Ultrasound apparatuses for thermally-induced renal neuromodulation

• US 8,845,629 B2
• Filed: 04/05/2010
• Issued: 09/30/2014
• Est. Priority Date: 04/08/2002
• Status: Active Grant

• Current Assignee: Medtronic Ireland Manufacturing Unlimited Company (Medtronic Plc)
• Original Assignee: Medtronic Ardian Luxembourg SARL (Medtronic Plc)
• Inventors: Demarais, Denise, Zadno, Nicolas, Clark, Benjamin J., Thai, Erik, Levin, Howard R., Gelfand, Mark
• Primary Examiner(s): Dvorak, Linda
• Assistant Examiner(s): SMITH, KAITLYN ELIZABETH
• Application Number:
  US12/754,337
• Publication Number:
  US 20100191112A1
• Time in Patent Office: 1,639 Days
• Field of Search: 606 27- 31, 601/1, 601/15
• US Class Current: 606/27
• CPC Class Codes: A61B 18/02 by cooling, e.g. cryogenic techniques devices for cooling specific reflex points of the body within cell-life limits A61H39/06
• CPC Class Codes: A61B 18/04 by heating by applying electromagnetic radiation A61B18/18; hyperthermia using electric or magnetic fields, radiation or ultrasound A61N
• CPC Class Codes: A61B 18/12 by passing a current through the tissue to be heated, e.g. high-frequency current
• 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 2018/0022 Balloons
• 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: A61F 2007/126 for invasive application, e.g. for introducing into blood vessels
• CPC Class Codes: A61F 7/007 characterised by electric heating
• CPC Class Codes: A61F 7/12 Devices for heating or cooling internal body cavities
• CPC Class Codes: A61F 7/123 using a flexible balloon containing the thermal element
• CPC Class Codes: A61M 2210/1082 Kidney
• CPC Class Codes: A61M 5/44 having means for cooling or heating the devices or media
• CPC Class Codes: A61N 1/28 Apparatus for applying thermoelectric currents
• CPC Class Codes: A61N 1/36007 of urogenital or gastrointestinal organs, e.g. for incontinence control
• CPC Class Codes: A61N 1/403 for thermotherapy, e.g. hyperthermia
• CPC Class Codes: A61N 2007/003 Destruction of nerve tissue
• CPC Class Codes: A61N 2007/0078 with multiple treatment transducers
• CPC Class Codes: A61N 5/00 Radiation therapy ultrasound therapy A61N7/00; devices or apparatus applicable to both therapy and diagnosis A61B6/00
• CPC Class Codes: A61N 5/025 : Warming the body, e.g. hyperthermia treatment
• CPC Class Codes: A61N 5/045 : specially adapted for treatment inside the body
• CPC Class Codes: A61N 5/0603 : for treatment of body cavities
• CPC Class Codes: A61N 7/00 : Ultrasound therapy lithotripsy A61B17/22, A61B17/225; massage using supersonic vibration A61H23/00 ; using ultrasound for introducing media into the body A61M37/0092
• CPC Class Codes: A61N 7/02 : Localised ultrasound hyperthermia hyperthermia in general A61F7/00
• CPC Class Codes: A61N 7/022 : intracavitary

Abstract

Methods and apparatus are provided for thermally-induced renal neuromodulation. Thermally-induced renal neuromodulation may be achieved via direct and/or via indirect application of thermal energy to heat or cool neural fibers that contribute to renal function, or of vascular structures that feed or perfuse the neural fibers. In some embodiments, parameters of the neural fibers, of non-target tissue, or of the thermal energy delivery element, may be monitored via one or more sensors for controlling the thermally-induced neuromodulation. In some embodiments, protective elements may be provided to reduce a degree of thermal damage induced in the non-target tissues.

Claims

1. An ultrasound apparatus for thermally-induced renal neuromodulation, the apparatus comprising:

a catheter sized and shaped for delivery within a blood vessel to a vicinity of neural fibers that contribute to renal function;

an ultrasound transducer carried by the catheter, wherein the ultrasound transducer is configured to transmit ultrasound energy waves to target renal neural fibers outside of the blood vessel to thermally induce modulation of target neural fibers while protecting non-target tissue in the blood vessel wall from thermal injury; and

an expandable member carried by a distal region of the catheter,

wherein the expandable member is configured to vary between a reduced configuration for delivery and retrieval and an expanded deployed configuration, and

wherein the ultrasound transducer is positioned on a shaft of the catheter and within the expandable member.

2. The apparatus of claim 1 wherein the expandable member comprises an inflatable balloon.

3. The apparatus of claim 2 wherein the balloon comprises an acoustically transmissive portion configured to allow passage of the ultrasound energy waves to the target neural fibers.

4. The apparatus of claim 3 wherein the balloon further comprises an acoustically reflective portion configured to reflect ultrasound energy waves via the acoustically transmissive portion to the target neural fibers.

5. The apparatus of claim 4 wherein:

the ultrasound transducer comprises a first ultrasound transducer configured to deliver a first ultrasound energy wave, and wherein the apparatus further comprises a second ultrasound transducer configured to produce a second ultrasound energy wave; and

the acoustically reflective portion and the acoustically transmissive portion are configured to transmit the first and second ultrasound energy waves to a focal distance point proximate to the target neural fibers.

6. The apparatus of claim 5 wherein the balloon is configured to transmit the first and second ultrasound energy waves to the focal distance point via different transmission paths.

7. The apparatus of claim 5 wherein expansion of the balloon is calibrated to dynamically vary the focal distance point.

8. The apparatus of claim 3 wherein the ultrasound transducer comprises a concave transducer configured to self-focus the ultrasound energy wave to the target neural fibers.

9. The apparatus of claim 1, further comprising an ultrasound signal generator operatively connected to the ultrasound transducer, and wherein the ultrasound signal generator is configured to deliver thermal neuromodulation therapy via the ultrasound transducer to the target neural fibers.

10. The apparatus of claim 9, further comprising a temperature sensor.

11. The apparatus of claim 9 wherein a reverse thermal gradient is produced when the ultrasound transducer transmits focused ultrasound energy waves to the target renal neural fibers outside of the blood vessel, and wherein the reverse thermal gradient results in a temperature at a wall of the blood vessel wall being less than a temperature at the target neural fibers.

12. The apparatus of claim 1, further comprising an imaging transducer.