Search

US-20260123952-A1 - METHOD AND APPARATUS FOR TREATMENT OF PULMONARY CONDITIONS

US20260123952A1US 20260123952 A1US20260123952 A1US 20260123952A1US-20260123952-A1

Abstract

Apparatus and methods for deactivating bronchial nerves and ablating smooth muscle extending along a bronchial branch of a mammalian subject to treat asthma and related conditions. An ultrasonic transducer ( 11 ) is inserted into the bronchus as, for example, by advancing the distal end of a catheter ( 10 ) bearing the transducer into the bronchial section to be treated. The ultrasonic transducer emits ultrasound so as to heat tissues throughout a relatively large impact volume ( 13 ) to a temperature sufficient to inactivate nerve conduction and ablate smooth muscle but insufficient to cause rapid ablation or necrosis of the surrounding tissues. The treatment can be performed without locating or focusing on individual bronchial nerves or smooth muscle.

Inventors

  • Reinhard J. Warnking
  • Robert Pacheco
  • Subash Shrestha

Assignees

  • AerWave Medical, Inc.

Dates

Publication Date
20260507
Application Date
20231006

Claims (20)

  1. 1 . System for simultaneously inactivating bronchial nerve conduction and ablating smooth muscle in a mammalian subject, comprising: an elongated member supporting an ultrasound transducer adapted for insertion into a bronchial branch of a bronchial tree of the mammalian subject and for transmitting ultrasound energy; and an actuator or control unit electrically connected to the transducer, the actuator or control unit adapted to control the ultrasound transducer to i) transmit ultrasound energy at a sub-therapeutic level in a diagnostic mode; and ii) transmit ultrasound energy in an impact volume encompassing the bronchial branch in a therapeutic mode so that the ultrasound energy is applied at a therapeutic level sufficient to inactivate conduction of bronchial nerves and ablate smooth muscle throughout the impact volume in a therapeutic mode.
  2. 2 . The system of claim 1 , wherein the actuator or control unit transmits ultrasound energy in the diagnostic mode to generate a signal and integrate ultrasound echoes to measure bronchial diameter.
  3. 3 . The system of claim 1 , wherein the actuator or control unit is configured to analyze the impedance measurements to determine locations of bronchial cartilage rings and the actuator or control unit is additionally configured to activate the ultrasound transducer to transmit ultrasound therapeutic waveform energy between adjacent cartilaginous bronchial tissue.
  4. 4 . The system of claim 1 , wherein the actuator or control unit is configured to transmit ultrasound energy in the diagnostic mode to generate a signal and analyze ultrasound echoes to ensure circumferential coupling.
  5. 5 . The system of claim 1 , wherein the actuator or control unit is configured to transmit ultrasound energy in the diagnostic mode to generate a signal and analyze ultrasound echoes to ensure inter-cartilage positioning.
  6. 6 . The system of claim 1 , wherein analysis of the return signal of the transmitted pulse in the diagnostic mode determines one or both of a type or state of tissue.
  7. 7 . The system of claim 1 , wherein analysis of the return signal of the transmitted pulse in the diagnostic mode provides centering of the transducer in the bronchial branch.
  8. 8 . The system of claim 1 , wherein the actuator or control unit is configured to transmit ultrasound energy at the therapeutic level interleaved with transmitting in the diagnostic mode.
  9. 9 . The system of claim 1 , wherein the actuator or control unit is configured to transmit pulsed signals at the therapeutic level.
  10. 10 . The system of claim 1 , wherein the actuator or control unit further transmits ultrasound energy at the sub-therapeutic level after transmitting ultrasound energy at the therapeutic level has ablated peri bronchial tissues.
  11. 11 . The system of claim 1 , further comprising a balloon, the balloon containing cooling fluid.
  12. 12 . The system of claim 11 , wherein pulsating fluid within the balloon enables volumetric A mode diameter measurements by analyzing amplitude and signal width fluctuations.
  13. 13 . The system of claim 11 , wherein the cooling fluid is pulsated to provide pulsating flow to measure bronchial compliance and degree of smooth muscle ablation.
  14. 14 . The system of claim 11 , wherein the transducer emits ultrasonic energy at a sub-therapeutic level to detect heating of the fluid and/or efficacy of cooling.
  15. 15 . The system of claim 1 , further comprising at least one electrode for making impedance measurements along a wall of the bronchial branch to locate cartilaginous tissue and spaces or gaps between cartilaginous tissue.
  16. 16 . The system of claim 1 , wherein the transducer transmits ultrasound energy in the therapeutic mode to direct the ultrasound energy between cartilage rings.
  17. 17 . System for conducting pulmonary treatment in a mammalian subject, comprising: an elongated member having a balloon and an energy transducer within the balloon, the transducer adapted for insertion into a bronchial branch of a bronchial tree of the mammalian subject and for transmitting energy into surrounding tissue, and an actuator or control unit electrically connected to the transducer, the actuator or control unit being adapted to control the transducer to emit ultrasonic energy into an impact volume encompassing the bronchial branch so that the energy is applied at a therapeutic level sufficient to inactivate conduction of bronchial nerves throughout the impact volume; wherein the balloon contains cooling fluid and the cooling fluid is pulsated to measure bronchial compliance.
  18. 18 . The system of claim 17 , wherein the transducer emits ultrasound energy at a sub-therapeutic level in a diagnostic mode to measure bronchial diameter to optimize dosing.
  19. 19 . The system of claim 17 , wherein the cooling fluid is pulsated to generate an A-mode amplitude modulation to enable echo identification for bronchial diameter measurements.
  20. 20 . The system of claim 19 , wherein the pulsating fluid within the balloon enables volumetric A mode diameter measurements by analyzing amplitude and signal width fluctuations.

Description

BACKGROUND This application claims priority to provisional application Ser. No. 63/416,097 filed Oct. 14, 2022, the entire contents of which are incorporated herein by reference. FIELD OF THE INVENTION This invention relates to apparatus and methods for the treatment of pulmonary conditions such as asthma and COPD. BACKGROUND OF RELATED ART Successful treatment of pulmonary diseases such as asthma is important since these diseases represent a significant global health issue with reduced quality of life. While drug therapy (Bronchodilators, Anti Inflammatories and Leukotrines Modifiers) can be used to treat asthma, it is not always successful and very expensive. Asthma is a disorder that is characterized by airway constriction and inflammation resulting in breathing difficulties. Wheezing, shortness of breath and coughing are typical symptoms. These symptoms are caused by increased mucus production, airway inflammation and smooth muscle contraction resulting in airway obstruction. This obstruction can be treated by injuring and scarring the bronchial walls. This remodeling of the bronchial walls stiffens the bronchia and reduces contractility. Mechanical means and heat application have been proposed as in U.S. Pat. No. 8,267,094 B2. Other approaches focus on destruction of smooth muscle cells surrounding the bronchia as described in U.S. Patent No. 2012/0143099A1 and U.S. Pat. No. 7,906,124B2. Others describe applying RF energy to the bronchial wall and thereby directly widening the bronchia through a process such as disclosed in U.S. Pat. No. 7,740,017B2 and U.S. Pat. No. 8,161,978B2. Whatever the process, the bronchial wall will be damaged, and the procedure therefore has to be staged in order to limit damage and side effects as described in U.S. Pat. No. 7,740,017B2. European Patent No. EP2405841 describes applications of heat shocks through infused agents. Inactivating conduction of the nerves surrounding the bronchia has been proposed in U.S. Patent Publication No. 2012/0203216A1 through mechanical action i.e., puncturing, tearing, cutting nerve tissue. In other proposed or extant procedures, nerve tissue ablation is implemented by applying energy (RF, HIFU, Microwave, Radiation and Thermal Energy) directly to the nerves percutaneously. However, it is not taught how to identify the nerve location in order to align the energy focal zone (i.e., HIFU) with the nerve location. This is an issue since nerves are too small to be visualized with standard ultrasound, CT or MRI imaging methods. Therefore, the focal zone of the energy field cannot be predictably aligned with the target or nerve location. U.S. Pat. No. 8,088,127B2 teaches to denervate by applying RF energy to the bronchial wall with the catheter positioned inside the bronchial lumen. It is proposed to protect the bronchial wall through simultaneous cooling of the wall. This of course makes the device structure complicated and bulky and therefore difficult to deliver through a bronchoscope working channel. Also, the RF ablation is limited to the electrode contact area which requires adding together several energy applications to create a circumferential treatment volume. Numerous ablation sectors need to be pieced together to obtain a circumferential ablation zone with increased probability of affecting nerves. Due to catheter size and the need for multiple energy applications per bronchus, denervation with a cooled RF ablation device is practically limited to denervation in the left and right main bronchi in order to keep the overall number of energy applications low (at least 4 per bronchus) and therewith the procedure time acceptable. However, this main bronchial location carries the risk of esophageal and peri esophageal nerve damage which complicates the procedure further, requiring fluoroscopic monitoring of the distance between ablation and an esophageal marker-balloon. How to safely simplify lung denervation procedures by employing circumferential ultrasound in secondary bronchi is described in U.S. patent application Ser. No. 17/350,848, U.S. Patent Publication No. 2021/0316161. The sectorial RF ablation in main bronchi is not only complicated and time consuming but often also limited as far as efficacy is concerned because often RF energy delivery needs to be limited by reducing RF power or lesion geometry, i.e., foregoing posterior ablation segments to avoid damaging peri esophageal nerves or the esophagus located in the vicinity of the posterior section off the main bronchi. As described in U.S. Patent Application Publication No. 2021/0316161, efficacy of ultrasound denervation in secondary bronchi will not be negatively affected by these safety measures. However, there is a need for a device and method to increase efficacy further. In order to explain the difficulties associated with accomplishing this task without causing other damage, the anatomy of the bronchial system and nerves will now be described. Shown in FIG. 6 is an illustrat