Implantable responsive system for sensing and treating acute myocardial infarction

• US 6,112,116 A
• Filed: 02/22/1999
• Issued: 08/29/2000
• Est. Priority Date: 02/22/1999
• Status: Expired due to Term

• Current Assignee: Angel Medical Systems, Inc.
• Original Assignee: Cathco, Inc.
• Inventors: Fischell, David R., Fischell, Robert E., Fischell, Tim A.
• Primary Examiner(s): Getzow, Scott M.
• Application Number:
  US09/253,872
• Time in Patent Office: 554 Days
• Field of Search: 607/120, 607/3, 600/516, 600/517, 604/890.1, 604/891.1, 604/891.2
• US Class Current: 600/517
• CPC Class Codes: A61B 5/0031 Implanted circuitry
• CPC Class Codes: A61N 1/3702 Physiological parameters A61N1/365 takes precedence; evoked response A61N1/371
• CPC Class Codes: A61N 1/3956 Implantable devices for applying electric shocks to the heart, e.g. for cardioversion

Abstract

Disclosed is a completely implantable system that can detect the occurrence of a myocardial infarction, i.e., a heart attack, and automatically inject a thrombolytic and/or anti-thrombogenic agent into the bloodstream to promptly dissolve the thrombus that caused the myocardial infarction and prevent the formation of additional thrombi. It is well known that a myocardial infarction can be detected from a patient'"'"'s electrocardiogram by noting an ST segment voltage deviation as compared to the voltage of the patient'"'"'s TP or PQ segments. Upon detection of a myocardial infarction, an ST segment deviation electronic detection circuit within the implanted device can produce an output signal that can cause a thrombolytic and/or anti-thrombogenic agent contained within an implanted, pressurized reservoir to immediately and automatically release medications into the patient'"'"'s bloodstream. A patient warning system is provided by an audio alarm or an electrical tickle within the human body indicating that a myocardial infarction has been detected. The implanted system can also send a radio message to an externally located receiver that automatically dials an emergency rescue team to take the patient to a hospital for continuing treatment of his myocardial infarction. An implantable defibrillator or pacemaker that includes the capability for informing the patient that myocardial infarction has been detected is also disclosed. Still further, this invention could also be used without a defibrillator or pacemaker but as an implanted system (without medications) whose only function would be the detection and warning of myocardial infarction at the earliest possible time.

Claims

1. An automatic detection and responsive medication release system implanted within a human subject for the treatment of myocardial infarction, the system comprising:

a sensor having an output electrical signal, the sensor being adapted to detect a signal from within the human body that is indicative of the onset of myocardial infarction; and

a medication release device that contains electrical circuitry means that is electrically connected to the sensor, the electrical circuit means being adapted to provide a triggering signal when the output electrical signal from the sensor indicates the occurrence of a myocardial infarction, the medication release device also having at least one medication reservoir for storing a medication and also having a medication releasing means for causing that medication to be released into the bloodstream of the human subject when the triggering signal from the electrical circuitry means indicates that a myocardial infarction is occurring.

2. The medication release system of claim 1 wherein the sensor consists of at least two electrodes that are adapted to sense the electrogram from within the human subject.

3. The medication release system of claim 2 wherein at least one electrode is placed inside the right ventricle at or near the apex of the heart.

4. The medication release system of claim 2 wherein at least one electrode is placed in the right atrium.

5. The medication release system of claim 2 wherein at least one electrode is placed in the superior vena cava.

6. The medication release system of claim 2 wherein the medication release device is contained within a metal case and the system includes at least one active electrode and the metal case acts as a second electrode which is an indifferent electrode.

7. The medication release system of claim 1 wherein the sensor includes at least one subcutaneous electrode that is placed outside of the circulatory system of the human subject, the subcutaneous electrode being placed subcutaneously under the skin of the human subject.

8. The medication release system of claim 1 wherein the medication reservoir is formed from a metal bellows.

9. The medication release system of claim 1 wherein the medication in at least one medication reservoir is a thrombolytic agent.

10. The medication release system of claim 9 wherein the thrombolytic agent is streptokinase.

11. The medication release system of claim 9 wherein the thrombolytic agent is urokinase.

12. The medication release system of claim 9 wherein the thrombolytic agent is tissue plasminogen activator.

13. The medication release system of claim 9 wherein the thrombolytic agent is a mixture of two or more medications.

14. The medication release system of claim 1 wherein the medication is an anti-thrombogenic medication.

15. The medication release system of claim 14 wherein the medication is ReoPro.

16. The medication release system of claim 14 wherein the medication is heparin.

17. The medication release system of claim 1 wherein the medication within the medication release device is in the form of a powder.

18. The medication release system of claim 17 wherein the powder is a thrombolytic agent.

19. The medication release system of claim 18 wherein the thrombolytic agent is streptokinase powder.

20. The medication release system of claim 1 wherein there is exactly one medication reservoir.

21. The medication release system of claim 1 wherein there are exactly two medication reservoirs.

22. The medication release system of claim 1 wherein there are exactly three medication reservoirs.

23. The medication release system of claim 1 wherein the medication releasing means is a valve that is opened after the sensor senses the occurrence of a myocardial infarction.

24. The medication release system of claim 1 wherein the medication releasing means is a valve operated by means of changing the polarity of a chargeable magnet.

25. The medication release system of claim 1 wherein the medication releasing means is a conventional drug pump.

26. The medication release system of claim 1 wherein the electrical circuitry means includes the capability for recording the electrogram and playing back the electrogram at a later time.

27. The medication release system of claim 1 wherein the electrical circuitry means includes a command receiver for receiving programming commands by radio transmission from a physician'"'"'s programmer that is located externally from the human subject, the programming commands being capable of changing the operating modes of the medication release system.

28. The medication release system of claim 1 wherein the electrical circuitry means includes a radio transmitter for transmitting information from the implanted medication release system to the physician'"'"'s programmer.

29. The medication release system of claim 1 wherein the electrical circuitry means includes a radio transmitter for transmitting information to a receiver that is located within 200 meters of the human subject, the receiver being adapted to cause an alarm means to inform the human subject that his implanted medication release system has sensed the occurrence of a myocardial infarction.

30. The medication release system of claim 1 wherein the electrical circuitry means includes a radio transmitter for transmitting information to a receiver that is located within 200 meters of the human subject, the receiver being adapted to send a message to a medical rescue facility that the medication release system within the human subject has sensed the occurrence of a myocardial infarction.

31. The medication release system of claim 30 wherein the message received by the medical rescue facility includes the electrogram of the human subject.

32. The medication release system of claim 30 wherein the message received by the medical rescue service includes a medical history of the human subject.

33. The medication release system of claim 1 further comprising defibrillation means operated from automatic defibrillation circuitry implanted within the human subject.

34. The medication release system of claim 1 further comprising implantable heart pacemaker circuitry for pacing the heart of the human subject by means of electrical pulses.

35. The medication release system of claim 1 wherein the electrical circuitry means includes the capability for alarming the human subject that a myocardial infarction is occurring by causing an audio sound to be produced that can be heard by the human subject.

36. The medication release system of claim 1 wherein the electrical circuitry means includes the capability of alarming the human subject that a myocardial infarction is occurring by means of a subcutaneous electrical tickle that can be detected by the human subject.

37. The medication release system of claim 1 further comprising a patient operated initiator located external to the human subject, the patient operated initiator being adapted to send a radio signal to a command receiver within the medication release device, the radio signal being adapted to cause the release of medication from the implanted medication release device.

38. A system for indicating to a human subject that he is having a myocardial infarction, the system comprising:

an implantable sensor for detecting the occurrence of a myocardial infarction; and

an alarm means for informing the human subject that a myocardial infarction has been detected, the alarm means comprising an implanted radio transmitter that is adapted to send a radio signal that includes an alarm signal denoting the occurrence of a myocardial infarction to external receiving equipment, the external receiving equipment including an audio alarm to inform the patient that a myocardial infarction has been detected.

39. The system of claim 38 wherein the implantable sensor is two or more electrodes.

40. The system of claim 39 wherein one of the sensors is an active electrode and the implantable system includes a metal case which acts as an indifferent electrode.

41. The system of claim 40 wherein the sensor has an output electrical signal and there is electronic circuitry contained within the metal case, the electronic circuitry being adapted to detect a myocardial infarction from the sensor'"'"'s output electrical signal.

42. The system of claim 41 wherein the electronic circuitry within the metal case includes a detector for detecting an electrogram ST segment deviation as an indication of myocardial infarction.

43. The system of claim 41 wherein the electronic circuitry within the metal case includes the capability for recording an electrogram signal from the sensor, the recording being capable of being retained in memory for playback at a later time.

44. The system of claim 38 further including an implantable alarm means formed as part of the implantable system.

45. The system of claim 44 wherein the implantable alarm means is an implanted audio device that can be heard by the human subject.

46. The system of claim 38 wherein the external alarm means provides medical advice to the human subject.

47. The system of claim 38 wherein the external alarm means is adapted to call via a telephone link to an emergency medical services organization.

48. The system of claim 38 wherein the implantable system is adapted to store electrogram data and to send these data to the external receiving equipment by means of a radio signal from the radio transmitter of the implantable system.

49. The system of claim 48 wherein both real time and stored electrogram data that is sent to the external receiving equipment from the implantable system is sent via a telephone link to an emergency medical services organization.

50. The system of claim 38 further including a patient operated initiator adapted to trigger the start of electrogram storage in the implanted portion of the system.