generated signal.

16. The process of claim 15 wherein said light is passed into said amniotic fluid transcutaneously.

17. The process of claim 15 wherein said light is passed into said amniotic fluid transabdominally.

18. The process of claim 15 wherein said light is passed into said amniotic fluid transvaginally.

19. The process of claim 15 wherein said light is passed into said amniotic fluid transcervically.

20. The process of claim 15 wherein said light is passed into said amniotic fluid transamniotically.

21. The process of claim 15 wherein said wavelength required for excitation of said fluorescent pigments is in a range of about 300 to about 525 nm.

22. The process of claim 15 wherein said emitted photons has a wavelength in a range of about 460 to about 620 nm characteristic of fluorescence emitted by said bilirubin.

23. The process of claim 15 wherein said monochromatic light is an argon laser.