System for predicting defibrillation threshold based on patient data

• US 6,628,986 B1
• Filed: 10/16/2001
• Issued: 09/30/2003
• Est. Priority Date: 02/08/2000
• Status: Expired due to Fees

• Current Assignee: Pacesetter Incorporated (Abbott Laboratories Incorporated)
• Original Assignee: Pacesetter Incorporated (Abbott Laboratories Incorporated)
• Inventors: Adinolfi, David W., Kroll, Mark W., Mouchawar, Gabriel A.
• Primary Examiner(s): Schaetzle, Kennedy
• Assistant Examiner(s): DROESCH, KRISTEN L
• Application Number:
  US09/981,573
• Time in Patent Office: 714 Days
• Field of Search: 607/1-8, 607/72, 607/74, 607/30-32, 607/59-60, 600/300-301, 600/508, 128/906, 128/920, 128/923
• US Class Current: 607/8
• CPC Class Codes: A61N 1/37211 Means for communicating with stimulators
• CPC Class Codes: Y10S 128/923 by comparison of patient data to other data

Abstract

The implant guiding programmer is configured to automatically determine a defibrillation threshold (DFT) for a particular patient and to further determine an optimal implantation configuration for an implantable cardioverter fibrillator (ICD). In one implementation, to determine the DFT for the patient, the programmer correlates patient specific data with a predictive data base containing DFT information for an entire population of patients. The programmer additionally determines an optimal implantation configuration for the patient, wherein the optimal configuration is one which is capable of exceeding the DFT for the patient using minimal electrical pulse energy.

Claims

1. A system for determining a defibrillation threshold for a particular patient, the system comprising:

means for storing predictive information within a database correlating patient clinical data with defibrillation thresholds for a population of patients;

means for acquiring patient data for a particular patient; and

means for automatically determining the defibrillation threshold for the particular patient based upon the data for the particular patient in combination with the information correlating patient clinical data with defibrillation thresholds; and

means for updating the database to include patient data and the defibrillation threshold for the particular patient.

2. The system of claim 1, further comprising:

means for testing the defibrillation threshold for the particular patient to verify that it is accurate and, if it is not, determining a new defibrillation threshold by repeatedly fibrillating then defibrillating the particular patient'"'"'s heart using defibrillation pulses of differing energy.

3. A system for determining a defibrillation threshold for a particular patient and for also determining an implantation configuration for an implantable cardioverter defibrillator (ICD) for implant within the patient, the system comprising:

means for storing predictive information within a database correlating patient clinical data with defibrillation thresholds for a population of patients;

means for acquiring patient data for a particular patient;

means for automatically determining the defibrillation threshold for the particular patient based upon the data for the particular patient in combination with the information correlating patient clinical data with defibrillation thresholds;

means for storing predictive information correlating ICD implantation configurations with defibrillation thresholds for the population of patients; and

means for automatically determining an implantation configuration capable of providing defibrillation pulses achieving the defibrillation threshold for the particular patient based on the determined defibrillation threshold for the particular patient in combination with the information correlating ICD implantation configurations with defibrillation thresholds for the population of patients.

4. The system of claim 3, wherein the means for automatically determining the implantation configuration comprises:

means for imaging the thorax of the particular patient;

means for inputting parameters defining a plurality of ICD implantation configurations; and

means for automatically determining, from the image of the particular patient in combination with the implantation configuration parameters, the ICD implantation configurations sufficient to provide defibrillation pulses exceeding a defibrillation threshold of the particular patient by a predetermined safety margin.

5. The system of claim 3, wherein the means for automatically determining the implantation configuration comprises:

means for imaging the thorax of the particular patient;

means for inputting parameters defining the ICD and lead implantation configuration; and

means for automatically determining, from the image of the particular patient in combination with the implantation configuration parameters, whether the ICD implantation configuration is sufficient to provide defibrillation pulses exceeding a defibrillation threshold of the patient by a predetermined safety margin.

6. A system for determining a defibrillation threshold for a particular patient and for also determining an implantation configuration for an implantable cardioverter defibrillator (ICD) for implant within the patient, the system comprising:

a defibrillation threshold information storage unit for storing predictive information correlating patient clinical data with defibrillation thresholds for a population of patients;

an acquisition system for acquiring patient data for a particular patient;

a defibrillation threshold determination unit for determining the defibrillation threshold for the particular patient based upon the data for the patient in combination with the information correlating patient clinical data with defibrillation thresholds;

an implantation configuration storage unit for storing predictive information correlating ICD implantation configurations with defibrillation thresholds for a population of patients; and

an implantation configuration deternmination unit for automatically determining an implantation configuration capable of providing defibrillation pulses exceeding the defibillation threshold based on the predicted defibrillation threshold for the particular patient in combination with the information correlating ICD implantation configurations with defibrillation thresholds.

7. A system for determining a defibrillation threshold for a particular patient, the system comprising:

a defibrillation threshold information storage unit for storing predictive information correlating patient clinical data with defibrillation thresholds for a population of patients;

an acquisition system for acquiring patient data for a particular patient;

a thorax imaging unit for imaging the thorax of the patient;

a thorax modeling unit for modeling the thorax of the patient based upon images of the patient to generate a patient model specifying a default electrode size, shape and position;

an electrical pulse modeling unit for modeling distribution characteristics of electrical pulses in the patient based upon the patient model; and

a defibrillation threshold determination unit for determining the defibrillation threshold based upon the data for the patient in combination with the information correlating patient clinical data with defibrillation thresholds and also based on the distribution characteristics of electrical pulses in the patient and defibrillation criteria.

8. A method, performed by a programming device operative to program the operation of an implantable cardioverter defibrillator (ICD), for determining a defibrillation threshold for a particular patient, the method comprising:

accessing predictive information correlating patient clinical data with defibrillation thresholds for a population of patients;

acquiring patient data for the particular patient;

automatically determining the defibrillation threshold for the particular patient based upon the patient data for the particular patient in combination with the information correlating patient clinical data with defibrillation thresholds;

accessing predictive information correlating ICD implantation configurations with defibrillation thresholds for the population of patients; and

automatically determining an implantation configuration capable of providing defibrillation pulses exceeding the defibrillation threshold for the particular patient based on the determined defibrillation threshold for the particular patient and the information correlating ICD implantation configurations with defibrillation thresholds for the population of patients.

9. A method for determining a defibrillation threshold for a particular patient and for also determining an implantation configuration for an implantable cardioverter defibrillator (ICD) for implant within the patient, the method comprising:

accessing predictive information correlating patient clinical data with defibrillation thresholds for a population of patients;

acquiring patient data for the particular patient;

automatically determining the defibrillation threshold for the particular patient based upon the patient data for the particular patient in combination with the information correlating patient clinical data with defibrillation thresholds;

acquiring thorax imaging data of the particular patient'"'"'s thorax;

acquiring parameters defining a plurality of ICD implantation configurations; and

automatically determining, from the imaging data of the particular patient in combination with the implantation configuration parameters, ICD implantation configurations sufficient to provide defibrillation pulses exceeding the defibrilation threshold of the particular patient by a predetermined safety margin.

10. The method of claim 9, wherein automatically determining the ICD implantation configurations sufficient to provide defibrillation pulses exceeding the defibrillation threshold determined based on patient data comprises predicting the defibrillation threshold for the particular patient based on distribution characteristics of electrical pulses in the particular patient.

11. The method of claim 10, wherein predicting the defibrillation threshold based on distribution characteristics of electrical pulses in the particular patient comprises:

modeling the particular patient'"'"'s thorax based upon the thorax imaging data to generate a patient model;

modeling distribution characteristics of electrical pulses in the particular patient based upon the patient model;

specifying defibrillation electrode size, shape and position; and

predicting the defibrillation threshold based on the distribution characteristics of electrical pulses in the particular patient and a defibrillation criteria.

12. The method of claim 11, wherein modeling the thorax of the patient is performed to extract a shape and boundary of a plurality of structures in the thorax.

13. The method of claim 11, wherein modeling the thorax of the patient is performed to extract a shape and boundary of a plurality of structures in the thorax including at least individual chambers of the patient'"'"'s heart and major arteries and veins in the vicinity of the patient'"'"'s heart.

14. The method of claim 11, wherein modeling the thorax of the patient is performed to extract a shape and boundary of a plurality of structures in the thorax including one or more of the patient'"'"'s lungs, rib cage, sternum, fat around the patient'"'"'s heart, thoracic muscles, and cutaneous fat.

15. The method of claim 11, wherein acquiring ICD implantation configuration parameters comprises:

displaying a graphic representation of the model of the patient;

displaying a graphic representation of a default combination of ICD implantation configuration parameters including a default position of electrode leads; and

providing user modifications to the default combination of ICD implantation configuration parameters.

16. The method of claim 11, wherein modeling distribution characteristics of electrical pulses in the patient comprises:

assigning an electrical conductivity to each structure boundary; and

solving differential equations representative of electrical conduction characteristics to estimate one or more of electrical field strength, current density, and electrical potential within at least a portion of the patient.

17. The method of claim 16, wherein determining the defibrillation threshold is performed based on the estimates of one or more of the electrical field strength, the current density, and the electrical potential.

18. The method of claim 17, wherein the defibrillation threshold is estimated based on criteria specifying that a certain percentage of heart mass must experience an electrical field of at least a certain number of volts per centimeter.

19. The method of claim 17, wherein the defibrillation threshold is estimated based on criteria specifying that a 95% of heart mass must experience an electrical field of at least a 3-6 volts per centimeter.

20. The method of claim 9, further comprising:

acquiring information representative of medicines expected to be taken by the patient; and

wherein automatically determining whether the ICD configuration is sufficient to provide defibrillation pulses achieving a defibrillation threshold of the particular patient additionally takes into account any medicines expected to be taken by the particular patient.