# US 6,575,922 B1 · Ultrasound signal and temperature monitoring during sono-thrombolysis therapy > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 6,575,922 B1 - Document ID: US6575922B1 - Status: Granted - Kind: B1 - Application number: 09/691,471 - Filed: 2000-10-17 - Granted: 2003-06-10 - Earliest claimed: 2000-10-17 - Assignees: Walnut Technologies - Inventors: Jim Fearnside; Al Kyle - Web page: https://patentgrep.com/patent/US6575922B1 ## CPC - A61B 17/22004: {using mechanical vibrations, e.g. ultrasonic shock waves (A61B17/225 takes precedence)} - A61B 8/06: Measuring blood flow - A61B 8/481: {involving the use of contrast agents, e.g. microbubbles introduced into the bloodstream} - 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 2017/00092: {using thermocouples} - A61B 2017/00106: {ultrasonic} - A61B 2017/22009: {reduced or prevented} - 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 method for sono-thrombolysis is provided employing real-time, continuous intensity and temperature monitoring. The method generally includes the steps of establishing an ultrasound delivery column to the patient being treated for a thrombotic or embolic occlusion wherein the column includes an ultrasound transducer, a coupling medium and a hydrophone. The transducer is operated in a conventional manner to deliver ultrasound to the occlusion. During operation of the transducer, characteristics of the ultrasound being delivered to the occlusion are monitored on a real-time basis with the hydrophone. In addition, the methods includes monitoring temperature proximate the site of the occlusion, the temperature also being monitored on a real-time basis. Importantly, in response to the monitored characteristics of the ultrasound, intensity of the delivered ultrasound is controlled to be maintained within a desired intensity range. ## Claims ### Claim 1 A method of using ultrasound to treat a patient experiencing a thrombotic or embolic occlusion, the method comprising the steps of: establishing an ultrasound delivery column to the patient, the column comprising an ultrasound transducer, a coupling medium and a hydrophone; operating the transducer to deliver ultrasound to the occlusion; monitoring characteristics of the ultrasound being delivered to the occlusion on a real-time basis with the hydrophone; and in response to the monitored characteristics of the ultrasound, controlling intensity of the delivered ultrasound within a desired intensity range. ### Claim 2 (depends on 1) The method according to claim 1 wherein the desired intensity range has a pulse average intensity of about 1 watt/cm2. ### Claim 3 (depends on 1) The method according to claim 1 wherein the desired intensity range has a temporal average intensity of about 0.25 w/cm2. ### Claim 4 (depends on 1) The method according to claim 1 wherein the desired intensity range is a temporal average range of between about 0.06 w/cm2 and about 0.25 w/cm2. ### Claim 5 (depends on 1) The method according to claim 1 wherein the step of delivering ultrasound comprises delivering pulsed ultrasound. ### Claim 6 (depends on 5) The method according to claim 5 wherein the pulsed ultrasound is delivered with a 10% duty cycle. ### Claim 7 (depends on 1) The method according to claim 1 wherein the transducer delivers ultrasound at frequency of less than about 100 kHz. ### Claim 8 (depends on 1) The method according to claim 1 further comprising delivering a thrombolytic agent into the site of the occlusion. ### Claim 9 (depends on 1) The method according to claim 1 wherein the step of monitoring characteristics is performed using a hydrophone positioned between the transducer and the patient. ### Claim 10 (depends on 9) The method according to claim 9 wherein hydrophone is encased in the coupling medium. ### Claim 11 (depends on 10) The method according to claim 10 wherein the coupling medium is comprised of a silicone material. ### Claim 12 (depends on 1) The method according to claim 1 further comprising the steps of monitoring temperature of the patient on a real-time basis, wherein the temperature is monitored proximate the site of the occlusion. ### Claim 13 (depends on 12) The method according to claim 12 wherein the occlusion being treated is within the brain of the patient. ### Claim 14 (depends on 12) The method according to claim 12 further comprising the step of, in response to the monitored temperature, controlling a rise in temperature to less than about 2 deg C. ### Claim 15 (depends on 12) The method according to claim 12 further comprising the step of, in response to the monitored temperature, controlling a rise in temperature to less than about 1 deg C. ### Claim 16 (depends on 1) The method according to claim 1 wherein the step of monitoring characteristics of the ultrasound includes monitoring the presence of cavitation in the coupling medium. ### Claim 17 A method of using sono-thrombolysis for treatment of a patient experiencing a thrombotic or embolic occlusion in the brain, the method comprising the steps of: establishing an ultrasound delivery column to the patient, the column comprising an ultrasound transducer, a coupling medium and a hydrophone; operating the transducer to deliver ultrasound to the occlusion; monitoring characteristics of the ultrasound being delivered to the occlusion on a real-time basis with the hydrophone; monitoring temperature proximate the site of the occlusion, the temperature being monitored on a real-time basis; and in response to the monitored characteristics of the ultrasound, controlling intensity of the delivered ultrasound within a desired intensity range. ### Claim 18 (depends on 17) The method according to claim 17 wherein the step of monitoring temperature includes placing a temperature probe in a non-invasive location with respect to the skull of the patient. ### Claim 19 (depends on 17) The method according to claim 17 further comprising the step of, in response to the monitored temperature, controlling a rise in temperature to less than about 2 deg C. ### Claim 20 (depends on 17) The method according to claim 17 further comprising the step of, in response to the monitored temperature, controlling a rise in temperature to less than about 1 deg C. ### Claim 21 (depends on 17) The method according to claim 17 wherein the step of monitoring characteristics of the ultrasound includes monitoring the presence of cavitation in the coupling medium. ### Claim 22 (depends on 17) The method according to claim 17 further comprising delivering a dose of a