Fluid transfer unit of a tissue treatment system

Abstract

A fluid transfer unit of a tissue treatment system comprises a supply line, a first pump head having a first epicyclic roller train, wherein the first epicyclic roller train includes a first sun roller and one or more first planet rollers, a return line, and a second pump head having a second epicyclic roller train, wherein the second epicyclic roller train includes a second sun roller and one or more second planet rollers.

Description

FLUID TRANSFER UNIT OF A TISSUE TREATMENT SYSTEMBACKGROUNDFIELD

[0001] This application relates generally to medical apparatuses, systems, and methods that deliver energy and fluid to a device used to target an anatomical location of a subject. More specifically, this application relates to a fluid transfer unit integrated to the apparatuses, systems, and methods for the treatment of tissue, such as nerve tissue. This application also relates to a fluid transfer unit to deliver cooling fluid to a catheter-based intraluminal device.BACKGROUND INFORMATION

[0002] High blood pressure, also known as hypertension, commonly affects adults. Left untreated, hypertension can result in renal disease, arrhythmias, and heart failure. In recent years, the treatment of hypertension has focused on interventional approaches to inactivate the renal nerves surrounding a renal artery. Autonomic nerves tend to follow blood vessels to the organs that they innervate. Intraluminal devices, such as catheters, may reach specific structures, such as the renal nerves, which are proximate to the lumens in which the catheters travel. Accordingly, catheter-based systems can deliver energy from within the lumens to denervate the renal nerves in or in proximity to the vessel walls.

[0003] One approach to renal denervation uses radio frequency (RF) energy. The RF energy is delivered to a catheter having multiple electrodes placed against the intima of the renal artery to create an electrical field in the vessel wall and surrounding tissue. The electrical field results in resistive (ohmic) heating of the tissue to ablate the tissue and the1Attorney Docket: POMD00004599PRI_US01renal nerve passing through that tissue. To treat all the renal nerves surrounding the renal arteries, the RF electrodes are repositioned several times around the inside of the renal artery.

[0004] Many of the problems associated with RF systems are solved by a system having an ultrasound transducer that emits one or more therapeutic doses of unfocused ultrasound energy. The ultrasound transducer can be mounted at a distal end of catheter, and the unfocused ultrasound energy can heat tissue adjacent to a body lumen within which the catheter (and the transducer) is disposed. Such unfocused ultrasound energy may, for example, ablate target nerves surrounding the body lumen, without damaging non-target tissue such as the inner lining of the body lumen or unintended organs outside of the body lumen. The unfocused ultrasound energy system may also include a balloon mounted at the distal end of the catheter around the ultrasound transducer. A cooling fluid can be circulated through the balloon to cool the body lumen during ultrasound energy delivery. Such a design enables creation of one or more ablation zones sufficient to achieve long-term nerve inactivation at different locations around the circumference of the blood vessel.SUMMARY

[0005] The present disclosure is defined in the independent claims. Further embodiments of the present disclosure are defined in the dependent claims.

[0006] A fluid transfer unit of a tissue treatment system is provided herein. The fluid transfer unit includes a supply line and a first pump head. The first pump head has a first epicyclic roller train. The first epicyclic roller train includes a first sun roller and one or more first planet rollers. The fluid transfer unit further comprises a return line and a second pump head having a second epicyclic roller train. The second epicyclic roller train includes a second sun roller and one or more second planet rollers.2Attorney Docket: POMD00004599PRI_US01

[0007] A tissue treatment generator is provided herein. The tissue treatment generator includes an energy source to deliver energy to a tissue treatment catheter. The tissue treatment generator includes a fluid transfer unit as described herein.

[0008] A tissue treatment system is provided herein. The tissue treatment system includes a tissue treatment catheter. The tissue treatment catheter includes a catheter shaft having a fluid lumen, and a balloon mounted on the catheter shaft. The balloon has an interior in fluid communication with the fluid lumen. The tissue treatment system includes a fluid transfer unit as described herein.

[0009] The above summary does not include an exhaustive list of all aspects of the present disclosure. It is contemplated that the present disclosure includes all systems and methods that can be practiced from all suitable combinations of the various aspects summarized above, as well as those disclosed in the Detailed Description below and particularly pointed out in the claims filed with the application. Such combinations have particular advantages not specifically recited in the above summary.BRIEF DESCRIPTION OF THE DRAWINGS

[0010] The novel features of the invention are set forth with particularity in the claims that follow. A better understanding of the features and advantages of the present invention will be obtained by reference to the following detailed description that sets forth illustrative embodiments, in which the principles of the invention are utilized, and the accompanying drawings.

[0011] FIG. 1 is a perspective view of a tissue treatment system, in accordance with certain embodiments.

[0012] FIG. 2 is a perspective view of a tissue treatment catheter, in accordance with certain embodiments.3Attorney Docket: PGMD00004599PRI_US01

[0013] FIG. 3 is a perspective view of a portion of a tissue treatment catheter delivered into a body lumen, in accordance with certain embodiments.

[0014] FIG. 4 is a block diagram of a tissue treatment generator of a tissue treatment system, in accordance with certain embodiments.

[0015] FIG. 5 is a block diagram of a fluid transfer unit of a tissue treatment system, in accordance with certain embodiments.

[0016] FIG. 6 is a side view of a fluid transfer unit, in accordance with certain embodiments.

[0017] FIG. 7 is a perspective view of interior components of a fluid transfer unit, in accordance with certain embodiments.

[0018] FIG. 8 is a side view of meshed rollers of an epicyclic roller train, in accordance with certain embodiments.

[0019] FIG. 9 is a perspective view of a tissue treatment generator, in accordance with certain embodiments.

[0020] FIG. 10A is a perspective view of a first tubing cartridge and a second tubing cartridge, in accordance with certain embodiments.

[0021] FIG. 10B is a front view of the first and second tubing cartridges.

[0022] FIG. 10C is a side view of one of the first and second tubing cartridges.

[0023] FIG. 10D is a cutaway view of FIG. 10C.

[0024] FIG. 11 A is a perspective view of a fluid transfer unit of the tissue treatment generator of FIG. 9.

[0025] FIG. 1 IB is a front view of the fluid transfer unit of FIG. 11 A.

[0026] FIG. 11C is a side view of the fluid transfer unit of FIG. 11 A.

[0027] FIG. 1 ID is a cutaway view of FIG. 11C.4Attorney Docket: POMD00004599PRI_US01

[0028] FIG. 12A is a front view of the cartridges of FIGS 10A to 10D coupled to the fluid transfer unit of FIGS. 11A to 1 ID.

[0029] FIG. 12B is a perspective view of the cartridges of FIGS 10A to 10D coupled to the fluid transfer unit of FIGS. 11A to 1 ID.

[0030] FIG. 12C is a first cutaway side view of the cartridges of FIGS 10A to 10D coupled to the fluid transfer unit of FIGS. 11A to 1 ID.

[0031] FIG. 12D is a second cutaway side view of the cartridges of FIGS 10A to 10D coupled to the fluid transfer unit of FIGS. 11A to 1 ID.

[0032] FIG. 13 is a schematic representation of a tissue treatment system, in accordance with certain embodiments.

[0033] FIG. 14 is cutaway side view of a pulsatility mitigator.DETAILED DESCRIPTION

[0001] Systems that use energy, for example, at least one of unfocused ultrasound, radio frequency (RF), microwaves or light, to treat tissue, and methods of using the same are provided herein. In certain embodiments, energy may be delivered using a thermal energy emitter, for example, using at least one of acoustic-based tissue treatment transducers, tissue treatment electrodes for RF emission, one or more antennas for microwave emission, or tissue treatment lasers for light emission, apparatuses, systems, or portions thereof, are provided. The systems may be catheter-based. The systems may be delivered intraluminally (e.g., intravascularly) so as to place a thermal energy emitter within a target anatomical region of the subject, for example, within a suitable body lumen such as a blood vessel. Once properly positioned within the target anatomical region, the thermal energy emitter can be activated to deliver thermal energy. For example, unfocused ultrasonic energy may be emitted from a transducer radially outward so as to suitably heat, and thus treat, tissue within5Attorney Docket: POMD00004599PRI_US01the target anatomical region. The transducer or piezoelectric material can be activated at a frequency, duration, and energy level suitable for treating the ablation target, e.g., the targeted tissue.

[0002] In certain embodiments, the energy emitter comprises electrodes, which may be monopolar and embedded in or near a surface of a balloon wall, that emit thermal energy using radio frequencies relying on conduction of the heat from to the inner surface of the vessel wall.

[0003] In certain embodiments, the energy emitter comprises one or more antennas, e.g., an array of antennas, emitting microwave energy radiating from the emitter to form a volumetric field toward the targeted tissue. In certain embodiments, a cooling balloon may be provided to cool the one or more antennas and / or non-targeted tissue lying outside the target tissue zone that may be heated as a consequence of emitting micro wave energy from the one or more antennas. Micro wave energy may be delivered to target tissue for at least one energy application cycle, e.g., two to three energy application cycles, ranging from 10 seconds to 600 seconds at a frequency ranging from 900 MHz to 2.5 GHz.

[0004] In certain embodiments, the energy emitter comprises one or more laser fibers disposed on a surface of a balloon, which may emit, e.g., 1064 nm Nd: YAG-laser light using energy densities ranging from 4.5 to 30 J / mm2to generate thermal energy. In certain embodiments, the balloon may be perforated and a treatment / working flowrate of 40 mL / min may be used to remove blood cells from the vicinity of the optical fiber distal tip. In certain embodiments, a treatment dosage of 10 W power for 20 s may be used for at least one energy application cycle, e.g., two to three energy application cycles.

[0005] In certain embodiments, unfocused ultrasonic energy generated by a transducer or piezoelectric material, radio frequency (RF) energy transmitted by electrodes, micro wave energy generated by the one or more antennas, laser-light emitted by a laser may6Attorney Docket: POMD00004599PRIJJS01target select nerve tissue of the subject, and may heat such tissue in such a manner as to neuromodulate (e.g., fully or partially ablate, necrose, or stimulate) the nerve tissue.

[0006] Neuromodulating renal nerves may be used to treat various conditions, e.g., pulmonary hypertension, chronic kidney disease (CKD), atrial fibrillation, stroke, autonomic nervous system for use in treating a variety of medical conditions, arrhythmia, heart failure, end stage renal disease, myocardial infarction, anxiety, contrast nephropathy, diabetes, , nonalcoholic fatty liver disease, digestive disease, pancreatic cancer, other cancers, tumors, pain, polycystic kidney disease, asthma, sepsis, rheumatoid arthritis, chronic obstructive pulmonary disease (COPD), post-traumatic stress disorder (PTSD), sleep apnea, anxiety, depression, metabolic disorder, and insulin resistance, etc. It should be appreciated, however, that the balloon catheters suitably may be used to treat other nerves in and / or around a body lumen and other conditions, e.g., the nerves in and / or around a renal artery, superior mesenteric artery, inferior mesenteric artery, femoral artery, pelvic artery, portal vein, hepatic artery, common hepatic artery, gastroduodenal artery, splenic artery, gastric artery, celiac trunk, pulmonary artery, pulmonary vein, aorta, vena cava, etc., e.g., sympathetic nerves of the hepatic plexus within a hepatic artery responsible for blood glucose levels important to treating diabetes, or any suitable tissue, e.g., heart tissue triggering an abnormal heart rhythm, and is not limited to use in treating (e.g., neuromodulating) renal nerve tissue. In another example, a tissue treatment catheter is used to ablate sympathetic nerves of the renal arteries and a hepatic artery to treat diabetes or other metabolic disorders. In certain embodiments, the tissue treatment catheters are used to treat an autoimmune and / or inflammatory condition, such as rheumatoid arthritis, sepsis, Crohn’s disease, ulcerative colitis, and / or gastrointestinal motility disorders by neuromodulating sympathetic nerves within one or more of a splenic artery, celiac trunk, superior or inferior mesenteric artery. In certain embodiments, the tissue treatment catheter is used to ablate nerve fibers in the celiac7Attorney Docket: POMD00004599PRI_US01ganglion and / or renal arteries to treat hypertension. In certain embodiments, the transducers are used to treat pain, such as pain associated with pancreatic cancer, by, e.g., neuromodulating nerves that innervate the pancreas. Ultrasound, RF, microwave, or laser energy may also be used to ablate nerves of both the pulmonary vein and the renal arteries to treat atrial fibrillation. In still other examples, ultrasound, RF, micro wave, or laser energy may additionally or alternatively be used to ablate nerves innervating a carotid body in order to treat hypertension and / or chronic kidney disease.

[0007] Existing hypertension treatment systems, e.g. hypertension treatment systems, include generators to generate and deliver energy, e.g., RF or ultrasound energy, to a catheter-based intraluminal device. The treatment systems may also include components that engage with the generators to facilitate treatment. For example, fluid transfer cartridges can circulate inflation and / or cooling fluid into tissue treatment catheters. The fluid transfer cartridges contain numerous components, such as syringe pump components, conduits, fluidic plates, lighting, etc. As a result, the fluid transfer cartridges are expensive to manufacture. Yet, the fluid transfer cartridges are typically disposed of after use and, therefore, their use is not averaged over many cases and is costly. Alternative existing fluid pumps, such as peristaltic pumps, can be less costly, however, the pumping mechanisms may be unable to deliver fluid at a high enough pressure to facilitate long, narrow catheter fluid lumens, such as those required for catheters that access a renal artery via a radial approach. Accordingly, tissue treatment systems used to deliver energy and fluid to a catheter-based intraluminal device would benefit from fluid transfer components that are inexpensive and capable of delivering fluid at pressures high enough for use in a radial access balloon catheter.

[0008] As described below, embodiments can include a tissue treatment system having a fluid transfer unit configured to deliver an inflation fluid to a balloon. The treatment8Attorney Docket: POMD00004599PRI_US01system may be an ultrasound-based tissue treatment system, used to deliver unfocused ultrasonic energy radially outwardly to treat tissue within a target anatomical region, such as the renal nerves within a renal artery. Alternatively, the tissue treatment system may be used in other applications, such as to treat sympathetic nerves of the hepatic plexus within a hepatic artery. Thus, reference to the system as being a renal denervation system, or being used in treating, e.g., neuromodulating, renal nerve tissue is not limiting.

[0009] In various embodiments, description is made with reference to the figures. However, certain embodiments may be practiced without one or more of these specific details, or in combination with other known methods and configurations. In the following description, numerous specific details are set forth, such as specific configurations, dimensions, and processes, in order to provide a thorough understanding of the embodiments. In other instances, well-known processes and manufacturing techniques have not been described in particular detail in order to not unnecessarily obscure the description. Reference throughout this specification to “one embodiment,” “certain embodiments,” or the like, means that a particular feature, structure, configuration, or characteristic described is included in at least one embodiment. Thus, the appearance of the phrase “one embodiment,” “certain embodiments,” or the like, in various places throughout this specification are not necessarily referring to the same embodiment. Furthermore, the particular features, structures, configurations, or characteristics may be combined in any suitable manner in one or more embodiments.

[0010] The use of relative terms throughout the description may denote a relative position or direction. For example, “distal” may indicate a first direction relative to a reference point, such as a user. Similarly, “proximal” may indicate a second direction relative to the reference point, opposite to the first direction. Such terms are provided to establish relative frames of reference, however, and are not intended to limit the use or9Attorney Docket: POMD00004599PRI_US01orientation of tissue treatment system components, e.g., a fluid transfer unit or a generator, to a specific configuration described in the various embodiments below.

[0011] In an aspect, a tissue treatment system includes a fluid transfer unit. The fluid transfer unit can include a pump head that has an epicyclic roller train. More particularly, the epicyclic roller train can have rollers to roll over a fluid line and, thus, squeeze inflation fluid through the fluid line to a balloon of a tissue treatment catheter. The epicyclic roller train can include planet rollers. The planet rollers may be non-centrally supported between a sun roller and the fluid line. The described configuration can reduce components and, thus, manufacturing costs. Furthermore, engagement between the sun roller and the planet rollers can drive the planet rollers over the fluid line with enough force to generate high fluid pressures. Accordingly, the fluid transfer unit can reduce per procedure costs and facilitate treatment via radial access by the tissue treatment catheter.

[0012] In some variants, the one or more first planet rollers may be non-centrally supported between the supply line and the first sun roller to roll over the supply line when the sun roller rotates. In some variants, the one or more second planet rollers may be non- centrally supported between the return line and the second sun roller to roll over the return line when the second sun roller rotates.

[0013] In some variants, the fluid transfer unit may further comprise a controller configured to cause a first and second motor to respectively drive the first and second pump heads with a phase difference therebetween. In other variants, the fluid transfer unit may further comprise a motor coupled to a gear configured to drive the first and second pump heads with a phase difference therebetween. As a result, a fluctuation of the flow rate (also referred to as inflation pulsatility) generated by the pumps may be reduced. For example, the phase difference may allow multiphase dampening, i.e., allow to generate a more constant flow rate with the first and second pump heads in comparison to a single pump head or to10Attorney Docket: POMD00004599PRI_US01dual pump heads without a phase difference. The phase difference may be selected based on the number of planet rollers of the pump heads. In general, the phase difference may be maximized to minimize the fluctuation of the flow rate for a given configuration of the pump heads For example, in case of one planet roller per pump head, a phase difference may be 180 degrees, in case of two planet rollers per pump head, a phase difference may be 90 degrees and in case of four planet rollers per pump head, a phase difference may be 45 degrees. The fluctuation of the flow rate may further be reduced by increasing the number of planet rollers provided in at least one of the first and second pump heads. In case of coaxially aligned first and second pump heads, the phase difference may result in the first and second planet rollers being circumferentially offset around a rotation axis of the pump heads. For example, the timing of the first planet rollers interacting with (e.g., sliding over) the supply line may be different from the timing of the second planet rollers interacting with (e.g., sliding over) the return line, wherein the timing difference determines, e.g., corresponds to, the phase difference.

[0014] In some variants, at least one of the first and second sun rollers may include a plurality of sun teeth to engage a plurality of planet teeth of the respective one or more planet roller. The plurality of sun teeth may be loosely meshed with the plurality of planet teeth.

[0015] In some variants, the plurality of sun teeth may slide over the plurality of planet teeth when the sun roller rotates.

[0016] In some variants, a sun diameter of at least one of the first and second sun rollers may be greater than a planet diameter of the respective first and second planet rollers.

[0017] In some variants, the fluid transfer unit may further comprise a fluid reservoir and a pressure reservoir. The supply line may extend between the fluid reservoir and the pressure reservoir and the first pump head may drive fluid through the supply line from the fluid reservoir to the pressure reservoir.11Attorney Docket: POMD00004599PRI_US01

[0018] In some variants, a common drive shaft may engage the first sun roller and the second sun roller. Thus, both pump heads may be driven via a single motor.

[0019] In some variants, a first drive shaft engages the first sun roller and a second drive shaft engages the second sun roller. As a result, each of the sun rollers may be driven individually by respective motors.

[0020] In some variants, the fluid transfer unit may further comprise a proportional valve fluidly coupling the return line to, e.g., equalize a volumetric flow rate of an inflation fluid in the supply line and the return line even when the first and second pump heads are driven at different speeds.

[0021] In some variants, the fluid transfer unit may further comprise a housing accommodating the first and second pump heads and at least one of a first tubing cartridge configured to hold a portion of the supply line and to be releasably coupled to the housing to bring the portion of the supply line in engagement with the first pump head when coupled to the housing, and a second tubing cartridge configured to hold a portion of the return line and to be releasably coupled to the housing to bring the portion of the return line in engagement with the second pump head when coupled to the housing.

[0022] Each of the first and second tubing cartridges may comprise at least one coupling element. The housing may comprise a first spring-loaded coupling element configured to engage one of the at least one coupling elements of the first tubing cartridge to removably couple the first tubing cartridge to the housing. Additionally or alternatively, the housing may comprise a second spring-loaded coupling element configured to engage one of the at least one coupling elements of the second tubing cartridge to removably couple the second tubing cartridge to the housing. Alternative coupling elements are contemplated, for example clips, screws or any other known element suitable for releasably coupling the tubing cartridges to the housing.12Attorney Docket: POMD00004599PRI_US01

[0023] In some variants, the fluid transfer unit may comprise a pulsatility mitigator located in the supply line. As an example, the pulsatility mitigator may comprise at least one membrane configured to redirect a flow direction of a fluid within the pulsatility mitigator and / or at least one flow rectifying wing configured to redirect a flow direction of a fluid within the pulsatility mitigator. The fluid transfer unit may further comprise at least one of (i) at least one pressure sensor located in the supply line and configured to monitor the pressure in the supply line downstream from the pulsatility mitigator and (ii) at least one pressure sensor located in the return line to monitor the pressure in the return line.

[0024] In some examples, the fluid transfer unit may be configured to deliver an inflation fluid to the tissue treatment catheter. The fluid transfer unit may include a fluid line and a pump head. The pump head may have an epicyclic roller train. The epicyclic roller train includes a sun roller and one or more planet rollers. The one or more planet rollers may be non-centrally supported between the fluid line and the sun roller to roll over the fluid line when the sun roller rotates.

[0025] In some examples, the fluid transfer unit may be configured to deliver an inflation fluid through the fluid lumen to the balloon. The fluid transfer unit may include a fluid line, and a pump head. The pump head may have an epicyclic roller train. The epicyclic roller train may include a sun roller and one or more planet rollers. The one or more planet rollers may be non-centrally supported between the fluid line and the sun roller to roll over the fluid line when the sun roller rotates.

[0026] Referring to FIG. 1, a perspective view of a tissue treatment system is shown in accordance with certain embodiments. A tissue treatment system 100 is shown as including a tissue treatment catheter 102 connected to a tissue treatment generator 120 by a connection cable 140. In certain embodiments, the tissue treatment catheter 102 includes an ultrasound transducer (FIG. 2) within a balloon 112. The tissue treatment system 100 can13Attorney Docket: POMD00004599PRIJJS01include a fluid reservoir 110 to store an inflation fluid 111. The inflation fluid 111 may be a cooling fluid. The tissue treatment system 100 can include, e.g., integrated within the generator 120, a fluid transfer unit 130 to transfer or move the inflation fluid 111 into and out of the balloon 112. More particularly, the fluid transfer unit 130 of the tissue treatment system 100 may deliver the inflation fluid 111 to the tissue treatment catheter 102. For example, the fluid transfer unit 130 can include an epicyclic roller train, as described below, to pump the inflation fluid 111 at an inflation pressure to the balloon 112. The tissue treatment system 100 may also include a cooling unit, e.g., integrated within the generator 120, to cool the inflation fluid 111. Accordingly, the inflation fluid 111 can be delivered to the balloon 112 by the fluid transfer unit 130 at a temperature below ambient temperature. In certain embodiments, the tissue treatment system 100 includes an energy delivery unit, e.g., an ultrasonic energy source as described below, configured to control activation, e.g., energize, the ultrasound transducer to deliver energy to the target anatomy. More particularly, the ultrasonic energy source can deliver ultrasound energy to the tissue treatment catheter 102, e.g., through the connection cable 140.

[0027] In the embodiment shown in FIG. 1, the generator 120 is connected to the tissue treatment catheter 102 through an inflation tubing 138 for fluid transfer. In certain embodiments, the generator 120 interfaces with the fluid transfer unit 130 to provide the inflation fluid 111 to the tissue treatment catheter 102 for selectively inflating and deflating the balloon 112. The balloon 112 can be made from, e.g., nylon, a polyimide film, a thermoplastic elastomer (such as those marked under the trademark PEBAX™), a medicalgrade thermoplastic polyurethane elastomer (such as Pellethane®, Isothane®, or other suitable polymers or any combination thereof), but is not limited thereto.

[0028] Referring to FIG. 2, a perspective view of a tissue treatment catheter is shown in accordance with certain embodiments. The tissue treatment catheter 102 of the tissue14Attorney Docket: POMD00004599PRI_US01treatment system 100 can include a catheter shaft 202 having an elongated body extending from a proximal catheter end 204 to a distal catheter end 206. The balloon 112 may be mounted on the catheter shaft 202, e.g., at the distal catheter end 206. One or more energy transducers, such as an ultrasound transducer 208, may be mounted on the catheter shaft 202. For example, the ultrasound transducer 208 may be positioned on the catheter shaft 202 within an interior defined by the balloon 112.

[0029] The catheter shaft 202 can define one or more lumens such as: fluid lumen(s) to deliver an inflation / cooling fluid to the balloon 112, cable lumen(s) to provide electrical cable passageways to deliver energy to the ultrasound transducer 208, and guidewire lumens for exchanging guidewires, etc. The lumen(s) may be connected to corresponding connectors and / or terminal features, such as at the proximal catheter end 204. For example, the fluid lumens may connect to one or more fluid ports 210, which receive inflation / cooling fluid from the fluid transfer unit 130 of the tissue treatment system 100. Similarly, the electrical cables can connect to an external connector 212, which receives energy from the generator 120 of the tissue treatment system 100 through the connection cable 140.

[0030] Referring to FIG. 3, a perspective view of a portion of a tissue treatment catheter delivered into a body lumen is shown in accordance with certain embodiments. A distal portion of the tissue treatment catheter 102 may be inserted into a body lumen of a subject. The body lumen may be a vessel 300, e.g., a blood vessel such as a renal artery, which has several nerves 302. The vessel 300 can be a target vessel of an ablation procedure. More particularly, the nerves 302 can be an ablation target. The nerves 302 can surround the body lumen. For example, the nerves 302 may run in and around the blood vessel 300, such as through an outer layer, e.g., adventitia layer, of the vessel.

[0031] The distal portion of the tissue treatment catheter 102 may include an ultrasound transducer 208, the balloon 112 filled with the inflation fluid 111, a catheter shaft15Attorney Docket: POMD00004599PRI_US01202, and / or a guidewire support tip 304 configured to receive a guidewire 306. The transducer 208 may be disposed partially or completely within the balloon 112, which may be inflated with the inflation fluid 111. The inflation fluid 111 can include a liquid. The liquid may have a relatively high, as compared to gases, thermal capacity. For example, the liquid may include water, dextrose, or saline, and have a corresponding heat capacity. When the inflation fluid 111 is transferred into an interior 308 of the balloon 112, e.g., through a fluid lumen of the tissue treatment catheter 102 that is in fluid communication with the interior, the balloon can inflate into contact with a vessel wall 310 of the blood vessel 300. The vessel wall 310, and / or the nerves 302 extending within and around the vessel wall, can be an ablation target. In certain embodiments, the transducer 208 may be used to output acoustic energy to ablate the ablation target. Accordingly, the inflation fluid 111 can act as a heat sink to absorb heat generated by the ultrasound transducer 208 and / or delivered to the ablation target from the ultrasound transducer.

[0032] In certain embodiments, e.g., suitable for renal denervation, the balloon 112 is inflated while inserted in the body lumen of the patient during a procedure at a working pressure of about 10 to about 30 psi using the inflation fluid 111. The balloon 112 may be or include a compliant, semi-compliant, or non-compliant medical balloon. The balloon 112 is sized for insertion in the body lumen and, in the case of insertion into the renal artery, for example, the balloon 112 may be selected from available sizes including outer diameters of 3.5, 4.2, 5, 6, 7, or 8 mm, but not limited thereto. When activated, the transducer 208 can deliver the acoustic energy to the vessel wall 310 of the target vessel 300. The delivered energy can ablate and raise a temperature of the ablation target. The cooling fluid within the balloon 112, however, can be static and absorb heat to passively cool the ablation target and protect the target tissue and the transducer 208. The target tissue may therefore be treated by the delivered acoustic energy.16Attorney Docket: POMD00004599PRI_US01

[0033] Referring to FIG. 4, a block diagram of a tissue treatment generator 120 of a tissue treatment system is shown in accordance with certain embodiments. The block diagram represents an example implementation of the tissue treatment generator 120, which was introduced above. The generator 120 is shown as including a controller 402 having one or more processors 404, a memory 406, a user interface 408, and an ultrasound excitation source 410, but can include additional and / or alternative components. While not specifically shown, a processor 404 can be located on a control board, or more generally, a printed circuit board (PCB) along with additional circuitry of the generator 120. The processor 404 can communicate with the memory 406, which can include a non-transitory computer-readable medium storing instructions. The processor 404 can execute the instructions to cause the treatment system 100 to perform methods, such as delivering inflation fluid 111 through the inflation tubing 138 to the tissue treatment catheter 102 by the fluid transfer unit 130.

[0034] The user interface 408 can interact with the processor 404 to cause transmission of electrical signals at selected actuation frequencies to the ultrasound transducer 208 via wires of the connection cable 140 and the cabling that extends through the catheter shaft 202. These wires electrically couple the generator 120 to the transducer 208 so that the generator can send electrical signals to the transducer, and receive electrical signals from the transducer. The processor 404 can control the ultrasound excitation source 410 to control the amplitude and timing of the electrical signals so as to control the power level and duration of the ultrasound signals emitted by transducer 208. More generally, the generator 120 can control one or more ultrasound treatment parameters that are used to perform sonication. In certain embodiments, the excitation source can also detect electrical signals generated by transducer 208 and communicate such signals to the processor 404 and / or circuitry of a control board. While the ultrasound excitation source 410 is shown as being part of the controller 402, it is also possible that the ultrasound excitation source is external to17Attorney Docket: POMD00004599PRI_US01the controller while still being controlled by the controller, and more specifically, by the processor 404 of the generator controller.

[0035] The user interface 408 can include a touch screen and / or buttons, switches, etc., to allow for an operator (user) to enter patient data, select treatment parameters, view records stored on a storage / retrieval unit (not shown), and / or otherwise communicate with the processor 404. The user interface 408 can include a voice-activated mechanism to enter patient data or may be able to communicate with additional equipment so that control of the generator 120 is through a separate user interface, such as a wired or wireless remote control. In some embodiments, the user interface 408 is configured to receive operator-defined inputs, which can include, e.g., a duration of energy delivery, one or more other timing aspects of the energy delivery pulses (e.g., frequency, duty cycle, etc.), power, body lumen length, mode of operation, patient parameter, such as height and weight, and / or verification of artery diameter, or a combination thereof. Example modes of operation can include (but are not limited to): system initiation and set-up, catheter preparation, balloon inflation, verification of balloon apposition, pre-cooling, sonication, post-cooling, balloon deflation, and catheter removal, but are not limited thereto. In certain embodiments, the user interface 408 provides a graphical user interface (GUI) that instructs a user how to properly operate the treatment system 100. The user interface 408 can also be used to display treatment data for review and / or download, as well as to allow for software updates, and / or the like.

[0036] The generator 120 can also control a cooling fluid supply subsystem 420, which can include the fluid transfer unit 130 and fluid reservoir 110, and can also include components such as fluid pumps and / or the like. The cooling fluid supply subsystem 420 is fluidically coupled to one or more fluid lumens within the catheter shaft 202 which in turn are fluidically coupled to the balloon 112. The cooling fluid supply subsystem 420 can be configured to circulate a cooling liquid through the tissue treatment catheter 102 to the18Attorney Docket: POMD00004599PRI_US01transducer 208 in the balloon 112. The cooling fluid supply subsystem 420 may include elements such as the fluid reservoir 110 for holding the cooling fluid 111, pumps (e.g., peristaltic pumps), and / or a refrigerating coil (not shown), or the like for providing a supply of cooling fluid to the interior space of the balloon at a controlled temperature, desirably at or below body temperature. The processor 404 interfaces with the cooling fluid supply subsystem 420 to control the flow of cooling fluid 111 into and out of the balloon 112. For example, the processor 404 can control motor control devices linked to drive motors associated with pumps for controlling the speed of operation of pumps. Such motor control devices can be used, for example, where the pumps are positive displacement pumps, such as peristaltic pumps and / or pumps having an epicyclic roller train, as described below.

[0037] Referring to FIG. 5, a block diagram of a fluid transfer unit 130 of a tissue treatment system is shown in accordance with certain embodiments. The fluid transfer unit 130 is indicated as a closed system by a dotted line in FIG. 5. It will be appreciated, however, that the closed system can also contain the fluid reservoir 110 and / or the balloon 112, e.g., may include the cooling fluid supply system 420. More particularly, the fluid transfer unit 130 may be considered to include the fluid reservoir 110 and / or the balloon 112. Representing the fluid transfer unit 130 as shown can, however, underscore the modularity of the tissue treatment system and, in particular, the fluid transfer unit 130 as a replaceable component that can be installed and removed for disposal without having to replace other components of the tissue treatment generator 120.

[0038] The fluid transfer unit 130 of the tissue treatment system 100, which delivers the inflation fluid 111 from the fluid reservoir 110 to the balloon 112, can include a fluid line 502. The fluid line 502 can be part of the inflation tubing 138. The fluid line 502 can include one or more tubes, e.g., flexible tubing, to connect to an outlet and / or inlet of the fluid reservoir 110. Similarly, the one or more tubes can connect to an inlet and / or outlet fluid19Attorney Docket: POMD00004599PRI_US01ports 210 of the tissue treatment catheter 102. For example, a supply line 504 of the fluid line502 may connect the fluid reservoir 110 outlet to an inlet fluid port 210 to deliver inflation fluid 111 to the balloon 112, and a return line 506 of the fluid line 502 may connect an outlet fluid port 210 to the fluid reservoir 110 to return inflation fluid 111 from the balloon 112 to the fluid reservoir 110. Accordingly, the fluid line 502 can provide a fluidic circuit to circulate inflation fluid 111 through the balloon 112 for cooling the transducer 208 during a procedure.

[0039] The fluid transfer unit 130 can include one or more pump heads to move the inflation fluid 111 through the fluid line 502. In certain embodiments, a first pump head 508 is coupled to the supply line 504 to move fluid from the fluid reservoir 110 toward the balloon 112. Similarly, a second pump head 510 can be coupled to the return line 506 to move fluid from the balloon 112 to the fluid reservoir 110. More particularly, the fluid transfer unit 130 can include dual pump heads 508, 510, the first pump head 508 providing positive pressure and the second pump head 510 providing negative pressure, to create sufficient head pressure to circulate the inflation fluid 111 through the tissue treatment system. As described below, each pump head 508, 510 can include a roller train to function as a peristaltic pump for compressing the tubing of the fluid line 502 and drawing the inflation fluid 111 through the tubing in the pumping direction, e.g., to or from the balloon 112. In other embodiments, only a first pump head 508 is utilized in the fluid transfer unit 130.

[0040] The inflation fluid 111 pumped to the balloon 112 can be a cooling fluid that protects the vessel wall 310 during a procedure. When the cooling fluid is circulated through the balloon 112, the fluid transfer unit 130 can have two pump heads, e.g., the first pump head 508 and the second pump head 510. Alternatively, the tissue treatment catheter 102 may have a one-way catheter design in which the cooling fluid is vented into the vessel 300.20Attorney Docket: POMD00004599PRI_US01In such case, the fluid transfer unit 130 may not have the second pump head 510 or the return line 506.

[0041] As described below, the pump head(s) 508, 510 of the fluid transfer unit 130 can be peristaltic pump(s). Peristaltic pumps have pressure characteristics that may not be ideal for an interventional catheterization procedure utilizing the balloon 112 that ideally remains at a constant diameter when inflated. More particularly, peristaltic pumps can generate cyclical pressure in the inflation fluid 111 and balloon 112, leading to inflation pulsatility, e.g., a balloon 112 that expands and contracts cyclically. To reduce a likelihood of such pulsatility, the fluid transfer unit 130 can include a pressure reservoir 520. The pressure reservoir 520 may, for example, include a positive pressure reservoir 520 in line with the supply line 504. For example, a first segment of the fluid line 502 may extend between the fluid reservoir 110 and the pressure reservoir 520. Similarly, a second segment of the fluid line 502 may extend from the pressure reservoir 520 to the balloon 112. The first pump head 508 can drive fluid through the fluid line 502 from the fluid reservoir 110 to the pressure reservoir 520. The pressure reservoirs 520 can include an air trap that contains air and inflation fluid 111. The pressure reservoir 520 can dampen pulses from the first pump head 508 by creating a buffer. More particularly, pressure pulses can, rather than being transmitted to the balloon 112, compress the air in the pressure reservoir 520. The air compression can stabilize the fluid pressure, resulting in a reduction of balloon diameter changes during the procedure.

[0042] Optionally, the fluid transfer unit 130 can include a pressure reservoir 520 in line with the return line 506. Whereas the pressure reservoir 520 in line with the supply line 504 may be termed a positive pressure reservoir, the pressure reservoir 520 in line with the return line 506 can be termed a negative pressure reservoir. The negative pressure reservoir can include an air trap that, like the positive pressure reservoir, dampens pulses on the return21Attorney Docket: POMD00004599PRI_US01side of the fluid transfer unit 130. More particularly, the negative pressure reservoir can absorb pressure pulses generated by the pulsatile pumping of the second pump head 510 to reduce variation in balloon diameter.

[0043] The fluid transfer unit 130 may include one or more pressure sensors 522 to monitor the pressure of the inflation fluid 111. In certain embodiments, a pressure sensor 522 is coupled to the supply line 504, e.g., connected to the positive pressure reservoir.Alternatively or additionally, a pressure sensor 522 can be coupled to the return line 506, e.g., connected to the negative pressure reservoir. The pressure sensor(s) 522 can detect pressure in the inflation fluid 111 and generate corresponding electrical signals that can be monitored by the processor 404. More particularly, the processor 404 can receive the pressure signals and determine, based on the pressure signals, pumping parameters for the pump head(s). The processor 404 can drive the pump head(s) based on the pumping parameters to achieve a desired inflation of the balloon 112.

[0044] Inflation fluid 111 may be pumped through the supply line 504 and the return line 506 at a same rate. For example, as described below, the first pump head 508 and the second pump head 510 may be driven by a same motor or drive shaft that turns the pump heads at a same rate. In some cases, however, it may be desirable or necessary to run the pump heads 508, 510 at different speeds. In such cases, volumetric flow rate of the inflation fluid 111 in the supply line 504 and the return line 506 may nonetheless be equalized by a proportional valve 523. The proportional valve 523 can fluidly couple the return line 506 to the supply line 504 through a coupling line 524. More particularly, the proportional valve 523 can direct some of the inflation fluid 111 returning from the balloon 112 through the second pump head 510 toward the supply line 504. The redirected fluid can enter and add to the total volumetric flow rate of the inflation fluid 111 in the supply line 504. Accordingly, even when the second pump head 510 is pumping at a faster rate than the first pump head22Attorney Docket: POMD00004599PRI_US01508, the volumetric flow rate of the supply line 504 and the return line 506, at locations between the pump heads 508, 510 and the balloon 112, may be the same. Alternatively or additionally, the rerouting of inflation fluid 111 can be used to adjust the pressure going to the inlet of the balloon 112 without needing to change a motor speed of the first pump head 508. The proportional valve 523 can, accordingly, adjust for asymmetries or pressure fluctuations in the pump head operation.

[0045] The fluid transfer unit 130 can include a one-way valve 526 in the fluid line 502. For example, the valve 526 may be coupled in line with the fluid line 502 between the fluid reservoir 110 and the first pump head 508. The one-way valve 526 can prevent backflow into the fluid reservoir 110 through the supply line 504. For example, the valve 526 may be located between the fluid reservoir 110 and a location at which the coupling line 524 enters the supply line 504. Fluid diverted into the supply line 504 from the return line 506 may therefore flow distally toward the balloon 112, rather than proximally toward the fluid reservoir 110.

[0046] Referring to FIG. 6, a side view of a fluid transfer unit is shown in accordance with certain embodiments. The fluid transfer unit 130 may include a pump casing 602 within which the first pump head 508 is contained. More particularly, the pump casing 602 can be an outer housing that contains, e.g., the epicyclic roller train described below. The pump casing 602 may have ports through which the fluid line 502 passes. For example, the fluid line 502 can engage the first pump head 508 components within the pump casing 602, and can having a first segment extending outward to be connected to the fluid reservoir 110 and a second segment extending outward to connect to a fluid port 210 of the tissue treatment catheter 102.

[0047] The pump casing 602 and the fluid line 502 may be provided in a kit that can be easily swapped out. For example, the pump casing 602 may be screwed onto an outer23Attorney Docket: POMD00004599PRI_US01surface of the tissue treatment generator 120. Installation of the pump casing 602 may include engaging a sun roller of the first pump head 508 to a drive shaft of a motor within the generator, for example. The ability to quickly install and uninstall the fluid transfer unit 130 on the generator can reduce size or form factor, and may potentially reduce disposal costs of the tissue treatment system. The first pump head 508 and tubing may be relatively low-cost items, and making those components disposable, while reusing the drive motor within the generator, can provide a cost effective solution. Furthermore, the attachment and detachment of the pump casing 602 to the generator can be performed easily with no tools, given that the fasteners used to secure the pump casing 602 to the generator may be simple thumb screws, magnets, snap-fit fasteners, clips, etc. As such, the disposable pump head and tubing assembly can provide an easy to use solution that is cost effective and less wasteful than existing approaches.

[0048] Referring to FIG. 7, a perspective view of interior components of a fluid transfer unit is shown in accordance with certain embodiments. Internal components of the first pump head 508, e.g., within the pump casing 602, can include peristaltic pumping components. For example, the first pump head 508 can include an epicyclic roller train 702. The epicyclic roller train 702 can provide sufficient pumping pressure in view of the roller structures described below. More particularly, the epicyclic roller train 702 can include a profiled sun roller 704 that reliably and efficiently transmits power to profiled planet rollers 706. The planet rollers 706 can, in turn, roll over the fluid line 502 to squeeze fluid toward (or in the case of the second pump head 510, away from) the balloon 112. The profiled rollers 704, 706 can engage each other by fit, rather than by friction alone, which can reduce a likelihood of slipping between the rollers 704, 706, and promote transmission of more power from a drive shaft 703 to the fluid line 502.24Attorney Docket: POMD00004599PRI_US01

[0049] In addition to having good power transmission, the epicyclic roller train 702 can be manufactured at a low cost. The low cost allows for the first pump head 508 to be replaced after each procedure at minimal cost. More particularly, the pump head design described herein is disposable, and inexpensive, so that a new sterile pump head can be provided after each procedure, and disposed of afterward.

[0050] The epicyclic roller train 702 can include a sun roller 704 and one or more planet rollers 706. The sun roller 704 may be centrally supported on the drive shaft 703. More particularly, the drive shaft 703 can extend from a drive motor, and engage an interior surface of the sun roller 704, within a central hole of the sun roller 704. The drive shaft 703 may be keyed, for example, to engage a corresponding key way within a central hole of the sun roller 704. By contrast, the planet roller 706 may be non-centrally supported around the sun roller 704. For example, the planet rollers 706 can be supported between the fluid line 502 and the sun roller 704. Rather than being supported on a central shaft, however, the planet rollers 706 can be squeezed between the fluid line 502 and the sun roller 704, allowing the planet rollers 706 to roll freely over the fluid line 502 when the sun roller 704 rotates, as described below. More particularly, a distance between a center of the planet rollers 706 and the drive shaft 703 can vary as the sun roller 704 rotates.

[0051] When the sun roller 704 rotates, an outer surface of the sun roller 704 can engage and drive outer surfaces of the planet rollers 706. In certain embodiments, the sun roller 704 includes several sun teeth 708 to engage several planet teeth 710 of the planet rollers 706. The teeth may mesh, as described below, such that the sun teeth 708 press against and push the planet teeth 710 in a rotational direction. As the planet teeth 710 move in the rotational direction, the planet rollers 706 can roller over the fluid line 502 to squeeze the fluid line 502, and the inflation fluid 111 within the fluid line 502, in the direction of the sun roller 704 rotation. For example, when the sun roller 704 of FIG. 7 rotates about the25Attorney Docket: POMD00004599PRI_US01drive shaft 703 in a clockwise direction, the planet rollers 706 drive the inflation fluid 111 through the fluid line 502 in the clockwise direction about an axis of the drive shaft 703.

[0052] The profiled shape of the sun and planet rollers of the planetary roller system can reduce a likelihood of slipping of the planet rollers 706. More particularly, in a dosing pump configuration having smooth rollers, the rollers may slip when a threshold fluid pressure occurs in the fluid line 502. The introduction of sun teeth 708 and planet teeth 710 can provide positive surface engagement, rather than friction alone, to increase power transmission and drive the planet rollers 706 over the fluid line 502 to generate higher pumping pressures. For example, it was discovered that a similar design having smooth rollers may generate approximately 30 psi fluid pressures in the fluid line 502, and the introduction of sun teeth 708 and planet teeth 710 described herein increased the fluid pressures for an otherwise similar design to 70 psi of head pressure. Such head pressure can be used to peristaltically pump cooling fluid to a balloon 112 through small-diameter fluid lumens, such as those used in small-diameter catheters utilized in radial access applications.

[0053] The epicyclic roller train 702 can differ in various respects from an epicyclic gear train. For example, as described below, the tooth engagement can include a combination of slip and push components, rather than the rolling that is typical of closely meshed gear trains. Furthermore, rather than being supported on a central shaft or prongs of a carrier, the planet rollers 706 can be freely supported between the fluid line 502 and the planet roller 706 at their outer surfaces. More particularly, the planet rollers 706 can be rolled within an annular space formed between an inward-facing surface of the fluid line 502 and an outer surface of the sun roller 704. The fluid line 502 may not extend fully around the sun roller 704, however, and a portion of the annular space may be formed between the outer surface of the sun roller 704 and an arcuate guide 712.26Attorney Docket: POMD00004599PRI_US01

[0054] The arcuate guide 712 can be a curved ledge extending inward from the pump casing 602. The arcuate guide 712 can have an inward-facing surface that the planet rollers 706 can roll onto and over between a first location of the fluid line 502 and a second location of the fluid line 502. The arcuate guide 712 can complete the annular space through which the planet rollers 706 revolve about the sun roller 704. The fluid line 502 can extend past lateral edges of the arcuate guide 712 to enter and exit the pump casing 602 (FIG. 6). An inner surface of the arcuate guide 712 may be smooth.

[0055] In certain embodiments, the planet rollers 706 are supported by a carrier (not shown). The planet rollers 706 can be linked to each other by one or more members of the carrier. For example, the planet rollers 706 may be mounted on respective prongs extending from ends of a ring or spoked carrier, e.g., a carrier having a Y-shape. The carrier arms can therefore maintain the planet rollers 706 at a predetermined spatial relationship to each other, e.g., at a same distance from a center of the carrier. Accordingly, the carrier may constrain and / or stabilize movement of the planet rollers 706 relative to each other.

[0056] Relative sizes of the sun roller 704 and the planet rollers 706 can affect pump head operation. A diameter of the sun roller 704, i.e., a sun diameter, can be measured along a line extending radially through a central axis of the sun roller 704 between outer tooth extremities (a major diameter of the sun roller 704). Similarly, a diameter of the planet rollers 706, i.e., a roller diameter, can be measured along a line extending radially through a central axis of the planet roller 706 between outer tooth extremities (a major diameter of the planet roller 706). The sun diameter and the planet diameter in FIG. 7 appear equal, however, in certain embodiments the sun diameter of the sun roller 704 is greater than the planet diameter of the planet roller 706. The larger sun roller 704 can allow for more planet rollers 706 to be located circumferentially about the planet roller 706. Using more planet rollers 706 can reduce pulsatility in the fluid line 502. Accordingly, the sun diameter and the27Attorney Docket: POMD00004599PRIJJS01planet diameter can be selected to reduce pulsatility despite the use of a peristaltic pumping action.

[0057] Referring to FIG. 8, a side view of meshed rollers of an epicyclic roller train is shown in accordance with certain embodiments. In certain embodiments, the rollers of the epicyclic roller train 702 may be represented as a hybrid between a gear train, having meshing teeth, and a roller train, having smooth, frictionally engaging rollers. More particularly, the sun teeth 708 of the sun roller 704 may be loosely meshed with the planet teeth 710 of the planet roller 706, providing for a roller engagement that includes both positive tooth engagement (during first angles of rotation) and frictional engagement or slipping of teeth (during second angles of rotation). The hybrid function can derive from the non-centrally supported planet rollers 706 squeezed between, and allowed some degree of relative radial movement with, the fluid line 502 and the sun roller 704. Accordingly, the epicyclic roller train 702 can allow for some variation in the fit between the rollers and the fluid line 502 without relying entirely on friction that can reduce force transmission and pumping pressure capabilities.

[0058] Still referring to FIG. 8, each roller tooth may have an apex and a valley. As shown, an apex of the sun roller 704 may engage a valley of the planet roller 706 at a first rotational position. As the sun roller 704 rotates, the sun tooth 708 can push against the planet tooth 710. Rather than rolling against the planet tooth 710, as may be typical of a gear train, the sun tooth 708 can slide over the planet tooth 710 between the valley and an apex of the planet tooth 710. More particularly, the sun teeth 708 can slide over the planet teeth 710 when the sun roller 704 rotates within the first pump head 508. During the sliding, there can be direct force input between surfaces as well as frictional force applied between the surfaces. The total power transmitted may therefore be higher than the power transmission between purely frictionally engaged surfaces and lower than power transmission between closely28Attorney Docket: POMD00004599PRI_US01meshed gear teeth. Unlike closely meshed gear teeth, however, the loosely meshed roller teeth can remain engaged, either directly or frictionally, when the non-centrally supported planet rollers 706 shift within the annular space between the sun roller 704 and the fluid line 502. Accordingly, an optimal power transmission may be achieved within the geometric constraints of the system.

[0059] Referring again to FIG. 5, the fluid transfer unit 130 can include the first pump head 508 and the second pump head 510. The second pump head 510 can include components similar to the first pump head 508. For example, the second pump head 510 can include a second epicyclic roller train. The second epicyclic roller train can include a second sun roller and one or more second planet rollers. The one or more second planet rollers may be non-centrally supported between the return line and the second sun roller to roll over the return line when the second sun roller rotates. Accordingly, although the individual components of the second epicyclic gear train are not shown, it will be appreciated that such components are similar to those described with respect to the first pump head 508, and those descriptions equally apply to the second pump head 510.

[0060] The several pump heads of the fluid transfer unit 130 may be arranged in series to boost pumping performance. For example, the first pump head 508 can provide positive pressure and the second pump head 510 can provide negative pressure to increase a head pressure and flow rate needed for small diameter catheters, such as the tissue treatment catheter 102 configured for radial access of the renal arteries. In certain embodiments, the several pump heads may be driven by a same drive shaft. For example, the drive shaft 703 shown in FIG. 7 can extend and engage the second sun roller of the second epicyclic gear train. More particularly, the drive shaft 703 can engage the sun roller 704 and the second sun roller, and rotation of the drive shaft 703 can cause rotation of respective planet rollers that move inflation fluid 111 through respective portions of the fluid line 502. For example, the29Attorney Docket: POMD00004599PRI_US01inflation fluid 111 can be moved through the supply line 504 by the planet rollers 706 and the inflation fluid 111 can be moved through the return line 506 by the second planet rollers.

[0061] The configuration of the fluid line 502, i.e., how the fluid line 502 is routed over the planet rollers 706, can allow one set of planet rollers 706 to push fluid toward the balloon 112 and one set of planet rollers 706 to pull fluid from the balloon 112. In certain embodiments, the supply line 504 can run over the planet rollers 706 such that, when the sun roller 704 rotates, the planet rollers 706 are driven over the supply line 504 to move inflation fluid 111 distally within the supply line 504. Similarly, the one or more planet rollers 706 may be non-centrally supported between the return line 506 and the sun roller 704 to roll over the return line 506 when the sun roller 704 rotates and moves inflation fluid 111 distally within the return line 506. The single drive shaft 703 can drive both pump heads at a same speed to circulate the inflation fluid 111. The synchronized pumping by the single drive shaft 703 may allow for a single motor to be used, which can reduce cost and contribute to efficient pumping.

[0062] Other fluid line configurations may be used. For example, the return line 506 may run under the planet rollers 706, in place of the arcuate guide 712 shown in FIG. 7. Accordingly, the planet rollers 706 can rotate in a rotational direction, e.g., clockwise, to drive fluid distally within both the supply line 504 and the return line 506. More particularly, a planet roller 706 can move over the supply line 504 during a first portion of a revolution, e.g., the upper half of the annular space, and the planet roller 706 can move over the return line 506 during a second portion of the revolution, e.g., the lower half of the annular space where the arcuate guide 712 would otherwise be located. By running the fluid line 502 over the top and bottom of a single first pump head 508, the need for a second pump head can be obviated and manufacturing costs can be reduced.30Attorney Docket: POMD00004599PRI_US01

[0063] Referring to FIG. 9, a perspective view of a tissue treatment generator 800, in accordance with certain embodiments is provided. The tissue treatment generator 800 comprises first and second tubing cartridges 900A, 900B configured to engage first and second pump heads 1002A, 1002B as discussed in more detail with reference to FIGS. 12A to 12D below. The tissue treatment generator 800 further comprises a first motor 1010A configured to drive a first drive shaft that engages a first sun roller of a first pump head 1002 A and a second motor 1010B configured to drive a second drive shaft that engages a second sun roller of a second pump head 1002B. The shown positions and sizes are schematically for an ease of understanding and may differ in embodiments of the tissue treatment generator 800. The different parts of the tissue treatment generator 800 are discussed below in more detail with reference to Figs 10A to 12D.

[0064] The tubing cartridges 900A, 900B are shown in more detail and in different perspectives in FIGS. 10A to 10D. As is best seen in the cutaway view of a tubing cartridge 900A, 900B shown in FIG. 10D, each tubing cartridge 900A, 900B comprises a main body 902, a grip or handle 904 for inserting and removing the tubing cartridge to and from the tissue treatment generator 800. The shown tubing cartridges 900A, 900B further comprise multiple coupling elements 906, 908 and a portion of a fluid line 502. The fluid line 502 may be the supply line 504 or the return line 506. As can be seen, the fluid line 502 may comprise an arced portion that is configured to be engaged by planet rollers 706. The planet rollers 706 may slide over the arced portion to move the fluid located within the fluid line 502 as indicated in FIGS. 12C and 12D.

[0065] FIGS. 11A to 1 ID show different views of a part of a fluid transfer unit 1000 of the tissue treatment generator of FIG. 9. FIG. 11 A shows a perspective view of the part of the fluid transfer unit 1000. The shown part comprises the first and second pump heads 1002A, 1002B and a housing accommodating the pump heads 1002A, 1002B. The shown31Attorney Docket: POMD00004599PRI_US01part of the fluid transfer unit 1000 further comprises multiple coupling elements 1006A, 1006B, 1008A, 1008B attached to the housing and configured to engage the complementary coupling elements 906, 908 of the tubing cartridges 900A, 900B to couple the tubing cartridges 900A, 900B to the housing of the fluid transfer unit 1000. The shown part of the fluid transfer unit 1000 still further comprises the first and second motors 1010A, 1010B coupled to the first and second pump heads 1002A, 1002B, respectively. The first and second pump heads 1002 A, 1002B each comprise a sun roller and multiple planet rollers 1004 A, 1004B as best seen in FIG. 11B. In the shown variant, the pump heads 1002A, 1002B are identical in construction and located coaxially along a rotation axis (not shown) that extends through the first and second sun rollers. The first and second pump heads 1002 A, 1002B are circumferentially offset from each other, as can be directly seen from the different circumferential positions of the respective planet rollers 1004A, 1004B. Due to the circumferential offset between the pump heads 1002 A, 1002B, a phase difference between the pump heads 1002 A, 1002B is induced i.e., the planet rollers 1004 A, 1004B of the respective pumping heads 1002A, 1002B interact with the supply line 504 and the return line 506 at different times. As a result, fluctuations of the generated flow rate are reduced. The pump heads 1002 A, 1002B may be driven individually by the respective first and second motors 1010A, 1010B, e.g. at the same speed to achieve a constant phase difference for reducing the fluctuations of the generated flow rate as explained herein. Alternatively, the pump heads 1002A, 1002B may be driven at different speeds.

[0066] As can be best seen in Fig. 1 ID, one of the coupling elements 1006A of the fluid transfer unit 1000 comprises a spring 1016A allowing for a fast and easy coupling and decoupling with one of the tubing cartridges 900A, 900B by preloading the coupling element 1006A comprising the spring 1016A. In more detail, the coupling elements 906, 908 of the tubing cartridges 900A, 900B may comprise notches and the coupling elements 1006 A,32Attorney Docket: POMD00004599PRI_US011008A of the fluid transfer unit 1000 may comprise protrusions to be positioned in the notches for coupling the tubing cartridges 900A, 900B to the housing of the fluid transfer unit 1000. At least one of the protrusions may be disengaged from a corresponding notch by applying a force overcoming the spring force of the spring 1016A. Other forms of coupling the tubing cartridges 900A, 900B to the housing of the fluid transfer unit 1000 are contemplated, e.g. using clips, clamps, screws, springs, or a combination thereof.

[0067] FIG. 12A to 12D are different views of the fluid transfer unit 1000 with the tubing cartridges 900A, 900B coupled to the housing of the fluid transfer unit 1000. As can be best seen in FIGS. 12C and 12D, the planet rollers 1004A of the shown pump head 1002A are configured to slide over the fluid line 502 when the pump head 1002A is rotated. While the planet rollers 1004 A are schematically depicted with a smooth surface, the sun roller 704 and the planet rollers 706 as shown in FIG. 7 may be used with the pump heads 1002A, 1002B shown best in FIGS. 11A to 11D, 12C and 12D.

[0068] FIG. 13 is a schematic representation of a tissue treatment system 100 similar to the tissue treatment system 100 shown in FIG. 1. The system 100 includes a fluid reservoir 110 to store an inflation fluid 111. The inflation fluid 111 may be a cooling fluid. A supply line 504 and a return line 506 are each connected to the fluid reservoir 110 via an interface 1100, e.g., a bag spike 1100 having two adapters. The system 100 further includes an irrigation pump 1110 located in the supply line 504 and comprising a first pump head 508, 1002A (Fig. 5 and 12C) for pumping fluid through the supply line 504 to a tissue treatment catheter 102. Downstream of the irrigation pump 1110, a first pressure sensor 522, a pulsatility mitigator 1120 and a second pressure sensor 522 are located before a first fluid port 210 configured to couple the supply line 504 to the catheter 102. In the shown supply line 504, the first and second pressure sensors 522 allow determination of the effect of the pulsatility mitigator 1120. In detail, the first and second pressure sensors 522 may monitor a33Attorney Docket: POMD00004599PRIJJS01pressure in the supply line 504 and the pulsatility, i.e. a fluctuation of the pressure. Thus, the flow rate may be determined upstream and downstream from the pulsatility mitigator 1120. In some variants, the first pressure sensor 522 may be mitigated and only the pressure downstream of the pulsatility mitigator 1120, which corresponds to the pulsatility in the tissue treatment catheter 102, may be monitored.

[0069] In some variants, the pulsatility mitigator 1120 may be a pulsatility mitigation chamber 1120 as shown in FIG. 14. The shown pulsatility mitigation chamber 1120 comprises an inlet 1122, an outlet 1124 and a cavity 1126 fluidically coupling the inlet 1122 and the outlet 1124. The cavity 1126 comprises a pulsation buffering membrane 1128 and multiple flow rectifying wings 1130. The buffering membrane 1128 and the multiple flow rectifying wings 1130 are each configured to (re-)direct the flow of the inflation fluid 111 through the cavity 1126 as indicated in FIG. 14. As a result of controlling the flow (redirection, pulsatility of the flow rate and the pressure in the supply line 504 can be reduced. In other variants, pulsatility mitigation chamber 1120 may comprise different configurations of membranes and flow rectifying wings, e.g., different numbers and or forms. More generally, the pulsatility mitigator 1120 may be any known device suitable to reduce the pulsatility.

[0070] Returning to FIG. 13, the inflation fluid 111 may flow through the tissue treatment catheter 102 and then out of the tissue treatment catheter 102 via a second fluid port 210 into the return line 506. At least one of the first and second fluid ports 210 may be a Luer adapter. A third pressure sensor 522 and a return pump 1140 comprising a second pump head 510, 1002B are located in the return line 506, wherein, in the shown example, the third pressure sensor 522 is located between the second fluid port 210 and the return pump 1140. In the shown configuration, the two pumps 1110, 1140 may synergistically work together to, e.g., control a flow rate through the tissue treatment catheter 102 and thus a pressure in a34Attorney Docket: POMD00004599PRI_US01balloon 112 coupled to the tissue treatment catheter 102, wherein pulsatility may be reduced due to the pulsatility mitigator 1120.

[0071] Embodiments of a tissue treatment system are described above. More particularly, embodiments of the treatment system are described, either explicitly or implicitly. The following paragraphs summarize some of the described embodiments. More particularly, embodiments are described in the following enumerated examples.

[0072] Example 1. A fluid transfer unit of a tissue treatment system, comprising: a fluid line; and a pump head having an epicyclic roller train, wherein the epicyclic roller train includes a sun roller and one or more planet rollers, and wherein the one or more planet rollers are non-centrally supported between the fluid line and the sun roller to roll over the fluid line when the sun roller rotates.

[0073] Example 2. The fluid transfer unit of example 1, wherein the sun roller includes a plurality of sun teeth to engage a plurality of planet teeth of the planet rollers.

[0074] Example 3. The fluid transfer unit of example 2, wherein the plurality of sun teeth are loosely meshed with the plurality of planet teeth.

[0075] Example 4. The fluid transfer unit of example 2, wherein the plurality of sun teeth slide over the plurality of planet teeth when the sun roller rotates.

[0076] Example 5. The fluid transfer unit of any of examples 1 through 4, wherein a sun diameter of the sun roller is greater than a planet diameter of the planet roller.

[0077] Example 6. The fluid transfer unit of any of examples 1 through 5 further comprising: a fluid reservoir; a pressure reservoir, wherein the fluid line extends between the fluid reservoir and the pressure reservoir, and wherein the pump head drives fluid through the fluid line from the fluid reservoir to the pressure reservoir.

[0078] Example 7. The fluid transfer unit of any of examples 1 through 6, wherein the fluid line is a supply line and further comprising: a return line; and a second pump head35Attorney Docket: POMD00004599PRI_US01having a second epicyclic roller train, wherein the second epicyclic roller train includes a second sun roller and one or more second planet rollers, and wherein the one or more second planet rollers are non-centrally supported between the return line and the second sun roller to roll over the return line when the second sun roller rotates.

[0079] Example 8. The fluid transfer unit of any of examples 1 through 7, wherein a drive shaft engages the sun roller and the second sun roller.

[0080] Example 9. The fluid transfer unit of any of examples 1 through 6, wherein the fluid line is a supply line, and further comprising a return line, and wherein the one or more planet rollers are non-centrally supported between the return line and the sun roller to roll over the return line when the sun roller rotates.

[0081] Example 10. The fluid transfer unit of any of examples 1 through 6, wherein the fluid line is a supply line, and further comprising a return line, and a proportional valve fluidly coupling the return line to the supply line.

[0082] Example 11. A tissue treatment generator, comprising: an ultrasonic energy source to deliver ultrasound energy to a tissue treatment catheter; and a fluid transfer unit to deliver an inflation fluid to the tissue treatment catheter, wherein the fluid transfer unit includes: a fluid line, and a pump head having an epicyclic roller train, wherein the epicyclic roller train includes a sun roller and one or more planet rollers, and wherein the one or more planet rollers are non-centrally supported between the fluid line and the sun roller to roll over the fluid line when the sun roller rotates.

[0083] Example 12. The tissue treatment generator of example 11, wherein the sun roller includes a plurality of sun teeth to engage a plurality of planet teeth of the planet rollers.

[0084] Example 13. The tissue treatment generator of any of examples 11 through 12, wherein a sun diameter of the sun roller is greater than a planet diameter of the planet roller.36Attorney Docket: POMD00004599PRI_US01

[0085] Example 14. The tissue treatment generator of any of examples 11 through 13 further comprising: a fluid reservoir; a pressure reservoir, wherein the fluid line extends between the fluid reservoir and the pressure reservoir, and wherein the pump head drives fluid through the fluid line from the fluid reservoir to the pressure reservoir.

[0086] Example 15. The tissue treatment generator of any of examples 11 through 14, wherein the fluid line is a supply line and further comprising: a return line; and a second pump head having a second epicyclic roller train, wherein the second epicyclic roller train includes a second sun roller and one or more second planet rollers, and wherein the one or more second planet rollers are non-centrally supported between the return line and the second sun roller to roll over the return line when the second sun roller rotates.

[0087] Example 16. The tissue treatment generator of any of examples 11 through 14, wherein the fluid line is a supply line, and further comprising a return line, and wherein the one or more planet rollers are non-centrally supported between the return line and the sun roller to roll over the return line when the sun roller rotates.

[0088] Example 17. The tissue treatment generator of any of examples 11 through 14, wherein the fluid line is a supply line, and further comprising a return line, and a proportional valve fluidly coupling the return line to the supply line.

[0089] Example 18. A tissue treatment system, comprising: a tissue treatment catheter including a catheter shaft having a fluid lumen, and a balloon mounted on the catheter shaft, wherein the balloon has an interior in fluid communication with the fluid lumen; and a fluid transfer unit to deliver an inflation fluid through the fluid lumen to the balloon, wherein the fluid transfer unit includes: a fluid line, and a pump head having an epicyclic roller train, wherein the epicyclic roller train includes a sun roller and one or more planet rollers, and wherein the one or more planet rollers are non-centrally supported between the fluid line and the sun roller to roll over the fluid line when the sun roller rotates.37Attorney Docket: POMD00004599PRI_US01

[0090] Example 19. The tissue treatment system of example 18, wherein the sun roller includes a plurality of sun teeth to engage a plurality of planet teeth of the planet rollers.

[0091] Example 20. The tissue treatment system of any of examples 18 through 19, wherein a sun diameter of the sun roller is greater than a planet diameter of the planet roller.

[0092] Example 21. The tissue treatment system of any of examples 18 through 20 further comprising: a fluid reservoir; a pressure reservoir, wherein the fluid line extends between the fluid reservoir and the pressure reservoir, and wherein the pump head drives fluid through the fluid line from the fluid reservoir to the pressure reservoir.

[0093] Example 22. The tissue treatment system of any of examples 18 through 21, wherein the fluid line is a supply line and further comprising: a return line; and a second pump head having a second epicyclic roller train, wherein the second epicyclic roller train includes a second sun roller and one or more second planet rollers, and wherein the one or more second planet rollers are non-centrally supported between the return line and the second sun roller to roll over the return line when the second sun roller rotates.

[0094] Example 23. The tissue treatment system of any of examples 18 through 21, wherein the fluid line is a supply line, and further comprising a return line, and wherein the one or more planet rollers are non-centrally supported between the return line and the sun roller to roll over the return line when the sun roller rotates.

[0095] Example 24. The tissue treatment system of any of examples 18 through 21, wherein the fluid line is a supply line, and further comprising a return line, and a proportional valve fluidly coupling the return line to the supply line.

[0096] In the foregoing specification, the present disclosure has been described with reference to specific exemplary embodiments thereof. It will be evident that various modifications may be made thereto without departing from the broader spirit and scope of the38Attorney Docket: POMD00004599PRI_US01present disclosure as set forth in the following claims. The specification and drawings are, accordingly, to be regarded in an illustrative sense rather than a restrictive sense.39Attorney Docket: POMD00004599PRI_US01

Claims

CLAIMSWhat is claimed is:

1. A fluid transfer unit of a tissue treatment system, comprising: a supply line; a first pump head having a first epicyclic roller train, wherein the first epicyclic roller train includes a first sun roller and one or more first planet rollers; a return line; and a second pump head having a second epicyclic roller train, wherein the second epicyclic roller train includes a second sun roller and one or more second planet rollers.

2. The fluid transfer unit of claim 1, wherein the one or more first planet rollers are non- centrally supported between the fluid line and the first sun roller to roll over the fluid line when the first sun roller rotates.

3. The fluid transfer unit of claim 1 or 2, wherein the one or more second planet rollers are non-centrally supported between the return line and the second sun roller to roll over the return line when the second sun roller rotates.

4. The fluid transfer unit of any of claims 1 through 3, further comprising (i) a controller configured to cause a first and a second motor to respectively drive the first and second pump heads with a phase difference therebetween or (ii) a motor coupled to a gear configured to drive the first and second pump heads with a phase difference therebetween.

5. The fluid transfer unit of any of claims 1 through 4, wherein at least one of the first and second sun rollers includes a plurality of sun teeth to engage a plurality of planet teeth of40Attorney Docket: POMD00004599PRIJJS01the respective one or more planet rollers.

6. The fluid transfer unit of claim 5, wherein the plurality of sun teeth are loosely meshed with the plurality of planet teeth.

7. The fluid transfer unit of claim 5, wherein the plurality of sun teeth slide over the plurality of planet teeth when the sun roller rotates.

8. The fluid transfer unit of any of claims 1 through 7, wherein a sun diameter of at least one of the first and second sun rollers is greater than a planet diameter of the respective first and second planet rollers.

9. The fluid transfer unit of any of claims 1 through 8 further comprising: a fluid reservoir; a pressure reservoir, wherein the supply line extends between the fluid reservoir and the pressure reservoir, and wherein the first pump head drives fluid through the supply line from the fluid reservoir to the pressure reservoir.

10. The fluid transfer unit of any of claims 1 through 9, wherein a common drive shaft engages the first sun roller and the second sun roller.

11. The fluid transfer unit of any of claims 1 through 9, wherein a first drive shaft engages the first sun roller and a second drive shaft engages the second sun roller.

12. The fluid transfer unit of any of claims 1 through 11, further comprising a41Attorney Docket: POMD00004599PRI_US01proportional valve fluidly coupling the return line to the supply line.

13. The fluid transfer unit of any of claims 1 through 12, further comprising: a housing accommodating the first and second pump heads; and at least one of: a first tubing cartridge configured to hold a portion of the supply line and to be releasably coupled to the housing to bring the portion of the supply line in engagement with the first pump head when coupled to the housing; and a second tubing cartridge configured to hold a portion of the return line and to be releasably coupled to the housing to bring the portion of the return line in engagement with the second pump head when coupled to the housing.

14. The fluid transfer unit of claim 13, wherein each of the first and second tubing cartridges comprises at least one coupling element; and wherein the housing comprises at least one of: a first spring-loaded coupling element configured to engage one of the at least one coupling elements of the first tubing cartridge to removably couple the first tubing cartridge to the housing; and a second spring-loaded coupling element configured to engage one of the at least one coupling elements of the second tubing cartridge to removably couple the second tubing cartridge to the housing.

15. The fluid transfer unit of any of claims 1 through 14, further comprising a pulsatility mitigator located in the supply line and comprising at least one of: at least one membrane configured to redirect a flow direction of a fluid within the42Attorney Docket: POMD00004599PRI_US01pulsatility mitigator; and at least one flow rectifying wing configured to redirect a flow direction of a fluid within the pulsatility mitigator.

16. The fluid transfer unit of claim 15, further comprising at least one of: at least one pressure sensor located in the supply line and configured to monitor the pressure in the supply line downstream from the pulsatility mitigator; and at least one pressure sensor located in the return line to monitor the pressure in the return line.

17. A tissue treatment generator, comprising: an energy source to deliver energy to a tissue treatment catheter; and a fluid transfer unit comprising: a supply line; a first pump head having a first epicyclic roller train, wherein the first epicyclic roller train includes a first sun roller and one or more first planet rollers; a return line; and a second pump head having a second epicyclic roller train, wherein the second epicyclic roller train includes a second sun roller and one or more second planet rollers.

18. The tissue treatment generator of claim 17, wherein the one or more first planet rollers are non-centrally supported between the fluid line and the first sun roller to roll over the fluid line when the first sun roller rotates.

19. The tissue treatment generator of claim 17 or 18, wherein the one or more second43Attorney Docket: POMD00004599PRI_US01planet rollers are non-centrally supported between the return line and the second sun roller to roll over the return line when the second sun roller rotates.

20. The tissue treatment generator of any of claims 17 through 19, further comprising (i) a controller configured to cause a first and a second motor to respectively drive the first and second pump heads with a phase difference therebetween or (ii) a motor coupled to a gear configured to drive the first and second pump heads with a phase difference therebetween.

21. The tissue treatment generator of any of claims 17 through 20, wherein at least one of the first and second sun rollers includes a plurality of sun teeth to engage a plurality of planet teeth of the respective one or more planet rollers.

22. The tissue treatment generator of claim 21, wherein the plurality of sun teeth are loosely meshed with the plurality of planet teeth.

23. The tissue treatment generator of claim 21, wherein the plurality of sun teeth slide over the plurality of planet teeth when the sun roller rotates.

24. The tissue treatment generator of any of claims 17 through 23, wherein a sun diameter of at least one of the first and second sun rollers is greater than a planet diameter of the respective first and second planet rollers.

25. The tissue treatment generator of any of claims 17 through 24 further comprising: a fluid reservoir; a pressure reservoir, wherein the supply line extends between the fluid reservoir and44Attorney Docket: POMD00004599PRI_US01the pressure reservoir, and wherein the first pump head drives fluid through the supply line from the fluid reservoir to the pressure reservoir.

26. The tissue treatment generator of any of claims 17 through 25, wherein a common drive shaft engages the first sun roller and the second sun roller.

27. The tissue treatment generator of any of claims 17 through 25, wherein a first drive shaft engages the first sun roller and a second drive shaft engages the second sun roller.

28. The tissue treatment generator of any of claims 17 through 27, further comprising a proportional valve fluidly coupling the return line to the supply line.

29. The tissue treatment generator of any of claims 17 through 28, further comprising: a housing accommodating the first and second pump heads; and at least one of: a first tubing cartridge configured to hold a portion of the supply line and to be releasably coupled to the housing to bring the portion of the supply line in engagement with the first pump head when coupled to the housing; and a second tubing cartridge configured to hold a portion of the return line and to be releasably coupled to the housing to bring the portion of the return line in engagement with the second pump head when coupled to the housing.

30. The tissue treatment generator of claim 29, wherein each of the first and second tubing cartridges comprises at least one coupling element; and wherein the housing comprises at least one of:45Attorney Docket: POMD00004599PRI_US01a first spring-loaded coupling element configured to engage one of the at least one coupling elements of the first tubing cartridge to removably couple the first tubing cartridge to the housing; and a second spring-loaded coupling element configured to engage one of the at least one coupling elements of the second tubing cartridge to removably couple the second tubing cartridge to the housing.

31. The tissue treatment generator of any of claims 17 through 30, further comprising a pulsatility mitigator located in the supply line and comprising at least one of: at least one membrane configured to redirect a flow direction of a fluid within the pulsatility mitigator; and at least one flow rectifying wing configured to redirect a flow direction of a fluid within the pulsatility mitigator.

32. The tissue treatment generator of claim 31, further comprising at least one of: at least one pressure sensor located in the supply line and configured to monitor the pressure in the supply line downstream from the pulsatility mitigator; and at least one pressure sensor located in the return line to monitor the pressure in the return line.

33. A tissue treatment system, comprising: a tissue treatment catheter including a catheter shaft having a fluid lumen, and a balloon mounted on the catheter shaft, wherein the balloon has an interior in fluid communication with the fluid lumen; and a fluid transfer unit comprising:46Attorney Docket: POMD00004599PRI_US01comprising a supply line; a first pump head having a first epicyclic roller train, wherein the first epicyclic roller train includes a first sun roller and one or more first planet rollers; a return line; and a second pump head having a second epicyclic roller train, wherein the second epicyclic roller train includes a second sun roller and one or more second planet rollers.

34. The tissue treatment system of claim 33, wherein the one or more first planet rollers are non-centrally supported between the fluid line and the first sun roller to roll over the fluid line when the first sun roller rotates.

35. The tissue treatment system of claim 33 or 34, wherein the one or more second planet rollers are non-centrally supported between the return line and the second sun roller to roll over the return line when the second sun roller rotates.

36. The tissue treatment system of any of claims 33 through 35, further comprising (i) a controller configured to cause a first and a second motor to respectively drive the first and second pump heads with a phase difference therebetween or (ii) a motor coupled to a gear configured to drive the first and second pump heads with a phase difference therebetween.

37. The tissue treatment system of any of claims 33 through 36, wherein at least one of the first and second sun rollers includes a plurality of sun teeth to engage a plurality of planet teeth of the respective one or more planet rollers.47Attorney Docket: POMD00004599PRI_US0138. The tissue treatment system of claim 37, wherein the plurality of sun teeth are loosely meshed with the plurality of planet teeth.

39. The tissue treatment system of claim 37, wherein the plurality of sun teeth slide over the plurality of planet teeth when the sun roller rotates.

40. The tissue treatment system of any of claims 33 through 39, wherein a sun diameter of at least one of the first and second sun rollers is greater than a planet diameter of the respective first and second planet rollers.

41. The tissue treatment system of any of claims 33 through 40 further comprising: a fluid reservoir; a pressure reservoir, wherein the supply line extends between the fluid reservoir and the pressure reservoir, and wherein the first pump head drives fluid through the supply line from the fluid reservoir to the pressure reservoir.

42. The tissue treatment system of any of claims 33 through 41, wherein a common drive shaft engages the first sun roller and the second sun roller.

43. The tissue treatment system of any of claims 33 through 41, wherein a first drive shaft engages the first sun roller and a second drive shaft engages the second sun roller.

44. The tissue treatment system of any of claims 33 through 43, further comprising a proportional valve fluidly coupling the return line to the supply line.48Attorney Docket: POMD00004599PRI_US0145. The tissue treatment system of any of claims 33 through 44, further comprising: a housing accommodating the first and second pump heads; and at least one of: a first tubing cartridge configured to hold a portion of the supply line and to be releasably coupled to the housing to bring the portion of the supply line in engagement with the first pump head when coupled to the housing; and a second tubing cartridge configured to hold a portion of the return line and to be releasably coupled to the housing to bring the portion of the return line in engagement with the second pump head when coupled to the housing.

46. The tissue treatment system of claim 45, wherein each of the first and second tubing cartridges comprises at least one coupling element; and wherein the housing comprises at least one of: a first spring-loaded coupling element configured to engage one of the at least one coupling elements of the first tubing cartridge to removably couple the first tubing cartridge to the housing; and a second spring-loaded coupling element configured to engage one of the at least one coupling elements of the second tubing cartridge to removably couple the second tubing cartridge to the housing.

47. The tissue treatment system of any of claims 33 through 46, further comprising a pulsatility mitigator located in the supply line and comprising at least one of: at least one membrane configured to redirect a flow direction of a fluid within the pulsatility mitigator; and at least one flow rectifying wing configured to redirect a flow direction of a fluid49Attorney Docket: POMD00004599PRI_US01within the pulsatility mitigator.

48. The tissue treatment system of claim 47, further comprising at least one of: at least one pressure sensor located in the supply line and configured to monitor the pressure in the supply line downstream from the pulsatility mitigator; and at least one pressure sensor located in the return line to monitor the pressure in the return line.50Attorney Docket: POMD00004599PRI_US01

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