Portable device for sensing cardiac function and automatically delivering electrical therapy

• US 5,078,134 A
• Filed: 05/29/1990
• Issued: 01/07/1992
• Est. Priority Date: 04/25/1988
• Status: Expired due to Term

• Current Assignee: Zoll Medical Corporation (Asahi Kasei Corporation)
• Original Assignee: Zoll Lifecor Corporation (Asahi Kasei Corporation)
• Inventors: Russial, Joseph F., Bowling, Larry D., Heilman, Marlin S., Brandt, Arlan J.
• Primary Examiner(s): Jaworski, Francis
• Assistant Examiner(s): MANUEL, GEORGE C
• Application Number:
  US07/528,883
• Time in Patent Office: 588 Days
• Field of Search: 128/421, 128/419 D, 128/419 PG, 128/696, 128/702, 128/734, 128/783
• US Class Current: 607/4
• CPC Class Codes: A61B 5/0006 ECG or EEG signals
• CPC Class Codes: A61B 5/6831 Straps, bands or harnesses
• CPC Class Codes: A61N 1/046 Specially adapted for shock therapy, e.g. defibrillation
• CPC Class Codes: A61N 1/0472 Structure-related aspects
• CPC Class Codes: A61N 1/048 Electrodes characterised by a specific connection between lead and electrode
• CPC Class Codes: A61N 1/0484 Garment electrodes worn by the patient
• CPC Class Codes: A61N 1/0492 Patch electrodes A61N1/0412, A61N1/0428 take precedence
• CPC Class Codes: A61N 1/3625 External stimulators
• CPC Class Codes: A61N 1/3904 External heart defibrillators [EHD]

Abstract

A patient-worn harness or vest protects at-risk patients from the possibly fatal results of heart arrhythmias. The harness or vest incorporates sensing electrodes for monitoring heart condition, a microprocessor and memory for processing signals received from the sending electrodes and comparing same with patient'"'"'s data, and skin-contacting pulsing electrodes for applying electrical pulses to the patient'"'"'s chest wall responsive to signals received from the microprocessor. The electrodes include automatic tightening and electrolyte gel release mechanisms for reducing impedance at the electrode-skin interface. A servicing subsystem is provided for the harness or vest and may be used to interface with the harness or vest and may be used to interface with the harness or vest and also to communicate with remote health care personnel through a suitable telephone link.

Claims

1. An electrode assembly for delivering electrical therapy to the body of a patient responsive to sensing of the occurrence of a treatable condition, comprising:

electrode means having a conductive surface adapted for placement adjacent the patient'"'"'s skin, for applying appropriate electrical pulses to the patient; and

impedance reducing means, contained within said electrode means for delivery to the patient'"'"'s skin by said electrode means responsive to sensing of said treatable condition by a sensing means, for reducing the impedance between the conductive surface of the electrode means and the patient'"'"'s skin.

2. The assembly as claimed in claim 1, wherein said impedance reducing means comprises means for releasing conductive fluid between the conductive surface of said electrode means and the patient'"'"'s skin.

3. The assembly as claimed in claim 2, wherein said means for releasing conductive fluid is contained in a housing and comprises:

a fluid container chamber;

a fluid containing sac located within said fluid container chamber; and

a puncture mechanism for puncturing said fluid containing sac.

4. The assembly as claimed in claim 2, further comprising channel means in the conductive surface of said electrode means for receiving the conductive fluid and spreading the same over the conductive surface.

5. The assembly as claimed in claim 2 wherein the fluid is contained in at least one flexible fluid sac within the assembly, and wherein the means for releasing includes pressure means for squeezing the sac, and means for establishing a connection between the sac and said conductive surface responsive to operation of the pressure means for delivering fluid under pressure from the sac to said conductive surface.

6. The assembly as claimed in claim 5 wherein the means for establishing a connection comprises sealed conduit means extending between said sac and said surface, said conduit means being adapted to be forced open by pressure exerted thereon from the fluid in the sac responsive to operation of the pressure means.

7. The assembly as claimed in claim 5 wherein the conduit means is comprised of two laminated layers of sheet material which also comprise the sac.

8. The assembly as claimed in claim 7 which includes a third layer of sheet material laminated over one of said two layers and forming therewith a gas pressure chamber over the sac, the pressure means including means for supplying gas under pressure to said chamber for squeezing the sac.

9. The assembly as claimed in claim 5 future comprises a gas pressure chamber means over a least a part of an external surface of the sac, and the pressure means includes means for supplying gas under pressure to said chamber for squeezing the sac.

10. The assembly as claimed in claim 9 wherein the sac is comprised of two laminated layers of sheet material and wherein the pressure chamber is defined between one of said layers and a third layer of sheet material which is laminated thereto.

11. The assembly as defined in claim 10 wherein the means for establishing a connection comprises sealed conduit means comprised of the two laminated layers and adapted to be forced opened by pressure fluid from the sac responsive to operation of the pressure means.

12. The assembly as defined in claim 11 wherein the sac, the pressure chamber and the conduit means are replicated over an area of said laminated layers, and wherein channels are comprised of said one of said laminated layers and said third laminated layer for connecting the respective chambers to a common source of pressurized gas.

13. The assembly as claimed in claim 5 wherein the pressure means comprises a chamber means around at least a part of the sac for receiving gas under pressure for squeezing the sac, a source of pressurized gas and transfer means for the gas between said source and said chamber.

14. The assembly as claimed in claim 13 wherein the source of gas under pressure comprises a cartridge within the assembly containing an electrically activated gas-generating chemical.

15. An electrode assembly for automatically delivering electrical therapy to the heart of a patient upon the occurrence of a treatable heart arrhythmia, comprising:

electrode means adapted for contact with a patient'"'"'s skin, for sensing the existence of a treatable arrhythmia and applying appropriate electrical pulses to the heart; and

impedance reducing means, contained with said electrode means and delivered to a patient'"'"'s skin by said electrode means responsive to sensing of said arrhythmia by a sensing means, for reducing the impedance between the electrode means and the patient'"'"'s skin.

16. The assembly as claimed in claim 15, further comprising:

monitoring means for continuously monitoring a patient'"'"'s heart condition from the information sensed by said electrode means;

discrimination means for receiving signals from said monitoring means and determining the presence of a treatable heart arrhythmia from stored information;

a source of electrical energy; and

switching means actuated by said discrimination means in response to said determination of a treatable arrhythmia for connecting said source of electrical energy to said electrode means for applying appropriate electrical pulses to the heart.

17. The assembly as claimed in claim 16, further comprising channel means in the conductive surface of said electrode means for receiving the conductive fluid and spreading the same over the conductive surface.

18. The assembly as claimed in claim 15, wherein said conductive fluid is contained in a housing comprising:

a fluid container chamber;

a fluid containing sac located within said fluid container chamber; and

a puncture mechanism to puncture said fluid containing sac for releasing conductive fluid.

19. An electrode assembly for applying electrical therapy to the heart of a patient, comprising:

monitoring means for continuously sensing a patient'"'"'s heart condition;

discrimination means for receiving signals from said monitoring means and determining the presence of a treatable heart arrythmia;

conductive electrode means adapted to contact the patient'"'"'s skin;

a source of electrical energy;

switching means actuated by said discrimination means in response to determination of a treatable arrhythmia for connecting said source of electrical energy to said conductive electrode means for applying appropriate electrical pulses to the heart; and

impedance reducing means for releasing a conductive fluid between said conductive electrode means and the patient'"'"'s skin to reduce impedance therebetween and responsive to said discrimination mean upon detection of said treatable heart arrhythmia by a sensing means.

20. The assembly as claimed in claim 19, further comprising signal generating means actuated by the discrimination means responsive to detection of a treatable arrythmia for warning the patient of the impending application of an electrical pulse, and a patient-activated switch means for delaying the connection of the source of electrical energy to the conductive electrode means.

21. The assembly as claimed in claim 20, wherein said switching means comprises two switches, both of which must be activated to delay connection of the source of electrical energy to the conductive electrode means.

22. The assembly as claimed in claim 19, further comprising channel means in a surface of said conductive electrode means for receiving fluid and spreading the fluid over the surface.

23. An electrode assembly for delivering electrical therapy to the body of a patient upon the occurrence of a treatable condition comprising:

a layer of conductive material for placement adjacent a patient'"'"'s skin for applying appropriate electrical pulses to the patient;

a first sheet of flexible material positioned over the conductive material;

a second sheet of flexible material laminated over the first sheet, and forming in combination therewith;

(a) a least one fluid-containing at least one sac (b) conduit means for connecting said at least one sac with said layer of conductive material; and

(c) a frangible seal between the at least one sac and the conduit means;

a third sheet of flexible material laminated over the second sheet and defining therewith at least one chamber at least partly surrounding said at least one sac for receipt therein of gas under pressure effective for squeezing said at least one sac so as to pressurize the fluid therein thereby fracturing said seal and allowing fluid from the at least one sac to pass through said conduit means to the layer of conductive material for reducing impedance between said layer and the patients skin; and

gas supply means for supplying gas under pressure to said at least one chamber upon detection of said treatable condition.

24. An assembly as claimed in claim 23 wherein the at least one sac, the conduit means, the frangible seal and the at least one chamber are replicated over a common area of said sheets and wherein the gas supply means is connected to each of the respective chambers.

25. An assembly as claimed in claim 24 which includes passage means connecting at least two of said chambers defined between the second and third sheets for the delivery of gas between the chambers.

26. An assembly as claimed in claim 23 wherein the second and third sheets have respective nesting blister formations, forming said at least one chamber therebetween, and the blister formation in the second sheet forming said fluid-containing sac in combination with an area of the first sheet.

27. An assembly as defined in claim 23 wherein the gas supply means comprises a compartment in the assembly containing an electrically activated gas generating chemical substance and passage means comprised of said second and third sheet for connecting said compartment to said chamber.

28. As assembly as defined in claim 23 which includes a compartment containing a tactile stimulator for applying mechanical stimulation to the patient'"'"'s skin responsive to a signal received by the stimulator.

29. An assembly as defined in claim 28 wherein the stimulator comprises an electric motor with a shaft-mounted off-balance weight.

30. A system for applying electrical therapy to a patient upon detection of a treatable condition comprising detection electrode means for contacting the patient'"'"'s skin to detect the treatable condition, treatment electrode means for contacting the patient'"'"'s skin for applying electrical impulses thereto responsive to the detection of the treatable condition, electronic means including a source of electrical energy for supplying electrical pulses to the treatment electrode means and discrimination means for receiving electrical impulses from the detection electrode means and actuating said source of electrical energy, readout means connected with the electronic means to provide a visible readout including the treatable condition, and tactile stimulation means connected to the source of electrical energy for applying mechanical stimulation to the patients skin prompting the patient to view the readout means.

31. A system as defined in claim 30 wherein the detection electrode means, the treatment electrode means, the tactile stimulation means and the electronic means are all carried by a body-encompassing structure and the readout means extends from said structure on a flexible lead.

32. A system as defined in claim 31 wherein the bodyencompassing structure includes a first chest-encompassing belt carrying the detection electrode means, the treatment electrode means and the tactile stimulation means, and wherein said lead extends from said chest-encompassing belt.

33. A system as defined in claim 32 wherein said body encompassing structure includes a waist-encompassing belt and said electronic means is suspended from said waist encompassing belt.

34. A system as defined in claim 32 wherein said body encompassing structure includes a second chest-encompassing belt below the first chest-encompassing belt, and the electronic means is carried by the second chest-encompassing belt.

35. A system for applying electrical therapy to a patient upon detection of a treatable condition comprising a first body-encompassing structure having a first belt for surrounding the patient'"'"'s chest and an over-the shoulder strap connected to the first belt, a second body-encompassing structure including a second belt for surrounding the patient'"'"'s torso below the first belt, detection electrode means carried by said first structure for contacting the patient'"'"'s skin and detecting a treatable condition, treatment electrode means carried by the first structure for contacting the patient'"'"'s skin and applying electrical therapy to the patient upon the detection of the treatable condition, electronic means supported by the second structure for receiving signals from the detection electrode means and delivering electrical pulses to the treatment electrode means, and electrical conductor means connecting the electronic means to the electrode means and to the treatment electrode means.

36. A system as claimed in claim 35 wherein the second belt has a suspended holster structure for supporting the electronic means against the patient'"'"'s upper leg region.

37. A system as claimed in claim 35 wherein the second belt is adapted to surround the patient'"'"'s chest below the first belt and has a support for the electronic means on the second belt.

38. A system as claimed in claim 37 wherein the second belt and the over-the-shoulder strap are interconnected by a yoke.

39. A system as claimed in claim 37 wherein the electronic means includes a flexible housing means adaptable to the curvature of the patient'"'"'s chest.

40. A system as claimed in claim 39 wherein the housing means includes a plurality of separate housing elements each containing parts of the electronic means with mechanical and electrical connections between said housing elements and said parts respectively.

41. A system as claimed in claim 35 which includes a remote read-out device connected by an elongate flexible lead to said electronic means.

42. A system as claimed in claim 35 wherein the treatment electrode means comprises a first treatment electrode positioned on the first body-encompassing structure for location over the patient'"'"'s heart, and a second treatment electrode positioned on the first body-encompassing structure for location against the patient'"'"'s back.

43. A system as defined in claim 42 wherein the second treatment electrode has a larger skin-contacting area than the first treatment electrode.

44. A system as defined in claim 42 wherein each treatment electrode comprises impedance reducing means for reducing impedance between the electrode and the patient'"'"'s skin upon detection of the treatable condition.

45. A system as claimed in claim 44 wherein the impedance reducing means comprises means for extruding an impedance-reducing fluid from the electrode to flow between a treatment surface of the electrode and the patient'"'"'s skin.

46. A system as claimed in claim 45 wherein the impedance reducing means comprises at least one squeezable fluid sac within the electrode a sealed conduit between the sac and the treatment surface of the electrode, a frangible seal between the sac and the conduit, and pressure means for squeezing the sac upon detection of the treatable condition applying pressure to the fluid contained therein effective for breaking said seal and allowing the fluid to flow to said treatment surface.

47. A system as claimed in claim 46 wherein the pressure means includes a pressure chamber around a part of the sac for receiving gas under pressure effective for squeezing the sac, a source of gas under pressure contained within the electrode and means for delivering gas under pressure from the source to the chamber upon detection of the treatable condition.

48. A system as claimed in claim 47 wherein the source of gas under pressure includes an electrically activated gas producing chemical substance contained in a compartment within the electrode said compartment being connected to said pressure chamber by at least one gas passage.

49. A system as claimed in claim 35 wherein the detection electrode means comprises plural detection electrodes positioned on said first body-encompassing structure for multi-axis sensing of a treatable condition.

50. A system as claimed in claim 35 wherein the first belt comprises an endless first layer which includes conductor means for the electrode means and a second layer with opposite end portions and attachment means for releasably connecting the end portions in a plurality of selected positions adjusting the overall length of the second layer.

51. A system as claimed in claim 50 wherein the end portions of the second layer are substantially non-extensible and the second layer includes an elastically extensible portion between said end portions.

52. A system as claimed in claim 35 wherein the first belt includes tightness increasing means for increasing the tightness of the belt and thereby reducing impedance between the treatment electrode means and the patient'"'"'s skin upon detection of the treatable condition.