Fetal electrode apparatus

• US 4,501,276 A
• Filed: 07/16/1982
• Issued: 02/26/1985
• Est. Priority Date: 07/16/1982
• Status: Expired due to Fees

• Current Assignee: Kontron Inc (Roche Holding AG)
• Original Assignee: Illinois Tool Works Inc.
• Inventors: Lombardi, Edward J.
• Primary Examiner(s): Cohen, Lee S.
• Application Number:
  US06/399,073
• Time in Patent Office: 956 Days
• Field of Search: 128/642, 128/784, 128/785, 128/786, 128/419 P
• US Class Current: 600/376
• CPC Class Codes: A61B 5/288 for foetal cardiography, e.g. scalp electrodes
• CPC Class Codes: A61B 5/4362 Assessing foetal parameters

Abstract

An apparatus for use in monitoring fetal vital signs with monitoring equipment is disclosed. The apparatus includes a form sustaining guide tube, a sleeve, a fetal electrode structure having a piston member and a body member, at least two active fetal electrodes and a lead wire for connecting the active fetal electrodes to monitoring equipment. At least a portion of the guide tube and the body member are slideably disposed within the sleeve. The active fetal electrodes are attached to this piston member and their free ends are disposed within channels defined by the body member. The channels project arcuately outwardly by a predetermined radius of curvature so as to define a continuous outwardly advancing open passage through the body member. The body member also includes a shoulder to preclude movement of the body member within the sleeve by more than a predetermined distance. The apparatus is inserted through passages of a woman in labor brought into contact with the fetal scalp. By exerting pressure, the guide tube advances in the sleeve and releasably contacts the piston member which in turn advances the active fetal electrodes through and out of the channels with an outward curvature and into the fetal scalp.

Claims

1. An apparatus for use in monitoring fetal vital signs with monitoring equipment, insertable through the vagina and the cervix of a woman in labor into a fetal scalp, comprising:

(a) a form-sustaining guide tube having a forward end portion and adapted to be inserted through the vagina and cervix of the woman in labor;

(b) a sleeve having a forward end portion, the sleeve being disposed about the forward end portion of the guide tube, and the sleeve being configured to allow slideable movement of the forward end portion of the guide tube within the sleeve;

(c) a piston member slideably disposed within the sleeve for releasably engaging the forward end portion of the guide tube;

(d) a body member including;

(i) a rearward portion releasably disposed within the sleeve adjacent the piston member;

(ii) a forward portion having a shoulder releasably engaging the forward end portion of the sleeve and configured to preclude the forward portion of the body member from moving within the sleeve along the longitudinal axis of the sleeve toward the piston member by more than a predetermined distance, said forward portion of the body member effecting releasable contact with the fetal scalp; and

(iii) at least two channels passing from the rearward portion of the body member and advancing outwardly along the longitudinal axis of the sleeve through the forward portion of the body member, said channels defining continuous open passages through the body member;

(e) at least two resilient active electrode members mounted on the piston member and having a free end slideably disposed within the channels, said active electrode members being of sufficient length for the free ends to pass through the channels and advance into the fetal scalp as the guide tube engages the piston member and causes the active electrodes to advance along the channels and out of the forward portion of the body member; and

(f) means for electrically connecting the active electrode members to the monitoring equipment.

2. The apparatus of claim 1 further comprising a reference electrode mounted on said piston member and means for electrically connecting the reference electrode to the monitoring equipment.

3. The apparatus of claim 2 wherein the piston member includes a head member dimensioned to slideably advance within the sleeve along the axis of the sleeve upon releasable contact with the guide tube.

4. The apparatus of claim 3 wherein the rearward portion of the body member includes a housing having a frustoconical configured inner wall with slots defining said channels.

5. The apparatus of claim 4 wherein the forward portion of the body member is a plug member having a frustoconical configured outer wall for mating engagement with the inner wall of the housing.

6. The apparatus of claim 5 wherein the inner wall of the housing and the outer wall of the plug member have a frustoconical, curved configuration which taper radially outwardly along the longitudinal axis of the sleeve from the rearward portion to the forward portion of the body member at a curvature of a predetermined radius.

7. The apparatus of claim 6 wherein the head member defines a cavity having an opening adjacent the body member.

8. The apparatus of claim 7 wherein the rearward portion of the body member is configured and dimensioned to fit within the opening and cavity of the head member in substantially sealed relation therewith.

9. The apparatus of claim 8 wherein the piston member further includes a retainer cap member for effecting releasable contact with the forward end portion of the guide tube and secured to the head member.

10. The apparatus of claim 9 wherein the channels are defined by the slots in the inner wall of the housing so that the electrodes exit the forward portion of the body member in radial symmetry.

11. The apparatus of claim 9 wherein the means for electrically connecting the active electrode members to the monitoring equipment includes an insulated wire electrically connected to the active electrode members.

12. The apparatus of claim 11 wherein the means for electrically connecting the reference electrode to the monitoring equipment includes an insulated wire electrically connected to the reference electrode.

13. The apparatus of claim 12 wherein there are four active electrode members and four channels passing through the body member.

14. The apparatus of claim 13 wherein the active electrode members have free end portions which terminate in beveled tips.

15. The apparatus of claim 14 wherein the reference electrode comprises a metal disk secured to the piston member.

16. The apparatus of claim 15 wherein the reference electrode is secured to the piston member between the head member and retainer cap member.

17. The apparatus of claim 16 wherein the sleeve has an inner surface adjacent the guide tube with a multiplicity of members projecting radially inwardly.

18. The apparatus of claim 17 wherein the projecting members are ribs.

19. The apparatus of claim 18 wherein the forward end portion of the guide tube has an outer surface which contacts the ribs of the inner surface of the sleeve, said outer surface and ribs being configured and dimensioned for retainably contacting each other yet allowing slideable movement along the longitudinal axis of the sleeve upon movement of the guide tube.

20. The apparatus of claim 19 wherein the sleeve and the piston member have a generally cylindrical configuration and the sleeve has an inside diameter greater than the outside diameter of the guide tube.

21. The apparatus of claim 20 wherein the body member is a synthetic resin plastic.

22. The apparatus of claim 21 wherein the piston member is a synthetic resin plastic.

23. The apparatus of claim 22 wherein the active electrodes are a spring stainless steel alloy.

24. The apparatus of claim 1 wherein the forward end portion of the guide tube includes a junction member slideably engaging the sleeve and for releasable contact with the piston member.

25. The apparatus of claim 24 wherein the junction member includes means for precluding movement of the junction member along the axis of the sleeve by more than a predetermined distance in both directions of movement.

26. A fetal scalp electrode apparatus for use with fetal monitoring equipment comprising:

(a) a sleeve;

(b) a form-sustaining guide tube having a forward end portion which is slideably disposed within the sleeve, said guide tube configured and dimensioned to pass through the vagina and cervix of a woman in labor;

(c) a piston member having a rearward end surface and a forward end surface and slideably disposed within the sleeve for the rearward end surface to releasably engage the forward end portion of the guide tube as the guide tube advances through the sleeve;

(d) at least two flexible, elongated active electrode legs, each attached to the piston member and having a free end projecting in a direction away from the guide tube;

(e) lead means for electrically connecting the active electrode legs to the monitoring equipment; and

(f) a body member including;

(i) an internal face disposed within the sleeve for releasably engaging the forward end surface of the piston member as the piston member and guide tube advance through the sleeve;

(ii) an external face having a shoulder means releasably contacting the sleeve and precluding the body member from sliding within sleeve toward the piston member by more than a predetermined distance, said external face configured for releasably contacting the fetal scalp; and

(iii) at least two channels, each channel surrounding a portion of the respective electrode leg and defining a continuous passage through the body member for slideable passage of the electrode leg therein, each channel having a predetermined curvature advancing outwardly from the internal face of the body member to the external face of the body member imparting on the active electrode leg an outwardly advancing curvature of a predetermined radius as the active electrode leg advances through the channel during the action of the guide tube on the piston member, said active electrode legs being of a sufficient length for the free ends to pass through the channels and out of the external face of the body member into the fetal scalp.

27. The apparatus of claim 26 wherein there are four active electrode legs and four channels.

28. The apparatus of claim 27 further comprising means for obtaining a sealed-tight relation between the piston member and the body member.

29. A fetal electrode apparatus for monitoring fetal heart rate with monitoring equipment comprising:

(a) a form-sustaining guide tube having a forward end portion and adapted to advance through the passage of a woman in labor and to be positioned adjacent to the fetus;

(b) a generally cylindrical sleeve member surrounding the forward end portion of the guide tube and configured for effecting slideable movement of the guide tube along the longitudinal axis of the sleeve member;

(c) a cylindrical piston member slideably disposed within the sleeve member adjacent the forward end portion of the guide tube and configured for releasable contact with the forward end portion of the guide tube and slideable advancement along the longitudinal axis of the sleeve member by the action of the guide tube;

(d) four flexible, electrically conductive, active electrodes connected to the piston member and projecting generally along the longitudinal axis of the sleeve member;

(e) insulated lead means for electrically connecting the active electrodes to the monitoring equipment;

(f) a reference electrode mounted on the piston member;

(g) insulated lead means for electrically connecting the reference electrode to the monitoring equipment; and

(h) a body member having;

(i) a rearward portion releasably disposed within the sleeve member adjacent the piston member;

(ii) a forward portion with a shoulder releasably engaging the sleeve member and configured to permit movement of the body member along the axis of the sleeve in one direction by a predetermined distance, said forward portion effecting releasable contact with the fetus; and

(iii) four channels defining continuous open passages through the body member, each channel slideably surrounding a portion of the respective active electrode and having an outwardly projecting curvature of a predetermined radius from the rearward portion to the forward portion of the body member for deflecting the electrode out of general alignment with the longitudinal axis of the sleeve member and imparting said curvature of the predetermined radius on the active electrode as the active electrode advances through the channel during the action of the guide tube on the piston member, said electrodes being of sufficient length for a portion thereof to pass out of the channels and contact the fetus.

30. The apparatus of claim 29 further comprising means for obtaining a sealed-tight relation between the piston member and the body member.

31. The apparatus of claim 30 wherein the forward end portion of the guide tube includes a junction member slideably engaging the sleeve member for releasable contact with the piston member.

32. The apparatus of claim 31 wherein the junction member includes means for precluding movement of the junction member along the axis of the sleeve by more than a predetermined distance in both directions of movement.

33. A fetal monitoring instrument comprising:

(a) an elongated member having a forward end portion and adapted to be inserted through a vagina and cervix of a woman in labor;

(b) a sleeve having a forward end portion, the sleeve being disposed about the forward end portion of the elongated member, and the sleeve being configured to allow slideable movement of the forward end portion of the elongated member within the sleeve along the longitudinal axis of the sleeve;

(c) a piston member slideably disposed within the sleeve for releasable contact with the forward end portion of the elongated member;

(d) a body member including;

(i) a rearward portion releasably disposed within the sleeve adjacent the piston member;

(ii) a forward portion having a shoulder releasably engaging the forward end portion of the sleeve and configured to preclude the forward portion of the body member from moving within the sleeve along the longitudinal axis of the sleeve toward the piston member by more than a predetermined distance, said forward portion of the body member configured for releasably contacting a fetal scalp; and

(iii) at least two channels passing from the rearward portion of the body member and advancing arcuately outwardly through the forward portion of the body member, said channels defining continuous open passages through the body member; and

(e) at least two resilient members mounted on the piston member and having free end portions slideably disposed within the channels, said resilient members being of sufficient length to pass through the channels and advance into the fetal scalp as the elongated member engages the piston member and causes the free end portions of the resilient members to advance along the channels and out of the forward portion of the body member, at least one of said resilient members being an electrode; and

(f) means for electrically connecting the electrode to the fetal monitoring instrument.

34. A fetal scalp electrode structure for use with fetal monitoring equipment comprising:

(a) a piston member having a rearward end surface and a forward end surface;

(b) at least two resilient active electrode legs, each having one end attached to the piston member and a free end projecting in a direction away from the piston member;

(c) lead means for electrically connecting the active electrode legs to the monitoring equipment; and

(d) a cylindrical body member including;

(i) an internal end face disposed adjacent the piston member for releasably engaging the forward end surface of the piston member as the piston member advances toward the body member;

(ii) an external end face having a shoulder projecting radially outwardly from the longitudinal axis of the body member, said external end face configured for releasably contacting the fetal scalp; and

(iii) at least two channels, each channel surrounding a portion of the respective electrode leg and defining a continuous passage through the body member for slideable passage of the active electrode leg therein, each channel having a predetermined curvature advancing outwardly from the internal end face of the body member to the external end face of the body member imparting on the electrode leg an outwardly advancing curvature of a predetermined radius as the electrode leg advances through the channel due to the action of the piston member, said electrode legs being of a sufficient length for the free ends to pass through the channels and out of the external end face of the body member into the fetal scalp.

35. The fetal scalp electrode structure of claim 34 further comprising means for obtaining a sealed-tight relation between the piston member and the body member.

36. The apparatus of claim 35 wherein there are four active electrode legs and four channels.

37. An apparatus for use in monitoring fetal vital signs with monitoring equipment, insertable through the vagina and the cervix of a woman in labor into a fetal scalp, comprising:

(a) a form-sustaining guide tube adapted to be inserted through the vagina and cervix of the woman in labor;

(b) a junction member secured to an end of the guide tube;

(c) a sleeve having a forward end portion, the sleeve being disposed about the junction member, and the sleeve being configured to allow slideable movement of the junction member along the longitudinal axis of the sleeve;

(d) a piston member releasably disposed within the sleeve for sliding therein and releasably engaging the junction member;

(e) a body member including;

(i) a rearward portion releasably disposed within the sleeve adjacent the piston member;

(ii) a forward portion effecting releasable contact with the fetal scalp; and

(iii) at least two channels passing from the rearward portion of the body member and advancing outwardly through the forward portion of the body member, said channels defining continuous open passages through the body member;

(f) at least two resilient, active electrode members mounted on the piston member and having free ends slideably disposed within the channels, said active electrode members being of sufficient length for the free ends to pass through the channels and advance into the fetal scalp as the junction member contacts the piston member and causes the active electrode members to advance along the channels and out of the forward portion of the body member; and

(g) means for electrically connecting the active electrode members to the monitoring equipment.

38. The apparatus of claim 37 further comprising a reference electrode mounted on said piston member and means for electrically connecting the reference electrode to the monitoring equipment.

39. The apparatus of claim 38 further comprising means for advancing the junction member along the longitudinal axis of the sleeve by a predetermined distance.

40. The apparatus of claim 39 wherein the junction member slides within the sleeve and the sleeve has an inner surface adjacent the junction member with a multiplicity of rib members projecting radially inwardly.

41. The apparatus of claim 40 wherein the junction member advancing means includes a first flange positioned on the junction member and configured for engaging the rib members and precluding advancement of the junction member along the longitudinal axis of the sleeve in a direction by more than a predetermined distance.

42. The apparatus of claim 41 wherein the junction member advancing means further includes a second flange positioned on the junction member and spaced from the first flange, said second flange configured for engaging the rib members and precluding advancement of the junction member along the longitudinal axis of the sleeve in the other direction by more than a predetermined distance.

43. The apparatus of claim 42 wherein the forward portion of the body member has a shoulder releasably engaging the forward end portion of the sleeve and configured to preclude the forward portion of the body member from moving within the sleeve along the longitudinal axis of the sleeve toward the piston member by more than a predetermined distance.

44. A fetal electrode apparatus for monitoring the fetal heart rate with monitoring equipment comprising:

(a) form-sustaining guide tube having a forward end portion and adapted to advance through the passage of a woman in labor and to be positioned adjacent to a fetus;

(b) a hollow coupling member having an end fixedly secured within the forward end portion of the guide tube;

(c) a generally cylindrical sleeve surrounding the coupling member and configured for effecting slideable movement of the coupling member along the longitudinal axis of the sleeve;

(d) a cylindrical piston member slideably disposed within the sleeve adjacent the coupling member and configured for releasable contact with the coupling member and slideable advancement along the longitudinal axis of the sleeve by the action of the coupling member and guide tube;

(e) four flexible, electrically conductive, active electrodes connected to the piston member and having free ends projecting generally along the longitudinal axis of the sleeve in a direction away from the coupling member;

(f) insulated lead means for electrically connecting the active electrodes to the monitoring equipment;

(g) a reference electrode mounted on the piston member;

(h) insulated lead means for electrically connecting the reference electrode to the monitoring equipment; and

(i) a body member having;

(i) a housing, at least a portion being releasably disposed within the sleeve adjacent the piston member;

(ii) a plug member secured within the housing, said plug member effecting releasable contact with the fetus; and

(iii) four channels defining continuous open passages through the body member, the channels slideably surrounding a portion of the active electrodes and having an outwardly projecting curvature of a predetermined radius while passing through the body member for deflecting the electrodes out of general alignment with the longitudinal axis of the sleeve and imparting said curvature of the predetermined radius on the active electrodes as the active electrodes advance through the channels during the action of the guide tube and coupling member on the piston member, said electrodes being of sufficient length for their ends to pass out of the channels and into the fetal scalp.

45. The apparatus of claim 44 further comprising means for advancing the coupling member along the longitudinal axis of the sleeve by a predetermined distance.

46. The apparatus of claim 45 wherein the coupling member slides within the sleeve and the sleeve has an inner surface adjacent the coupling member with a multiplicity of rib members projecting radially inwardly.

47. The apparatus of claim 46 wherein the coupling member advancing means includes a first flange positioned on the coupling member and configured for engaging the rib members and precluding advancement of the coupling member along the longitudinal axis of the sleeve in a direction by more than a predetermined distance.

48. The apparatus of claim 47 wherein the coupling member advancing means further includes a second flange positioned on the coupling member and spaced apart from the first flange, said second flange configured for engaging the rib members and precluding advancement of the junction member along the longitudinal axis of the sleeve in the other direction by more than a predetermined distance.

49. The apparatus of claim 48 wherein the forward portion of the body member has a shoulder releasably engaging the sleeve and configured to preclude the forward portion of the housing from moving within the sleeve along the longitudinal axis of the sleeve toward the piston member by more than a predetermined distance.

50. An electrode apparatus for use with monitoring equipment, insertable through the vagina and the cervix of a woman in labor into a fetus, comprising:

(a) a sleeve;

(b) an elongated member having at least a forward end portion which is slideably disposed within the sleeve, said elongated member and sleeve configured and dimensioned to pass through the vagina and cervix of the woman;

(c) a piston member having a rearward end surface and a forward end surface and slideably disposed within the sleeve for the rearward end surface to releasably engage the forward end portion of the elongated member as the elongated member advances through the sleeve;

(d) at least two flexible, elongated active electrode legs, each leg attached to the piston member and having a free end projecting in a direction away from the elongated member;

(e) lead means for electrically connecting the active electrode legs to the monitoring equipment; and

(f) a body member including;

(i) an internal face disposed within the sleeve for releasably engaging the forward end surface of the piston member as the piston member and elongated member advance through the sleeve;

(ii) an external face having a shoulder means releasably contacting the sleeve and precluding the body member from sliding within sleeve toward the piston member by more than a predetermined distance; and

(iii) at least two channels, each channel surrounding a portion of the respective electrode leg and defining a continuous passage through the body member for slideable passage of the electrode leg therein, each channel having a predetermined curvature advancing outwardly from the internal face of the body member to the external face of the body member imparting on the active electrode leg an outwardly advancing curvature of a predetermined radius as the active electrode leg advances through the channel during the action of the elongated member on the piston member, at least one of said active electrode legs being of a sufficient length for the free end to pass through the channel and out of the external face of the body member.

51. A fetal electrode apparatus for monitoring fetal heart rate with monitoring equipment comprising:

(a) an elongated member having a forward end portion;

(b) a sleeve member surrounding at least the forward end portion of the elongated member and configured for effecting slideable movement of the elongated member along the longitudinal axis of the sleeve member, said sleeve member and elongated member adapted to advance through the passage of a woman in labor and to be positioned adjacent to the fetus;

(c) a piston member slideably disposed within the sleeve member adjacent the forward end portion of the elongated member and configured for releasable contact with the forward end portion of the elongated member and slideable advancement along the longitudinal axis of the sleeve member by the action of the elongated member;

(d) at least four flexible, electrically conductive, active electrodes connected to the piston member and projecting generally along the longitudinal axis of the sleeve member;

(e) insulated lead means for electrically connecting the active electrodes to the monitoring equipment;

(f) a reference electrode mounted on the piston member;

(g) insulated lead means for electrically connecting the reference electrode to the monitoring equipment; and

(h) a body member having;

(i) a rearward portion releasably disposed within the sleeve member adjacent the piston member;

(ii) a forward portion with a shoulder releasably engaging the sleeve member and configured to permit movement of the body member along the axis of the sleeve in one direction by a predetermined distance; and

(iii) four channels defining continuous open passages through the body member, each channel slideably surrounding a portion of the respective active electrode and having an outwardly projecting curvature of a predetermined radius from the rearward portion to the forward portion of the body member for deflecting the electrode out of general alignment with the longitudinal axis of the sleeve member and imparting said curvature of the predetermined radius on the active electrode as the active electrode advances through the channel during the action of the elongated member on the piston member, at least one of said electrodes being of sufficient length for a portion thereof to pass out of the channel and contact the fetus.

52. An apparatus for use in monitoring fetal vital signs with monitoring equipment, insertable through the vagina and the cervix of a woman in labor into a fetal scalp, comprising:

(a) an elongated member having a forward end portion and adapted to be inserted through the vagina and cervix of the woman in labor;

(b) a sleeve having a forward end portion, the sleeve being disposed about at least the forward end portion of the elongated member and being configured to allow slideable movement of the forward end portion of the elongated member within the sleeve;

(c) a piston member slideably disposed within the sleeve for releasably engaging the forward end portion of the elongated member;

(d) a body member including;

(i) a rearward portion releasably disposed within the sleeve adjacent the piston member;

(ii) a forward portion having a shoulder releasably engaging the forward end portion of the sleeve and configured to preclude the forward portion of the body member from moving within the sleeve along the longitudinal axis of the sleeve toward the piston member by more than a predetermined distance; and

(iii) at least two channels passing from the rearward portion of the body member and advancing outwardly along the longitudinal axis of the sleeve through the forward portion of the body member, said channels defining continuous open passages through the body member;

(e) at least two resilient active electrode members mounted on the piston member and having free ends slideably disposed within the channels, said active electrode members being of sufficient length for the free ends to pass through the channels and advance into the fetal scalp as the elongated member engages the piston member and causes the active electrode members to advance along the channels and out of the forward portion of the body member;

(f) means for electrically connecting the active electrode members to the monitoring equipment;

(g) a reference electrode secured to the piston member; and

(h) means for electrically connecting the reference electrode to the monitoring equipment.