Tissue treatment

Abstract

There is provided in accordance with an exemplary embodiment of the a method of selectively treating tissue using non-focused ultrasound energy delivered intrabody comprising: selectively determining a target tissue in a wall of a lumen or cavity; selecting parameters sufficient to provide a desired effect in the target tissue; and applying the parameters to treat the target tissue using non-focused ultrasound to achieve the desired effect.

1 . A method of setting up a treatment system for non-focused ultrasound energy delivered intrabody comprising:
 selectively determining a target tissue in a wall of a lumen or cavity;   selecting parameters sufficient to provide a desired therapeutic effect in said target tissue and which start a thermal damage effect only at a distance of at least 0.2 mm from an inner side of said wall; and   setting up a treatment system using said parameters.   
     
     
         2 . A method according to  claim 1 , further comprising deciding an amount of desired thermal damage. 
     
     
         3 . A method according to  claim 2 , wherein said amount of thermal damage comprises a volume where thermal damage is desired. 
     
     
         4 . A method according to  claim 2 , wherein said amount of thermal damage comprises the degree of thermal damage. 
     
     
         5 . A method according to  claim 1 , further comprising selecting an anatomical location from which to treat said target tissue. 
     
     
         6 . A method according to  claim 5 , wherein said anatomical location comprises a renal artery and said target tissue comprises renal artery nerves. 
     
     
         7 . A method according to  claim 5 , wherein said anatomical location comprises an aorta and said target tissue comprises renal nerves. 
     
     
         8 . A method according to  claim 5 , wherein said anatomical location comprises a carotid artery and said target tissue comprises nerves. 
     
     
         9 . A method according to  claim 1 , wherein selecting comprises taking blood cooling into account. 
     
     
         10 . A method according to  claim 1 , wherein selecting comprises selecting in a manner which avoids significant stenosis. 
     
     
         11 . A method according to  claim 1 , wherein selecting comprises selecting in a manner which avoids significant damage to non-target tissue. 
     
     
         12 . A method according to  claim 1 , wherein selecting comprises selecting in a manner which avoids significant shrinkage in target tissue. 
     
     
         13 . A method according to  claim 1 , wherein said desired effect comprises denaturing at least some of said target tissue. 
     
     
         14 . A method according to  claim 13 , further comprising applying said ultrasound energy so as to not denature at least some part of said target tissue. 
     
     
         15 . A method according to  claim 1 , wherein said target tissue and said parameters are preselected so that said parameters have said desired effect on said target. 
     
     
         16 . A method according to  claim 1 , wherein said selecting comprises determining according to an attenuation coefficient of tissues. 
     
     
         17 . A method according to  claim 1 , further comprising selecting a margin of safety. 
     
     
         18 . A method according to  claim 17 , wherein said selecting a margin of safety comprises selecting an allowed amount of thermal damage to tissues surrounding said target tissue. 
     
     
         19 . A method according to  claim 17 , wherein said selecting a margin of safety comprises reducing or preventing contraction of said lumen or said cavity. 
     
     
         20 . A method according to  claim 1 , wherein said selectively determining said target tissue comprises selecting a type of tissue. 
     
     
         21 . A method according to  claim 20 , wherein said type of tissue comprises nerve tissue. 
     
     
         22 . A method according to  claim 20 , wherein said target tissue is selected from tissue located at a tissue layer selected from the group comprising peri-adventitia, adventitia, media, intima. 
     
     
         23 . A method according to  claim 1 , wherein said target tissue is located less than 10 mm from a renal ostium. 
     
     
         24 . A method according to  claim 1 , wherein said determining initial parameters comprises determining according to a distance of said target tissue from an intima. 
     
     
         25 . A method according to  claim 24 , wherein said target tissue is outside said wall of said lumen or said cavity. 
     
     
         26 . A method according to  claim 1 , further comprising selecting a frequency of treatment in the range of 8-25 Mhz. 
     
     
         27 . A method according to  claim 1 , further comprising selecting an ultrasound intensity in the range of 1-100 Watt/square centimeter. 
     
     
         28 . A method according to  claim 1 , wherein said target tissue is a renal nerve, and said parameters are an applied frequency of 10[MHz]- 22 [MHz], and an intensity of 10-40[W/cm̂2]. 
     
     
         29 . A method according to  claim 1 , wherein a duration of said treatment is 5-30 seconds. 
     
     
         30 . A method according to  claim 1 , wherein a length of said lumen or cavity is less than 20 mm. 
     
     
         31 . A method according to  claim 1 , comprising applying said parameters to selectively treat said target tissue using non-focused ultrasound to achieve said desired effect. 
     
     
         32 . A method according to  claim 31 , further comprising obtaining feedback associated with said treatment. 
     
     
         33 . A method according to  claim 32 , further comprising adjusting said parameters according to said feedback and retreating said target tissue. 
     
     
         34 . A method according to  claim 31 , further comprising a controlled adjustable treatment according to online measurements including at least one of the following group of measurements: flow measurements, current measurement, voltage measurement, power measurement, acoustic backscatter measurements, temperature measurements, pressure measurements. 
     
     
         35 . A method according to  claim 31 , wherein treating comprises applying said ultrasound away from said wall but inside a body. 
     
     
         36 . A method according to  claim 31 , applying so that a desired effect comprises temporary change in tissue functionality is achieved. 
     
     
         37 . A method according to  claim 31 , wherein said applying said parameters comprises applying said parameters in an open loop manner. 
     
     
         38 . A method according to  claim 31 , wherein applying comprises applying said ultrasound energy so as to not denature most of the tissue between said target tissue and an edge of said wall. 
     
     
         39 . A method according to  claim 31 , wherein applying comprises maintaining blood in said lumen at a temperature below 50 degrees Celsius. 
     
     
         40 . A method according to  claim 31 , wherein applying comprises maintaining blood in said lumen at a temperature below 43 degrees Celsius. 
     
     
         41 . A method according to  claim 31 , wherein said applying comprises heating a nerve while not heating tissue outside of a fat sheath surrounding said nerve. 
     
     
         42 . A method according to  claim 31 , wherein said applying comprises localizing heating by having a gradient of cooling from blood and a gradient of heating from a distance. 
     
     
         43 . A method according to  claim 31 , wherein applying comprises heating nerves sufficiently to reduce renal norepinephrine levels by at least 50%. 
     
     
         44 . A method according to  claim 31 , wherein applying comprises heating a part of a nerve to necrosis while not heating another part of said nerve in a same axial location along said nerve to necrosis. 
     
     
         45 . A method according to  claim 31 , further comprising adjusting a property of at least one of said target tissue, said wall and blood in said lumen to provide said desired effect. 
     
     
         46 . A method according to  claim 45 , wherein said property comprises a rate of heat removal. 
     
     
         47 . A method according to  claim 45 , wherein said property comprises a flow rate of said blood. 
     
     
         48 . A method according to  claim 45 , wherein said property comprises a temperature. 
     
     
         49 . A method according to  claim 31 , wherein said applying comprises applying said ultrasound energy so as to treat a patient suffering from hypertension. 
     
     
         50 . A method according to  claim 31 , wherein said applying comprises applying said ultrasound energy so as to prevent signals from propagating through at least one renal nerve. 
     
     
         51 . A method according to  claim 31 , wherein said applying comprises applying said ultrasound energy so as to position said treatment area with an accuracy of better than 0.2 mm along an axis perpendicular to said wall. 
     
     
         52 . A system for treating a blood vessel wall comprising:
 a catheter;   at least one ultrasound emitter mounted on the catheter and adapted for emitting unfocused ultrasound at a frequency of 10-40 Mhz at a target tissue located a distance from an intima of the blood vessel wall with a power setting sufficient to heat said target tissue; and   a controller,   wherein the controller is configured to deliver enough power to heat said target tissue to a selected size and to a desired thermal effect, said thermal effect starting only after at least a distance of 0.2 mm from said wall.   
     
     
         53 . A system according to  claim 52  wherein said target tissue comprises nerves, and said desired thermal effect comprises reducing signals through said nerves by at least 50%. 
     
     
         54 . A system according to  claim 52 , wherein said catheter is configured so that said emitter does not contact said wall. 
     
     
         55 . A system according to  claim 52 , wherein said controller is configured to selectively treat a volume of tissue distanced from an intima of a blood vessel wall. 
     
     
         56 . A system according to  claim 52 , wherein said controller is configured for thermal treatment of renal nerves. 
     
     
         57 . A system according to  claim 52 , wherein said controller is configured for treatment accuracy of better than 0.5 mm positioning of the treatment area, along a dimension perpendicular to said blood vessel. 
     
     
         58 . A system according to  claim 52 , wherein said controller is configured for treatment specificity which avoids significant vessel stenosis as an aftermath of said treatment. 
     
     
         59 . A system according to  claim 52 , wherein said controller is configured to selectively heat nerves within a fat sheath thereof. 
     
     
         60 . A system according to  claim 52 , wherein said controller is configured with a protocol including a plurality of treatment regions and sufficient to reduce hypertension if applied to renal nerves. 
     
     
         61 . A system according to  claim 52 , wherein said controller is pre-configured with sets of parameters matching different target tissues and target tissue locations. 
     
     
         62 . A system according to  claim 52 , wherein said controller includes a feedback circuit for real-time control of settings of said system. 
     
     
         63 . A method of setting up a device to selectively treating tissue using non-focused ultrasound energy delivered intrabody comprising:
 setting up said device to be suitable for heating a selected area of tissue at a selected location from an arterial wall.   
     
     
         64 - 67 . (canceled) 
     
     
         68 . A method of setting up a device to selectively treating tissue using non-focused ultrasound energy delivered intrabody comprising:
 setting up said device to be suitable for heating nerve tissue while not heating, to a tissue damaging level, tissue outside a fat sheath surrounding said nerve.   
     
     
         69 . A method of reducing blood pressure comprising:
 applying unfocused ultrasonic energy to the renal ostium from within a blood vessel, said energy sufficient to disrupt signals propagating through renal nerves.   
     
     
         70 - 71 . (canceled) 
     
     
         72 . A method for treating a patient experiencing a clinical disorder, the method comprising:
 positioning at least one unfocused ultrasound emitter at an anatomical location proximate to a target tissue;   selectively delivering unfocused ultrasound energy to the target tissue; and   selectively causing thermal damage to at least a portion of the target tissue, to provide a desired treatment, no significant thermal damage being caused closer than 0.2 mm to said wall.   
     
     
         73 . The method of  claim 72  wherein the target tissue comprises body lumen, fat, nerves, vasa vasora, lymph, tumor, connective tissue, or plaque. 
     
     
         74 . The method of  claim 72  wherein the anatomical location comprises a blood vessel or artery. 
     
     
         75 . The method of  claim 74  wherein the anatomical location is the renal artery and the target tissue comprises one or more renal artery nerves. 
     
     
         76 . The method of  claim 74  wherein the at least one unfocused ultrasound emitter is configured not to touch the wall of the blood vessel or artery. 
     
     
         77 . The method of  claim 74  wherein the at least one unfocused ultrasound emitter is positioned as to not substantially block blood flow in the blood vessel or artery. 
     
     
         78 . The method of  claim 77  wherein the at least one unfocused ultrasound emitter, in operation, is cooled by the blood flow. 
     
     
         79 . The method of  claim 72  wherein the clinical disorder comprises at least one of sleep apnea, obesity, diabetes, end stage renal disease, lesion on a body lumen, contrast nephropathy, heart arrhythmia, congestive heart failure, and hypertension. 
     
     
         80 . The method of  claim 74  further comprising determining the distance from the blood vessel or artery wall to the target tissue and selecting the frequency of the unfocused ultrasound energy based upon on said distance of the target tissue. 
     
     
         81 . The method of  claim 72  wherein the frequency of the unfocused ultrasound energy is 10-22 Mhz. 
     
     
         82 . The method of  claim 72  wherein the target tissue comprises a treatment region. 
     
     
         83 . The method of  claim 82  further comprising determining the treatment region and selecting the intensity of the unfocused ultrasound energy according to the size of the treatment region. 
     
     
         84 . The method of  claim 77  further comprising delivering the at least one unfocused ultrasound emitter intrabody within the blood vessel or artery by a delivery catheter and configuring the delivery catheter to prevent the at least one unfocused ultrasound emitter from touching the wall of the blood vessel or artery. 
     
     
         85 . The method of  claim 72  further comprising selecting the target tissue using parameters obtained from an equation based upon empirical data. 
     
     
         86 . The method of  claim 85  wherein the equation is:
     x ( f,I ) [mm]=( C 6 +a *Exp(flow* b )− C 2*log( C 3 *I  [W/cm̂2]))/( C 4 *f  [MHz]+ C 5)
 
 Wherein, “I” is excitation intensity [W/cm̂2]; “f” is working excitation frequency [MHz]; “x” is minimal radial distance from the artery wall [mm]; and “flow” is blood flow rate in the artery [ml/mm]. 
 
     
     
         87 . The method of  claim 72  further comprising receiving feedback indicating the thermal damage to the target tissue. 
     
     
         88 . The method of  claim 87  further comprising modifying the parameters in response to said feedback. 
     
     
         89 . The method of  claim 72  further comprising selectively delivering the unfocused ultrasound energy in a manner such that there is no significant damage to non-target tissue. 
     
     
         90 . The method of  claim 72  further comprising selectively delivering the unfocused ultrasound energy in a manner such that there is no significant stenosis. 
     
     
         91 . The method of  claim 72  further comprising delivering unfocused ultrasound energy to at least one treatment region, each treatment region being at a separate circumferential location. 
     
     
         92 . The method of  claim 91  wherein the duration that unfocused ultrasound energy is delivered to the target tissue is 5-30 seconds per treatment region. 
     
     
         93 . The method of  claim 91  wherein the treatment comprises between 1 and 8 treatment regions.