Techniques for use with nerve tissue

• US 10,383,685 B2
• Filed: 05/05/2016
• Issued: 08/20/2019
• Est. Priority Date: 05/07/2015
• Status: Active Grant

• Current Assignee: Symap Medical suzhou Ltd
• Original Assignee: Pythagoras Medical Ltd.
• Inventors: Gross, Yossi, Zadok, Yehuda
• Primary Examiner(s): Della, Jaymi E
• Assistant Examiner(s): Collins, Sean W
• Application Number:
  US15/147,081
• Publication Number:
  US 20160324572A1
• Time in Patent Office: 1,202 Days
• CPC Class Codes: A61B 18/1206 Generators therefor
• CPC Class Codes: A61B 18/1492 having a flexible, catheter-like structure, e.g. for heart ablation A61B18/1477 takes precedence
• CPC Class Codes: A61B 2018/00214 Expandable means emitting energy, e.g. by elements carried thereon
• CPC Class Codes: A61B 2018/00404 Blood vessels other than those in or around the heart
• CPC Class Codes: A61B 2018/00434 Neural system
• CPC Class Codes: A61B 2018/00511 Kidney
• CPC Class Codes: A61B 2018/00577 Ablation
• CPC Class Codes: A61B 2018/00642 with feedback, i.e. closed loop control
• CPC Class Codes: A61B 2018/00702 Power or energy
• CPC Class Codes: A61B 2018/00773 Sensed parameters
• CPC Class Codes: A61B 2090/064 for measuring force, pressure or mechanical tension
• CPC Class Codes: A61B 2505/05 Surgical care
• CPC Class Codes: A61B 2562/0247 Pressure sensors
• CPC Class Codes: A61B 5/02007 Evaluating blood vessel condition, e.g. elasticity, compliance
• CPC Class Codes: A61B 5/0215 by means inserted into the body catheters A61M25/00
• CPC Class Codes: A61B 5/024 Detecting, measuring or recording pulse rate or heart rate A61B5/0205, A61B5/021 take precedence
• CPC Class Codes: A61B 5/4848 Monitoring or testing the effects of treatment, e.g. of medication
• CPC Class Codes: A61B 5/6852 Catheters

Abstract

A method is provided, comprising: (1) applying an excitatory current to renal nerve fibers of a subject; (2) determining a change in a parameter of the subject in response to the excitatory current, the parameter being a fastest rate of increase in arterial pressure during a systolic upstroke of an arterial pressure wave of the subject; (3) in response to the change, deciding whether to ablate the renal nerve fibers; and (4) in response to the deciding, applying ablation energy to the renal nerve fibers. Other embodiments are also described.

Claims

1. A method, comprising:

applying an excitatory current to renal nerve fibers of a subject;

determining a change in a parameter of the subject in response to the excitatory current, the parameter being a fastest rate of increase in arterial pressure during a systolic upstroke of an arterial pressure wave of the subject;

in response to the change, deciding whether to ablate or to not ablate the renal nerve fibers; and

in response to a decision to ablate, applying ablation energy to the renal nerve fibers.

2. The method according to claim 1, wherein:

the renal nerve fibers comprise renal nerve fibers proximate to a first location of a renal artery wall and renal nerve fibers proximate to a second location of the renal artery wall;

applying the excitatory current comprises applying the excitatory current to the renal nerve fibers proximate to the first location of the renal artery wall, deciding whether to ablate or to not ablate the renal nerve fibers comprises deciding whether to ablate or to not ablate the renal nerve fibers proximate to the first location of the renal artery wall, and

the method further comprises;

applying the excitatory current to the renal nerve fibers proximate to the second location of the renal artery wall;

determining a second change in the parameter in response to the excitatory current applied to the renal nerve fibers proximate to the second location of the renal artery wall; and

in response to the second change, making a second decision to ablate or to not ablate the renal nerve fibers proximate to the second location of the renal artery wall.

3. A method, comprising:

measuring a first value of a parameter of a subject while the subject is at rest, the parameter being a fastest rate of increase in arterial pressure during a systolic upstroke of an arterial pressure wave of the subject;

applying an excitatory current to renal nerve fibers of the subject;

while applying the excitatory current, measuring a second value of the parameter;

in response to a difference between the first value and the second value, deciding whether to ablate or to not ablate the renal nerve fibers; and

in response to a decision to ablate, applying ablation energy to the renal nerve fibers.

4. A method, comprising:

applying an excitatory current to renal nerve fibers of a subject;

determining a change in a parameter of the subject in response to the excitatory current, the parameter being a fastest rate of increase in arterial pressure during a systolic upstroke of an arterial pressure wave of the subject;

in response to the change, selecting an ablation modality from a plurality of ablation modalities; and

in response to the selecting, ablating the renal nerve fibers using the selected ablation modality.

5. A method, comprising:

applying a first application of excitatory current to renal nerve fibers of a subject;

determining a first change in a parameter of the subject in response to the first application of excitatory current, the parameter being a fastest rate of increase in arterial pressure during a systolic upstroke of an arterial pressure wave of the subject;

subsequently, applying a first application of ablation energy to the renal nerve fibers;

subsequently, applying a second application of excitatory current to the renal nerve fibers of the subject;

determining a second change in the parameter in response to the second application of excitatory current;

determining a difference between the first change and the second change;

deciding whether to apply or to not apply a second application of ablation energy to the renal nerve fibers; and

in response to a decision to apply the second application of ablation energy, applying the second application of ablation energy to the renal nerve fibers.

6. A method, comprising:

transluminally advancing a distal portion of a longitudinal member of a device into a renal artery of a subject;

operating the device to drive an electrode disposed on the distal portion of the longitudinal member to apply an excitatory current to nerve tissue of the renal artery;

receiving (i) a first value, the first value being indicative of a parameter of the subject before a start of the application of the excitatory current, and (ii) a second value, the second value being indicative of the parameter of the subject after the start of the application of the excitatory current, the parameter being a fastest rate of increase in arterial pressure during a systolic upstroke of an arterial pressure wave of the subject;

determining if a difference between the first value and the second value is smaller than a threshold difference; and

in response to the determining;

only if the determined difference is smaller than the threshold difference, withdrawing the longitudinal member from the subject without having applied ablation energy to the renal artery.

7. Apparatus comprising:

a transluminal electrode catheter, comprising;

a flexible shaft, dimensioned for advancement of a distal portion of the shaft into a renal artery of a subject;

a plurality of electrodes disposed at the distal portion of the shaft;

an arterial blood pressure sensor; and

a control unit, electrically coupled to the catheter, and configured to;

use the arterial blood pressure sensor to measure a first value of a parameter of the subject while the subject is at rest, the parameter being a fastest rate of increase in arterial pressure during a systolic upstroke of an arterial pressure wave of the subject, drive at least one of the electrodes to apply an excitatory current to renal nerve fibers of the subject, while applying the excitatory current, use the arterial blood pressure sensor to measure a second value of the parameter, determine if a difference between the first value and the second value is greater than a threshold difference, and

in response to the determining;

only if the determined difference is greater than the threshold difference, enable an ablation function of the control unit and drive at least one of the electrodes to apply ablation energy to the renal nerve fibers.