Birth monitoring system
A medical transponder, including an ultrasonic sensor that detects impinging ultrasonic waves and generates electrical signals in response thereto; an electrical connection which receives said signals; and an electromagnetic RF transmitter coupled to said electrical connection and which generates an RF signal in response to said detected waves.
1. A birth monitoring system, comprising:
an ultrasonic transmitter comprising at least one transmission element;
an electromagnetic RF receiver comprising at least one RF antenna;
at least two transponders adapted to attach to a cervix and which generate RF signals responsive to excitation by an ultrasonic signal;
a signal distinguisher which distinguishes between RF signals from different transponders; and
a controller configured to analyzes said RF signals to produce an indication of a progress of a birth.
2. A system according to claim 1 , wherein said indication comprises a dilation of said cervix.
3. A system according to claim 1 , wherein said indication comprises a station of a fetal head.
4. A system according to claim 1 , wherein said indication comprises an orientation of a fetal head.
5. A system according to claim 1 , wherein said system is adapted to be worn by a mother being monitored.
6. A system according to claim 1 , wherein said distinguisher is part of said controller.
7. A system according to claim 1 , wherein at least one of the transponders comprises:
an ultrasonic sensor that detects impinging ultrasonic waves and generates electrical signals in response thereto;
an electrical connection which receives said signals; and
an electromagnetic RF transmitter coupled to said electrical connection and which generates an RF signal in response to said detected waves.
8. A system according to claim 7 , wherein said electrical connection comprises circuitry.
9. A system according to claim 8 , wherein said circuitry comprises a driving circuitry.
10. A system according to claim 8 , wherein said circuitry comprises a tuning circuitry.
11. A system according to claim 8 , wherein said circuitry comprises a non-linear element which generates harmonics.
12. A system according to claim 8 , wherein said circuitry modifies a frequency of said detected ultrasonic waves to generate a frequency for said transmitted RF waves.
13. A system according to claim 12 , wherein said modifying comprises multiplying.
14. A system according to claim 12 , wherein said modifying comprises a frequency shifting.
15. A system according to claim 12 , wherein said circuitry comprises a variable element for generating different frequencies from a same base circuit.
16. A system according to claim 12 , wherein said circuitry resonates with said impinging waves to generate said transmitted waves.
17. A system according to claim 12 , wherein said circuitry comprises a modulation circuitry that uses said impinging waves to modulate said transmitted waves.
18. A system according to claim 12 , comprising at least one additional sensor and wherein said circuitry modulates said transmitted wave using a signal from said sensor.
19. A system according to claim 7 , wherein said electromagnetic RF transmitter has an output lower than said signal.
20. A system according to claim 7 , wherein said electrical connection drives said RF transmitter with substantially no delay relative to said ultrasonic detection.
21. A system according to claim 7 , wherein said at least one of the transponders comprises a covering adapted to protect said transponder from fluids and pressures extant in a birth canal.
22. A system according to claim 21 , wherein said covering is disposable.
23. A system according to claim 7 , wherein said transponder is powered solely by said detected ultrasonic waves.
24. A system according to claim 7 , wherein said at least one of the transponders is powered by a transmitted power field.
25. A system according to claim 7 , wherein said at least one of the transponders is powered by an integral power source.
26. A system according to claim 7 , wherein said at least one of the transponders comprises a separate transmission antenna spatially displaced from said sensor by a wire, to a distance at least 10 times a maximal dimension of said sensor.
27. A system according to claim 26 , wherein said wire is long enough to reach from a cervix to outside of a body, through a birth canal.
28. A system according to claim 27 , wherein said birth canal is a human birth canal.
29. A system according to claim 27 , wherein said birth canal is an equine or bovine birth canal.
30. A system according to claim 1 , wherein at least one of the transponders is small enough to avoid interfering with a birth process, when implanted in a birth canal.
31. A system according to claim 1 , wherein at least one of the transponders comprises an integral anchor adapted for attachment to cervical tissue.
32. A system according to claim 1 , wherein at least one of the transponders comprises:
a detection sensor;
an anchor for attaching said sensor to a location of a body;
at least one wire electrically coupled to said sensor; and
a transmitter, electrically coupled to said at least one wire and adapted to be placed at a distance front said sensor, which distance is at least 10 times greater than a maximum dimension of said sensor.
33. A system according to claim 32 , wherein said detection sensor is an ultrasound sensor.
34. A system according to claim 32 , wherein the transmitter electrically coupled to said sensor comprises an electromagnetic RF transmitter.
35. A system according to claim 1 , comprising a processor configured for determining a time of flight of said ultrasonic wave from a difference between a time of arrival of said RF wave and a time of transmission of said ultrasonic wave.
36. A system according to claim 1 , wherein said distinguisher is capable of distinguishing between RF signals by their frequencies.
37. A system according to claim 1 , comprising an ultrasonic transmitter capable of producing a broad band pulse, and each of the transponders respond to a different portion of said broad band pulse.
38. A system according to claim 1 , wherein at least one of said transponders is configured to transmit RF waves having a frequency that is a small integer multiple of a frequency of said ultrasonic wave.
39. A system according to claim 1 , wherein said RF receiver is near-field receiver.
40. A system according to claim 1 , comprising a plurality of RF receiving antennas and a processor configured to determining phase information from RF signals received by the antennas.
41. A system according to claim 40 , wherein said processor is configured to reconstructing an orientation of said transponder from said phase information.
42. A system according to claim 1 , wherein at least one of said transponders is adapted for insertion in a body.
43. A system according to claim 42 , wherein said transponder is adapted for insertion into tissue adjacent a birth canal.
44. A system according to claim 43 , wherein said birth canal is a human birth canal.
45. A system according to claim 43 , wherein said birth canal is an equine or bovine birth canal.
46. A system according to claim 1 , wherein at least one of the transponders is adapted to be attached to a fetal head.