# US 2014/0155788 A1 · Portable device to initiate and monitor treatment of stroke victims in the field

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- Number: US 2014/0155788 A1
- Document ID: US20140155788A1
- Status: Published application
- Kind: A1
- Application number: 13/892,187
- Filed: 2013-05-10
- Published: 2014-06-05
- Earliest claimed: 2012-05-11
- Assignees: The Regents of the University of California
- Applicants: The Regents of the University of California
- Inventors: Thilo Hoelscher; Arne Voie
- Web page: https://patentgrep.com/patent/US20140155788A1

## CPC

- 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})
- A61B 8/0808: {for diagnosis of the brain}
- A61B 8/481: {involving the use of contrast agents, e.g. microbubbles introduced into the bloodstream}
- A61B 2017/22008: {used or promoted}
- A61H 23/0245: {with ultrasonic transducers, e.g. piezoelectric}
- A61H 2201/0176: By stopping operation
- A61H 2201/018: By limiting the applied torque or force
- A61H 2201/105: with means for delivering media, e.g. drugs or cosmetics
- A61H 2201/1604: Head
- A61H 2201/5002: Means for controlling a set of similar massage devices acting in sequence at different locations on a patient
- A61H 2201/5005: for controlling frequency distribution, modulation or interference of a driving signal
- A61H 2201/5043: Displays
- A61H 2201/5058: Sensors or detectors
- A61H 2201/5097: wireless
- A61H 2205/02: Head
- A61N 2007/0039: {using microbubbles}
- A61N 2007/0052: {using the same transducer for therapy and imaging}
- A61N 2007/0078: {with multiple treatment transducers}
- 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)
- A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D)
- A61H: PHYSICAL THERAPY APPARATUS, e.g. DEVICES FOR LOCATING OR STIMULATING REFLEX POINTS IN THE BODY; ARTIFICIAL RESPIRATION; MASSAGE; BATHING DEVICES FOR SPECIAL THERAPEUTIC OR HYGIENIC PURPOSES OR SPECIFIC PARTS OF THE BODY (electrotherapy, magnetotherapy, radiation therapy or ultrasound therapy A61N)

## Abstract

Methods and apparatuses are provided for initiating stroke treatment “in the field” and/or during the transport of the patient to a care facility. The capability is provided to adjust automatically to the individual “therapeutic window” for each single patient, which is crucial because of the significant differences in skull morphology between humans of different age, gender and race. Further, the methods and apparatuses are based on the use of non-invasive application of ultrasound, as well as the non-invasive application of ultrasound in combination with an acoustically active agent, such as microbubbles, where stable cavitation of the microbubbles caused by the ultrasound may be relied upon as an underlying mechanism for both the therapeutic application as well as its control.

## Claims

### Claim 1

A method, comprising:
non-invasively applying ultrasound energy to a cranium of a patient via first and second ultrasound transducers attached at disparate locations about the cranium of the patient; and
controlling application of the ultrasound energy such that the first and second ultrasound transducers alternately apply the ultrasound energy in pulses to the cranium of the patient, wherein the non-invasive application of the ultrasound energy occurs in the field.

### Claim 2 (depends on 1)

The method of claim 1, wherein the non-invasive application of the ultrasound energy occurs in the field and prior to arrival of the patient at a care facility.

### Claim 3 (depends on 1)

The method of claim 1, wherein the disparate locations about the cranium of the patient comprise temporal bone regions forward of the ears of the patient.

### Claim 4 (depends on 1)

The method of claim 1 further comprising, intravenously administering an acoustically active agent to the patient.

### Claim 5 (depends on 4)

The method of claim 4, wherein the acoustically active agent comprises microbubbles.

### Claim 6 (depends on 4)

The method of claim 4 further comprising, exciting the acoustically active agent by the ultrasound energy to cause stable cavitation, and detecting a state of inertial cavitation of the acoustically active agent as an indication that the application of the ultrasound energy has exceeded a level commensurate with a therapeutic window.

### Claim 7 (depends on 6)

The method of claim 6, wherein the controlling of the application of the ultrasound energy comprises controlling an output power of the ultrasound energy such that stable cavitation is maintained, the stable cavitation triggering a plurality of biophysical effects in the patient.

### Claim 8 (depends on 7)

The method of claim 7, wherein the controlling of the output power of the ultrasound energy is performed either automatically or manually.

### Claim 9 (depends on 8)

The method of claim 8 further comprising, performing the automatic control of the output power of the ultrasound energy in accordance with at least one of patient-specific characteristics

### Claim 10 (depends on 9)

The method of claim 9, wherein the at least one of the patient-specific characteristics comprises age, gender, race, skull bone characteristics, and morphology.

### Claim 11 (depends on 6)

The method of claim 6 further comprising, reducing an output power of the ultrasound energy upon the acoustically active agent reaching the state of inertial cavitation.

### Claim 12 (depends on 1)

The method of claim 1 further comprising, performing the non-invasive application of the ultrasound energy and the controlling of the application of the ultrasound energy to counteract effects of at least one of, myocardial infarction, deep vein thrombosis, and a cerebrovascular accident due to ischemia.

### Claim 13 (depends on 1)

The method of claim 1, wherein each of the first and second ultrasound transducers are connected via cables to a portable, battery-operated power and control device, and wherein the first and second ultrasound transducers comprise one of single-use ultrasound transducers and multiple-use ultrasound transducers.

### Claim 14 (depends on 13)

The method of claim 13, wherein the single-use ultrasound transducers comprise disk-shaped piezo-electric elements.

### Claim 15 (depends on 13)

The method of claim 13, wherein the single-use ultrasound transducers operate at either a frequency of 200 kHz or in a band of frequencies centered about 200 kHz, and wherein the single-use ultrasound transducers receive acoustic signals in a minimum bandwidth between 100 to 300 kHz.

### Claim 16

An apparatus, comprising:
a first ultrasound transducer element;
a second ultrasound transducer element; and
a power and control module, the power and control module being portable and battery-operated, and generating ultrasound energy to be transmitted in an alternating and pulsed fashion by the first and second ultrasound transducer elements, noninvasively, to the skull of a patient.

### Claim 17 (depends on 16)

The apparatus of claim 16, wherein the power and control module further comprises circuitry for the generation of the ultrasound energy at an acoustic output power level and frequency to cause at least one of stable cavitation and inertial cavitation of an acoustically active agent.

### Claim 18 (depends on 16)

The apparatus of claim 16, wherein the first and second ultrasound transducer elements comprise disk-shaped piezo-electric elements operative at either a frequency of 200 kHz or in a band of frequencies centered about 200 kHz.

### Claim 19 (depends on 18)

The apparatus of claim 18, wherein each of the disk-shaped piezo-electric elements have a diameter ranging from 2 to 3 cm, a radius ranging from 1 to 1.5 cm, and a thickness of 2 mm.

### Claim 20 (depends on 18)

The apparatus of claim 18, wherein two faces of each of the disk-shaped piezo-electric elements are coated with an electricity-conducting material comprising electrodes of each of the first and second ultrasound transducer elements.

### Claim 21 (depends on 20)

The apparatus of claim 20, wherein the two faces of each of the disk-shaped piezo-electric elements are coated with at least one of a quarter-wave matching layer on a side facing the patient to aid in energy transmission, a backing layer on a side facing away from the patient, a shielding layer preventing electro-magnetic interference, and an insulating coating preventing inadvertent shock to the patient.

### Claim 22 (depends on 16)

The apparatus of claim 16, wherein each of the first and second ultrasound transducer elements comprise flat, unfocused disks.

### Claim 23 (depends on 16)

The apparatus of claim 16, wherein each of the first and second ultrasound transducer elements are driven by the power and control module with a pulse duration between 10 to 1000 μs and a duty cycle between 1 to 50%.

### Claim 24 (depends on 16)

The apparatus of claim 16, wherein each of the first and second ultrasound transducer elements receive acoustic signals from within the skull of the patient to detect whether a response of the acoustically active agent administered to the patient is stable cavitation or inertial cavitation.

### Claim 25 (depends on 16)

The apparatus of claim 16, wherein each of the first and second ultrasound transducer elements is operative within a minimum bandwidth in the range of 100 to 300 kHz.

### Claim 26 (depends on 16)

The apparatus of claim 16, wherein each of the first and second ultrasound transducer elements are configured to capture a subharmonic frequency and a first ultraharmonic frequency.

### Claim 27 (depends on 26)

The apparatus of claim 26, wherein the subharmonic frequency is 100 kHz and the ultraharmonic frequency is 300 kHz.

### Claim 28 (depends on 16)

The apparatus of claim 16, wherein each of the first and second ultrasound transducer elements are designed for single-use application and packaged so as to maintain sterility until used.

### Claim 29 (depends on 16)

The apparatus of claim 16, wherein each of the first and second ultrasound transducer elements are contained in a gel-pad portion, the gel-pad portion being pliant to conform to the shape of the skull of the patient, and aiding in transmission of the ultrasound energy into a target region of the brain of the patient.

### Claim 30 (depends on 29)

The apparatus of claim 29, wherein a section of the gel-pad portion contacting the scalp of the patient comprises a peel-away strip configured to expose a layer of adhesive to maintain each of the first and second ultrasound transducer elements in place.

### Claim 31 (depends on 16)

The apparatus of claim 16, where each of the first and second ultrasound transducer elements have a minimum half-life of twenty-four hours.

### Claim 32 (depends on 1)

The apparatus of claim 1, wherein the power and control module comprises a switching circuit in which a 200 kHz continuous wave signal is switched from one set of conductors to another set of conductors at predefined timepoints to create alternating bursts from the first and second ultrasound transducer elements.

### Claim 33 (depends on 32)

The apparatus of claim 32, wherein the predefined timepoints occur at every 100 μs.

### Claim 34 (depends on 32)

The apparatus of claim 32, wherein a transmit signal is generated using an oscillation circuit tuned to a nominal 200 kHz continuous sine wave.

### Claim 35 (depends on 34)

The apparatus of claim 34, wherein the 200 kHz continuous sine wave is amplified to an appropriate power level, and applied to the switching circuit.

### Claim 36 (depends on 32)

The apparatus of claim 32, wherein the switching circuit creates an on time followed by an off time for each of the first and second ultrasound transducer elements, such that when one of the first and second ultrasound transducer elements is in an on state, the other of the first and second ultrasound transducer elements is in an off state.

### Claim 37 (depends on 36)

The apparatus of claim 36, wherein the on and off times comprise 100 μs periods.

### Claim 38 (depends on 36)

The apparatus of claim 36, wherein the one of the first and second ultrasound transducer elements in the on state transmits the ultrasound energy through the skull of the patient, and the other of the first and second ultrasound transducer elements in the off state receives acoustic signals and is utilized as a passive cavitation detector.

### Claim 39 (depends on 16)

The apparatus of claim 16 further comprising, two cables, each of which operatively connect each of the first and second ultrasound transducer elements to the power and control module.

### Claim 40 (depends on 16)

The apparatus of claim 16, wherein the power and control module further comprises a control display for displaying visual information to a user of the apparatus.

### Claim 41 (depends on 16)

The apparatus of claim 16, wherein the power and control module is configured to verify that each of the first and second ultrasound transducers are energized.

### Claim 42 (depends on 16)

The apparatus of claim 16, wherein the power and control module is configured to allow for automated adjustment of acoustic output power of the ultrasound energy.

### Claim 43 (depends on 16)

The apparatus of claim 16, wherein the power and control module is configured to allow for manual adjustment of acoustic output power of the ultrasound energy.

### Claim 44 (depends on 16)

The apparatus of claim 16, wherein the power and control module comprises three lights for indicating cavitation control and an upper power limit of the ultrasound energy.