US20060106308A1 - Blood flow reestablishment determination - Google Patents
Blood flow reestablishment determination Download PDFInfo
- Publication number
- US20060106308A1 US20060106308A1 US11/291,355 US29135505A US2006106308A1 US 20060106308 A1 US20060106308 A1 US 20060106308A1 US 29135505 A US29135505 A US 29135505A US 2006106308 A1 US2006106308 A1 US 2006106308A1
- Authority
- US
- United States
- Prior art keywords
- catheter
- ultrasound
- vascular occlusion
- treatment site
- ultrasonic
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
- 230000017531 blood circulation Effects 0.000 title claims abstract description 46
- 238000011282 treatment Methods 0.000 claims abstract description 132
- 238000000034 method Methods 0.000 claims abstract description 66
- 230000001225 therapeutic effect Effects 0.000 claims abstract description 56
- 150000001875 compounds Chemical class 0.000 claims abstract description 55
- 238000005259 measurement Methods 0.000 claims abstract description 20
- 210000005166 vasculature Anatomy 0.000 claims abstract description 15
- 238000012544 monitoring process Methods 0.000 claims abstract description 6
- 238000002604 ultrasonography Methods 0.000 claims description 139
- 239000012530 fluid Substances 0.000 claims description 46
- 238000009529 body temperature measurement Methods 0.000 claims description 13
- 230000009467 reduction Effects 0.000 claims description 6
- 238000011156 evaluation Methods 0.000 claims description 3
- 206010053648 Vascular occlusion Diseases 0.000 claims 24
- 208000021331 vascular occlusion disease Diseases 0.000 claims 24
- 238000004090 dissolution Methods 0.000 abstract description 37
- 239000012809 cooling fluid Substances 0.000 description 29
- 239000000463 material Substances 0.000 description 25
- 238000012545 processing Methods 0.000 description 13
- WABPQHHGFIMREM-UHFFFAOYSA-N lead(0) Chemical compound [Pb] WABPQHHGFIMREM-UHFFFAOYSA-N 0.000 description 11
- 230000008901 benefit Effects 0.000 description 10
- 210000004204 blood vessel Anatomy 0.000 description 10
- 238000011144 upstream manufacturing Methods 0.000 description 10
- 239000008280 blood Substances 0.000 description 8
- 210000004369 blood Anatomy 0.000 description 8
- 230000033001 locomotion Effects 0.000 description 8
- 238000010586 diagram Methods 0.000 description 6
- 239000003814 drug Substances 0.000 description 6
- 230000006870 function Effects 0.000 description 6
- 230000001965 increasing effect Effects 0.000 description 6
- 230000004044 response Effects 0.000 description 6
- 229940079593 drug Drugs 0.000 description 5
- 230000000694 effects Effects 0.000 description 5
- 230000003287 optical effect Effects 0.000 description 5
- 239000000126 substance Substances 0.000 description 5
- 230000008859 change Effects 0.000 description 4
- 239000004020 conductor Substances 0.000 description 4
- 239000000835 fiber Substances 0.000 description 4
- 238000004364 calculation method Methods 0.000 description 3
- 239000000203 mixture Substances 0.000 description 3
- 230000002093 peripheral effect Effects 0.000 description 3
- 238000004382 potting Methods 0.000 description 3
- 208000031104 Arterial Occlusive disease Diseases 0.000 description 2
- 239000004698 Polyethylene Substances 0.000 description 2
- 239000004642 Polyimide Substances 0.000 description 2
- 208000007536 Thrombosis Diseases 0.000 description 2
- 230000002411 adverse Effects 0.000 description 2
- 238000002399 angioplasty Methods 0.000 description 2
- 208000021328 arterial occlusion Diseases 0.000 description 2
- 210000001367 artery Anatomy 0.000 description 2
- 239000000919 ceramic Substances 0.000 description 2
- 230000002490 cerebral effect Effects 0.000 description 2
- 238000010790 dilution Methods 0.000 description 2
- 239000012895 dilution Substances 0.000 description 2
- 201000010099 disease Diseases 0.000 description 2
- 208000037265 diseases, disorders, signs and symptoms Diseases 0.000 description 2
- 230000002708 enhancing effect Effects 0.000 description 2
- 239000003269 fluorescent indicator Substances 0.000 description 2
- 238000001415 gene therapy Methods 0.000 description 2
- 229910052451 lead zirconate titanate Inorganic materials 0.000 description 2
- 230000010363 phase shift Effects 0.000 description 2
- 229920001721 polyimide Polymers 0.000 description 2
- -1 polytetrafluoroethylene Polymers 0.000 description 2
- 229920001343 polytetrafluoroethylene Polymers 0.000 description 2
- 239000004810 polytetrafluoroethylene Substances 0.000 description 2
- 230000000644 propagated effect Effects 0.000 description 2
- 239000007787 solid Substances 0.000 description 2
- 230000002537 thrombolytic effect Effects 0.000 description 2
- 230000002792 vascular Effects 0.000 description 2
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- 206010051055 Deep vein thrombosis Diseases 0.000 description 1
- HTTJABKRGRZYRN-UHFFFAOYSA-N Heparin Chemical compound OC1C(NC(=O)C)C(O)OC(COS(O)(=O)=O)C1OC1C(OS(O)(=O)=O)C(O)C(OC2C(C(OS(O)(=O)=O)C(OC3C(C(O)C(O)C(O3)C(O)=O)OS(O)(=O)=O)C(CO)O2)NS(O)(=O)=O)C(C(O)=O)O1 HTTJABKRGRZYRN-UHFFFAOYSA-N 0.000 description 1
- 208000031481 Pathologic Constriction Diseases 0.000 description 1
- 239000004952 Polyamide Substances 0.000 description 1
- 108010023197 Streptokinase Proteins 0.000 description 1
- 108090000373 Tissue Plasminogen Activator Proteins 0.000 description 1
- 102000003978 Tissue Plasminogen Activator Human genes 0.000 description 1
- 108090000435 Urokinase-type plasminogen activator Proteins 0.000 description 1
- 102000003990 Urokinase-type plasminogen activator Human genes 0.000 description 1
- 206010047249 Venous thrombosis Diseases 0.000 description 1
- HZEWFHLRYVTOIW-UHFFFAOYSA-N [Ti].[Ni] Chemical compound [Ti].[Ni] HZEWFHLRYVTOIW-UHFFFAOYSA-N 0.000 description 1
- 238000002679 ablation Methods 0.000 description 1
- 238000005299 abrasion Methods 0.000 description 1
- 230000004913 activation Effects 0.000 description 1
- 210000003484 anatomy Anatomy 0.000 description 1
- 239000003146 anticoagulant agent Substances 0.000 description 1
- 239000007864 aqueous solution Substances 0.000 description 1
- 230000004323 axial length Effects 0.000 description 1
- 230000004071 biological effect Effects 0.000 description 1
- 230000036772 blood pressure Effects 0.000 description 1
- 238000009954 braiding Methods 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 230000006835 compression Effects 0.000 description 1
- 238000007906 compression Methods 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 239000010949 copper Substances 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 230000002596 correlated effect Effects 0.000 description 1
- 239000002178 crystalline material Substances 0.000 description 1
- 230000002939 deleterious effect Effects 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 238000005553 drilling Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000002068 genetic effect Effects 0.000 description 1
- 229960002897 heparin Drugs 0.000 description 1
- 229920000669 heparin Polymers 0.000 description 1
- 229920001903 high density polyethylene Polymers 0.000 description 1
- 238000003384 imaging method Methods 0.000 description 1
- 238000002347 injection Methods 0.000 description 1
- 239000007924 injection Substances 0.000 description 1
- 238000003780 insertion Methods 0.000 description 1
- 230000037431 insertion Effects 0.000 description 1
- 230000003834 intracellular effect Effects 0.000 description 1
- 238000013532 laser treatment Methods 0.000 description 1
- HFGPZNIAWCZYJU-UHFFFAOYSA-N lead zirconate titanate Chemical compound [O-2].[O-2].[O-2].[O-2].[O-2].[Ti+4].[Zr+4].[Pb+2] HFGPZNIAWCZYJU-UHFFFAOYSA-N 0.000 description 1
- 239000004973 liquid crystal related substance Substances 0.000 description 1
- 229920001684 low density polyethylene Polymers 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000003550 marker Substances 0.000 description 1
- 230000007246 mechanism Effects 0.000 description 1
- 229910001000 nickel titanium Inorganic materials 0.000 description 1
- 229920001778 nylon Polymers 0.000 description 1
- 230000003534 oscillatory effect Effects 0.000 description 1
- 238000013021 overheating Methods 0.000 description 1
- 238000006213 oxygenation reaction Methods 0.000 description 1
- 230000035790 physiological processes and functions Effects 0.000 description 1
- 229920002647 polyamide Polymers 0.000 description 1
- 229920000728 polyester Polymers 0.000 description 1
- 229920000573 polyethylene Polymers 0.000 description 1
- 239000004814 polyurethane Substances 0.000 description 1
- 229920002635 polyurethane Polymers 0.000 description 1
- 230000002250 progressing effect Effects 0.000 description 1
- 230000001737 promoting effect Effects 0.000 description 1
- 230000001902 propagating effect Effects 0.000 description 1
- 108090000623 proteins and genes Proteins 0.000 description 1
- 102000004169 proteins and genes Human genes 0.000 description 1
- 238000004080 punching Methods 0.000 description 1
- 239000010453 quartz Substances 0.000 description 1
- 230000003134 recirculating effect Effects 0.000 description 1
- 238000012827 research and development Methods 0.000 description 1
- 208000037803 restenosis Diseases 0.000 description 1
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N silicon dioxide Inorganic materials O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 1
- 239000000243 solution Substances 0.000 description 1
- 229910001220 stainless steel Inorganic materials 0.000 description 1
- 239000010935 stainless steel Substances 0.000 description 1
- 230000036262 stenosis Effects 0.000 description 1
- 208000037804 stenosis Diseases 0.000 description 1
- 229960005202 streptokinase Drugs 0.000 description 1
- 230000000153 supplemental effect Effects 0.000 description 1
- 238000002560 therapeutic procedure Methods 0.000 description 1
- 229920002725 thermoplastic elastomer Polymers 0.000 description 1
- 229960000187 tissue plasminogen activator Drugs 0.000 description 1
- 238000012546 transfer Methods 0.000 description 1
- 150000003673 urethanes Chemical class 0.000 description 1
- 229960005356 urokinase Drugs 0.000 description 1
- 210000003462 vein Anatomy 0.000 description 1
Images
Classifications
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B17/00—Surgical instruments, devices or methods, e.g. tourniquets
- A61B17/22—Implements for squeezing-off ulcers or the like on the inside of inner organs of the body; Implements for scraping-out cavities of body organs, e.g. bones; Calculus removers; Calculus smashing apparatus; Apparatus for removing obstructions in blood vessels, not otherwise provided for
- A61B17/22004—Implements for squeezing-off ulcers or the like on the inside of inner organs of the body; Implements for scraping-out cavities of body organs, e.g. bones; Calculus removers; Calculus smashing apparatus; Apparatus for removing obstructions in blood vessels, not otherwise provided for using mechanical vibrations, e.g. ultrasonic shock waves
- A61B17/22012—Implements for squeezing-off ulcers or the like on the inside of inner organs of the body; Implements for scraping-out cavities of body organs, e.g. bones; Calculus removers; Calculus smashing apparatus; Apparatus for removing obstructions in blood vessels, not otherwise provided for using mechanical vibrations, e.g. ultrasonic shock waves in direct contact with, or very close to, the obstruction or concrement
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B17/00—Surgical instruments, devices or methods, e.g. tourniquets
- A61B2017/00017—Electrical control of surgical instruments
- A61B2017/00022—Sensing or detecting at the treatment site
- A61B2017/00057—Light
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B17/00—Surgical instruments, devices or methods, e.g. tourniquets
- A61B2017/00017—Electrical control of surgical instruments
- A61B2017/00022—Sensing or detecting at the treatment site
- A61B2017/00084—Temperature
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B17/00—Surgical instruments, devices or methods, e.g. tourniquets
- A61B2017/00017—Electrical control of surgical instruments
- A61B2017/00022—Sensing or detecting at the treatment site
- A61B2017/00084—Temperature
- A61B2017/00101—Temperature using an array of thermosensors
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B17/00—Surgical instruments, devices or methods, e.g. tourniquets
- A61B17/22—Implements for squeezing-off ulcers or the like on the inside of inner organs of the body; Implements for scraping-out cavities of body organs, e.g. bones; Calculus removers; Calculus smashing apparatus; Apparatus for removing obstructions in blood vessels, not otherwise provided for
- A61B17/22004—Implements for squeezing-off ulcers or the like on the inside of inner organs of the body; Implements for scraping-out cavities of body organs, e.g. bones; Calculus removers; Calculus smashing apparatus; Apparatus for removing obstructions in blood vessels, not otherwise provided for using mechanical vibrations, e.g. ultrasonic shock waves
- A61B17/22012—Implements for squeezing-off ulcers or the like on the inside of inner organs of the body; Implements for scraping-out cavities of body organs, e.g. bones; Calculus removers; Calculus smashing apparatus; Apparatus for removing obstructions in blood vessels, not otherwise provided for using mechanical vibrations, e.g. ultrasonic shock waves in direct contact with, or very close to, the obstruction or concrement
- A61B17/2202—Implements for squeezing-off ulcers or the like on the inside of inner organs of the body; Implements for scraping-out cavities of body organs, e.g. bones; Calculus removers; Calculus smashing apparatus; Apparatus for removing obstructions in blood vessels, not otherwise provided for using mechanical vibrations, e.g. ultrasonic shock waves in direct contact with, or very close to, the obstruction or concrement the ultrasound transducer being inside patient's body at the distal end of the catheter
- A61B2017/22021—Implements for squeezing-off ulcers or the like on the inside of inner organs of the body; Implements for scraping-out cavities of body organs, e.g. bones; Calculus removers; Calculus smashing apparatus; Apparatus for removing obstructions in blood vessels, not otherwise provided for using mechanical vibrations, e.g. ultrasonic shock waves in direct contact with, or very close to, the obstruction or concrement the ultrasound transducer being inside patient's body at the distal end of the catheter electric leads passing through the catheter
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B17/00—Surgical instruments, devices or methods, e.g. tourniquets
- A61B17/22—Implements for squeezing-off ulcers or the like on the inside of inner organs of the body; Implements for scraping-out cavities of body organs, e.g. bones; Calculus removers; Calculus smashing apparatus; Apparatus for removing obstructions in blood vessels, not otherwise provided for
- A61B2017/22082—Implements for squeezing-off ulcers or the like on the inside of inner organs of the body; Implements for scraping-out cavities of body organs, e.g. bones; Calculus removers; Calculus smashing apparatus; Apparatus for removing obstructions in blood vessels, not otherwise provided for after introduction of a substance
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B17/00—Surgical instruments, devices or methods, e.g. tourniquets
- A61B17/22—Implements for squeezing-off ulcers or the like on the inside of inner organs of the body; Implements for scraping-out cavities of body organs, e.g. bones; Calculus removers; Calculus smashing apparatus; Apparatus for removing obstructions in blood vessels, not otherwise provided for
- A61B2017/22082—Implements for squeezing-off ulcers or the like on the inside of inner organs of the body; Implements for scraping-out cavities of body organs, e.g. bones; Calculus removers; Calculus smashing apparatus; Apparatus for removing obstructions in blood vessels, not otherwise provided for after introduction of a substance
- A61B2017/22084—Implements for squeezing-off ulcers or the like on the inside of inner organs of the body; Implements for scraping-out cavities of body organs, e.g. bones; Calculus removers; Calculus smashing apparatus; Apparatus for removing obstructions in blood vessels, not otherwise provided for after introduction of a substance stone- or thrombus-dissolving
Definitions
- the preferred embodiments of the present invention relate to methods and apparatuses for monitoring the efficacy of a clot dissolution treatment.
- the methods and apparatuses are particularly well suited for use with an ultrasonic catheter configured to deliver ultrasonic energy and a therapeutic compound to a treatment site.
- U.S. Pat. Nos. 4,821,740, 4,953,565 and 5,007,438 disclose the use of ultrasonic energy to enhance the effect of various therapeutic compounds.
- An ultrasonic catheter can be used to deliver ultrasonic energy and a therapeutic compound to a treatment site in a patient's body.
- Such an ultrasonic catheter typically includes an ultrasound assembly configured to generate ultrasonic energy and a fluid delivery lumen for delivering the therapeutic compound to the treatment site.
- ultrasonic catheters can be used to treat human blood vessels that have become partially or completely occluded by plaque, thrombi, emboli or other substances that reduce the blood carrying capacity of the vessel.
- the ultrasonic catheter is used to deliver solutions containing dissolution compounds directly to the occlusion site.
- Ultrasonic energy generated by the ultrasound assembly enhances the therapeutic effect of the dissolution compounds.
- an ultrasound-enhanced thrombolytic therapy dissolves blood clots in arteries and veins in the treatment of diseases such as peripheral arterial occlusion or deep vein thrombosis.
- ultrasonic energy enhances thrombolysis with agents such as urokinase, tissue plasminogen activator (“TPA”) and the like.
- Ultrasonic catheters can also be used to enhance gene therapy at a treatment site within the patient's body.
- U.S. Pat. No. 6,135,976 discloses an ultrasonic catheter having one or more expandable sections capable of occluding a section of a body lumen, such as a blood vessel.
- a gene therapy composition is then delivered to the occluded vessel through the catheter fluid delivery lumen.
- Ultrasonic energy generated by the ultrasound assembly is applied to the occluded vessel, thereby enhancing the delivery of a genetic composition into the cells of the occluded vessel.
- Ultrasonic catheters can also be used to enhance delivery and activation of light activated drugs.
- U.S. Pat. No. 6,176,842 discloses methods for using an ultrasonic catheter to treat biological tissues by delivering a light activated drug to the biological tissues and exposing the light activated drug to ultrasound energy.
- a clot dissolution treatment is progressing too slowly, it may be desired to increase the delivery of therapeutic compound or ultrasonic energy to the treatment site in an attempt to cause the treatment to progress faster.
- an improved ultrasonic catheter capable of monitoring the progression or efficacy of a clot dissolution treatment.
- a method for monitoring a clot dissolution treatment in a patient's vasculature comprises positioning a catheter at a treatment site in the patient's vasculature.
- the method further comprises performing a clot dissolution treatment at the treatment site.
- the clot dissolution treatment comprises delivering ultrasonic energy and a therapeutic compound from the catheter to the treatment site such that a clot located at the treatment site at least partially dissolves.
- the method further comprises delivering a thermal measurement signal from a first portion of the catheter to the treatment site during the clot dissolution treatment.
- the method further comprises receiving the thermal measurement signal at a second portion of the catheter.
- the method further comprises comparing the delivered thermal measurement signal with the received thermal measurement signal to evaluate a blood flow rate at the treatment site.
- a method comprises positioning a catheter at a treatment site in a patient's vasculature.
- a blockage is located at the treatment site.
- the method further comprises performing a medical treatment at the treatment site.
- the medical treatment is configured to reduce the blockage.
- the method further comprises making a plurality of thermal energy measurements at the treatment site while the medical treatment is being performed.
- the method further comprises evaluating the reduction in the blockage based on the plurality of thermal energy measurements.
- an ultrasound catheter for evaluating the efficacy of a clot dissolution treatment comprises an upstream region.
- the catheter further comprises a downstream region located opposite the upstream region.
- the catheter further comprises a treatment zone partially extending into both the upstream region and the downstream region.
- the catheter further comprises an ultrasonic assembly positioned within the treatment zone.
- the ultrasonic assembly comprises at least one ultrasound radiating member configured to perform a clot dissolution treatment.
- the catheter further comprises a thermal energy source positioned in the upstream region.
- the thermal energy source is configured to deliver a thermal measurement signal to the treatment zone during the clot dissolution treatment.
- the catheter further comprises a thermal energy detector positioned in the downstream region.
- the thermal energy detector is configured to receive the thermal measurement signal from the treatment zone.
- the catheter further comprises control circuitry configured to compare the thermal measurement signal delivered from the thermal energy source to the thermal measurement signal received at the thermal energy detector.
- an apparatus comprises a catheter having an upstream region, a downstream region and a treatment zone partially extending into both the upstream region and the downstream region.
- the apparatus further comprises an ultrasonic assembly positioned within the treatment zone.
- the ultrasonic assembly comprises at least one ultrasound radiating member configured to perform a clot dissolution treatment.
- the apparatus further comprises a thermal energy detector positioned in the treatment zone.
- the thermal energy detector is configured to make a plurality of thermal energy measurements during the clot dissolution treatment.
- the apparatus further comprises means for measuring thermal dilution in the treatment zone during the clot dissolution treatment.
- a method comprises positioning a catheter having an ultrasound radiating member proximal to an obstruction in a patient's vasculature.
- the method further comprises performing an obstruction dissolution treatment by applying a therapeutic compound and ultrasonic energy to the obstruction such that the obstruction is at least partially dissolved.
- the method further comprises sensing an at least partial reestablishment of blood flow past the partially dissolved obstruction.
- the method further comprises adjusting the obstruction dissolution treatment in response to the at least partial reestablishment of blood flow.
- FIG. 1 is a schematic illustration of an ultrasonic catheter configured for insertion into large vessels of the human body.
- FIG. 2 is a cross-sectional view of the ultrasonic catheter of FIG. 1 taken along line 2 - 2 .
- FIG. 3 is a schematic illustration of an elongate inner core configured to be positioned within the central lumen of the catheter illustrated in FIG. 2 .
- FIG. 4 is a cross-sectional view of the elongate inner core of FIG. 3 taken along line 4 - 4 .
- FIG. 5 is a schematic wiring diagram illustrating a preferred technique for electrically connecting five groups of ultrasound radiating members to form an ultrasound assembly.
- FIG. 6 is a schematic wiring diagram illustrating a preferred technique for electrically connecting one of the groups of FIG. 5 .
- FIG. 7A is a schematic illustration of the ultrasound assembly of FIG. 5 housed within the inner core of FIG. 4 .
- FIG. 7B is a cross-sectional view of the ultrasound assembly of FIG. 7A taken along line 7 B- 7 B.
- FIG. 7C is a cross-sectional view of the ultrasound assembly of FIG. 7A taken along line 7 C- 7 C.
- FIG. 7D is a side view of an ultrasound assembly center wire twisted into a helical configuration.
- FIG. 8 illustrates the energy delivery section of the inner core of FIG. 4 positioned within the energy delivery section of the tubular body of FIG. 2 .
- FIG. 9 illustrates a wiring diagram for connecting a plurality of temperature sensors with a common wire.
- FIG. 10 is a block diagram of a feedback control system for use with an ultrasonic catheter.
- FIG. 11A is a side view of a treatment site.
- FIG. 11B is a side view of the distal end of an ultrasonic catheter positioned at the treatment site of FIG. 11A .
- FIG. 11C is a cross-sectional view of the distal end of the ultrasonic catheter of FIG. 11B positioned at the treatment site before a treatment.
- FIG. 11D is a cross-sectional view of the distal end of the ultrasonic catheter of FIG. 11C , wherein an inner core has been inserted into the tubular body to perform a treatment.
- FIG. 12 is a schematic diagram illustrating one arrangement for using thermal measurements for detecting reestablishment of blood flow.
- FIG. 13A is an exemplary plot of temperature as a function of time at a thermal source.
- FIG. 13B is an exemplary plot of temperature as a function of time at a thermal detector
- an ultrasonic catheter having various features and advantages.
- features and advantages include the ability to monitor the progression or efficacy of a clot dissolution treatment.
- the catheter has the ability to adjust the delivery of a therapeutic compound based on the progression of the clot dissolution treatment.
- Preferred embodiments of an ultrasonic catheter having certain of these features and advantages are described herein. Methods of using such an ultrasonic catheter are also described herein.
- the ultrasonic catheters described herein can be used to enhance the therapeutic effects of therapeutic compounds at a treatment site within a patient's body.
- therapeutic compound refers broadly, without limitation, to a drug, medicament, dissolution compound, genetic material or any other substance capable of effecting physiological functions. Additionally, any mixture comprising any such substances is encompassed within this definition of “therapeutic compound”, as well as any substance falling within the ordinary meaning of these terms.
- the enhancement of the effects of therapeutic compounds using ultrasonic energy is described in U.S. Pat. Nos. 5,318,014, 5,362,309, 5,474,531, 5,628,728, 6,001,069 and 6,210,356, the entire disclosure of which are hereby incorporated by herein by reference.
- suitable therapeutic compounds include, but are not limited to, an aqueous solution containing Heparin, Uronkinase, Streptokinase, TPA and BB-10153 (manufactured by British Biotech, Oxford, UK).
- ultrasonic catheters disclosed herein may also find utility in applications where the ultrasonic energy itself provides a therapeutic effect.
- therapeutic effects include preventing or reducing stenosis and/or restenosis; tissue ablation, abrasion or disruption; promoting temporary or permanent physiological changes in intracellular or intercellular structures; and rupturing micro-balloons or micro-bubbles for therapeutic compound delivery.
- Further information about such methods can be found in U.S. Pat. Nos. 5,261,291 and 5,431,663, the entire disclosure of which are hereby incorporated by herein by reference. Further information about using cavitation to produce biological effects can be found in U.S. Pat. No. RE36,939.
- the ultrasonic catheters described herein are configured for applying ultrasonic energy over a substantial length of a body lumen, such as, for example, the larger vessels located in the leg.
- a body lumen such as, for example, the larger vessels located in the leg.
- certain features and aspects of the present invention may be applied to catheters configured to be inserted into the small cerebral vessels, in solid tissues, in duct systems and in body cavities.
- Such catheters are described in U.S. patent application Ser. No. 10/309,417, filed Dec. 3, 2002. Additional embodiments that may be combined with certain features and aspects of the embodiments described herein are described in U.S. patent application Ser. No. 10/291,891, filed Nov. 7, 2002, the entire disclosure of which is hereby incorporated herein by reference.
- an ultrasonic catheter 10 configured for use in the large vessels of a patient's anatomy is schematically illustrated.
- the ultrasonic catheter 10 illustrated in FIG. 1 can be used to treat long segment peripheral arterial occlusions, such as those in the vascular system of the leg.
- the ultrasonic catheter 10 generally comprises a multi-component, elongate flexible tubular body 12 having a proximal region 14 and a distal region 15 .
- the tubular body 12 includes a flexible energy delivery section 18 and a distal exit port 29 located in the distal region 15 of the catheter 10 .
- a backend hub 33 is attached to the proximal region 14 of the tubular body 12 , the backend hub 33 comprising a proximal access port 31 , an inlet port 32 and a cooling fluid fitting 46 .
- the proximal access port 31 can be connected to control circuitry 100 via cable 45 .
- the tubular body 12 and other components of the catheter 10 can be manufactured in accordance with any of a variety of techniques well known in the catheter manufacturing field. Suitable materials and dimensions can be readily selected based on the natural and anatomical dimensions of the treatment site and on the desired percutaneous access site.
- the proximal region 14 of the tubular body 12 comprises a material that has sufficient flexibility, kink resistance, rigidity and structural support to push the energy delivery section 18 through the patient's vasculature to a treatment site.
- materials include, but are not limited to, extruded polytetrafluoroethylene (“PTFE”), polyethylenes (“PE”), polyamides and other similar materials.
- PTFE polytetrafluoroethylene
- PE polyethylenes
- polyamides polyamides and other similar materials.
- the proximal region 14 of the tubular body 12 is reinforced by braiding, mesh or other constructions to provide increased kink resistance and pushability.
- nickel titanium or stainless steel wires can be placed along or incorporated into the tubular body 12 to reduce kinking.
- the tubular body 12 has an outside diameter between about 0.060 inches and about 0.075 inches. In another embodiment, the tubular body 12 has an outside diameter of about 0.071 inches. In certain embodiments, the tubular body 12 has an axial length of approximately 105 centimeters, although other lengths may by appropriate for other applications.
- the energy delivery section 18 of the tubular body 12 preferably comprises a material that is thinner than the material comprising the proximal region 14 of the tubular body 12 or a material that has a greater acoustic transparency. Thinner materials generally have greater acoustic transparency than thicker materials. Suitable materials for the energy delivery section 18 include, but are not limited to, high or low density polyethylenes, urethanes, nylons, and the like. In certain modified embodiments, the energy delivery section 18 may be formed from the same material or a material of the same thickness as the proximal region 14 .
- the tubular body 12 is divided into at least three sections of varying stiffness.
- the first section which preferably includes the proximal region 14 , has a relatively higher stiffness.
- the second section which is located in an intermediate region between the proximal region 14 and the distal region 15 of the tubular body 12 , has a relatively lower stiffness. This configuration further facilitates movement and placement of the catheter 10 .
- the third section which preferably includes the energy delivery section 18 , generally has a lower stiffness than the second section.
- FIG. 2 illustrates a cross section of the tubular body 12 taken along line 2 - 2 in FIG. 1 .
- three fluid delivery lumens 30 are incorporated into the tubular body 12 .
- more or fewer fluid delivery lumens can be incorporated into the tubular body 12 .
- the arrangement of the fluid delivery lumens 30 preferably provides a hollow central lumen 51 passing through the tubular body 12 .
- the cross-section of the tubular body 12 is preferably substantially constant along the length of the catheter 10 .
- substantially the same cross-section is present in both the proximal region 14 and the distal region 15 of the catheter 10 , including the energy delivery section 18 .
- the central lumen 51 has a minimum diameter greater than about 0.030 inches. In another embodiment, the central lumen 51 has a minimum diameter greater than about 0.037 inches. In one preferred embodiment, the fluid delivery lumens 30 have dimensions of about 0.026 inches wide by about 0.0075 inches high, although other dimensions may be used in other applications.
- the central lumen 51 preferably extends through the length of the tubular body 12 .
- the central lumen 51 preferably has a distal exit port 29 and a proximal access port 31 .
- the proximal access port 31 forms part of the backend hub 33 , which is attached to the proximal region 14 of the catheter 10 .
- the backend hub 33 preferably further comprises cooling fluid fitting 46 , which is hydraulically connected to the central lumen 51 .
- the backend hub 33 also preferably comprises a therapeutic compound inlet port 32 , which is in hydraulic connection with the fluid delivery lumens 30 , and which can be hydraulically coupled to a source of therapeutic compound via a hub such as a Luer fitting.
- the central lumen 51 is configured to receive an elongate inner core 34 of which a preferred embodiment is illustrated in FIG. 3 .
- the elongate inner core 34 preferably comprises a proximal region 36 and a distal region 38 .
- Proximal hub 37 is fitted on the inner core 34 at one end of the proximal region 36 .
- One or more ultrasound radiating members are positioned within an inner core energy delivery section 41 located within the distal region 38 .
- the ultrasound radiating members form an ultrasound assembly 42 , which will be described in greater detail below.
- the inner core 34 preferably has a cylindrical shape, with an outer diameter that permits the inner core 34 to be inserted into the central lumen 51 of the tubular body 12 via the proximal access port 31 .
- Suitable outer diameters of the inner core 34 include, but are not limited to, about 0.010 inches to about 0.100 inches. In another embodiment, the outer diameter of the inner core 34 is between about 0.020 inches and about 0.080 inches. In yet another embodiment, the inner core 34 has an outer diameter of about 0.035 inches.
- the inner core 34 preferably comprises a cylindrical outer body 35 that houses the ultrasound assembly 42 .
- the ultrasound assembly 42 comprises wiring and ultrasound radiating members, described in greater detail in FIGS. 5 through 7 D, such that the ultrasound assembly 42 is capable of radiating ultrasonic energy from the energy delivery section 41 of the inner core 34 .
- the ultrasound assembly 42 is electrically connected to the backend hub 33 , where the inner core 34 can be connected to control circuitry 100 via cable 45 (illustrated in FIG. 1 ).
- an electrically insulating potting material 43 fills the inner core 34 , surrounding the ultrasound assembly 42 , thus preventing movement of the ultrasound assembly 42 with respect to the outer body 35 .
- the thickness of the outer body 35 is between about 0.0002 inches and 0.010 inches. In another embodiment, the thickness of the outer body 35 is between about 0.0002 inches and 0.005 inches. In yet another embodiment, the thickness of the outer body 35 is about 0.0005 inches.
- the ultrasound assembly 42 comprises a plurality of ultrasound radiating members that are divided into one or more groups.
- FIGS. 5 and 6 are schematic wiring diagrams illustrating one technique for connecting five groups of ultrasound radiating members 40 to form the ultrasound assembly 42 .
- the ultrasound assembly 42 comprises five groups G 1 , G 2 , G 3 , G 4 , G 5 of ultrasound radiating members 40 that are electrically connected to each other.
- the five groups are also electrically connected to the control circuitry 100 .
- ultrasonic energy As used herein, the terms “ultrasonic energy”, “ultrasound” and “ultrasonic” are broad terms, having their ordinary meanings, and further refer to, without limitation, mechanical energy transferred through longitudinal pressure or compression waves. Ultrasonic energy can be emitted as continuous or pulsed waves, depending on the requirements of a particular application. Additionally, ultrasonic energy can be emitted in waveforms having various shapes, such as sinusoidal waves, triangle waves, square waves, or other wave forms. Ultrasonic energy includes sound waves. In certain embodiments, the ultrasonic energy has a frequency between about 20 kHz and about 20 MHz. For example, in one embodiment, the waves have a frequency between about 500 kHz and about 20 MHz.
- the waves have a frequency between about 1 MHz and about 3 MHz. In yet another embodiment, the waves have a frequency of about 2 MHz.
- the average acoustic power is between about 0.01 watts and 300 watts. In one embodiment, the average acoustic power is about 15 watts.
- an ultrasound radiating member refers to any apparatus capable of producing ultrasonic energy.
- an ultrasound radiating member comprises an ultrasonic transducer, which converts electrical energy into ultrasonic energy.
- a suitable example of an ultrasonic transducer for generating ultrasonic energy from electrical energy includes, but is not limited to, piezoelectric ceramic oscillators.
- Piezoelectric ceramics typically comprise a crystalline material, such as quartz, that change shape when an electrical current is applied to the material. This change in shape, made oscillatory by an oscillating driving signal, creates ultrasonic sound waves.
- ultrasonic energy can be generated by an ultrasonic transducer that is remote from the ultrasound radiating member, and the ultrasonic energy can be transmitted, via, for example, a wire that is coupled to the ultrasound radiating member.
- the control circuitry 100 preferably comprises, among other things, a voltage source 102 .
- the voltage source 102 comprises a positive terminal 104 and a negative terminal 106 .
- the negative terminal 106 is connected to common wire 108 , which connects the five groups G 1 -G 5 of ultrasound radiating members 40 in series.
- the positive terminal 104 is connected to a plurality of lead wires 110 , which each connect to one of the five groups G 1 -G 5 of ultrasound radiating members 40 .
- each of the five groups G 1 -G 5 is connected to the positive terminal 104 via one of the lead wires 110 , and to the negative terminal 106 via the common wire 108 .
- each group G 1 -G 5 comprises a plurality of ultrasound radiating members 40 .
- Each of the ultrasound radiating members 40 is electrically connected to the common wire 108 and to the lead wire 110 via one of two positive contact wires 112 .
- a constant voltage difference will be applied to each ultrasound radiating member 40 in the group.
- the group illustrated in FIG. 6 comprises twelve ultrasound radiating members 40 , one of ordinary skill in the art will recognize that more or fewer ultrasound radiating members 40 can be included in the group. Likewise, more or fewer than five groups can be included within the ultrasound assembly 42 illustrated in FIG. 5 .
- FIG. 7A illustrates one preferred technique for arranging the components of the ultrasound assembly 42 (as schematically illustrated in FIG. 5 ) into the inner core 34 (as schematically illustrated in FIG. 4 ).
- FIG. 7A is a cross-sectional view of the ultrasound assembly 42 taken within group G 1 in FIG. 5 , as indicated by the presence of four lead wires 110 .
- group G 1 in FIG. 5 the ultrasound assembly 42
- lead wires 110 the lead wire connecting group G 5
- the common wire 108 comprises an elongate, flat piece of electrically conductive material in electrical contact with a pair of ultrasound radiating members 40 .
- Each of the ultrasound radiating members 40 is also in electrical contact with a positive contact wire 112 .
- Lead wires 110 are preferably separated from the other components of the ultrasound assembly 42 , thus preventing interference with the operation of the ultrasound radiating members 40 as described above.
- the inner core 34 is filled with an insulating potting material 43 , thus deterring unwanted electrical contact between the various components of the ultrasound assembly 42 .
- FIGS. 7B and 7C illustrate cross sectional views of the inner core 34 of FIG. 7A taken along lines 7 B- 7 B and 7 C- 7 C, respectively.
- the ultrasound radiating members 40 are mounted in pairs along the common wire 108 .
- the ultrasound radiating members 40 are connected by positive contact wires 112 , such that substantially the same voltage is applied to each ultrasound radiating member 40 .
- the common wire 108 preferably comprises wide regions 108 W upon which the ultrasound radiating members 40 can be mounted, thus reducing the likelihood that the paired ultrasound radiating members 40 will short together.
- the common wire 108 may have a more conventional, rounded wire shape.
- the common wire 108 is twisted to form a helical shape before being fixed within the inner core 34 .
- the ultrasound radiating members 40 are oriented in a plurality of radial directions, thus enhancing the radial uniformity of the resulting ultrasonic energy field.
- each group G 1 , G 2 , G 3 , G 4 , G 5 can be independently powered.
- each group can be individually turned on or off, or can be driven with an individualized power. This provides the advantage of allowing the delivery of ultrasonic energy to be “turned off” in regions of the treatment site where treatment is complete, thus preventing deleterious or unnecessary ultrasonic energy to be applied to the patient.
- FIGS. 5 through 7 illustrate a plurality of ultrasound radiating members grouped spatially. That is, in such embodiments, all of the ultrasound radiating members within a certain group are positioned adjacent to each other, such that when a single group is activated, ultrasonic energy is delivered at a specific length of the ultrasound assembly.
- the ultrasound radiating members of a certain group may be spaced apart from each other, such that the ultrasound radiating members within a certain group are not positioned adjacent to each other.
- ultrasonic energy can be delivered from a larger, spaced apart portion of the energy delivery section.
- Such modified embodiments may be advantageous in applications wherein it is desired to deliver a less focussed, more diffuse ultrasonic energy field to the treatment site.
- the ultrasound radiating members 40 comprise rectangular lead zirconate titanate (“PZT”) ultrasound transducers that have dimensions of about 0.017 inches by about 0.010 inches by about 0.080 inches. In other embodiments, other configurations may be used. For example, disc-shaped ultrasound radiating members 40 can be used in other embodiments.
- the common wire 108 comprises copper, and is about 0.005 inches thick, although other electrically conductive materials and other dimensions can be used in other embodiments.
- Lead wires 110 are preferably 36-gauge electrical conductors, while positive contact wires 112 are preferably 42-gauge electrical conductors. However, one of ordinary skill in the art will recognize that other wire gauges can be used in other embodiments.
- suitable frequencies for the ultrasound radiating member 40 include, but are not limited to, from about 20 kHz to about 20 MHz. In one embodiment, the frequency is between about 500 kHz and 20 MHz, and in another embodiment the frequency is between about 1 MHz and 3 MHz. In yet another embodiment, the ultrasound radiating members 40 are operated with a frequency of about 2 MHz.
- FIG. 8 illustrates the inner core 34 positioned within the tubular body 12 . Details of the ultrasound assembly 42 , provided in FIG. 7A , are omitted for clarity. As described above, the inner core 34 can be slid within the central lumen 51 of the tubular body 12 , thereby allowing the inner core energy delivery section 41 to be positioned within the tubular body energy delivery section 18 .
- the materials comprising the inner core energy delivery section 41 , the tubular body energy delivery section 18 , and the potting material 43 all comprise materials having a similar acoustic impedance, thereby minimizing ultrasonic energy losses across material interfaces.
- FIG. 8 further illustrates placement of fluid delivery ports 58 within the tubular body energy delivery section 18 .
- holes or slits are formed from the fluid delivery lumen 30 through the tubular body 12 , thereby permitting fluid flow from the fluid delivery lumen 30 to the treatment site.
- a source of therapeutic compound coupled to the inlet port 32 provides a hydraulic pressure which drives the therapeutic compound through the fluid delivery lumens 30 and out the fluid delivery ports 58 .
- fluid delivery ports 58 can be selected to provide uniform fluid flow from the fluid delivery lumen 30 to the treatment site.
- fluid delivery ports 58 closer to the proximal region of the energy delivery section 18 have smaller diameters than fluid delivery ports 58 closer to the distal region of the energy delivery section 18 , thereby allowing uniform delivery of fluid across the entire energy delivery section 18 .
- the fluid delivery ports 58 have a diameter between about 0.0005 inches to about 0.0050 inches.
- the fluid delivery ports 58 have a diameter between about 0.001 inches to about 0.005 inches in the proximal region of the energy delivery section 18 , and between about 0.005 inches to 0.0020 inches in the distal region of the energy delivery section 18 .
- the increase in size between adjacent fluid delivery ports 58 depends on the material comprising the tubular body 12 , and on the size of the fluid delivery lumen 30 .
- the fluid delivery ports 58 can be created in the tubular body 12 by punching, drilling, burning or ablating (such as with a laser), or by any other suitable method. Therapeutic compound flow along the length of the tubular body 12 can also be increased by increasing the density of the fluid delivery ports 58 toward the distal region 15 of the tubular body 12 .
- the size, location and geometry of the fluid delivery ports 58 can be selected to provide such non-uniform fluid flow.
- cooling fluid lumens 44 are formed between an outer surface 39 of the inner core 34 and an inner surface 16 of the tubular body 12 .
- a cooling fluid is introduced through the proximal access port 31 such that cooling fluid flow is produced through cooling fluid lumens 44 and out distal exit port 29 (see FIG. 1 ).
- the cooling fluid lumens 44 are preferably evenly spaced around the circumference of the tubular body 12 (that is, at approximately 120° increments for a three-lumen configuration), thereby providing uniform cooling fluid flow over the inner core 34 . Such a configuration is desired to remove unwanted thermal energy at the treatment site.
- the flow rate of the cooling fluid and the power to the ultrasound assembly 42 can be adjusted to maintain the temperature of the inner core energy delivery section 41 within a desired range.
- the inner core 34 can be rotated or moved within the tubular body 12 . Specifically, movement of the inner core 34 can be accomplished by maneuvering the proximal hub 37 while holding the backend hub 33 stationary.
- the inner core outer body 35 is at least partially constructed from a material that provides enough structural support to permit movement of the inner core 34 within the tubular body 12 without kinking of the tubular body 12 .
- the inner core outer body 35 preferably comprises a material having the ability to transmit torque. Suitable materials for the inner core outer body 35 include, but are not limited to, polyimides, polyesters, polyurethanes, thermoplastic elastomers and braided polyimides.
- the fluid delivery lumens 30 and the cooling fluid lumens 44 are open at the distal end of the tubular body 12 , thereby allowing the therapeutic compound and the cooling fluid to pass into the patient's vasculature at the distal exit port.
- the fluid delivery lumens 30 can be selectively occluded at the distal end of the tubular body 12 , thereby providing additional hydraulic pressure to drive the therapeutic compound out of the fluid delivery ports 58 .
- the inner core 34 can prevented from passing through the distal exit port by configuring the inner core 34 to have a length that is less than the length of the tubular body 12 .
- a protrusion is formed on the inner surface 16 of the tubular body 12 in the distal region 15 , thereby preventing the inner core 34 from passing through the distal exit port 29 .
- the catheter 10 further comprises an occlusion device (not shown) positioned at the distal exit port 29 .
- the occlusion device preferably has a reduced inner diameter that can accommodate a guidewire, but that is less than the outer diameter of the central lumen 51 .
- suitable inner diameters for the occlusion device include, but are not limited to, about 0.005 inches to about 0.050 inches.
- the occlusion device has a closed end, thus preventing cooling fluid from leaving the catheter 10 , and instead recirculating to the proximal region 14 of the tubular body 12 .
- the tubular body 12 further comprises one or more temperature sensors 20 , which are preferably located within the energy delivery section 18 .
- the proximal region 14 of the tubular body 12 includes a temperature sensor lead wire (not shown) which can be incorporated into cable 45 (illustrated in FIG. 1 ).
- Suitable temperature sensors include, but are not limited to, temperature sensing diodes, thermistors, thermocouples, resistance temperature detectors (“RTDs”) and fiber optic temperature sensors which use thermalchromic liquid crystals.
- Suitable temperature sensor 20 geometries include, but are not limited to, a point, a patch or a stripe.
- the temperature sensors 20 can be positioned within one or more of the fluid delivery lumens 30 , and/or within one or more of the cooling fluid lumens 44 .
- FIG. 9 illustrates one embodiment for electrically connecting the temperature sensors 20 .
- each temperature sensor 20 is coupled to a common wire 61 and is associated with an individual return wire 62 .
- n+1 wires can be used to independently sense the temperature at n distinct temperature sensors 20 .
- the temperature at a particular temperature sensor 20 can be determined by closing a switch 64 to complete a circuit between that thermocouple's individual return wire 62 and the common wire 61 .
- the temperature can be calculated from the voltage in the circuit using, for example, a sensing circuit 63 , which can be located within the external control circuitry 100 .
- each temperature sensor 20 is independently wired.
- 2n wires pass through the tubular body 12 to independently sense the temperature at n independent temperature sensors 20 .
- the flexibility of the tubular body 12 can be improved by using fiber optic based temperature sensors 20 . In such embodiments, flexibility can be improved because only n fiber optic members are used to sense the temperature at n independent temperature sensors 20 .
- FIG. 10 illustrates one embodiment of a feedback control system 68 that can be used with the catheter 10 .
- the feedback control system 68 can be integrated into the control system that is connected to the inner core 34 via cable 45 (as illustrated in FIG. 1 ).
- the feedback control system 68 allows the temperature at each temperature sensor 20 to be monitored and allows the output power of the energy source 70 to be adjusted accordingly.
- a physician can, if desired, override the closed or open loop system.
- the feedback control system 68 preferably comprises an energy source 70 , power circuits 72 and a power calculation device 74 that is coupled to the ultrasound radiating members 40 .
- a temperature measurement device 76 is coupled to the temperature sensors 20 in the tubular body 12 .
- a processing unit 78 is coupled to the power calculation device 74 , the power circuits 72 and a user interface and display 80 .
- the temperature at each temperature sensor 20 is determined by the temperature measurement device 76 .
- the processing unit 78 receives each determined temperature from the temperature measurement device 76 .
- the determined temperature can then be displayed to the user at the user interface and display 80 .
- the processing unit 78 comprises logic for generating a temperature control signal.
- the temperature control signal is proportional to the difference between the measured temperature and a desired temperature.
- the desired temperature can be determined by the user (set at the user interface and display 80 ) or can be preset within the processing unit 78 .
- the temperature control signal is received by the power circuits 72 .
- the power circuits 72 are preferably configured to adjust the power level, voltage, phase and/or current of the electrical energy supplied to the ultrasound radiating members 40 from the energy source 70 . For example, when the temperature control signal is above a particular level, the power supplied to a particular group of ultrasound radiating members 40 is preferably reduced in response to that temperature control signal. Similarly, when the temperature control signal is below a particular level, the power supplied to a particular group of ultrasound radiating members 40 is preferably increased in response to that temperature control signal.
- the processing unit 78 preferably monitors the temperature sensors 20 and produces another temperature control signal which is received by the power circuits 72 .
- the processing unit 78 preferably further comprises safety control logic.
- the safety control logic detects when the temperature at a temperature sensor 20 has exceeded a safety threshold.
- the processing unit 78 can then provide a temperature control signal which causes the power circuits 72 to stop the delivery of energy from the energy source 70 to that particular group of ultrasound radiating members 40 .
- the ultrasound radiating members 40 are mobile relative to the temperature sensors 20 , it can be unclear which group of ultrasound radiating members 40 should have a power, voltage, phase and/or current level adjustment. Consequently, each group of ultrasound radiating member 40 can be identically adjusted in certain embodiments.
- the power, voltage, phase, and/or current supplied to each group of ultrasound radiating members 40 is adjusted in response to the temperature sensor 20 which indicates the highest temperature. Making voltage, phase and/or current adjustments in response to the temperature sensed by the temperature sensor 20 indicating the highest temperature can reduce overheating of the treatment site.
- the processing unit 78 also receives a power signal from a power calculation device 74 .
- the power signal can be used to determine the power being received by each group of ultrasound radiating members 40 .
- the determined power can then be displayed to the user on the user interface and display 80 .
- the feedback control system 68 can be configured to maintain tissue adjacent to the energy delivery section 18 below a desired temperature. For example, it is generally desirable to prevent tissue at a treatment site from increasing more than 6° C.
- the ultrasound radiating members 40 can be electrically connected such that each group of ultrasound radiating members 40 generates an independent output. In certain embodiments, the output from the power circuit maintains a selected energy for each group of ultrasound radiating members 40 for a selected length of time.
- the processing unit 78 can comprise a digital or analog controller, such as for example a computer with software.
- the processing unit 78 can include a central processing unit (“CPU”) coupled through a system bus.
- the user interface and display 80 can comprise a mouse, a keyboard, a disk drive, a display monitor, a nonvolatile memory system, or any another.
- Also preferably coupled to the bus is a program memory and a data memory.
- a profile of the power to be delivered to each group of ultrasound radiating members 40 can be incorporated into the processing unit 78 , such that a preset amount of ultrasonic energy to be delivered is pre-profiled.
- the power delivered to each group of ultrasound radiating members 40 can then be adjusted according to the preset profiles.
- the ultrasound radiating members 40 are preferably operated in a pulsed mode.
- the time average power supplied to the ultrasound radiating members 40 is preferably between about 0.1 watts and 2 watts and more preferably between about 0.5 watts and 1.5 watts. In certain preferred embodiments, the time average power is approximately 0.6 watts or 1.2 watts.
- the duty cycle is preferably between about 1% and 50% and more preferably between about 5% and 25%. In certain preferred embodiments, the duty ratio is approximately 7.5% or 15%.
- the pulse averaged power is preferably between about 0.1 watts and 20 watts and more preferably between approximately 5 watts and 20 watts. In certain preferred embodiments, the pulse averaged power is approximately 8 watts and 16 watts.
- the amplitude during each pulse can be constant or varied.
- the pulse repetition rate is preferably between about 5 Hz and 150 Hz and more preferably between about 10 Hz and 50 Hz. In certain preferred embodiments, the pulse repetition rate is approximately 30 Hz.
- the pulse duration is preferably between about 1 millisecond and 50 milliseconds and more preferably between about 1 millisecond and 25 milliseconds. In certain preferred embodiments, the pulse duration is approximately 2.5 milliseconds or 5 milliseconds.
- the ultrasound radiating members 40 are operated at an average power of approximately 0.6 watts, a duty cycle of approximately 7.5%, a pulse repetition rate of 30 Hz, a pulse average electrical power of approximately 8 watts and a pulse duration of approximately 2.5 milliseconds.
- the ultrasound radiating members 40 used with the electrical parameters described herein preferably has an acoustic efficiency greater than 50% and more preferably greater than 75%.
- the ultrasound radiating members 40 can be formed a variety of shapes, such as, cylindrical (solid or hollow), flat, bar, triangular, and the like.
- the length of the ultrasound radiating members 40 is preferably between about 0.1 cm and about 0.5 cm.
- the thickness or diameter of the ultrasound radiating members 40 is preferably between about 0.02 cm and about 0.2 cm.
- FIGS. 11A through 11D illustrate a method for using the ultrasonic catheter 10 .
- a guidewire 84 similar to a guidewire used in typical angioplasty procedures is directed through a patient's vessels 86 to a treatment site 88 which includes a clot 90 .
- the guidewire 84 is directed through the clot 90 .
- Suitable vessels 86 include, but are not limited to, the large periphery and the small cerebral blood vessels of the body.
- the ultrasonic catheter 10 also has utility in various imaging applications or in applications for treating and/or diagnosing other diseases in other body parts.
- the tubular body 12 is slid over and is advanced along the guidewire 84 using conventional over-the-guidewire techniques.
- the tubular body 12 is advanced until the energy delivery section 18 of the tubular body 12 is positioned at the clot 90 .
- radiopaque markers are positioned along the energy delivery section 18 of the tubular body 12 to aid in the positioning of the tubular body 12 within the treatment site 88 .
- the guidewire 84 is then withdrawn from the tubular body 12 by pulling the guidewire 84 from the proximal region 14 of the catheter 10 while holding the tubular body 12 stationary. This leaves the tubular body 12 positioned at the treatment site 88 .
- the inner core 34 is then inserted into the tubular body 12 until the ultrasound assembly is positioned at least partially within the energy delivery section 18 of the tubular body 12 .
- the ultrasound assembly 42 is activated to deliver ultrasonic energy through the energy delivery section 18 to the clot 90 .
- suitable ultrasonic energy is delivered with a frequency between about 20 kHz and about 20 MHz.
- the ultrasound assembly 42 comprises sixty ultrasound radiating members 40 spaced over a length between approximately 30 cm and 50 cm.
- the catheter 10 can be used to treat an elongate clot 90 without requiring movement of or repositioning of the catheter 10 during the treatment.
- the inner core 34 can be moved or rotated within the tubular body 12 during the treatment. Such movement can be accomplished by maneuvering the proximal hub 37 of the inner core 34 while holding the backend hub 33 stationary.
- arrows 48 indicate that a cooling fluid flows through the cooling fluid lumen 44 and out the distal exit port 29 .
- arrows 49 indicate that a therapeutic compound flows through the fluid delivery lumen 30 and out the fluid delivery ports 58 to the treatment site 88 .
- the cooling fluid can be delivered before, after, during or intermittently with the delivery of ultrasonic energy.
- the therapeutic compound can be delivered before, after, during or intermittently with the delivery of ultrasonic energy. Consequently, the steps illustrated in FIGS. 11A through 11D can be performed in a variety of different orders than as described above.
- the therapeutic compound and ultrasonic energy are preferably applied until the clot 90 is partially or entirely dissolved. Once the clot 90 has been dissolved to the desired degree, the tubular body 12 and the inner core 34 are withdrawn from the treatment site 88 .
- the various embodiments of the ultrasound catheters disclosed herein can be used with a therapeutic compound to dissolve a clot and reestablish blood flow in a blood vessel.
- a therapeutic compound can have adverse side effects such that it is generally undesirable to continue to administer the therapeutic compound after blood flow has been reestablished.
- generating ultrasonic energy tends to create heat, which can damage the blood vessel. It is therefore generally undesirable to continue operating the ultrasound radiating members after the clot has been sufficiently dissolved.
- the treatment of the patient may need to move to another stage.
- certain treatment parameters for example, flow of therapeutic compound, ultrasound frequency, ultrasound power, ultrasound pulsing parameters, position of the ultrasound radiating members, and so
- the methods and apparatuses for determining when blood flow has been reestablished and/or the degree to which blood flow has been reestablished, as disclosed herein, can be used with a feedback control system.
- a feedback control system can be a closed or open loop system that is configured to adjust the treatment parameters in response to the data received from the apparatus.
- the physician can, if desired, override the closed or open loop system.
- the data can be displayed to the physician or a technician such that the physician or technician can adjust treatment parameters and/or make decisions as to the treatment of the patient.
- one or more temperature sensors positioned on or within the catheter can be used to detect and/or measure the reestablishment of blood flow at a clot dissolution treatment site.
- the temperature sensor can be used to measure and analyze the temperature of the cooling fluid, the therapeutic compound and/or the blood surrounding the catheter.
- temperature sensors can be mounted on the outside of the catheter, on the ultrasound radiating members in the inner core, or in any of the fluid lumens to detect differential temperatures of the blood, cooling fluid, or therapeutic compound along the catheter length as a function of time. See, for example, the positioning of the temperature sensors 20 illustrated in FIG. 8 .
- FIG. 12 A preferred embodiment for using thermal measurements to detect and/or measure the reestablishment of blood flow during a clot dissolution treatment is illustrated schematically in FIG. 12 .
- a catheter 10 is positioned through a clot 90 at a treatment site 88 in a patient's vasculature 86 .
- the catheter 10 includes at least an upstream thermal source 120 and a downstream thermal detector 122 .
- the thermal source 120 and thermal detector 122 can be positioned on, within, or integral with the catheter 10 .
- the thermal source 120 comprises any source of thermal energy, such as a resistance heater.
- one or more of the ultrasound radiating members comprising the ultrasound assembly can function as a source of thermal energy.
- the thermal detector 122 comprises any device capable of detecting the presence (or absence) of thermal energy, such as a diode, thermistor, thermocouple, and so forth.
- one or more of the ultrasound radiating members can be used as a thermal detector by measuring changes in their electrical characteristics (such as, for example, impedance or resonating frequency).
- the thermal source 120 supplies thermal energy into its surrounding environment. For example, if the thermal source 120 is affixed to the outer surface of the catheter 10 , then thermal energy is supplied into the surrounding bloodstream. Likewise, if the thermal source is positioned within the fluid delivery lumens 30 and/or the cooling fluid lumens 44 (illustrated in FIG. 8 ), then thermal energy is supplied into the fluid contained therein.
- FIG. 13A illustrates that when the thermal source 120 supplies thermal energy into the surrounding environment, a “thermal pulse” 124 is created therein.
- a thermal pulse 124 is created therein.
- the medium into which thermal energy is supplied has a flow rate, then the thermal pulse 124 will propagate with the medium.
- the thermal pulse 124 can propagate, for example, by mass transfer (that is, due to physical movement of the heated medium) or by thermal conduction (that is, due to thermal energy propagating through a stationary medium).
- the resultant thermal pulse 124 will likewise flow downstream through the cooling fluid lumen.
- the resultant thermal pulse 124 will flow downstream through the patient's vasculature 86 .
- the thermal pulse 124 can propagate according to other thermal propagation mechanisms.
- the characteristics of the thermal pulse 124 will change. For example, some of the excess thermal energy in the thermal pulse 124 will dissipate into surrounding tissues and/or surrounding catheter structures, thereby reducing the intensity of the thermal pulse 124 . Additionally, as the thermal pulse 124 passes through and/or reflects from various materials (such as, for example, clot, blood, tissue, and so forth), the pulse width may increase. When the thermal pulse 124 reaches the thermal detector 122 , its characteristics can be measured and analyzed, thereby providing information about blood flow at the treatment site 88 .
- the characteristics (such as, for example, pulse width and intensity) of a thermal pulse supplied from the exterior of the catheter to the surrounding bloodstream will remain substantially unchanged between the thermal source and the thermal detector. This indicates that little thermal energy dissipated into surrounding tissues between the thermal source and the thermal detector, and therefore that the thermal pulse propagated rapidly (that is, high blood flow rate at the treatment site).
- the same characteristics of a thermal pulse supplied from the exterior of the catheter to the surrounding bloodstream will substantially change between the thermal source and the thermal detector. This indicates that a substantial amount of thermal energy dissipated into surrounding tissues between the thermal source and the thermal detector, and therefore that the thermal pulse propagated slowly (that is, low blood flow rate at the treatment site).
- thermal pulse intensity reduction In applications where the thermal pulse is supplied from and detected in one of the fluid lumens positioned in the interior of the catheter, reestablishment of blood flow can be evaluated based on the thermal pulse intensity reduction. Specifically, as a clot dissolution treatment progresses, less clot material will be available to absorb energy from the thermal pulse. Thus, in such applications, a high thermal pulse intensity reduction indicates little clot dissolution has occurred, while a low thermal pulse intensity reduction indicates that the clot dissolution treatment has progressed significantly.
- the amount of time required for the thermal pulse 124 to propagate from the thermal source 120 to the thermal detector 122 provides an indication of the propagation speed of the pulse, thus providing a further indication of blood flow rate at the treatment site 88 .
- FIGS. 13A and 13B illustrate that a thermal pulse 124 created at the thermal source 120 at time t o can be detected at the thermal detector 122 at a later time t o + ⁇ t.
- the time differential ⁇ t, along with the distance between the thermal source 120 and the thermal detector 122 can provide information about the blood flow rate between those two points, thereby allowing the progression of a clot dissolution treatment to be evaluated.
- the thermal pulse 124 need not be a single spike, as illustrated in FIG. 13 , but rather can be a square wave or a sinusoidal signal.
- a thermal signal phase shift between the thermal source and the thermal detector provides a measure of the volumetric flow rate between such points. This provides yet another variable for evaluating the progression of a clot dissolution treatment.
- the catheter comprises a temperature sensor without a thermal source. See, for example, the embodiment illustrated in FIG. 8 .
- a temperature sensor without a thermal source.
- the shape of a reference time-temperature curve can be determined under reference conditions. During the clot dissolution treatment, the shape of the time-temperature curve can be compared to the reference time-temperature curve, and significant alternations can trigger the processing unit 78 to trigger an alarm via the user interface and display 80 (see FIG. 10 ).
- blood flow evaluations can be made based on algorithms other than the thermal pulse delay, thermal dilution, and thermal signal phase shift algorithms disclosed herein.
- certain of the concepts disclosed herein can be applied to optical, Doppler, electromagnetic, and other flow evaluation algorithms some of which are described below.
- the distal region of the catheter includes an optical sensing system, such as, for example, a fiber optic or pass detector, to determine the degree to which a clot has been dissolved and/or the degree to which blood flow has been reestablished.
- an optical sensing system such as, for example, a fiber optic or pass detector
- the therapeutic compound may contain fluorescent indicators and the sensing system can be used to observe the intrinsic fluorescence of the therapeutic compound or extrinsic fluorescent indicators that are provided in the therapeutic compound.
- the optical sensing system can be used to differentiate between a condition where a therapeutic compound is located proximal to a clotted area (that is, a substantially obstructed vessel) and a condition where predominately blood is located around a previously clotted area (that is, a substantially unobstructed vessel).
- a color detector can be used to monitor the fluid color around the clotted area to differentiate between a substantially clot and therapeutic compound condition (that is, a substantially obstructed vessel) and a substantially blood only condition (this is, a substantially open vessel).
- the color detector can be used to differentiate between the walls of the blood vessel (that is, open vessel) and a clot (that is, obstructed vessel).
- the sensing system can be configured to sense differences outside the visible light range.
- an infrared detection system can be configured to sense differences between the walls of the blood vessel and a clot.
- the optical sensor can be positioned upstream, downstream and/or within the clot.
- the optical measurements can be correlated with clinical data so as to quantify the degree to which blood flow has been reestablished.
- the catheter can be configured to use a Doppler frequency shift and/or flight to determine if blood flow has been reestablished. That is, the frequency shift of the ultrasonic energy as it passes through a clotted vessel and/or the time required for the ultrasonic energy to pass through a clotted vessel can be used to determine the degree to which the clot has been dissolved. In one arrangement, this can be accomplished internally using the ultrasound radiating members of the catheter and/or using ultrasonic receiving members positioned in the catheter. In another arrangement, the sensing ultrasonic energy can be generated outside the patient's body and/or received outside the patient's body (for example, via a cuff placed around the treatment site).
- blood pressure could be used to determine blood flow reestablishment.
- the ultrasound radiating members can be used to detect pressure in the internal fluid column.
- individual sensors or lumens can be used.
- a sensor can be configured to monitor the color or temperature of a portion of the patient's body that is affected by the clot. For example, for a clot in the leg, toe color and temperature indicates reestablished blood flow in the leg. As with all the embodiments described herein, such information can be integrated into a control feedback system as described above.
- an accelerometer or motion detector can be configured to sense the vibration in the catheter or in a portion of the patient's body caused by reestablished blood flow.
- one or more electromagnetic flow sensors can be used to sense reestablished blood flow near the clotted area.
- markers for example, dye, bubbles, cold, heat, and so forth
- the marker can be injected at an upstream point. Sensing the passage of such markers past a detector positioned downstream of the upstream injection point indicates blood flow. The rate of passage indicates the degree to which blood flow has been reestablished.
- an external plethysmograph band can be used to determine blood flow. This could be oriented with respect to the catheter radially or in another dimension.
- blood oxygenation can be used to determine the presence of blood flow.
Landscapes
- Health & Medical Sciences (AREA)
- Surgery (AREA)
- Engineering & Computer Science (AREA)
- Life Sciences & Earth Sciences (AREA)
- Medical Informatics (AREA)
- Molecular Biology (AREA)
- Vascular Medicine (AREA)
- Orthopedic Medicine & Surgery (AREA)
- Biomedical Technology (AREA)
- Heart & Thoracic Surgery (AREA)
- Mechanical Engineering (AREA)
- Nuclear Medicine, Radiotherapy & Molecular Imaging (AREA)
- Animal Behavior & Ethology (AREA)
- General Health & Medical Sciences (AREA)
- Public Health (AREA)
- Veterinary Medicine (AREA)
- Media Introduction/Drainage Providing Device (AREA)
- Surgical Instruments (AREA)
- Measuring Pulse, Heart Rate, Blood Pressure Or Blood Flow (AREA)
- Ultra Sonic Daignosis Equipment (AREA)
Abstract
Description
- This application is a continuation of U.S.
patent application 10/320,847 (filed 16 Dec. 2002), which claims priority under 35 U.S.C. § 119(e) from U.S. Provisional Patent Application Ser. No. 60/341,430, entitled “Methods and Apparatus for Determining Reestablishment of Blood Flow” and filed Dec. 14, 2001; as well as U.S. Provisional Application Ser. No. 60/347,350, entitled “Methods and Apparatus for Determining Reestablishment of Blood Flow” and filed Jan. 10, 2002; as well as U.S. Provisional Application Ser. No. 60/369,453, entitled “Methods and Apparatus for Determining Reestablishment of Blood Flow” and filed Apr. 2, 2002. The entire disclosure of all four of these priority documents is hereby incorporated by reference in its entirety. - 1. Field of the Invention
- The preferred embodiments of the present invention relate to methods and apparatuses for monitoring the efficacy of a clot dissolution treatment. The methods and apparatuses are particularly well suited for use with an ultrasonic catheter configured to deliver ultrasonic energy and a therapeutic compound to a treatment site.
- 2. Description of the Related Art
- Several medical applications use ultrasonic energy. For example, U.S. Pat. Nos. 4,821,740, 4,953,565 and 5,007,438 disclose the use of ultrasonic energy to enhance the effect of various therapeutic compounds. An ultrasonic catheter can be used to deliver ultrasonic energy and a therapeutic compound to a treatment site in a patient's body. Such an ultrasonic catheter typically includes an ultrasound assembly configured to generate ultrasonic energy and a fluid delivery lumen for delivering the therapeutic compound to the treatment site.
- As taught in U.S. Pat. No. 6,001,069, such ultrasonic catheters can be used to treat human blood vessels that have become partially or completely occluded by plaque, thrombi, emboli or other substances that reduce the blood carrying capacity of the vessel. To remove or reduce the occlusion, the ultrasonic catheter is used to deliver solutions containing dissolution compounds directly to the occlusion site. Ultrasonic energy generated by the ultrasound assembly enhances the therapeutic effect of the dissolution compounds. For example, in one application of such an ultrasonic catheter, an ultrasound-enhanced thrombolytic therapy dissolves blood clots in arteries and veins in the treatment of diseases such as peripheral arterial occlusion or deep vein thrombosis. In such applications, ultrasonic energy enhances thrombolysis with agents such as urokinase, tissue plasminogen activator (“TPA”) and the like.
- Ultrasonic catheters can also be used to enhance gene therapy at a treatment site within the patient's body. For example, U.S. Pat. No. 6,135,976 discloses an ultrasonic catheter having one or more expandable sections capable of occluding a section of a body lumen, such as a blood vessel. A gene therapy composition is then delivered to the occluded vessel through the catheter fluid delivery lumen. Ultrasonic energy generated by the ultrasound assembly is applied to the occluded vessel, thereby enhancing the delivery of a genetic composition into the cells of the occluded vessel.
- Ultrasonic catheters can also be used to enhance delivery and activation of light activated drugs. For example, U.S. Pat. No. 6,176,842 discloses methods for using an ultrasonic catheter to treat biological tissues by delivering a light activated drug to the biological tissues and exposing the light activated drug to ultrasound energy.
- In certain medical procedures, it is desirable to provide no more therapeutic compound or ultrasonic energy to the treatment site than necessary to perform a medical treatment. For example, certain therapeutic compounds, although effective in dissolving blockages in the vascular system, may have adverse side effects on other biological systems. In addition, certain therapeutic compounds are expensive, and thus it is desired to use such therapeutic compounds judiciously. Likewise, excess ultrasonic energy applied to patient's vasculature may have unwanted side effects. Thus, as a treatment progresses, it may be desired to reduce, and eventually terminate, the flow of therapeutic compound or the supply of ultrasonic energy to a treatment site. On the other hand, if a clot dissolution treatment is progressing too slowly, it may be desired to increase the delivery of therapeutic compound or ultrasonic energy to the treatment site in an attempt to cause the treatment to progress faster. To date, it has been difficult to monitor the progression or efficacy of a clot dissolution treatment, and therefore to adjust the flow of therapeutic compound or the delivery of ultrasonic energy to the treatment site accordingly.
- Therefore, a need exists for an improved ultrasonic catheter capable of monitoring the progression or efficacy of a clot dissolution treatment. Preferably, it is possible to adjust the flow of therapeutic compound and/or the delivery of ultrasonic energy to the treatment site as the clot dissolution treatment progresses, eventually terminating the flow of therapeutic compound and the delivery of ultrasonic energy when the treatment has concluded.
- As such, according to one embodiment of the present invention, a method for monitoring a clot dissolution treatment in a patient's vasculature comprises positioning a catheter at a treatment site in the patient's vasculature. The method further comprises performing a clot dissolution treatment at the treatment site. The clot dissolution treatment comprises delivering ultrasonic energy and a therapeutic compound from the catheter to the treatment site such that a clot located at the treatment site at least partially dissolves. The method further comprises delivering a thermal measurement signal from a first portion of the catheter to the treatment site during the clot dissolution treatment. The method further comprises receiving the thermal measurement signal at a second portion of the catheter. The method further comprises comparing the delivered thermal measurement signal with the received thermal measurement signal to evaluate a blood flow rate at the treatment site.
- According to another embodiment of the present invention, a method comprises positioning a catheter at a treatment site in a patient's vasculature. A blockage is located at the treatment site. The method further comprises performing a medical treatment at the treatment site. The medical treatment is configured to reduce the blockage. The method further comprises making a plurality of thermal energy measurements at the treatment site while the medical treatment is being performed. The method further comprises evaluating the reduction in the blockage based on the plurality of thermal energy measurements.
- According to another embodiment of the present invention, an ultrasound catheter for evaluating the efficacy of a clot dissolution treatment comprises an upstream region. The catheter further comprises a downstream region located opposite the upstream region. The catheter further comprises a treatment zone partially extending into both the upstream region and the downstream region. The catheter further comprises an ultrasonic assembly positioned within the treatment zone. The ultrasonic assembly comprises at least one ultrasound radiating member configured to perform a clot dissolution treatment. The catheter further comprises a thermal energy source positioned in the upstream region. The thermal energy source is configured to deliver a thermal measurement signal to the treatment zone during the clot dissolution treatment. The catheter further comprises a thermal energy detector positioned in the downstream region. The thermal energy detector is configured to receive the thermal measurement signal from the treatment zone. The catheter further comprises control circuitry configured to compare the thermal measurement signal delivered from the thermal energy source to the thermal measurement signal received at the thermal energy detector.
- According to another embodiment of the present invention, an apparatus comprises a catheter having an upstream region, a downstream region and a treatment zone partially extending into both the upstream region and the downstream region. The apparatus further comprises an ultrasonic assembly positioned within the treatment zone. The ultrasonic assembly comprises at least one ultrasound radiating member configured to perform a clot dissolution treatment. The apparatus further comprises a thermal energy detector positioned in the treatment zone. The thermal energy detector is configured to make a plurality of thermal energy measurements during the clot dissolution treatment. The apparatus further comprises means for measuring thermal dilution in the treatment zone during the clot dissolution treatment.
- According to another embodiment of the present invention, a method comprises positioning a catheter having an ultrasound radiating member proximal to an obstruction in a patient's vasculature. The method further comprises performing an obstruction dissolution treatment by applying a therapeutic compound and ultrasonic energy to the obstruction such that the obstruction is at least partially dissolved. The method further comprises sensing an at least partial reestablishment of blood flow past the partially dissolved obstruction. The method further comprises adjusting the obstruction dissolution treatment in response to the at least partial reestablishment of blood flow.
-
FIG. 1 is a schematic illustration of an ultrasonic catheter configured for insertion into large vessels of the human body. -
FIG. 2 is a cross-sectional view of the ultrasonic catheter ofFIG. 1 taken along line 2-2. -
FIG. 3 is a schematic illustration of an elongate inner core configured to be positioned within the central lumen of the catheter illustrated inFIG. 2 . -
FIG. 4 is a cross-sectional view of the elongate inner core ofFIG. 3 taken along line 4-4. -
FIG. 5 is a schematic wiring diagram illustrating a preferred technique for electrically connecting five groups of ultrasound radiating members to form an ultrasound assembly. -
FIG. 6 is a schematic wiring diagram illustrating a preferred technique for electrically connecting one of the groups ofFIG. 5 . -
FIG. 7A is a schematic illustration of the ultrasound assembly ofFIG. 5 housed within the inner core ofFIG. 4 . -
FIG. 7B is a cross-sectional view of the ultrasound assembly ofFIG. 7A taken alongline 7B-7B. -
FIG. 7C is a cross-sectional view of the ultrasound assembly ofFIG. 7A taken alongline 7C-7C. -
FIG. 7D is a side view of an ultrasound assembly center wire twisted into a helical configuration. -
FIG. 8 illustrates the energy delivery section of the inner core ofFIG. 4 positioned within the energy delivery section of the tubular body ofFIG. 2 . -
FIG. 9 illustrates a wiring diagram for connecting a plurality of temperature sensors with a common wire. -
FIG. 10 is a block diagram of a feedback control system for use with an ultrasonic catheter. -
FIG. 11A is a side view of a treatment site. -
FIG. 11B is a side view of the distal end of an ultrasonic catheter positioned at the treatment site ofFIG. 11A . -
FIG. 11C is a cross-sectional view of the distal end of the ultrasonic catheter ofFIG. 11B positioned at the treatment site before a treatment. -
FIG. 11D is a cross-sectional view of the distal end of the ultrasonic catheter ofFIG. 11C , wherein an inner core has been inserted into the tubular body to perform a treatment. -
FIG. 12 is a schematic diagram illustrating one arrangement for using thermal measurements for detecting reestablishment of blood flow. -
FIG. 13A is an exemplary plot of temperature as a function of time at a thermal source. -
FIG. 13B is an exemplary plot of temperature as a function of time at a thermal detector - As described above, it is desired to provide an ultrasonic catheter having various features and advantages. Examples of such features and advantages include the ability to monitor the progression or efficacy of a clot dissolution treatment. In another embodiments, the catheter has the ability to adjust the delivery of a therapeutic compound based on the progression of the clot dissolution treatment. Preferred embodiments of an ultrasonic catheter having certain of these features and advantages are described herein. Methods of using such an ultrasonic catheter are also described herein.
- The ultrasonic catheters described herein can be used to enhance the therapeutic effects of therapeutic compounds at a treatment site within a patient's body. As used herein, the term “therapeutic compound” refers broadly, without limitation, to a drug, medicament, dissolution compound, genetic material or any other substance capable of effecting physiological functions. Additionally, any mixture comprising any such substances is encompassed within this definition of “therapeutic compound”, as well as any substance falling within the ordinary meaning of these terms. The enhancement of the effects of therapeutic compounds using ultrasonic energy is described in U.S. Pat. Nos. 5,318,014, 5,362,309, 5,474,531, 5,628,728, 6,001,069 and 6,210,356, the entire disclosure of which are hereby incorporated by herein by reference. Specifically, for applications that treat human blood vessels that have become partially or completely occluded by plaque, thrombi, emboli or other substances that reduce the blood carrying capacity of a vessel, suitable therapeutic compounds include, but are not limited to, an aqueous solution containing Heparin, Uronkinase, Streptokinase, TPA and BB-10153 (manufactured by British Biotech, Oxford, UK).
- Certain features and aspects of the ultrasonic catheters disclosed herein may also find utility in applications where the ultrasonic energy itself provides a therapeutic effect. Examples of such therapeutic effects include preventing or reducing stenosis and/or restenosis; tissue ablation, abrasion or disruption; promoting temporary or permanent physiological changes in intracellular or intercellular structures; and rupturing micro-balloons or micro-bubbles for therapeutic compound delivery. Further information about such methods can be found in U.S. Pat. Nos. 5,261,291 and 5,431,663, the entire disclosure of which are hereby incorporated by herein by reference. Further information about using cavitation to produce biological effects can be found in U.S. Pat. No. RE36,939.
- The ultrasonic catheters described herein are configured for applying ultrasonic energy over a substantial length of a body lumen, such as, for example, the larger vessels located in the leg. However, it should be appreciated that certain features and aspects of the present invention may be applied to catheters configured to be inserted into the small cerebral vessels, in solid tissues, in duct systems and in body cavities. Such catheters are described in U.S. patent application Ser. No. 10/309,417, filed Dec. 3, 2002. Additional embodiments that may be combined with certain features and aspects of the embodiments described herein are described in U.S. patent application Ser. No. 10/291,891, filed Nov. 7, 2002, the entire disclosure of which is hereby incorporated herein by reference.
- For purposes of summarizing the invention and the advantages achieved over the prior art, certain objects and advantages of the invention have been described above. It is to be understood that not necessarily all such objects or advantages may be achieved in accordance with any particular embodiment of the invention. Thus, for example, those skilled in the art will recognize that the invention may be embodied or carried out in a manner that achieves or optimizes one advantage or group of advantages as taught herein without necessarily achieving other objects or advantages as may be taught or suggested herein.
- All of these embodiments are intended to be within the scope of the invention herein disclosed. These and other embodiments of the present invention will become readily apparent to those skilled in the art from the following detailed description of the preferred embodiments having reference to the attached figures, the invention not being limited to any particular preferred embodiment(s) disclosed.
- With initial reference to
FIG. 1 , anultrasonic catheter 10 configured for use in the large vessels of a patient's anatomy is schematically illustrated. For example, theultrasonic catheter 10 illustrated inFIG. 1 can be used to treat long segment peripheral arterial occlusions, such as those in the vascular system of the leg. - As illustrated in
FIG. 1 , theultrasonic catheter 10 generally comprises a multi-component, elongate flexibletubular body 12 having aproximal region 14 and adistal region 15. Thetubular body 12 includes a flexibleenergy delivery section 18 and adistal exit port 29 located in thedistal region 15 of thecatheter 10. Abackend hub 33 is attached to theproximal region 14 of thetubular body 12, thebackend hub 33 comprising aproximal access port 31, aninlet port 32 and a coolingfluid fitting 46. Theproximal access port 31 can be connected to controlcircuitry 100 viacable 45. - The
tubular body 12 and other components of thecatheter 10 can be manufactured in accordance with any of a variety of techniques well known in the catheter manufacturing field. Suitable materials and dimensions can be readily selected based on the natural and anatomical dimensions of the treatment site and on the desired percutaneous access site. - For example, in a preferred embodiment the
proximal region 14 of thetubular body 12 comprises a material that has sufficient flexibility, kink resistance, rigidity and structural support to push theenergy delivery section 18 through the patient's vasculature to a treatment site. Examples of such materials include, but are not limited to, extruded polytetrafluoroethylene (“PTFE”), polyethylenes (“PE”), polyamides and other similar materials. In certain embodiments, theproximal region 14 of thetubular body 12 is reinforced by braiding, mesh or other constructions to provide increased kink resistance and pushability. For example, nickel titanium or stainless steel wires can be placed along or incorporated into thetubular body 12 to reduce kinking. - In an embodiment configured for treating thrombus in the arteries of the leg, the
tubular body 12 has an outside diameter between about 0.060 inches and about 0.075 inches. In another embodiment, thetubular body 12 has an outside diameter of about 0.071 inches. In certain embodiments, thetubular body 12 has an axial length of approximately 105 centimeters, although other lengths may by appropriate for other applications. - The
energy delivery section 18 of thetubular body 12 preferably comprises a material that is thinner than the material comprising theproximal region 14 of thetubular body 12 or a material that has a greater acoustic transparency. Thinner materials generally have greater acoustic transparency than thicker materials. Suitable materials for theenergy delivery section 18 include, but are not limited to, high or low density polyethylenes, urethanes, nylons, and the like. In certain modified embodiments, theenergy delivery section 18 may be formed from the same material or a material of the same thickness as theproximal region 14. - In certain embodiments, the
tubular body 12 is divided into at least three sections of varying stiffness. The first section, which preferably includes theproximal region 14, has a relatively higher stiffness. The second section, which is located in an intermediate region between theproximal region 14 and thedistal region 15 of thetubular body 12, has a relatively lower stiffness. This configuration further facilitates movement and placement of thecatheter 10. The third section, which preferably includes theenergy delivery section 18, generally has a lower stiffness than the second section. -
FIG. 2 illustrates a cross section of thetubular body 12 taken along line 2-2 inFIG. 1 . In the embodiment illustrated inFIG. 2 , threefluid delivery lumens 30 are incorporated into thetubular body 12. In other embodiments, more or fewer fluid delivery lumens can be incorporated into thetubular body 12. The arrangement of thefluid delivery lumens 30 preferably provides a hollowcentral lumen 51 passing through thetubular body 12. The cross-section of thetubular body 12, as illustrated inFIG. 2 , is preferably substantially constant along the length of thecatheter 10. Thus, in such embodiments, substantially the same cross-section is present in both theproximal region 14 and thedistal region 15 of thecatheter 10, including theenergy delivery section 18. - In certain embodiments, the
central lumen 51 has a minimum diameter greater than about 0.030 inches. In another embodiment, thecentral lumen 51 has a minimum diameter greater than about 0.037 inches. In one preferred embodiment, thefluid delivery lumens 30 have dimensions of about 0.026 inches wide by about 0.0075 inches high, although other dimensions may be used in other applications. - As described above, the
central lumen 51 preferably extends through the length of thetubular body 12. As illustrated inFIG. 1 , thecentral lumen 51 preferably has adistal exit port 29 and aproximal access port 31. Theproximal access port 31 forms part of thebackend hub 33, which is attached to theproximal region 14 of thecatheter 10. Thebackend hub 33 preferably further comprises coolingfluid fitting 46, which is hydraulically connected to thecentral lumen 51. Thebackend hub 33 also preferably comprises a therapeuticcompound inlet port 32, which is in hydraulic connection with thefluid delivery lumens 30, and which can be hydraulically coupled to a source of therapeutic compound via a hub such as a Luer fitting. - The
central lumen 51 is configured to receive an elongateinner core 34 of which a preferred embodiment is illustrated inFIG. 3 . The elongateinner core 34 preferably comprises aproximal region 36 and adistal region 38.Proximal hub 37 is fitted on theinner core 34 at one end of theproximal region 36. One or more ultrasound radiating members are positioned within an inner coreenergy delivery section 41 located within thedistal region 38. The ultrasound radiating members form anultrasound assembly 42, which will be described in greater detail below. - As shown in the cross-section illustrated in
FIG. 4 , which is taken along lines 4-4 inFIG. 3 , theinner core 34 preferably has a cylindrical shape, with an outer diameter that permits theinner core 34 to be inserted into thecentral lumen 51 of thetubular body 12 via theproximal access port 31. Suitable outer diameters of theinner core 34 include, but are not limited to, about 0.010 inches to about 0.100 inches. In another embodiment, the outer diameter of theinner core 34 is between about 0.020 inches and about 0.080 inches. In yet another embodiment, theinner core 34 has an outer diameter of about 0.035 inches. - Still referring to
FIG. 4 , theinner core 34 preferably comprises a cylindricalouter body 35 that houses theultrasound assembly 42. Theultrasound assembly 42 comprises wiring and ultrasound radiating members, described in greater detail inFIGS. 5 through 7 D, such that theultrasound assembly 42 is capable of radiating ultrasonic energy from theenergy delivery section 41 of theinner core 34. Theultrasound assembly 42 is electrically connected to thebackend hub 33, where theinner core 34 can be connected to controlcircuitry 100 via cable 45 (illustrated inFIG. 1 ). Preferably, an electrically insulatingpotting material 43 fills theinner core 34, surrounding theultrasound assembly 42, thus preventing movement of theultrasound assembly 42 with respect to theouter body 35. In one embodiment, the thickness of theouter body 35 is between about 0.0002 inches and 0.010 inches. In another embodiment, the thickness of theouter body 35 is between about 0.0002 inches and 0.005 inches. In yet another embodiment, the thickness of theouter body 35 is about 0.0005 inches. - In a preferred embodiment, the
ultrasound assembly 42 comprises a plurality of ultrasound radiating members that are divided into one or more groups. For example,FIGS. 5 and 6 are schematic wiring diagrams illustrating one technique for connecting five groups ofultrasound radiating members 40 to form theultrasound assembly 42. As illustrated inFIG. 5 , theultrasound assembly 42 comprises five groups G1, G2, G3, G4, G5 ofultrasound radiating members 40 that are electrically connected to each other. The five groups are also electrically connected to thecontrol circuitry 100. - As used herein, the terms “ultrasonic energy”, “ultrasound” and “ultrasonic” are broad terms, having their ordinary meanings, and further refer to, without limitation, mechanical energy transferred through longitudinal pressure or compression waves. Ultrasonic energy can be emitted as continuous or pulsed waves, depending on the requirements of a particular application. Additionally, ultrasonic energy can be emitted in waveforms having various shapes, such as sinusoidal waves, triangle waves, square waves, or other wave forms. Ultrasonic energy includes sound waves. In certain embodiments, the ultrasonic energy has a frequency between about 20 kHz and about 20 MHz. For example, in one embodiment, the waves have a frequency between about 500 kHz and about 20 MHz. In another embodiment, the waves have a frequency between about 1 MHz and about 3 MHz. In yet another embodiment, the waves have a frequency of about 2 MHz. The average acoustic power is between about 0.01 watts and 300 watts. In one embodiment, the average acoustic power is about 15 watts.
- As used herein, the term “ultrasound radiating member” refers to any apparatus capable of producing ultrasonic energy. For example, in one embodiment, an ultrasound radiating member comprises an ultrasonic transducer, which converts electrical energy into ultrasonic energy. A suitable example of an ultrasonic transducer for generating ultrasonic energy from electrical energy includes, but is not limited to, piezoelectric ceramic oscillators. Piezoelectric ceramics typically comprise a crystalline material, such as quartz, that change shape when an electrical current is applied to the material. This change in shape, made oscillatory by an oscillating driving signal, creates ultrasonic sound waves. In other embodiments, ultrasonic energy can be generated by an ultrasonic transducer that is remote from the ultrasound radiating member, and the ultrasonic energy can be transmitted, via, for example, a wire that is coupled to the ultrasound radiating member.
- Still referring to
FIG. 5 , thecontrol circuitry 100 preferably comprises, among other things, avoltage source 102. Thevoltage source 102 comprises apositive terminal 104 and anegative terminal 106. Thenegative terminal 106 is connected tocommon wire 108, which connects the five groups G1-G5 ofultrasound radiating members 40 in series. Thepositive terminal 104 is connected to a plurality oflead wires 110, which each connect to one of the five groups G1-G5 ofultrasound radiating members 40. Thus, under this configuration, each of the five groups G1-G5, one of which is illustrated inFIG. 6 , is connected to thepositive terminal 104 via one of thelead wires 110, and to thenegative terminal 106 via thecommon wire 108. - Referring now to
FIG. 6 , each group G1-G5 comprises a plurality ofultrasound radiating members 40. Each of theultrasound radiating members 40 is electrically connected to thecommon wire 108 and to thelead wire 110 via one of twopositive contact wires 112. Thus, when wired as illustrated, a constant voltage difference will be applied to eachultrasound radiating member 40 in the group. Although the group illustrated inFIG. 6 comprises twelveultrasound radiating members 40, one of ordinary skill in the art will recognize that more or fewerultrasound radiating members 40 can be included in the group. Likewise, more or fewer than five groups can be included within theultrasound assembly 42 illustrated inFIG. 5 . -
FIG. 7A illustrates one preferred technique for arranging the components of the ultrasound assembly 42 (as schematically illustrated inFIG. 5 ) into the inner core 34 (as schematically illustrated inFIG. 4 ).FIG. 7A is a cross-sectional view of theultrasound assembly 42 taken within group G1 inFIG. 5 , as indicated by the presence of fourlead wires 110. For example, if a cross-sectional view of theultrasound assembly 42 was taken within group G4 inFIG. 5 , only onelead wire 110 would be present (that is, the one lead wire connecting group G5). - Referring still to
FIG. 7A , thecommon wire 108 comprises an elongate, flat piece of electrically conductive material in electrical contact with a pair ofultrasound radiating members 40. Each of theultrasound radiating members 40 is also in electrical contact with apositive contact wire 112. Because thecommon wire 108 is connected to thenegative terminal 106, and thepositive contact wire 112 is connected to thepositive terminal 104, a voltage difference can be created across eachultrasound radiating member 40. Leadwires 110 are preferably separated from the other components of theultrasound assembly 42, thus preventing interference with the operation of theultrasound radiating members 40 as described above. For example, in one preferred embodiment, theinner core 34 is filled with an insulatingpotting material 43, thus deterring unwanted electrical contact between the various components of theultrasound assembly 42. -
FIGS. 7B and 7C illustrate cross sectional views of theinner core 34 ofFIG. 7A taken alonglines 7B-7B and 7C-7C, respectively. As illustrated inFIG. 7B , theultrasound radiating members 40 are mounted in pairs along thecommon wire 108. Theultrasound radiating members 40 are connected bypositive contact wires 112, such that substantially the same voltage is applied to eachultrasound radiating member 40. As illustrated inFIG. 7C , thecommon wire 108 preferably comprises wide regions 108W upon which theultrasound radiating members 40 can be mounted, thus reducing the likelihood that the pairedultrasound radiating members 40 will short together. In certain embodiments, outside the wide regions 108W, thecommon wire 108 may have a more conventional, rounded wire shape. - In a modified embodiment, such as illustrated in
FIG. 7D , thecommon wire 108 is twisted to form a helical shape before being fixed within theinner core 34. In such embodiments, theultrasound radiating members 40 are oriented in a plurality of radial directions, thus enhancing the radial uniformity of the resulting ultrasonic energy field. - One of ordinary skill in the art will recognize that the wiring arrangement described above can be modified to allow each group G1, G2, G3, G4, G5 to be independently powered. Specifically, by providing a separate power source within the
control system 100 for each group, each group can be individually turned on or off, or can be driven with an individualized power. This provides the advantage of allowing the delivery of ultrasonic energy to be “turned off” in regions of the treatment site where treatment is complete, thus preventing deleterious or unnecessary ultrasonic energy to be applied to the patient. - The embodiments described above, and illustrated in
FIGS. 5 through 7 , illustrate a plurality of ultrasound radiating members grouped spatially. That is, in such embodiments, all of the ultrasound radiating members within a certain group are positioned adjacent to each other, such that when a single group is activated, ultrasonic energy is delivered at a specific length of the ultrasound assembly. However, in modified embodiments, the ultrasound radiating members of a certain group may be spaced apart from each other, such that the ultrasound radiating members within a certain group are not positioned adjacent to each other. In such embodiments, when a single group is activated, ultrasonic energy can be delivered from a larger, spaced apart portion of the energy delivery section. Such modified embodiments may be advantageous in applications wherein it is desired to deliver a less focussed, more diffuse ultrasonic energy field to the treatment site. - In a preferred embodiment, the
ultrasound radiating members 40 comprise rectangular lead zirconate titanate (“PZT”) ultrasound transducers that have dimensions of about 0.017 inches by about 0.010 inches by about 0.080 inches. In other embodiments, other configurations may be used. For example, disc-shapedultrasound radiating members 40 can be used in other embodiments. In a preferred embodiment, thecommon wire 108 comprises copper, and is about 0.005 inches thick, although other electrically conductive materials and other dimensions can be used in other embodiments. Leadwires 110 are preferably 36-gauge electrical conductors, whilepositive contact wires 112 are preferably 42-gauge electrical conductors. However, one of ordinary skill in the art will recognize that other wire gauges can be used in other embodiments. - As described above, suitable frequencies for the
ultrasound radiating member 40 include, but are not limited to, from about 20 kHz to about 20 MHz. In one embodiment, the frequency is between about 500 kHz and 20 MHz, and in another embodiment the frequency is between about 1 MHz and 3 MHz. In yet another embodiment, theultrasound radiating members 40 are operated with a frequency of about 2 MHz. -
FIG. 8 illustrates theinner core 34 positioned within thetubular body 12. Details of theultrasound assembly 42, provided inFIG. 7A , are omitted for clarity. As described above, theinner core 34 can be slid within thecentral lumen 51 of thetubular body 12, thereby allowing the inner coreenergy delivery section 41 to be positioned within the tubular bodyenergy delivery section 18. For example, in a preferred embodiment, the materials comprising the inner coreenergy delivery section 41, the tubular bodyenergy delivery section 18, and thepotting material 43 all comprise materials having a similar acoustic impedance, thereby minimizing ultrasonic energy losses across material interfaces. -
FIG. 8 further illustrates placement offluid delivery ports 58 within the tubular bodyenergy delivery section 18. As illustrated, holes or slits are formed from thefluid delivery lumen 30 through thetubular body 12, thereby permitting fluid flow from thefluid delivery lumen 30 to the treatment site. Thus, a source of therapeutic compound coupled to theinlet port 32 provides a hydraulic pressure which drives the therapeutic compound through thefluid delivery lumens 30 and out thefluid delivery ports 58. - By evenly spacing the
fluid delivery lumens 30 around the circumference of thetubular body 12, as illustrated inFIG. 8 , a substantially even flow of therapeutic compound around the circumference of thetubular body 12 can be achieved. In addition, the size, location and geometry of thefluid delivery ports 58 can be selected to provide uniform fluid flow from thefluid delivery lumen 30 to the treatment site. For example, in one embodiment,fluid delivery ports 58 closer to the proximal region of theenergy delivery section 18 have smaller diameters thanfluid delivery ports 58 closer to the distal region of theenergy delivery section 18, thereby allowing uniform delivery of fluid across the entireenergy delivery section 18. - For example, in one embodiment in which the
fluid delivery ports 58 have similar sizes along the length of thetubular body 12, thefluid delivery ports 58 have a diameter between about 0.0005 inches to about 0.0050 inches. In another embodiment in which the size of thefluid delivery ports 58 changes along the length of thetubular body 12, thefluid delivery ports 58 have a diameter between about 0.001 inches to about 0.005 inches in the proximal region of theenergy delivery section 18, and between about 0.005 inches to 0.0020 inches in the distal region of theenergy delivery section 18. The increase in size between adjacentfluid delivery ports 58 depends on the material comprising thetubular body 12, and on the size of thefluid delivery lumen 30. Thefluid delivery ports 58 can be created in thetubular body 12 by punching, drilling, burning or ablating (such as with a laser), or by any other suitable method. Therapeutic compound flow along the length of thetubular body 12 can also be increased by increasing the density of thefluid delivery ports 58 toward thedistal region 15 of thetubular body 12. - It should be appreciated that it may be desirable to provide non-uniform fluid flow from the
fluid delivery ports 58 to the treatment site. In such embodiment, the size, location and geometry of thefluid delivery ports 58 can be selected to provide such non-uniform fluid flow. - Referring still to
FIG. 8 , placement of theinner core 34 within thetubular body 12 further defines coolingfluid lumens 44. Coolingfluid lumens 44 are formed between anouter surface 39 of theinner core 34 and aninner surface 16 of thetubular body 12. In certain embodiments, a cooling fluid is introduced through theproximal access port 31 such that cooling fluid flow is produced through coolingfluid lumens 44 and out distal exit port 29 (seeFIG. 1 ). The coolingfluid lumens 44 are preferably evenly spaced around the circumference of the tubular body 12 (that is, at approximately 120° increments for a three-lumen configuration), thereby providing uniform cooling fluid flow over theinner core 34. Such a configuration is desired to remove unwanted thermal energy at the treatment site. As will be explained below, the flow rate of the cooling fluid and the power to theultrasound assembly 42 can be adjusted to maintain the temperature of the inner coreenergy delivery section 41 within a desired range. - In a preferred embodiment, the
inner core 34 can be rotated or moved within thetubular body 12. Specifically, movement of theinner core 34 can be accomplished by maneuvering theproximal hub 37 while holding thebackend hub 33 stationary. The inner coreouter body 35 is at least partially constructed from a material that provides enough structural support to permit movement of theinner core 34 within thetubular body 12 without kinking of thetubular body 12. Additionally, the inner coreouter body 35 preferably comprises a material having the ability to transmit torque. Suitable materials for the inner coreouter body 35 include, but are not limited to, polyimides, polyesters, polyurethanes, thermoplastic elastomers and braided polyimides. - In a preferred embodiment, the
fluid delivery lumens 30 and the coolingfluid lumens 44 are open at the distal end of thetubular body 12, thereby allowing the therapeutic compound and the cooling fluid to pass into the patient's vasculature at the distal exit port. Or, if desired, thefluid delivery lumens 30 can be selectively occluded at the distal end of thetubular body 12, thereby providing additional hydraulic pressure to drive the therapeutic compound out of thefluid delivery ports 58. In either configuration, theinner core 34 can prevented from passing through the distal exit port by configuring theinner core 34 to have a length that is less than the length of thetubular body 12. In other embodiments, a protrusion is formed on theinner surface 16 of thetubular body 12 in thedistal region 15, thereby preventing theinner core 34 from passing through thedistal exit port 29. - In still other embodiments, the
catheter 10 further comprises an occlusion device (not shown) positioned at thedistal exit port 29. The occlusion device preferably has a reduced inner diameter that can accommodate a guidewire, but that is less than the outer diameter of thecentral lumen 51. Thus, theinner core 34 is prevented from extending through the occlusion device and out thedistal exit port 29. For example, suitable inner diameters for the occlusion device include, but are not limited to, about 0.005 inches to about 0.050 inches. In other embodiments, the occlusion device has a closed end, thus preventing cooling fluid from leaving thecatheter 10, and instead recirculating to theproximal region 14 of thetubular body 12. These and other cooling fluid flow configurations permit the power provided to theultrasound assembly 42 to be increased in proportion to the cooling fluid flow rate. Additionally, certain cooling fluid flow configurations can reduce exposure of the patient's body to cooling fluids. - In certain embodiments, as illustrated in
FIG. 8 , thetubular body 12 further comprises one ormore temperature sensors 20, which are preferably located within theenergy delivery section 18. In such embodiments, theproximal region 14 of thetubular body 12 includes a temperature sensor lead wire (not shown) which can be incorporated into cable 45 (illustrated inFIG. 1 ). Suitable temperature sensors include, but are not limited to, temperature sensing diodes, thermistors, thermocouples, resistance temperature detectors (“RTDs”) and fiber optic temperature sensors which use thermalchromic liquid crystals.Suitable temperature sensor 20 geometries include, but are not limited to, a point, a patch or a stripe. Thetemperature sensors 20 can be positioned within one or more of thefluid delivery lumens 30, and/or within one or more of the coolingfluid lumens 44. -
FIG. 9 illustrates one embodiment for electrically connecting thetemperature sensors 20. In such embodiments, eachtemperature sensor 20 is coupled to acommon wire 61 and is associated with anindividual return wire 62. Accordingly, n+1 wires can be used to independently sense the temperature at ndistinct temperature sensors 20. The temperature at aparticular temperature sensor 20 can be determined by closing aswitch 64 to complete a circuit between that thermocouple'sindividual return wire 62 and thecommon wire 61. In embodiments wherein thetemperature sensors 20 comprise thermocouples, the temperature can be calculated from the voltage in the circuit using, for example, asensing circuit 63, which can be located within theexternal control circuitry 100. - In other embodiments, each
temperature sensor 20 is independently wired. In such embodiments, 2n wires pass through thetubular body 12 to independently sense the temperature at nindependent temperature sensors 20. In still other embodiments, the flexibility of thetubular body 12 can be improved by using fiber optic basedtemperature sensors 20. In such embodiments, flexibility can be improved because only n fiber optic members are used to sense the temperature at nindependent temperature sensors 20. -
FIG. 10 illustrates one embodiment of afeedback control system 68 that can be used with thecatheter 10. Thefeedback control system 68 can be integrated into the control system that is connected to theinner core 34 via cable 45 (as illustrated inFIG. 1 ). Thefeedback control system 68 allows the temperature at eachtemperature sensor 20 to be monitored and allows the output power of theenergy source 70 to be adjusted accordingly. A physician can, if desired, override the closed or open loop system. - The
feedback control system 68 preferably comprises anenergy source 70,power circuits 72 and apower calculation device 74 that is coupled to theultrasound radiating members 40. Atemperature measurement device 76 is coupled to thetemperature sensors 20 in thetubular body 12. Aprocessing unit 78 is coupled to thepower calculation device 74, thepower circuits 72 and a user interface anddisplay 80. - In operation, the temperature at each
temperature sensor 20 is determined by thetemperature measurement device 76. Theprocessing unit 78 receives each determined temperature from thetemperature measurement device 76. The determined temperature can then be displayed to the user at the user interface anddisplay 80. - 82 The
processing unit 78 comprises logic for generating a temperature control signal. The temperature control signal is proportional to the difference between the measured temperature and a desired temperature. The desired temperature can be determined by the user (set at the user interface and display 80) or can be preset within theprocessing unit 78. - The temperature control signal is received by the
power circuits 72. Thepower circuits 72 are preferably configured to adjust the power level, voltage, phase and/or current of the electrical energy supplied to theultrasound radiating members 40 from theenergy source 70. For example, when the temperature control signal is above a particular level, the power supplied to a particular group ofultrasound radiating members 40 is preferably reduced in response to that temperature control signal. Similarly, when the temperature control signal is below a particular level, the power supplied to a particular group ofultrasound radiating members 40 is preferably increased in response to that temperature control signal. After each power adjustment, theprocessing unit 78 preferably monitors thetemperature sensors 20 and produces another temperature control signal which is received by thepower circuits 72. - The
processing unit 78 preferably further comprises safety control logic. The safety control logic detects when the temperature at atemperature sensor 20 has exceeded a safety threshold. Theprocessing unit 78 can then provide a temperature control signal which causes thepower circuits 72 to stop the delivery of energy from theenergy source 70 to that particular group ofultrasound radiating members 40. - Because, in certain embodiments, the
ultrasound radiating members 40 are mobile relative to thetemperature sensors 20, it can be unclear which group ofultrasound radiating members 40 should have a power, voltage, phase and/or current level adjustment. Consequently, each group ofultrasound radiating member 40 can be identically adjusted in certain embodiments. In a modified embodiment; the power, voltage, phase, and/or current supplied to each group ofultrasound radiating members 40 is adjusted in response to thetemperature sensor 20 which indicates the highest temperature. Making voltage, phase and/or current adjustments in response to the temperature sensed by thetemperature sensor 20 indicating the highest temperature can reduce overheating of the treatment site. - The
processing unit 78 also receives a power signal from apower calculation device 74. The power signal can be used to determine the power being received by each group ofultrasound radiating members 40. The determined power can then be displayed to the user on the user interface anddisplay 80. - As described above, the
feedback control system 68 can be configured to maintain tissue adjacent to theenergy delivery section 18 below a desired temperature. For example, it is generally desirable to prevent tissue at a treatment site from increasing more than 6° C. As described above, theultrasound radiating members 40 can be electrically connected such that each group ofultrasound radiating members 40 generates an independent output. In certain embodiments, the output from the power circuit maintains a selected energy for each group ofultrasound radiating members 40 for a selected length of time. - The
processing unit 78 can comprise a digital or analog controller, such as for example a computer with software. When theprocessing unit 78 is a computer it can include a central processing unit (“CPU”) coupled through a system bus. As is well known in the art, the user interface anddisplay 80 can comprise a mouse, a keyboard, a disk drive, a display monitor, a nonvolatile memory system, or any another. Also preferably coupled to the bus is a program memory and a data memory. - In lieu of the series of power adjustments described above, a profile of the power to be delivered to each group of
ultrasound radiating members 40 can be incorporated into theprocessing unit 78, such that a preset amount of ultrasonic energy to be delivered is pre-profiled. In such embodiments, the power delivered to each group ofultrasound radiating members 40 can then be adjusted according to the preset profiles. - The
ultrasound radiating members 40 are preferably operated in a pulsed mode. For example, in one embodiment, the time average power supplied to theultrasound radiating members 40 is preferably between about 0.1 watts and 2 watts and more preferably between about 0.5 watts and 1.5 watts. In certain preferred embodiments, the time average power is approximately 0.6 watts or 1.2 watts. The duty cycle is preferably between about 1% and 50% and more preferably between about 5% and 25%. In certain preferred embodiments, the duty ratio is approximately 7.5% or 15%. The pulse averaged power is preferably between about 0.1 watts and 20 watts and more preferably between approximately 5 watts and 20 watts. In certain preferred embodiments, the pulse averaged power is approximately 8 watts and 16 watts. The amplitude during each pulse can be constant or varied. - In one embodiment, the pulse repetition rate is preferably between about 5 Hz and 150 Hz and more preferably between about 10 Hz and 50 Hz. In certain preferred embodiments, the pulse repetition rate is approximately 30 Hz. The pulse duration is preferably between about 1 millisecond and 50 milliseconds and more preferably between about 1 millisecond and 25 milliseconds. In certain preferred embodiments, the pulse duration is approximately 2.5 milliseconds or 5 milliseconds.
- In one particular embodiment, the
ultrasound radiating members 40 are operated at an average power of approximately 0.6 watts, a duty cycle of approximately 7.5%, a pulse repetition rate of 30 Hz, a pulse average electrical power of approximately 8 watts and a pulse duration of approximately 2.5 milliseconds. - The
ultrasound radiating members 40 used with the electrical parameters described herein preferably has an acoustic efficiency greater than 50% and more preferably greater than 75%. Theultrasound radiating members 40 can be formed a variety of shapes, such as, cylindrical (solid or hollow), flat, bar, triangular, and the like. The length of theultrasound radiating members 40 is preferably between about 0.1 cm and about 0.5 cm. The thickness or diameter of theultrasound radiating members 40 is preferably between about 0.02 cm and about 0.2 cm. -
FIGS. 11A through 11D illustrate a method for using theultrasonic catheter 10. As illustrated inFIG. 11A , aguidewire 84 similar to a guidewire used in typical angioplasty procedures is directed through a patient'svessels 86 to atreatment site 88 which includes aclot 90. Theguidewire 84 is directed through theclot 90.Suitable vessels 86 include, but are not limited to, the large periphery and the small cerebral blood vessels of the body. Additionally, as mentioned above, theultrasonic catheter 10 also has utility in various imaging applications or in applications for treating and/or diagnosing other diseases in other body parts. - As illustrated in
FIG. 11B , thetubular body 12 is slid over and is advanced along theguidewire 84 using conventional over-the-guidewire techniques. Thetubular body 12 is advanced until theenergy delivery section 18 of thetubular body 12 is positioned at theclot 90. In certain embodiments, radiopaque markers (not shown) are positioned along theenergy delivery section 18 of thetubular body 12 to aid in the positioning of thetubular body 12 within thetreatment site 88. - As illustrated in
FIG. 11C , theguidewire 84 is then withdrawn from thetubular body 12 by pulling theguidewire 84 from theproximal region 14 of thecatheter 10 while holding thetubular body 12 stationary. This leaves thetubular body 12 positioned at thetreatment site 88. - As illustrated in
FIG. 11D , theinner core 34 is then inserted into thetubular body 12 until the ultrasound assembly is positioned at least partially within theenergy delivery section 18 of thetubular body 12. Once theinner core 34 is properly positioned, theultrasound assembly 42 is activated to deliver ultrasonic energy through theenergy delivery section 18 to theclot 90. As described above, in one embodiment, suitable ultrasonic energy is delivered with a frequency between about 20 kHz and about 20 MHz. - In a certain embodiment, the
ultrasound assembly 42 comprises sixtyultrasound radiating members 40 spaced over a length between approximately 30 cm and 50 cm. In such embodiments, thecatheter 10 can be used to treat anelongate clot 90 without requiring movement of or repositioning of thecatheter 10 during the treatment. However, it will be appreciated that in modified embodiments theinner core 34 can be moved or rotated within thetubular body 12 during the treatment. Such movement can be accomplished by maneuvering theproximal hub 37 of theinner core 34 while holding thebackend hub 33 stationary. - Referring again to
FIG. 11D ,arrows 48 indicate that a cooling fluid flows through the coolingfluid lumen 44 and out thedistal exit port 29. Likewise,arrows 49 indicate that a therapeutic compound flows through thefluid delivery lumen 30 and out thefluid delivery ports 58 to thetreatment site 88. - The cooling fluid can be delivered before, after, during or intermittently with the delivery of ultrasonic energy. Similarly, the therapeutic compound can be delivered before, after, during or intermittently with the delivery of ultrasonic energy. Consequently, the steps illustrated in
FIGS. 11A through 11D can be performed in a variety of different orders than as described above. The therapeutic compound and ultrasonic energy are preferably applied until theclot 90 is partially or entirely dissolved. Once theclot 90 has been dissolved to the desired degree, thetubular body 12 and theinner core 34 are withdrawn from thetreatment site 88. - As described above, the various embodiments of the ultrasound catheters disclosed herein can be used with a therapeutic compound to dissolve a clot and reestablish blood flow in a blood vessel. After the clot is sufficiently dissolved and blood flow is reestablished, it is generally undesirable to continue to administer the therapeutic compound and/or ultrasonic energy. For example, the therapeutic compound can have adverse side effects such that it is generally undesirable to continue to administer the therapeutic compound after blood flow has been reestablished. In addition, generating ultrasonic energy tends to create heat, which can damage the blood vessel. It is therefore generally undesirable to continue operating the ultrasound radiating members after the clot has been sufficiently dissolved. Moreover, after blood flow has been reestablished, the treatment of the patient may need to move to another stage. Thus, it is desired to develop a method and apparatus that can determine when the clot has been sufficiently dissolved and/or when blood flow has been sufficiently reestablished such that the treatment can be stopped and/or adjusted.
- It is also desirable to measure or monitor the degree to which a clot has been dissolved and/or correspondingly the degree to which blood flow has been reestablished. Such information could be used to determine the effectiveness of the treatment. For example, if the blood flow is being reestablished too slowly, certain treatment parameters (for example, flow of therapeutic compound, ultrasound frequency, ultrasound power, ultrasound pulsing parameters, position of the ultrasound radiating members, and so forth) can be adjusted or modified to increase the effectiveness of the treatment. In other instances, after blood flow is reestablished the treatment may be halted to prevent unnecessary delivery of drug and ultrasound energy. In yet another instance, information on treatment effectiveness can be used to determine if an ultrasound radiating member has malfunctioned. Thus, it is also desired to develop a method and/or an apparatus for determining the degree to which a clot has been dissolved and/or the degree to which blood flow has been reestablished.
- It will be appreciated that such methods and apparatuses for determining when blood flow has been reestablished and/or the degree to which blood flow has been reestablished also have utility outside the context of ultrasonic catheters. For example, such information can be used in conjunction with other technologies and methodologies that are used to clear an obstruction in a blood vessel (for example, angioplasty, laser treatments, therapeutic compounds used without ultrasonic energy or with other sources of energy, and so forth). Such techniques can also be used with catheters configured to clot dissolution in both the large and small vasculature.
- The methods and apparatuses for determining when blood flow has been reestablished and/or the degree to which blood flow has been reestablished, as disclosed herein, can be used with a feedback control system. For example, one compatible feedback control system is described above with reference to FIG. 10. In general, the feedback control system can be a closed or open loop system that is configured to adjust the treatment parameters in response to the data received from the apparatus. The physician can, if desired, override the closed or open loop system. In other arrangements, the data can be displayed to the physician or a technician such that the physician or technician can adjust treatment parameters and/or make decisions as to the treatment of the patient.
- In one embodiment, one or more temperature sensors positioned on or within the catheter can be used to detect and/or measure the reestablishment of blood flow at a clot dissolution treatment site. The temperature sensor can be used to measure and analyze the temperature of the cooling fluid, the therapeutic compound and/or the blood surrounding the catheter. For example, in one arrangement, temperature sensors can be mounted on the outside of the catheter, on the ultrasound radiating members in the inner core, or in any of the fluid lumens to detect differential temperatures of the blood, cooling fluid, or therapeutic compound along the catheter length as a function of time. See, for example, the positioning of the
temperature sensors 20 illustrated inFIG. 8 . - A preferred embodiment for using thermal measurements to detect and/or measure the reestablishment of blood flow during a clot dissolution treatment is illustrated schematically in
FIG. 12 . Acatheter 10 is positioned through aclot 90 at atreatment site 88 in a patient'svasculature 86. Thecatheter 10 includes at least an upstreamthermal source 120 and a downstreamthermal detector 122. - The
thermal source 120 andthermal detector 122 can be positioned on, within, or integral with thecatheter 10. Thethermal source 120 comprises any source of thermal energy, such as a resistance heater. For example, in one embodiment, one or more of the ultrasound radiating members comprising the ultrasound assembly can function as a source of thermal energy. However, it will be recognized that the techniques disclosed herein can also be used with a catheter that does not comprise ultrasound radiating members. Thethermal detector 122 comprises any device capable of detecting the presence (or absence) of thermal energy, such as a diode, thermistor, thermocouple, and so forth. In one embodiment, one or more of the ultrasound radiating members can be used as a thermal detector by measuring changes in their electrical characteristics (such as, for example, impedance or resonating frequency). - In such embodiments, the
thermal source 120 supplies thermal energy into its surrounding environment. For example, if thethermal source 120 is affixed to the outer surface of thecatheter 10, then thermal energy is supplied into the surrounding bloodstream. Likewise, if the thermal source is positioned within thefluid delivery lumens 30 and/or the cooling fluid lumens 44 (illustrated inFIG. 8 ), then thermal energy is supplied into the fluid contained therein. -
FIG. 13A illustrates that when thethermal source 120 supplies thermal energy into the surrounding environment, a “thermal pulse” 124 is created therein. For example, if thethermal source 120 is affixed to the outer surface of thecatheter 10 or is affixed within thefluid delivery lumens 30 and/or the cooling fluid lumens 44 (illustrated inFIG. 8 ), then athermal pulse 124 is created therein. If the medium into which thermal energy is supplied has a flow rate, then thethermal pulse 124 will propagate with the medium. Thethermal pulse 124 can propagate, for example, by mass transfer (that is, due to physical movement of the heated medium) or by thermal conduction (that is, due to thermal energy propagating through a stationary medium). For example, if thermal energy is supplied into a cooling fluid lumen through which a cooling fluid is flowing, then the resultantthermal pulse 124 will likewise flow downstream through the cooling fluid lumen. Similarly, if thermal energy is supplied into the surrounding bloodstream, and if the bloodstream is not completely occluded, then the resultantthermal pulse 124 will flow downstream through the patient'svasculature 86. In other embodiments, thethermal pulse 124 can propagate according to other thermal propagation mechanisms. - As the
thermal pulse 124 propagates downstream, the characteristics of thethermal pulse 124 will change. For example, some of the excess thermal energy in thethermal pulse 124 will dissipate into surrounding tissues and/or surrounding catheter structures, thereby reducing the intensity of thethermal pulse 124. Additionally, as thethermal pulse 124 passes through and/or reflects from various materials (such as, for example, clot, blood, tissue, and so forth), the pulse width may increase. When thethermal pulse 124 reaches thethermal detector 122, its characteristics can be measured and analyzed, thereby providing information about blood flow at thetreatment site 88. - For example, in certain applications the characteristics (such as, for example, pulse width and intensity) of a thermal pulse supplied from the exterior of the catheter to the surrounding bloodstream will remain substantially unchanged between the thermal source and the thermal detector. This indicates that little thermal energy dissipated into surrounding tissues between the thermal source and the thermal detector, and therefore that the thermal pulse propagated rapidly (that is, high blood flow rate at the treatment site). In other applications, the same characteristics of a thermal pulse supplied from the exterior of the catheter to the surrounding bloodstream will substantially change between the thermal source and the thermal detector. This indicates that a substantial amount of thermal energy dissipated into surrounding tissues between the thermal source and the thermal detector, and therefore that the thermal pulse propagated slowly (that is, low blood flow rate at the treatment site).
- In applications where the thermal pulse is supplied from and detected in one of the fluid lumens positioned in the interior of the catheter, reestablishment of blood flow can be evaluated based on the thermal pulse intensity reduction. Specifically, as a clot dissolution treatment progresses, less clot material will be available to absorb energy from the thermal pulse. Thus, in such applications, a high thermal pulse intensity reduction indicates little clot dissolution has occurred, while a low thermal pulse intensity reduction indicates that the clot dissolution treatment has progressed significantly.
- Moreover, the amount of time required for the
thermal pulse 124 to propagate from thethermal source 120 to thethermal detector 122 provides an indication of the propagation speed of the pulse, thus providing a further indication of blood flow rate at thetreatment site 88. Specifically,FIGS. 13A and 13B illustrate that athermal pulse 124 created at thethermal source 120 at time to can be detected at thethermal detector 122 at a later time to+Δt. The time differential Δt, along with the distance between thethermal source 120 and thethermal detector 122 can provide information about the blood flow rate between those two points, thereby allowing the progression of a clot dissolution treatment to be evaluated. - One of ordinary skill in the art will recognize that the
thermal pulse 124 need not be a single spike, as illustrated inFIG. 13 , but rather can be a square wave or a sinusoidal signal. In such embodiments, if the thermal signal is delivered into the bloodstream, a thermal signal phase shift between the thermal source and the thermal detector provides a measure of the volumetric flow rate between such points. This provides yet another variable for evaluating the progression of a clot dissolution treatment. - In yet another preferred embodiment, the catheter comprises a temperature sensor without a thermal source. See, for example, the embodiment illustrated in
FIG. 8 . By monitoring the temperature as a function of time during a clot dissolution treatment, information relating to the efficacy of the treatment can be determined. In particular, as the treatment progresses, blood flow around the catheter will increase, thereby reducing the temperature at the treatment site: the blood flow acts as a supplemental cooling fluid. Thus, a temperature curve for the treatment can be created. Several different types of known curve fitting methods may be used, such as, for example, standard or non-linear curve fitting models, and typical shape function methodology. For more information, see U.S. Pat. No. 5,797,395 and the references identified therein, which are hereby incorporated by reference herein. - The shape of a reference time-temperature curve can be determined under reference conditions. During the clot dissolution treatment, the shape of the time-temperature curve can be compared to the reference time-temperature curve, and significant alternations can trigger the
processing unit 78 to trigger an alarm via the user interface and display 80 (seeFIG. 10 ). - It will be recognized that blood flow evaluations can be made based on algorithms other than the thermal pulse delay, thermal dilution, and thermal signal phase shift algorithms disclosed herein. In particular, certain of the concepts disclosed herein can be applied to optical, Doppler, electromagnetic, and other flow evaluation algorithms some of which are described below.
- For example, in one modified embodiment, the distal region of the catheter includes an optical sensing system, such as, for example, a fiber optic or pass detector, to determine the degree to which a clot has been dissolved and/or the degree to which blood flow has been reestablished. For example, in one arrangement, the therapeutic compound may contain fluorescent indicators and the sensing system can be used to observe the intrinsic fluorescence of the therapeutic compound or extrinsic fluorescent indicators that are provided in the therapeutic compound. In this manner, the optical sensing system can be used to differentiate between a condition where a therapeutic compound is located proximal to a clotted area (that is, a substantially obstructed vessel) and a condition where predominately blood is located around a previously clotted area (that is, a substantially unobstructed vessel). In another arrangement, a color detector can be used to monitor the fluid color around the clotted area to differentiate between a substantially clot and therapeutic compound condition (that is, a substantially obstructed vessel) and a substantially blood only condition (this is, a substantially open vessel). In yet another arrangement, the color detector can be used to differentiate between the walls of the blood vessel (that is, open vessel) and a clot (that is, obstructed vessel). In still other arrangements, the sensing system can be configured to sense differences outside the visible light range. For example, an infrared detection system can be configured to sense differences between the walls of the blood vessel and a clot.
- In such embodiments, the optical sensor can be positioned upstream, downstream and/or within the clot. The optical measurements can be correlated with clinical data so as to quantify the degree to which blood flow has been reestablished.
- In another embodiment, the catheter can be configured to use a Doppler frequency shift and/or flight to determine if blood flow has been reestablished. That is, the frequency shift of the ultrasonic energy as it passes through a clotted vessel and/or the time required for the ultrasonic energy to pass through a clotted vessel can be used to determine the degree to which the clot has been dissolved. In one arrangement, this can be accomplished internally using the ultrasound radiating members of the catheter and/or using ultrasonic receiving members positioned in the catheter. In another arrangement, the sensing ultrasonic energy can be generated outside the patient's body and/or received outside the patient's body (for example, via a cuff placed around the treatment site).
- In yet another embodiment, blood pressure could be used to determine blood flow reestablishment. In one arrangement, the ultrasound radiating members can be used to detect pressure in the internal fluid column. In other arrangements, individual sensors or lumens can be used.
- In another embodiment, a sensor can be configured to monitor the color or temperature of a portion of the patient's body that is affected by the clot. For example, for a clot in the leg, toe color and temperature indicates reestablished blood flow in the leg. As with all the embodiments described herein, such information can be integrated into a control feedback system as described above.
- In another embodiment, an accelerometer or motion detector can be configured to sense the vibration in the catheter or in a portion of the patient's body caused by reestablished blood flow.
- In another embodiment, one or more electromagnetic flow sensors can be used to sense reestablished blood flow near the clotted area.
- In another embodiment, markers (for example, dye, bubbles, cold, heat, and so forth) can be injected into the blood vessel through one or more lumens in the catheter. For example, the marker can be injected at an upstream point. Sensing the passage of such markers past a detector positioned downstream of the upstream injection point indicates blood flow. The rate of passage indicates the degree to which blood flow has been reestablished.
- In another embodiment, an external plethysmograph band can be used to determine blood flow. This could be oriented with respect to the catheter radially or in another dimension.
- In another embodiment, blood oxygenation can be used to determine the presence of blood flow.
- While the foregoing detailed description has described several embodiments of the apparatus and methods of the present invention, it is to be understood that the above description is illustrative only and not limited to the disclosed invention. It will be appreciated that the specific dimensions of the various catheters and inner cores can differ from those described above, and that the methods described can be used within any biological conduit in a patient's body, while remaining within the scope of the present invention. In particular, the methods for evaluating the efficacy of a clot dissolution treatment can be used to evaluate treatments performed with a the peripheral catheter disclosed herein, as well as with the small vessel catheter disclosed in U.S. patent application Ser. No. 10/309,417, filed Dec. 3, 2002. Thus, the present invention is to be limited only by the claims that follow.
Claims (27)
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US11/291,355 US20060106308A1 (en) | 2001-12-14 | 2005-12-01 | Blood flow reestablishment determination |
Applications Claiming Priority (5)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US34143001P | 2001-12-14 | 2001-12-14 | |
US34735002P | 2002-01-10 | 2002-01-10 | |
US36945302P | 2002-04-02 | 2002-04-02 | |
US10/320,847 US6979293B2 (en) | 2001-12-14 | 2002-12-16 | Blood flow reestablishment determination |
US11/291,355 US20060106308A1 (en) | 2001-12-14 | 2005-12-01 | Blood flow reestablishment determination |
Related Parent Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US10/320,847 Continuation US6979293B2 (en) | 2001-12-14 | 2002-12-16 | Blood flow reestablishment determination |
Publications (1)
Publication Number | Publication Date |
---|---|
US20060106308A1 true US20060106308A1 (en) | 2006-05-18 |
Family
ID=27407459
Family Applications (2)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US10/320,847 Expired - Lifetime US6979293B2 (en) | 2001-12-14 | 2002-12-16 | Blood flow reestablishment determination |
US11/291,355 Abandoned US20060106308A1 (en) | 2001-12-14 | 2005-12-01 | Blood flow reestablishment determination |
Family Applications Before (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US10/320,847 Expired - Lifetime US6979293B2 (en) | 2001-12-14 | 2002-12-16 | Blood flow reestablishment determination |
Country Status (6)
Country | Link |
---|---|
US (2) | US6979293B2 (en) |
EP (1) | EP1463454A1 (en) |
JP (1) | JP4167178B2 (en) |
AU (1) | AU2002357316A1 (en) |
CA (1) | CA2468975A1 (en) |
WO (1) | WO2003051208A1 (en) |
Cited By (17)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US8690818B2 (en) | 1997-05-01 | 2014-04-08 | Ekos Corporation | Ultrasound catheter for providing a therapeutic effect to a vessel of a body |
US8696612B2 (en) | 2001-12-03 | 2014-04-15 | Ekos Corporation | Catheter with multiple ultrasound radiating members |
US8740835B2 (en) | 2010-02-17 | 2014-06-03 | Ekos Corporation | Treatment of vascular occlusions using ultrasonic energy and microbubbles |
US8764700B2 (en) | 1998-06-29 | 2014-07-01 | Ekos Corporation | Sheath for use with an ultrasound element |
US8852166B1 (en) | 2002-04-01 | 2014-10-07 | Ekos Corporation | Ultrasonic catheter power control |
US9044568B2 (en) | 2007-06-22 | 2015-06-02 | Ekos Corporation | Method and apparatus for treatment of intracranial hemorrhages |
US9107590B2 (en) | 2004-01-29 | 2015-08-18 | Ekos Corporation | Method and apparatus for detecting vascular conditions with a catheter |
US9579494B2 (en) | 2013-03-14 | 2017-02-28 | Ekos Corporation | Method and apparatus for drug delivery to a target site |
US9849273B2 (en) | 2009-07-03 | 2017-12-26 | Ekos Corporation | Power parameters for ultrasonic catheter |
US10092742B2 (en) | 2014-09-22 | 2018-10-09 | Ekos Corporation | Catheter system |
US10182833B2 (en) | 2007-01-08 | 2019-01-22 | Ekos Corporation | Power parameters for ultrasonic catheter |
US10188410B2 (en) | 2007-01-08 | 2019-01-29 | Ekos Corporation | Power parameters for ultrasonic catheter |
US10232196B2 (en) | 2006-04-24 | 2019-03-19 | Ekos Corporation | Ultrasound therapy system |
US10656025B2 (en) | 2015-06-10 | 2020-05-19 | Ekos Corporation | Ultrasound catheter |
US10888657B2 (en) | 2010-08-27 | 2021-01-12 | Ekos Corporation | Method and apparatus for treatment of intracranial hemorrhages |
US11458290B2 (en) | 2011-05-11 | 2022-10-04 | Ekos Corporation | Ultrasound system |
US11553852B2 (en) | 2011-06-01 | 2023-01-17 | Koninklijke Philips N.V. | System for distributed blood flow measurement |
Families Citing this family (40)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6676626B1 (en) | 1998-05-01 | 2004-01-13 | Ekos Corporation | Ultrasound assembly with increased efficacy |
US20030013960A1 (en) | 2001-05-29 | 2003-01-16 | Makin Inder Raj. S. | Guiding ultrasound end effector for medical treatment |
US7846096B2 (en) | 2001-05-29 | 2010-12-07 | Ethicon Endo-Surgery, Inc. | Method for monitoring of medical treatment using pulse-echo ultrasound |
CA2457093C (en) * | 2001-08-20 | 2012-10-30 | Japan Science And Technology Agency | Method for identifying living tissue in ultrasonic diagnosis and ultrasonic diagnostic system |
US20040019318A1 (en) * | 2001-11-07 | 2004-01-29 | Wilson Richard R. | Ultrasound assembly for use with a catheter |
US7815596B2 (en) * | 2002-02-28 | 2010-10-19 | Cordis Corporation | Localized fluid delivery having a porous applicator and methods for using the same |
AU2003212481A1 (en) | 2002-02-28 | 2003-09-09 | Ekos Corporation | Ultrasound assembly for use with a catheter |
EP1583569A4 (en) * | 2003-01-03 | 2009-05-06 | Ekos Corp | Ultrasonic catheter with axial energy field |
WO2004093656A2 (en) | 2003-04-22 | 2004-11-04 | Ekos Corporation | Ultrasound enhanced central venous catheter |
JP2007520281A (en) * | 2004-01-29 | 2007-07-26 | イコス コーポレイション | Small vessel ultrasound catheter |
US7201737B2 (en) | 2004-01-29 | 2007-04-10 | Ekos Corporation | Treatment of vascular occlusions using elevated temperatures |
US7247141B2 (en) * | 2004-03-08 | 2007-07-24 | Ethicon Endo-Surgery, Inc. | Intra-cavitary ultrasound medical system and method |
US20050240123A1 (en) * | 2004-04-14 | 2005-10-27 | Mast T D | Ultrasound medical treatment system and method |
US7883468B2 (en) | 2004-05-18 | 2011-02-08 | Ethicon Endo-Surgery, Inc. | Medical system having an ultrasound source and an acoustic coupling medium |
US7951095B2 (en) | 2004-05-20 | 2011-05-31 | Ethicon Endo-Surgery, Inc. | Ultrasound medical system |
US7695436B2 (en) * | 2004-05-21 | 2010-04-13 | Ethicon Endo-Surgery, Inc. | Transmit apodization of an ultrasound transducer array |
US7473250B2 (en) * | 2004-05-21 | 2009-01-06 | Ethicon Endo-Surgery, Inc. | Ultrasound medical system and method |
US7806839B2 (en) | 2004-06-14 | 2010-10-05 | Ethicon Endo-Surgery, Inc. | System and method for ultrasound therapy using grating lobes |
KR100714682B1 (en) * | 2004-12-02 | 2007-05-04 | 삼성전자주식회사 | File system path processing device and method thereof |
JP4724827B2 (en) * | 2005-03-24 | 2011-07-13 | 国立大学法人山口大学 | Agitation treatment device and catheter |
US20090118612A1 (en) | 2005-05-06 | 2009-05-07 | Sorin Grunwald | Apparatus and Method for Vascular Access |
US7758505B2 (en) * | 2006-04-03 | 2010-07-20 | Elfi-Tech Ltd. | Methods and apparatus for non-invasive determination of patient's blood conditions |
EP2124732B1 (en) * | 2006-10-26 | 2015-12-09 | Medical Compression Systems (D.B.N.) Ltd. | System for deep vein thrombosis prevention and diagnosis |
US8192363B2 (en) | 2006-10-27 | 2012-06-05 | Ekos Corporation | Catheter with multiple ultrasound radiating members |
WO2009003138A1 (en) | 2007-06-26 | 2008-12-31 | Vasonova, Inc. | Apparatus and method for endovascular device guiding and positioning using physiological parameters |
US9717896B2 (en) | 2007-12-18 | 2017-08-01 | Gearbox, Llc | Treatment indications informed by a priori implant information |
US8636670B2 (en) | 2008-05-13 | 2014-01-28 | The Invention Science Fund I, Llc | Circulatory monitoring systems and methods |
US20090287120A1 (en) | 2007-12-18 | 2009-11-19 | Searete Llc, A Limited Liability Corporation Of The State Of Delaware | Circulatory monitoring systems and methods |
US20090234231A1 (en) * | 2008-03-13 | 2009-09-17 | Knight Jon M | Imaging Catheter With Integrated Contrast Agent Injector |
US20100063414A1 (en) * | 2008-08-25 | 2010-03-11 | Ekos Corporation | Lysis Indication |
US10853819B2 (en) | 2011-04-14 | 2020-12-01 | Elwha Llc | Cost-effective resource apportionment technologies suitable for facilitating therapies |
US10445846B2 (en) | 2011-04-14 | 2019-10-15 | Elwha Llc | Cost-effective resource apportionment technologies suitable for facilitating therapies |
EP2780081B1 (en) * | 2011-11-15 | 2017-05-10 | Boston Scientific Scimed, Inc. | Shaft with ultrasound transducers for nerve modulation |
EP3071125B1 (en) | 2013-11-18 | 2021-08-04 | Koninklijke Philips N.V. | Devices for thrombus dispersal |
EP3076881B1 (en) * | 2013-11-18 | 2022-01-05 | Koninklijke Philips N.V. | Guided thrombus dispersal catheter |
ES2879981T3 (en) * | 2015-05-29 | 2021-11-23 | Carag Ag | Catheter for measuring blood flow in a body tissue |
WO2017214573A1 (en) | 2016-06-09 | 2017-12-14 | C. R. Bard, Inc. | Systems and methods for correcting and preventing occlusion in a catheter |
CN110167466B (en) * | 2016-11-04 | 2023-07-04 | 莱斯桑柏特医疗解决方案股份有限公司 | Device for delivering mechanical waves through balloon catheter |
US10357262B2 (en) * | 2016-11-14 | 2019-07-23 | C. R. Bard, Inc. | Systems and methods to modify intravascular lesions |
US11679194B2 (en) | 2021-04-27 | 2023-06-20 | Contego Medical, Inc. | Thrombus aspiration system and methods for controlling blood loss |
Citations (97)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4754752A (en) * | 1986-07-28 | 1988-07-05 | Robert Ginsburg | Vascular catheter |
US4921478A (en) * | 1988-02-23 | 1990-05-01 | C. R. Bard, Inc. | Cerebral balloon angioplasty system |
US4948587A (en) * | 1986-07-08 | 1990-08-14 | Massachusetts Institute Of Technology | Ultrasound enhancement of transbuccal drug delivery |
US4951677A (en) * | 1988-03-21 | 1990-08-28 | Prutech Research And Development Partnership Ii | Acoustic imaging catheter and the like |
US5108369A (en) * | 1990-03-15 | 1992-04-28 | Diagnostic Devices Group, Limited | Dual-diameter multifunction catheter |
US5129883A (en) * | 1990-07-26 | 1992-07-14 | Michael Black | Catheter |
US5149319A (en) * | 1990-09-11 | 1992-09-22 | Unger Evan C | Methods for providing localized therapeutic heat to biological tissues and fluids |
US5178620A (en) * | 1988-06-10 | 1993-01-12 | Advanced Angioplasty Products, Inc. | Thermal dilatation catheter and method |
US5185071A (en) * | 1990-10-30 | 1993-02-09 | Board Of Regents, The University Of Texas System | Programmable electrophoresis with integrated and multiplexed control |
US5197946A (en) * | 1990-06-27 | 1993-03-30 | Shunro Tachibana | Injection instrument with ultrasonic oscillating element |
US5226421A (en) * | 1992-03-06 | 1993-07-13 | Cardiometrics, Inc. | Doppler elongate flexible member having an inflatable balloon mounted thereon |
US5318014A (en) * | 1992-09-14 | 1994-06-07 | Coraje, Inc. | Ultrasonic ablation/dissolution transducer |
US5344395A (en) * | 1989-11-13 | 1994-09-06 | Scimed Life Systems, Inc. | Apparatus for intravascular cavitation or delivery of low frequency mechanical energy |
US5345940A (en) * | 1991-11-08 | 1994-09-13 | Mayo Foundation For Medical Education And Research | Transvascular ultrasound hemodynamic and interventional catheter and method |
US5380273A (en) * | 1992-05-19 | 1995-01-10 | Dubrul; Will R. | Vibrating catheter |
US5399158A (en) * | 1990-05-31 | 1995-03-21 | The United States Of America As Represented By The Secretary Of The Army | Method of lysing thrombi |
US5405322A (en) * | 1993-08-12 | 1995-04-11 | Boston Scientific Corporation | Method for treating aneurysms with a thermal source |
US5431663A (en) * | 1990-12-10 | 1995-07-11 | Coraje, Inc. | Miniature ultrasonic transducer for removal of intravascular plaque and clots |
US5447509A (en) * | 1991-01-11 | 1995-09-05 | Baxter International Inc. | Ultrasound catheter system having modulated output with feedback control |
US5453575A (en) * | 1993-02-01 | 1995-09-26 | Endosonics Corporation | Apparatus and method for detecting blood flow in intravascular ultrasonic imaging |
US5523058A (en) * | 1992-09-16 | 1996-06-04 | Hitachi, Ltd. | Ultrasonic irradiation apparatus and processing apparatus based thereon |
US5533986A (en) * | 1994-02-18 | 1996-07-09 | Merit Medical Systems, Inc. | Catheter apparatus with means for subcutaneous delivery of anesthetic agent or other fluid medicament |
US5558092A (en) * | 1995-06-06 | 1996-09-24 | Imarx Pharmaceutical Corp. | Methods and apparatus for performing diagnostic and therapeutic ultrasound simultaneously |
US5603694A (en) * | 1995-10-17 | 1997-02-18 | Brown; Joe E. | Infusion coil apparatus and method for delivering fluid-based agents intravascularly |
US5620479A (en) * | 1992-11-13 | 1997-04-15 | The Regents Of The University Of California | Method and apparatus for thermal therapy of tumors |
US5628728A (en) * | 1995-05-31 | 1997-05-13 | Ekos Corporation | Medicine applying tool |
US5630837A (en) * | 1993-07-01 | 1997-05-20 | Boston Scientific Corporation | Acoustic ablation |
US5713831A (en) * | 1992-02-17 | 1998-02-03 | Olsson; Sten Bertil | Method and apparatus for arterial reperfusion through noninvasive ultrasonic action |
US5713848A (en) * | 1993-05-19 | 1998-02-03 | Dubrul; Will R. | Vibrating catheter |
US5725494A (en) * | 1995-11-30 | 1998-03-10 | Pharmasonics, Inc. | Apparatus and methods for ultrasonically enhanced intraluminal therapy |
US5733315A (en) * | 1992-11-13 | 1998-03-31 | Burdette; Everette C. | Method of manufacture of a transurethral ultrasound applicator for prostate gland thermal therapy |
US5735811A (en) * | 1995-11-30 | 1998-04-07 | Pharmasonics, Inc. | Apparatus and methods for ultrasonically enhanced fluid delivery |
US5775338A (en) * | 1997-01-10 | 1998-07-07 | Scimed Life Systems, Inc. | Heated perfusion balloon for reduction of restenosis |
US5916192A (en) * | 1991-01-11 | 1999-06-29 | Advanced Cardiovascular Systems, Inc. | Ultrasonic angioplasty-atherectomy catheter and method of use |
US5931805A (en) * | 1997-06-02 | 1999-08-03 | Pharmasonics, Inc. | Catheters comprising bending transducers and methods for their use |
US5935124A (en) * | 1997-12-02 | 1999-08-10 | Cordis Webster, Inc. | Tip electrode with multiple temperature sensors |
US5938595A (en) * | 1996-05-24 | 1999-08-17 | The Regents Of The University Of California | Fiber optic D dimer biosensor |
US5941068A (en) * | 1996-08-26 | 1999-08-24 | Corning Incorporated | Automotive hydrocarbon adsorber system |
US5957941A (en) * | 1996-09-27 | 1999-09-28 | Boston Scientific Corporation | Catheter system and drive assembly thereof |
US6024718A (en) * | 1996-09-04 | 2000-02-15 | The Regents Of The University Of California | Intraluminal directed ultrasound delivery device |
US6024703A (en) * | 1997-05-07 | 2000-02-15 | Eclipse Surgical Technologies, Inc. | Ultrasound device for axial ranging |
US6027515A (en) * | 1999-03-02 | 2000-02-22 | Sound Surgical Technologies Llc | Pulsed ultrasonic device and method |
US6033397A (en) * | 1996-03-05 | 2000-03-07 | Vnus Medical Technologies, Inc. | Method and apparatus for treating esophageal varices |
US6053868A (en) * | 1997-04-24 | 2000-04-25 | Sulzer Osypka Gmbh | Apparatus for a cardiological therapy |
US6078830A (en) * | 1997-10-01 | 2000-06-20 | Ep Technologies, Inc. | Molded catheter distal end assembly and process for the manufacture thereof |
US6096000A (en) * | 1997-06-23 | 2000-08-01 | Ekos Corporation | Apparatus for transport of fluids across, into or from biological tissues |
US6110098A (en) * | 1996-12-18 | 2000-08-29 | Medtronic, Inc. | System and method of mechanical treatment of cardiac fibrillation |
US6110314A (en) * | 1994-03-11 | 2000-08-29 | Intravascular Research Limited | Ultrasonic transducer array and method of manufacturing the same |
US6113570A (en) * | 1994-09-09 | 2000-09-05 | Coraje, Inc. | Method of removing thrombosis in fistulae |
US6113558A (en) * | 1997-09-29 | 2000-09-05 | Angiosonics Inc. | Pulsed mode lysis method |
US6113546A (en) * | 1998-07-31 | 2000-09-05 | Scimed Life Systems, Inc. | Off-aperture electrical connection for ultrasonic transducer |
US6176842B1 (en) * | 1995-03-08 | 2001-01-23 | Ekos Corporation | Ultrasound assembly for use with light activated drugs |
US6196973B1 (en) * | 1999-09-30 | 2001-03-06 | Siemens Medical Systems, Inc. | Flow estimation using an ultrasonically modulated contrast agent |
US6210356B1 (en) * | 1998-08-05 | 2001-04-03 | Ekos Corporation | Ultrasound assembly for use with a catheter |
US6221038B1 (en) * | 1996-11-27 | 2001-04-24 | Pharmasonics, Inc. | Apparatus and methods for vibratory intraluminal therapy employing magnetostrictive transducers |
US6228046B1 (en) * | 1997-06-02 | 2001-05-08 | Pharmasonics, Inc. | Catheters comprising a plurality of oscillators and methods for their use |
US6231516B1 (en) * | 1997-10-14 | 2001-05-15 | Vacusense, Inc. | Endoluminal implant with therapeutic and diagnostic capability |
US6235024B1 (en) * | 1999-06-21 | 2001-05-22 | Hosheng Tu | Catheters system having dual ablation capability |
US20010007940A1 (en) * | 1999-06-21 | 2001-07-12 | Hosheng Tu | Medical device having ultrasound imaging and therapeutic means |
US6277077B1 (en) * | 1998-11-16 | 2001-08-21 | Cardiac Pathways Corporation | Catheter including ultrasound transducer with emissions attenuation |
US20020000763A1 (en) * | 1998-11-20 | 2002-01-03 | Jones Joie P. | Methods for selectively dissolving and removing materials using ultra-high frequency ultrasound |
US20020019644A1 (en) * | 1999-07-12 | 2002-02-14 | Hastings Roger N. | Magnetically guided atherectomy |
US20020032394A1 (en) * | 2000-03-08 | 2002-03-14 | Axel Brisken | Methods, systems, and kits for plaque stabilization |
US6361554B1 (en) * | 1999-06-30 | 2002-03-26 | Pharmasonics, Inc. | Methods and apparatus for the subcutaneous delivery of acoustic vibrations |
US6361500B1 (en) * | 2000-02-07 | 2002-03-26 | Scimed Life Systems, Inc. | Three transducer catheter |
US6366719B1 (en) * | 2000-08-17 | 2002-04-02 | Miravant Systems, Inc. | Photodynamic therapy light diffuser |
US6372498B2 (en) * | 1997-12-31 | 2002-04-16 | Pharmasonics, Inc. | Methods, systems, and kits for intravascular nucleic acid delivery |
US20020045890A1 (en) * | 1996-04-24 | 2002-04-18 | The Regents Of The University O F California | Opto-acoustic thrombolysis |
US6387052B1 (en) * | 1991-01-29 | 2002-05-14 | Edwards Lifesciences Corporation | Thermodilution catheter having a safe, flexible heating element |
US6394997B1 (en) * | 1996-06-12 | 2002-05-28 | Jerome H. Lemelson | Medical devices using electrosensitive gels |
US20020068869A1 (en) * | 2000-06-27 | 2002-06-06 | Axel Brisken | Drug delivery catheter with internal ultrasound receiver |
US6423026B1 (en) * | 1999-12-09 | 2002-07-23 | Advanced Cardiovascular Systems, Inc. | Catheter stylet |
US6437487B1 (en) * | 2001-02-28 | 2002-08-20 | Acuson Corporation | Transducer array using multi-layered elements and a method of manufacture thereof |
US6503202B1 (en) * | 2000-06-29 | 2003-01-07 | Acuson Corp. | Medical diagnostic ultrasound system and method for flow analysis |
US6508775B2 (en) * | 2000-03-20 | 2003-01-21 | Pharmasonics, Inc. | High output therapeutic ultrasound transducer |
US6511478B1 (en) * | 2000-06-30 | 2003-01-28 | Scimed Life Systems, Inc. | Medical probe with reduced number of temperature sensor wires |
US6524251B2 (en) * | 1999-10-05 | 2003-02-25 | Omnisonics Medical Technologies, Inc. | Ultrasonic device for tissue ablation and sheath for use therewith |
US6524300B2 (en) * | 2000-01-03 | 2003-02-25 | Angiodynamics, Inc. | Infusion catheter with non-uniform drug delivery density |
US6537224B2 (en) * | 2001-06-08 | 2003-03-25 | Vermon | Multi-purpose ultrasonic slotted array transducer |
US6542767B1 (en) * | 1999-11-09 | 2003-04-01 | Biotex, Inc. | Method and system for controlling heat delivery to a target |
US20030069525A1 (en) * | 2000-03-08 | 2003-04-10 | Pharmasonics, Inc. | Methods, systems, and kits for plaque stabilization |
US6562021B1 (en) * | 1997-12-22 | 2003-05-13 | Micrus Corporation | Variable stiffness electrically conductive composite, resistive heating catheter shaft |
US6561998B1 (en) * | 1998-04-07 | 2003-05-13 | Transvascular, Inc. | Transluminal devices, systems and methods for enlarging interstitial penetration tracts |
US6575922B1 (en) * | 2000-10-17 | 2003-06-10 | Walnut Technologies | Ultrasound signal and temperature monitoring during sono-thrombolysis therapy |
US20030109812A1 (en) * | 2000-03-20 | 2003-06-12 | Pharmasonics, Inc. | High output therapeutic ultrasound transducer |
US6585763B1 (en) * | 1997-10-14 | 2003-07-01 | Vascusense, Inc. | Implantable therapeutic device and method |
US6589182B1 (en) * | 2001-02-12 | 2003-07-08 | Acuson Corporation | Medical diagnostic ultrasound catheter with first and second tip portions |
US20030135262A1 (en) * | 2002-01-15 | 2003-07-17 | Dretler Stephen P. | Apparatus for piezo-electric reduction of concretions |
US6607502B1 (en) * | 1998-11-25 | 2003-08-19 | Atrionix, Inc. | Apparatus and method incorporating an ultrasound transducer onto a delivery member |
US20040019318A1 (en) * | 2001-11-07 | 2004-01-29 | Wilson Richard R. | Ultrasound assembly for use with a catheter |
US20040024347A1 (en) * | 2001-12-03 | 2004-02-05 | Wilson Richard R. | Catheter with multiple ultrasound radiating members |
US20040049148A1 (en) * | 2001-12-03 | 2004-03-11 | Oscar Rodriguez | Small vessel ultrasound catheter |
US6723063B1 (en) * | 1998-06-29 | 2004-04-20 | Ekos Corporation | Sheath for use with an ultrasound element |
US6726698B2 (en) * | 1999-03-02 | 2004-04-27 | Sound Surgical Technologies Llc | Pulsed ultrasonic device and method |
US6733451B2 (en) * | 1999-10-05 | 2004-05-11 | Omnisonics Medical Technologies, Inc. | Apparatus and method for an ultrasonic probe used with a pharmacological agent |
US20060116610A1 (en) * | 2004-11-30 | 2006-06-01 | Omnisonics Medical Technologies, Inc. | Apparatus and method for an ultrasonic medical device with variable frequency drive |
US7077820B1 (en) * | 2002-10-21 | 2006-07-18 | Advanced Medical Optics, Inc. | Enhanced microburst ultrasonic power delivery system and method |
Family Cites Families (19)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS63135179A (en) | 1986-11-26 | 1988-06-07 | 立花 俊郎 | Subcataneous drug administration set |
US5588432A (en) | 1988-03-21 | 1996-12-31 | Boston Scientific Corporation | Catheters for imaging, sensing electrical potentials, and ablating tissue |
US5372138A (en) * | 1988-03-21 | 1994-12-13 | Boston Scientific Corporation | Acousting imaging catheters and the like |
US5158071A (en) | 1988-07-01 | 1992-10-27 | Hitachi, Ltd. | Ultrasonic apparatus for therapeutical use |
US5344435A (en) | 1988-07-28 | 1994-09-06 | Bsd Medical Corporation | Urethral inserted applicator prostate hyperthermia |
JPH02180275A (en) | 1988-12-29 | 1990-07-13 | Toshiro Tachibana | Medicine injection tool having ultrasonic wave oscillation element |
US6088613A (en) | 1989-12-22 | 2000-07-11 | Imarx Pharmaceutical Corp. | Method of magnetic resonance focused surgical and therapeutic ultrasound |
US5997497A (en) | 1991-01-11 | 1999-12-07 | Advanced Cardiovascular Systems | Ultrasound catheter having integrated drug delivery system and methods of using same |
DE69215722T3 (en) | 1991-03-22 | 2001-03-08 | Katsuro Tachibana | Amplifiers for ultrasound therapy of diseases and liquid pharmaceutical compositions containing them |
WO1993008863A2 (en) | 1991-11-08 | 1993-05-13 | Baxter International Inc. | Transport catheter and ultrasound probe for use with same |
US5362309A (en) | 1992-09-14 | 1994-11-08 | Coraje, Inc. | Apparatus and method for enhanced intravascular phonophoresis including dissolution of intravascular blockage and concomitant inhibition of restenosis |
JP2746021B2 (en) | 1992-10-20 | 1998-04-28 | 富士写真光機株式会社 | Ultrasonic probe |
US5735280A (en) | 1995-05-02 | 1998-04-07 | Heart Rhythm Technologies, Inc. | Ultrasound energy delivery system and method |
WO1997017018A1 (en) | 1995-11-09 | 1997-05-15 | Brigham & Women's Hospital | Aperiodic ultrasound phased array |
US6001069A (en) | 1997-05-01 | 1999-12-14 | Ekos Corporation | Ultrasound catheter for providing a therapeutic effect to a vessel of a body |
US6135976A (en) | 1998-09-25 | 2000-10-24 | Ekos Corporation | Method, device and kit for performing gene therapy |
US6296619B1 (en) | 1998-12-30 | 2001-10-02 | Pharmasonics, Inc. | Therapeutic ultrasonic catheter for delivering a uniform energy dose |
WO2001013357A1 (en) | 1999-08-16 | 2001-02-22 | Ekos Corporation | Ultrasound assembly for use with a catheter |
US7089063B2 (en) * | 2000-05-16 | 2006-08-08 | Atrionix, Inc. | Deflectable tip catheter with guidewire tracking mechanism |
-
2002
- 2002-12-16 US US10/320,847 patent/US6979293B2/en not_active Expired - Lifetime
- 2002-12-16 AU AU2002357316A patent/AU2002357316A1/en not_active Abandoned
- 2002-12-16 EP EP02805204A patent/EP1463454A1/en not_active Withdrawn
- 2002-12-16 WO PCT/US2002/040466 patent/WO2003051208A1/en active Application Filing
- 2002-12-16 CA CA002468975A patent/CA2468975A1/en not_active Abandoned
- 2002-12-16 JP JP2003552145A patent/JP4167178B2/en not_active Expired - Fee Related
-
2005
- 2005-12-01 US US11/291,355 patent/US20060106308A1/en not_active Abandoned
Patent Citations (99)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4948587A (en) * | 1986-07-08 | 1990-08-14 | Massachusetts Institute Of Technology | Ultrasound enhancement of transbuccal drug delivery |
US4754752A (en) * | 1986-07-28 | 1988-07-05 | Robert Ginsburg | Vascular catheter |
US4921478A (en) * | 1988-02-23 | 1990-05-01 | C. R. Bard, Inc. | Cerebral balloon angioplasty system |
US4951677A (en) * | 1988-03-21 | 1990-08-28 | Prutech Research And Development Partnership Ii | Acoustic imaging catheter and the like |
US5178620A (en) * | 1988-06-10 | 1993-01-12 | Advanced Angioplasty Products, Inc. | Thermal dilatation catheter and method |
US5344395A (en) * | 1989-11-13 | 1994-09-06 | Scimed Life Systems, Inc. | Apparatus for intravascular cavitation or delivery of low frequency mechanical energy |
US5108369A (en) * | 1990-03-15 | 1992-04-28 | Diagnostic Devices Group, Limited | Dual-diameter multifunction catheter |
US5399158A (en) * | 1990-05-31 | 1995-03-21 | The United States Of America As Represented By The Secretary Of The Army | Method of lysing thrombi |
US5197946A (en) * | 1990-06-27 | 1993-03-30 | Shunro Tachibana | Injection instrument with ultrasonic oscillating element |
US5129883A (en) * | 1990-07-26 | 1992-07-14 | Michael Black | Catheter |
US5149319A (en) * | 1990-09-11 | 1992-09-22 | Unger Evan C | Methods for providing localized therapeutic heat to biological tissues and fluids |
US5185071A (en) * | 1990-10-30 | 1993-02-09 | Board Of Regents, The University Of Texas System | Programmable electrophoresis with integrated and multiplexed control |
US5431663A (en) * | 1990-12-10 | 1995-07-11 | Coraje, Inc. | Miniature ultrasonic transducer for removal of intravascular plaque and clots |
US5447509A (en) * | 1991-01-11 | 1995-09-05 | Baxter International Inc. | Ultrasound catheter system having modulated output with feedback control |
US5916192A (en) * | 1991-01-11 | 1999-06-29 | Advanced Cardiovascular Systems, Inc. | Ultrasonic angioplasty-atherectomy catheter and method of use |
US6387052B1 (en) * | 1991-01-29 | 2002-05-14 | Edwards Lifesciences Corporation | Thermodilution catheter having a safe, flexible heating element |
US5345940A (en) * | 1991-11-08 | 1994-09-13 | Mayo Foundation For Medical Education And Research | Transvascular ultrasound hemodynamic and interventional catheter and method |
US5713831A (en) * | 1992-02-17 | 1998-02-03 | Olsson; Sten Bertil | Method and apparatus for arterial reperfusion through noninvasive ultrasonic action |
US5226421A (en) * | 1992-03-06 | 1993-07-13 | Cardiometrics, Inc. | Doppler elongate flexible member having an inflatable balloon mounted thereon |
US5380273A (en) * | 1992-05-19 | 1995-01-10 | Dubrul; Will R. | Vibrating catheter |
US5318014A (en) * | 1992-09-14 | 1994-06-07 | Coraje, Inc. | Ultrasonic ablation/dissolution transducer |
US5523058A (en) * | 1992-09-16 | 1996-06-04 | Hitachi, Ltd. | Ultrasonic irradiation apparatus and processing apparatus based thereon |
US5620479A (en) * | 1992-11-13 | 1997-04-15 | The Regents Of The University Of California | Method and apparatus for thermal therapy of tumors |
US5733315A (en) * | 1992-11-13 | 1998-03-31 | Burdette; Everette C. | Method of manufacture of a transurethral ultrasound applicator for prostate gland thermal therapy |
US5453575A (en) * | 1993-02-01 | 1995-09-26 | Endosonics Corporation | Apparatus and method for detecting blood flow in intravascular ultrasonic imaging |
US5713848A (en) * | 1993-05-19 | 1998-02-03 | Dubrul; Will R. | Vibrating catheter |
US5630837A (en) * | 1993-07-01 | 1997-05-20 | Boston Scientific Corporation | Acoustic ablation |
US5405322A (en) * | 1993-08-12 | 1995-04-11 | Boston Scientific Corporation | Method for treating aneurysms with a thermal source |
US5533986A (en) * | 1994-02-18 | 1996-07-09 | Merit Medical Systems, Inc. | Catheter apparatus with means for subcutaneous delivery of anesthetic agent or other fluid medicament |
US6238347B1 (en) * | 1994-03-11 | 2001-05-29 | Intravascular Research Limited | Ultrasonic transducer array and method of manufacturing the same |
US6110314A (en) * | 1994-03-11 | 2000-08-29 | Intravascular Research Limited | Ultrasonic transducer array and method of manufacturing the same |
US6113570A (en) * | 1994-09-09 | 2000-09-05 | Coraje, Inc. | Method of removing thrombosis in fistulae |
US6176842B1 (en) * | 1995-03-08 | 2001-01-23 | Ekos Corporation | Ultrasound assembly for use with light activated drugs |
US5628728A (en) * | 1995-05-31 | 1997-05-13 | Ekos Corporation | Medicine applying tool |
US5558092A (en) * | 1995-06-06 | 1996-09-24 | Imarx Pharmaceutical Corp. | Methods and apparatus for performing diagnostic and therapeutic ultrasound simultaneously |
US5603694A (en) * | 1995-10-17 | 1997-02-18 | Brown; Joe E. | Infusion coil apparatus and method for delivering fluid-based agents intravascularly |
US5725494A (en) * | 1995-11-30 | 1998-03-10 | Pharmasonics, Inc. | Apparatus and methods for ultrasonically enhanced intraluminal therapy |
US5735811A (en) * | 1995-11-30 | 1998-04-07 | Pharmasonics, Inc. | Apparatus and methods for ultrasonically enhanced fluid delivery |
US6033397A (en) * | 1996-03-05 | 2000-03-07 | Vnus Medical Technologies, Inc. | Method and apparatus for treating esophageal varices |
US20020045890A1 (en) * | 1996-04-24 | 2002-04-18 | The Regents Of The University O F California | Opto-acoustic thrombolysis |
US5938595A (en) * | 1996-05-24 | 1999-08-17 | The Regents Of The University Of California | Fiber optic D dimer biosensor |
US6394997B1 (en) * | 1996-06-12 | 2002-05-28 | Jerome H. Lemelson | Medical devices using electrosensitive gels |
US5941068A (en) * | 1996-08-26 | 1999-08-24 | Corning Incorporated | Automotive hydrocarbon adsorber system |
US6024718A (en) * | 1996-09-04 | 2000-02-15 | The Regents Of The University Of California | Intraluminal directed ultrasound delivery device |
US5957941A (en) * | 1996-09-27 | 1999-09-28 | Boston Scientific Corporation | Catheter system and drive assembly thereof |
US6221038B1 (en) * | 1996-11-27 | 2001-04-24 | Pharmasonics, Inc. | Apparatus and methods for vibratory intraluminal therapy employing magnetostrictive transducers |
US6110098A (en) * | 1996-12-18 | 2000-08-29 | Medtronic, Inc. | System and method of mechanical treatment of cardiac fibrillation |
US5775338A (en) * | 1997-01-10 | 1998-07-07 | Scimed Life Systems, Inc. | Heated perfusion balloon for reduction of restenosis |
US6053868A (en) * | 1997-04-24 | 2000-04-25 | Sulzer Osypka Gmbh | Apparatus for a cardiological therapy |
US6024703A (en) * | 1997-05-07 | 2000-02-15 | Eclipse Surgical Technologies, Inc. | Ultrasound device for axial ranging |
US5931805A (en) * | 1997-06-02 | 1999-08-03 | Pharmasonics, Inc. | Catheters comprising bending transducers and methods for their use |
US6228046B1 (en) * | 1997-06-02 | 2001-05-08 | Pharmasonics, Inc. | Catheters comprising a plurality of oscillators and methods for their use |
US6096000A (en) * | 1997-06-23 | 2000-08-01 | Ekos Corporation | Apparatus for transport of fluids across, into or from biological tissues |
US6113558A (en) * | 1997-09-29 | 2000-09-05 | Angiosonics Inc. | Pulsed mode lysis method |
US6078830A (en) * | 1997-10-01 | 2000-06-20 | Ep Technologies, Inc. | Molded catheter distal end assembly and process for the manufacture thereof |
US6231516B1 (en) * | 1997-10-14 | 2001-05-15 | Vacusense, Inc. | Endoluminal implant with therapeutic and diagnostic capability |
US6585763B1 (en) * | 1997-10-14 | 2003-07-01 | Vascusense, Inc. | Implantable therapeutic device and method |
US5935124A (en) * | 1997-12-02 | 1999-08-10 | Cordis Webster, Inc. | Tip electrode with multiple temperature sensors |
US6562021B1 (en) * | 1997-12-22 | 2003-05-13 | Micrus Corporation | Variable stiffness electrically conductive composite, resistive heating catheter shaft |
US6372498B2 (en) * | 1997-12-31 | 2002-04-16 | Pharmasonics, Inc. | Methods, systems, and kits for intravascular nucleic acid delivery |
US6561998B1 (en) * | 1998-04-07 | 2003-05-13 | Transvascular, Inc. | Transluminal devices, systems and methods for enlarging interstitial penetration tracts |
US6723063B1 (en) * | 1998-06-29 | 2004-04-20 | Ekos Corporation | Sheath for use with an ultrasound element |
US6113546A (en) * | 1998-07-31 | 2000-09-05 | Scimed Life Systems, Inc. | Off-aperture electrical connection for ultrasonic transducer |
US6210356B1 (en) * | 1998-08-05 | 2001-04-03 | Ekos Corporation | Ultrasound assembly for use with a catheter |
US6277077B1 (en) * | 1998-11-16 | 2001-08-21 | Cardiac Pathways Corporation | Catheter including ultrasound transducer with emissions attenuation |
US20020000763A1 (en) * | 1998-11-20 | 2002-01-03 | Jones Joie P. | Methods for selectively dissolving and removing materials using ultra-high frequency ultrasound |
US6433464B2 (en) * | 1998-11-20 | 2002-08-13 | Joie P. Jones | Apparatus for selectively dissolving and removing material using ultra-high frequency ultrasound |
US6607502B1 (en) * | 1998-11-25 | 2003-08-19 | Atrionix, Inc. | Apparatus and method incorporating an ultrasound transducer onto a delivery member |
US6726698B2 (en) * | 1999-03-02 | 2004-04-27 | Sound Surgical Technologies Llc | Pulsed ultrasonic device and method |
US6027515A (en) * | 1999-03-02 | 2000-02-22 | Sound Surgical Technologies Llc | Pulsed ultrasonic device and method |
US20010007940A1 (en) * | 1999-06-21 | 2001-07-12 | Hosheng Tu | Medical device having ultrasound imaging and therapeutic means |
US6235024B1 (en) * | 1999-06-21 | 2001-05-22 | Hosheng Tu | Catheters system having dual ablation capability |
US6361554B1 (en) * | 1999-06-30 | 2002-03-26 | Pharmasonics, Inc. | Methods and apparatus for the subcutaneous delivery of acoustic vibrations |
US20020019644A1 (en) * | 1999-07-12 | 2002-02-14 | Hastings Roger N. | Magnetically guided atherectomy |
US6196973B1 (en) * | 1999-09-30 | 2001-03-06 | Siemens Medical Systems, Inc. | Flow estimation using an ultrasonically modulated contrast agent |
US6524251B2 (en) * | 1999-10-05 | 2003-02-25 | Omnisonics Medical Technologies, Inc. | Ultrasonic device for tissue ablation and sheath for use therewith |
US6733451B2 (en) * | 1999-10-05 | 2004-05-11 | Omnisonics Medical Technologies, Inc. | Apparatus and method for an ultrasonic probe used with a pharmacological agent |
US6542767B1 (en) * | 1999-11-09 | 2003-04-01 | Biotex, Inc. | Method and system for controlling heat delivery to a target |
US6423026B1 (en) * | 1999-12-09 | 2002-07-23 | Advanced Cardiovascular Systems, Inc. | Catheter stylet |
US6524300B2 (en) * | 2000-01-03 | 2003-02-25 | Angiodynamics, Inc. | Infusion catheter with non-uniform drug delivery density |
US6361500B1 (en) * | 2000-02-07 | 2002-03-26 | Scimed Life Systems, Inc. | Three transducer catheter |
US20020032394A1 (en) * | 2000-03-08 | 2002-03-14 | Axel Brisken | Methods, systems, and kits for plaque stabilization |
US20030069525A1 (en) * | 2000-03-08 | 2003-04-10 | Pharmasonics, Inc. | Methods, systems, and kits for plaque stabilization |
US6508775B2 (en) * | 2000-03-20 | 2003-01-21 | Pharmasonics, Inc. | High output therapeutic ultrasound transducer |
US20030109812A1 (en) * | 2000-03-20 | 2003-06-12 | Pharmasonics, Inc. | High output therapeutic ultrasound transducer |
US20020068869A1 (en) * | 2000-06-27 | 2002-06-06 | Axel Brisken | Drug delivery catheter with internal ultrasound receiver |
US6503202B1 (en) * | 2000-06-29 | 2003-01-07 | Acuson Corp. | Medical diagnostic ultrasound system and method for flow analysis |
US6511478B1 (en) * | 2000-06-30 | 2003-01-28 | Scimed Life Systems, Inc. | Medical probe with reduced number of temperature sensor wires |
US6366719B1 (en) * | 2000-08-17 | 2002-04-02 | Miravant Systems, Inc. | Photodynamic therapy light diffuser |
US6575922B1 (en) * | 2000-10-17 | 2003-06-10 | Walnut Technologies | Ultrasound signal and temperature monitoring during sono-thrombolysis therapy |
US6589182B1 (en) * | 2001-02-12 | 2003-07-08 | Acuson Corporation | Medical diagnostic ultrasound catheter with first and second tip portions |
US6437487B1 (en) * | 2001-02-28 | 2002-08-20 | Acuson Corporation | Transducer array using multi-layered elements and a method of manufacture thereof |
US6537224B2 (en) * | 2001-06-08 | 2003-03-25 | Vermon | Multi-purpose ultrasonic slotted array transducer |
US20040019318A1 (en) * | 2001-11-07 | 2004-01-29 | Wilson Richard R. | Ultrasound assembly for use with a catheter |
US20040024347A1 (en) * | 2001-12-03 | 2004-02-05 | Wilson Richard R. | Catheter with multiple ultrasound radiating members |
US20040049148A1 (en) * | 2001-12-03 | 2004-03-11 | Oscar Rodriguez | Small vessel ultrasound catheter |
US20030135262A1 (en) * | 2002-01-15 | 2003-07-17 | Dretler Stephen P. | Apparatus for piezo-electric reduction of concretions |
US7077820B1 (en) * | 2002-10-21 | 2006-07-18 | Advanced Medical Optics, Inc. | Enhanced microburst ultrasonic power delivery system and method |
US20060116610A1 (en) * | 2004-11-30 | 2006-06-01 | Omnisonics Medical Technologies, Inc. | Apparatus and method for an ultrasonic medical device with variable frequency drive |
Cited By (27)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US8690818B2 (en) | 1997-05-01 | 2014-04-08 | Ekos Corporation | Ultrasound catheter for providing a therapeutic effect to a vessel of a body |
US8764700B2 (en) | 1998-06-29 | 2014-07-01 | Ekos Corporation | Sheath for use with an ultrasound element |
US9415242B2 (en) | 2001-12-03 | 2016-08-16 | Ekos Corporation | Catheter with multiple ultrasound radiating members |
US8696612B2 (en) | 2001-12-03 | 2014-04-15 | Ekos Corporation | Catheter with multiple ultrasound radiating members |
US10926074B2 (en) | 2001-12-03 | 2021-02-23 | Ekos Corporation | Catheter with multiple ultrasound radiating members |
US10080878B2 (en) | 2001-12-03 | 2018-09-25 | Ekos Corporation | Catheter with multiple ultrasound radiating members |
US8852166B1 (en) | 2002-04-01 | 2014-10-07 | Ekos Corporation | Ultrasonic catheter power control |
US9943675B1 (en) | 2002-04-01 | 2018-04-17 | Ekos Corporation | Ultrasonic catheter power control |
US9107590B2 (en) | 2004-01-29 | 2015-08-18 | Ekos Corporation | Method and apparatus for detecting vascular conditions with a catheter |
US11058901B2 (en) | 2006-04-24 | 2021-07-13 | Ekos Corporation | Ultrasound therapy system |
US10232196B2 (en) | 2006-04-24 | 2019-03-19 | Ekos Corporation | Ultrasound therapy system |
US10182833B2 (en) | 2007-01-08 | 2019-01-22 | Ekos Corporation | Power parameters for ultrasonic catheter |
US11925367B2 (en) | 2007-01-08 | 2024-03-12 | Ekos Corporation | Power parameters for ultrasonic catheter |
US10188410B2 (en) | 2007-01-08 | 2019-01-29 | Ekos Corporation | Power parameters for ultrasonic catheter |
US9044568B2 (en) | 2007-06-22 | 2015-06-02 | Ekos Corporation | Method and apparatus for treatment of intracranial hemorrhages |
US11672553B2 (en) | 2007-06-22 | 2023-06-13 | Ekos Corporation | Method and apparatus for treatment of intracranial hemorrhages |
US9849273B2 (en) | 2009-07-03 | 2017-12-26 | Ekos Corporation | Power parameters for ultrasonic catheter |
US9192566B2 (en) | 2010-02-17 | 2015-11-24 | Ekos Corporation | Treatment of vascular occlusions using ultrasonic energy and microbubbles |
US8740835B2 (en) | 2010-02-17 | 2014-06-03 | Ekos Corporation | Treatment of vascular occlusions using ultrasonic energy and microbubbles |
US10888657B2 (en) | 2010-08-27 | 2021-01-12 | Ekos Corporation | Method and apparatus for treatment of intracranial hemorrhages |
US11458290B2 (en) | 2011-05-11 | 2022-10-04 | Ekos Corporation | Ultrasound system |
US11553852B2 (en) | 2011-06-01 | 2023-01-17 | Koninklijke Philips N.V. | System for distributed blood flow measurement |
US9579494B2 (en) | 2013-03-14 | 2017-02-28 | Ekos Corporation | Method and apparatus for drug delivery to a target site |
US10092742B2 (en) | 2014-09-22 | 2018-10-09 | Ekos Corporation | Catheter system |
US10507320B2 (en) | 2014-09-22 | 2019-12-17 | Ekos Corporation | Catheter system |
US10656025B2 (en) | 2015-06-10 | 2020-05-19 | Ekos Corporation | Ultrasound catheter |
US11740138B2 (en) | 2015-06-10 | 2023-08-29 | Ekos Corporation | Ultrasound catheter |
Also Published As
Publication number | Publication date |
---|---|
US20030220568A1 (en) | 2003-11-27 |
AU2002357316A1 (en) | 2003-06-30 |
JP2005512630A (en) | 2005-05-12 |
CA2468975A1 (en) | 2003-06-26 |
WO2003051208A1 (en) | 2003-06-26 |
JP4167178B2 (en) | 2008-10-15 |
US6979293B2 (en) | 2005-12-27 |
EP1463454A1 (en) | 2004-10-06 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US6979293B2 (en) | Blood flow reestablishment determination | |
US20100063413A1 (en) | Lysis Indication | |
US20100063414A1 (en) | Lysis Indication | |
US11925367B2 (en) | Power parameters for ultrasonic catheter | |
US8192363B2 (en) | Catheter with multiple ultrasound radiating members | |
US7648478B2 (en) | Treatment of vascular occlusions using ultrasonic energy and microbubbles | |
US9943675B1 (en) | Ultrasonic catheter power control | |
US20190223894A1 (en) | Power parameters for ultrasonic catheter | |
US6958040B2 (en) | Multi-resonant ultrasonic catheter | |
US20050209578A1 (en) | Ultrasonic catheter with segmented fluid delivery | |
US7771372B2 (en) | Ultrasonic catheter with axial energy field | |
US7220239B2 (en) | Catheter with multiple ultrasound radiating members | |
US10092742B2 (en) | Catheter system | |
US9849273B2 (en) | Power parameters for ultrasonic catheter | |
US7201737B2 (en) | Treatment of vascular occlusions using elevated temperatures |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: HERCULES TECHNOLOGY II, L.P., CALIFORNIA Free format text: SECURITY AGREEMENT;ASSIGNOR:EKOS CORPORATION;REEL/FRAME:019550/0881 Effective date: 20070524 Owner name: HERCULES TECHNOLOGY II, L.P.,CALIFORNIA Free format text: SECURITY AGREEMENT;ASSIGNOR:EKOS CORPORATION;REEL/FRAME:019550/0881 Effective date: 20070524 |
|
STCB | Information on status: application discontinuation |
Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION |
|
AS | Assignment |
Owner name: EKOS CORPORATION, WASHINGTON Free format text: RELEASE BY SECURED PARTY;ASSIGNOR:HERCULES TECHNOLOGY II, L.P.;REEL/FRAME:030421/0867 Effective date: 20101021 |