Interstitial ultrasonic disposable applicator and method for tissue thermal conformal volume ablation and monitoring the same

Abstract

An interstitial ultrasound thermal ablation applicator for conformal treatment of inhomogeneous tumor lesions includes: a body having a longitudinal axis, the body defining a hollow central channel along the longitudinal axis; and a plurality of CMUT array transducers mounted on the body, arranged side by side to form a cylindrical shape, having azimuth plans parallel to a longitudinal axis of the body, each of the plurality of CMUT array transducers having elevation dimensions predetermined to steer emitted ultrasonic waves to obtain a conformal volume treatment of the tumor lesions. An electronic driving method for driving an applicator having multiple independent transducer elements arranged in rows and columns includes: controlling focal parameters of each row and column of transducer elements; and controlling a contribution of each row and column of transducer elements in a manner to provide a conformal ablated volume.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]Not applicable.STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT[0002]Not applicable.THE NAMES TO PARTIES TO A JOINT RESEARCH AGREEMENT[0003]Not applicable.INCORPORATION-BY-REFERENCE OF MATERIAL SUBMITTED ON A COMPACT DISC[0004]Not applicable.BACKGROUND OF THE INVENTION[0005]1. Field of the Invention[0006]The present invention relates generally to an ultrasound medical method and device for interstitial disposable use having multiple ultrasound capacitive micromachined ultrasonic transducers (CMUT) to thermally ablate a conformal volume lesion and to monitor the ablated volume with the same apparatus.[0007]2. Description of Related Art[0008]In recent advances of tumor treatments, surgical methods have progressed a great deal towards minimally invasive techniques to decrease operation morbidity, pain, and the duration of hospitalization for patients. Minimally invasive procedures such as endoscopy, endovascular surgery or per...

AI Technical Summary

Benefits of technology

The invention provides an improved ultrasonic thermal ablation applicator for the treatment of inhomogeneous lesions and for conformal volume ablation. The applicator has a cylindrical source with independent linear array transducer modules that allow interstitial use and direct contact with the tissue to be treated. It also has a needle shape with a diameter smaller than 4 mm to prevent damage to healthy tissue during insertion. The applicator has a smooth conformal ablation pattern using a predetermined width and limited number of electrical interconnections. Overall, this invention allows for improved treatment of tissue abnormalities with reduced risk to healthy tissue.

Problems solved by technology

Preliminary results demonstrate significant improvement of life expectancy, though the current devices cannot be used to create lesions that perfectly match the target volume.

Other drawbacks in RF and LITT hyperthermia treatments are overheating, which occurs for tissue in contact with or in close vicinity of the treatment device, lack of control in lesion homogeneity due to blood flow, and difficulty in real-time monitoring of the therapy.

However, current piezoelectric-based HIFU / HICU applicators show undesirable effects and shortcomings such as local tissue overheating at the transducer tissue interface and lack of control for the treatment volume (risk of ablation of healthy tissue or under treatment).

Current surgical products for interstitial HIFU / HICU procedures exhibit limited ablation capability features (focusing, conformal volume) and all require an active cooling system to avoid overheating of tissue in contact with the ultrasound source and therefore cannot be placed in direct contact with biologic tissue.

Finally, current products may not exhibit optimal MR compatibility since artifacts may occur due to the presence of air bubbles, metal parts etc.

Unfortunately, the apparatus as described still requires cooling fluid to be circulated inside said delivery system to regulate the temperature of the probe.

Furthermore, no conformal volume treatment methodology is described therein.

While transducers can be easily arranged longitudinally to form a linear phased array in circumference, it is not clear how the probe can achieve any focusing since the number of sectors is limited and no indication is provided for making it.

However none of the embodiments described can produce conformal volumetric lesions and, furthermore, the design requires the apparatus to be rotated or moved to treat or monitor a volume.

However, the frequency control is limited to switching between discrete frequencies within multiple narrowband harmonics of the fundamental.

However a number of problems still remain unsolved regarding, specifically, a conformal volume treatment method, a dedicated ultrasonic thermal ablation device, and a method of making the same.

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