Energy delivery algorithm for medical devices

• US 8,167,875 B2
• Filed: 01/12/2009
• Issued: 05/01/2012
• Est. Priority Date: 01/12/2009
• Status: Active Grant

• Current Assignee: Covidien LP (Medtronic Plc)
• Original Assignee: Tyco Healthcare Group LP (Medtronic Plc)
• Inventors: Podhajsky, Ronald J., Wham, Robert H., Riegner, Kari, Johnson, Kristin D., Case, Jason
• Primary Examiner(s): BOUCHELLE, LAURA A
• Application Number:
  US12/351,935
• Publication Number:
  US 20100179529A1
• Time in Patent Office: 1,205 Days
• Field of Search: 606/32, 606/34, 606 37- 42, 606 48- 52, 607/96, 607/98, 607/99, 607/101, 607/122
• US Class Current: 606/34
• CPC Class Codes: A61B 18/1206 Generators therefor
• CPC Class Codes: A61B 2018/00678 upper
• CPC Class Codes: A61B 2018/00702 Power or energy
• CPC Class Codes: A61B 2018/00875 Resistance or impedance

Abstract

A method for controlling energy applied to tissue as a function of at least one detected tissue property includes the initial step of applying energy to tissue. The method also includes the steps of initially adjusting the energy applied to tissue and determining a direction of change of the at least one detected tissue property. The method also includes the steps of subsequently adjusting the energy applied to tissue in the same direction as the initially adjusting step if the at least one detected tissue property is changing in a first direction and in the opposite direction to the initially adjusting step if the at least one detected tissue property is changing in a second direction and further adjusting the energy applied to the tissue in the same direction as the initially adjusting step if the at least one detected tissue property is changing in the second direction and in the opposite direction to the initially adjusting step if the at least one detected tissue property is changing in the first direction.

Claims

1. A method for controlling application of energy to tissue as a function of at least one detected tissue property, comprising the steps of:

applying energy to tissue;

detecting at least one tissue property, the detecting step including;

sensing an electrical conductance of the tissue; and

controlling the application of energy to the tissue in accordance with a detected slope of a control curve, the control curve representative of the sensed electrical conductance of the tissue as a function of tissue temperature, the controlling step including;

initially adjusting the energy applied to tissue and determining a direction of change of the detected slope of the control curve;

subsequently adjusting the energy applied to tissue in the same direction as the initially adjusting step if the detected slope of the control curve is changing in a first direction and in the opposite direction to the initially adjusting step if the detected slope of the control curve is changing in a second direction; and

further adjusting the energy applied to the tissue in the same direction as the initially adjusting step if the detected slope of the control curve is changing in the second direction and in the opposite direction to the initially adjusting step if the detected slope of the control curve is changing in the first direction.

2. A method according to claim 1, wherein the further adjusting step is repeated if the detected slope of the control curve is changing in the first direction.

3. A method according to claim 1, further comprising the step of repeating the subsequently adjusting step if the detected slope of the control curve is changing in the first direction.

4. A method according to claim 1, wherein the detecting step further includes the step of detecting a tissue temperature.

5. A method for controlling energy applied to tissue, comprising the steps of:

applying energy to tissue;

setting a variable corresponding to at least one of a detected tissue property and a detected energy property to a first of two states;

initially adjusting the energy applied to the tissue;

sensing a tissue conductance;

deriving a control curve as a function of the sensed tissue conductance and tissue temperature and determining a direction of change of the control curve;

subsequently adjusting the energy applied to the tissue based on the first state if the control curve is changing in a first direction and subsequently setting the variable to the first state;

adjusting the energy applied to the tissue opposite to that of the subsequently adjusting step based on the first state if the control curve is changing in a second direction and subsequently setting the variable to the second state;

further adjusting the energy applied to the tissue opposite to that of the subsequently adjusting step based on the second state if the control curve is changing in the first direction and subsequently setting the variable to one of the first and second states; and

adjusting the energy applied to the tissue in the same direction as the subsequently adjusting step based on the second state if the control curve is changing in the second direction and subsequently setting the variable to the first state.

6. A method according to claim 5, wherein the subsequently adjusting step further includes the step of adjusting the energy applied to tissue in the same direction as the initially adjusting step.

7. A method according to claim 5, wherein the initially adjusting step further includes the step of increasing the energy applied to tissue.

8. A method according to claim 5, wherein the setting step further includes the step of detecting a tissue temperature.