# US 11,432,802 B2 · System and method for controlling focused ultrasound treatment

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 11,432,802 B2
- Document ID: US11432802B2
- Status: Granted
- Kind: B2
- Application number: 16/921,395
- Filed: 2020-07-06
- Published: 2020-10-22
- Granted: 2022-09-06
- Earliest claimed: 2011-06-29
- Assignees: Sunnybrook Research Institute
- Applicants: Sunnybrook Research Institute
- Inventors: Meaghan Anne O'Reilly; Kullervo Henrik Hynynen
- Web page: https://patentgrep.com/patent/US11432802B2

## CPC

- A61B 8/481: {involving the use of contrast agents, e.g. microbubbles introduced into the bloodstream}
- A61B 8/0808: {for diagnosis of the brain}
- A61N 7/02: Localised ultrasound hyperthermia
- A61B 8/4488: {the transducer being a phased array}
- A61B 2017/00106: {ultrasonic}
- A61B 2090/374: {NMR or MRI}
- A61N 2007/0091: {with moving parts, e.g. transducers, lenses, reflectors}
- A61N 2007/0095: {by modifying an excitation signal}
- A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D)
- A61N: ELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY (measurement of bioelectric currents A61B; surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body A61B18/00; anaesthetic apparatus in general A61M; incandescent lamps H01K; infrared radiators for heating H05B)

## Abstract

A system and method for controlling the delivery of ultrasound energy to a subject is provided. In particular, such a system and method are capable of safely disrupting the blood-brain barrier. Ultrasound energy is delivered to produce cavitation of an ultrasound contrast agent at a selected pressure value. An acoustic signal is acquired following cavitation, from which a signal spectrum is produced. The signal spectrum is analyzed for the presence of harmonics, such as subharmonics or ultraharmonics. When subharmonics or ultraharmonics are present, the pressure value is decreased for subsequent sonications. If a previous sonication resulted in no subharmonics or ultraharmonics being generated, then the pressure value may be increased. In this manner, the blood-brain barrier can be advantageously disrupted while mitigating potentially injurious effects of the sonication.

## Claims

### Claim 1

A method for controlling delivery of ultrasound energy to a subject with a focused ultrasound (FUS) system, the steps of the method comprising:
a) administering an ultrasound contrast agent to a subject;
b) selecting a pressure value;
c) delivering ultrasound energy with a FUS system to a subject to produce cavitation of the contrast agent at the selected pressure;
d) receiving an acoustic signal from the cavitation produced in step c);
e) producing a signal spectrum from the acoustic signal received in step d);
f) analyzing the signal spectrum produced in step d) to identify whether at least one of subharmonics and ultraharmonics is present in the signal spectrum; and
g) updating the selected pressure value according to a weighting factor that decreases the pressure value to a target level as a normalized value of pressure for the at least one of subharmonics and ultraharmonics by using information related to whether at least one of subharmonics and ultraharmonics is present in the signal spectrum, the information being derived from the analyzed signal spectrum.

### Claim 2 (depends on 1)

The method as recited in claim 1 in which step g) includes decreasing the selected pressure value when at least one of subharmonics and ultraharmonics is present in the signal spectrum.

### Claim 3 (depends on 1)

The method as recited in claim 1 in which steps c)-g) are repeated for a selected period of time.

### Claim 4 (depends on 3)

The method as recited in claim 3 in which step g) includes increasing the selected pressure value when, in a previous repetition of step d), at least one of subharmonics and ultraharmonics was not present in the signal spectrum.