Drug delivery system for implantable medical device

• US 20020077620A1
• Filed: 12/18/2000
• Published: 06/20/2002
• Est. Priority Date: 12/18/2000
• Status: Active Grant

• Current Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Original Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Inventors: Sweeney, Robert J., Scheiner, Avram, Heil, Ronald W. Jr.
• Granted Patent: US 6,689,117 B2
• Time in Patent Office: Days
• US Class Current: 604/502
• CPC Class Codes: A61M 2205/3507 with implanted devices, e.g. external control
• CPC Class Codes: A61M 2205/3561 local, e.g. within room or hospital
• CPC Class Codes: A61M 5/1723 using feedback of body parameters, e.g. blood-sugar, pressure measurement of body parameters A61B5/00
• CPC Class Codes: A61N 1/30 Apparatus for iontophoresis, i.e. transfer of media in ionic state by an electromotoric force into the body, or cataphoresis

Abstract

A drug delivery system and method in which an implantable medical device communicates with and controls an external drug delivery device with low energy potential signals. The implantable device generates potential signals modulated with digitally encoded command information by operating a current source to cause corresponding electrical potentials that can be sensed at the skin surface by the external drug delivery device. The drug delivery device then demodulates the sensed potentials and decodes the digital data to extract command information therefrom to deliver a drug accordingly.

Claims

1. A drug delivery system, comprising:

an implantable medical device having a current source for transmitting potential signals modulated with digitally encoded command information to an external drug delivery device; and

,

an external drug delivery device for affixation to a patient having incorporated therein a data communications interface for demodulating potential signals sensed at a skin surface location, circuitry for deriving command information from the demodulated potential signals, and circuitry for controlling delivery of a drug in accordance with the command information.

2. The system of claim 1 wherein the potential signals are transmitted in the form of a carrier waveform digitally modulated with the digitally encoded command information by varying the amplitude of the carrier waveform.

3. The system of claim 1 wherein the potential signals are transmitted in the form of a carrier waveform digitally modulated with the digitally encoded command information by varying the frequency of the carrier waveform.

4. The system of claim 1 wherein the potential signals are transmitted in the form of a digital pulse train modulated with the digitally encoded information by varying the frequency of the pulses and amplitude modulating a carrier waveform with the modulated pulse train.

5. The system of claim 1 wherein the potential signals are transmitted in the form of a digital pulse train modulated with the digitally encoded information by varying the width of the pulses and amplitude modulating a carrier waveform with the modulated pulse train.

6. The system of claim 1 wherein the potential signals are transmitted in the form of a digital pulse train modulated with the digitally encoded information by varying the position of the pulses and amplitude modulating a carrier waveform with the modulated pulse train.

7. The system of claim 1 wherein the implantable medical device is a cardiac device comprising a sensing channel for sensing electrical activity occurring in a patient'"'"'s heart and generating sensing signals in accordance therewith, circuitry for extracting information from the sensing signals, and circuitry for detecting a particular medical condition from the extracted information and generating a command signal to the external drug delivery device if the medical condition is present.

8. The system of claim 1 wherein the implantable medical device comprises circuitry for performing an impedance measurement related to a physiological variable by injecting current between two electrodes from a constant current source and further wherein the constant current source is used for transmitting potential signals modulated with digitally encoded command information to the external drug delivery device

9. The system of claim 1 wherein the drug delivery device is an electrically modulated transdermal injector comprising:

a first electrode connected to a first drug reservoir for containing a drug and contacting a patient'"'"'s skin;

a second electrode for contacting a patient'"'"'s skin; and

,

a controllable power source for connecting to the electrodes and imposing a voltage therebetween.

10. The system of claim 7 wherein the cardiac device sends a command signal upon detection of a cardiac arrhythmia.

20. The method of claim 1 further comprising delivering the drug from the external delivery device by transdermal injection.

11. A method for drug delivery comprising:

generating potential signals modulated with command information from an implantable medical device by operating a current source to cause corresponding electrical potentials that can be sensed at a skin surface location;

receiving and demodulating sensed potential signals at a skin surface location;

deriving command information from the demodulated potential signals; and

,

controlling delivery of a drug from an external drug delivery device in accordance with the command information.

12. The method of claim 11 wherein the drug delivery device delivers the drug by electrically modulated transdermal injection.

13. The method of claim 11 further comprising transmitting the potential signals in the form of a carrier waveform digitally modulated with the digitally encoded command information by varying the amplitude of the carrier waveform.

14. The method of claim 11 further comprising transmitting the potential signals in the form of a carrier waveform digitally modulated with the digitally encoded command information by varying the frequency of the carrier waveform.

15. The method of claim 11 further comprising transmitting the potential signals in the form of a digital pulse train modulated with the digitally encoded information by varying the frequency of the pulses and amplitude modulating a carrier waveform with the modulated pulse train.

16. The method of claim 11 further comprising transmitting the potential signals in the form of a digital pulse train modulated with the digitally encoded information by varying the width of the pulses and amplitude modulating a carrier waveform with the modulated pulse train.

17. The method of claim 11 further comprising transmitting the potential signals in the form of a digital pulse train modulated with the digitally encoded information by varying the position of the pulses and amplitude modulating a carrier waveform with the modulated pulse train.

18. The method of claim 11 further comprising:

sensing electrical activity occurring in a patient'"'"'s heart and generating sensing signals in accordance therewith;

extracting information from the sensing signals and detecting a particular medical condition from the extracted information; and

,

generating potential signals modulated with command information from the implantable medical device by operating the current source to generate a command signal to the external drug delivery device if the medical condition is present.

19. The method of claim 11 further comprising performing an impedance measurement related to a physiological variable by injecting current between two electrodes from a constant current source and using the constant current source for transmitting potential signals modulated with digitally encoded command information to the external drug delivery device