CERVICAL DILATION MEASURING DEVICE

• US 3,768,459 A
• Filed: 06/28/1971
• Issued: 10/30/1973
• Est. Priority Date: 06/28/1971
• Status: Expired due to Term

• Current Assignee: Emerson T. Cannon, Richard M. Hebertson
• Original Assignee: Emerson T. Cannon, Richard M. Hebertson
• Inventors: Cannon, Emerson T., Hebertson, Richard M.
• Primary Examiner(s): Kamm, William E.
• Application Number:
  US05/157,154
• Time in Patent Office: 855 Days
• Field of Search: 128/2R,2S,2.1R,2.5R,1.3,1.5 33/174D 340/248,279,282
• US Class Current: 600/588
• CPC Class Codes: A61B 5/1076 for measuring dimensions inside body cavities, e.g. using catheters A61B3/1005 takes precedence
• CPC Class Codes: A61B 5/435 Assessing cervix alteration or dilation

Abstract

A measuring device for measuring cervix dilation is disclosed. The device comprises a miniature signal transmitting device attached to one side of the cervix, said transmitting device generating a signal whose intensity varies with the distance from said transmitting device. A miniature receiving device attached to or placed against an opposite side of the cervix from said transmitting device receives the transmitted signal and generates a signal proportional to said transmitted signal. The signal from said receiving device is passed through translation means to provide a visible display of the intensity of said transmitted signal. The intensity of said transmitted signal is proportional to the distance between the transmitting device and the receiving device.

Claims

1. An electromagnetic device for measuring cervical dilation comprising:

a. a first miniature induction coil having a resonant frequency between about 50 and 1000 KCS, said first coil having means to attach said coil to the cervix of a prospective mother, b. a second miniature coil having a resonant frequency substantially the same as said first coil, said second having means to attach said coil to the cervix of a prospective mother, c. calibrated power supply means producing an oscillating current of a frequency substantially matching the resonant frequency of said first miniature induction coil connected to said first miniature induction coil to provide predetermined amounts of induced energy in said second coil at predetermined distances from said first coil, d. translation means interconnected with said second coil to translate the intensity of voltage induced in said coil into a visible display linearly proportional to the distance separating said first and second coils.

2. The measuring device of claim 1 wherein the power supply means provides a low voltage, alternating current.

3. The measuring device of claim 2 wherein the power supply means provides an alternating current of less than about 25 volts.

4. The measuring device of claim 2 wherein the power supply means provides an alternating current of less than about 100 milliwatts.

5. The measuring device of claim 1 wherein said translation means comprises a peak follower interconnected with said second coil, a log amplifier interconnected with said peak follower, an anti-log amplifier interconnected with said log amplifier and a visual display device for converting an electrical signal into a visual display.

6. The measuring device of claim 1 wherein the induction coils have a high '"'"''"'"''"'"''"'"'Q'"'"''"'"''"'"''"'"' and a narrow frequency band pass.

7. The measuring device of claim 6 wherein the power supply means provides an oscillating current at a power of less than about 100 milliwatts, a voltage of less than about 25 volts and at a frequency within the band pass range of said coils.

8. The measuring device of claim 1 wherein each induction coil has a maximum dimension of about one-half inch.

9. A measuring device for measuring cervical dilation comprising:

a. first miniature signal transmitting device having attachment means so said device can be attached to one side Of the cervix, said transmitting device generating a signal of a substantially constant frequency;

b. a second miniature signal transmitting device having attachment means so said device can be attached to the opposite side of said cervix from said first transmitting device, said second transmitting device generating a signal which has a substantially constant frequency different from the frequency of the first transmitting device;

c. a remote receiving unit which receives an interference frequency transmitted from said transmitting device;

d. translation means for receiving said interference frequency from said receiving device and translating same to provide a visible display of the interference frequency received by the receiving device, said translation means including a visual display device calibrated to display said interference frequency proportionally to the distance between the first and second transmitting devices.

10. A measuring device for measuring cervical dilation comprising:

a. a miniature magnetic device producing a magnetic field, said device having attachment means to attach said device to the wall of said cervix;

b. a portable moving coil device placeable against the cervical wall opposite said miniature magnetic device having a moveable coil therein;

c. reciprocating means within said moving coil device interacting with said moveable coil to reciprocate said coil;

d. translation means interconnected with said coil for receiving the alternating current from said coil and translating same to provide a visible display of the intensity of the current induced in said coil.