Patent Description:
The present disclosure pertains to medical devices, and methods for manufacturing and using medical devices. More particularly, the disclosure is directed to devices and methods for removing occlusive material from a body lumen. Further, the invention is directed to an atherectomy device for forming a passageway through an occlusion of a body lumen, such as a blood vessel.

A wide variety of medical devices have been developed for medical use, for example, for use in accessing body cavities and interacting with fluids and structures in body cavities. Some of these devices may include guidewires, catheters, pumps, motors, controllers, filters, grinders, needles, valves, and delivery devices and/or systems used for delivering such devices. These devices are manufactured by any one of a variety of different manufacturing methods and may be used according to any one of a variety of methods. Of the known medical devices and methods, each has certain advantages and disadvantages.

<CIT> relates to an atherectomy catheter which includes an elongate flexible catheter body, a cutter near the distal end of the catheter body, a drive shaft connected to the cutter and extending within the catheter body, and an imaging element near the distal end of the catheter body.

<CIT> relates to an atherectomy device with a clutch between the motor and the drive shaft. The clutch includes two plates that rely on frictional to transmit torque from one plate to the other. The clutch has an attractive magnetic normal force that holds the plates together.

<CIT> describes atherectomy catheters, systems and methods that include longitudinally displaceable drive shafts that drive actuation of one or more cutters at the distal end of the catheter. The catheters may include one or more imaging sensors for imaging before, during or after cutting tissue. The imaging sensor may be rotated around the perimeter of the catheter independently of the rotation of the cutter.

This disclosure provides design, material, manufacturing method, and use alternatives for medical devices. As an example, atherectomy system includes a multiple use assembly and a single use assembly that is releasably engageable with the multiple use assembly. The multiple use assembly includes a drive motor having an output shaft and a first magnet coupling segment that is rotatably coupled to the output shaft. The multiple use assembly includes a controller that is adapted to control operation of the drive motor. The single use assembly includes a second magnetic coupling segment that is adapted to rotatably engage the first magnetic coupling segment and a spline shaft that is rotatably coupled with the second magnetic coupling segment. A drive gear assembly is translatable along the spline shaft. A drive shaft is operably coupled with the drive gear assembly and is adapted to rotatably engage an atherectomy burr.

Alternatively or additionally, the multiple use assembly may further include a user interface that is operably coupled with the controller.

Alternatively or additionally, the multiple use assembly may include one or more printed circuit boards that include the controller.

Alternatively or additionally, the multiple use assembly may further include a multiple use assembly housing.

Alternatively or additionally, the drive motor may be disposed within the multiple use assembly housing.

Alternatively or additionally, the controller that is adapted to control operation of the drive motor may be disposed within the multiple use assembly housing.

Alternatively or additionally, the single use assembly may further include a gear housing that is adapted to translate relative to the spline shaft.

Alternatively or additionally, the atherectomy system may further include a pumping section disposed within the gear housing.

Alternatively or additionally, the atherectomy system may further include a pump rotor that is operably secured to the drive shaft and disposed within the pumping section.

Alternatively or additionally, the single use assembly may further include a translation handle coupled to the gear housing, such that translating the translation handle causes the gear housing to translate relative to the spline shaft.

In another example, an atherectomy system includes a housing. A drive motor is disposed within the housing and includes an output shaft that extends to an exterior of the housing. A controller is disposed within the housing and is adapted to control operation of the drive motor. A first magnetic coupling segment is rotatably coupled to the output shaft exterior to the housing. The atherectomy system includes a single use assembly. The single use assembly includes a second magnetic coupling segment that is adapted to rotatably engage the first magnetic coupling segment and a spline shaft that is rotatably coupled with the second magnetic coupling segment. A drive gear assembly is translatable along the spline shaft and is operably coupled with a drive shaft that is adapted to rotatably engage an atherectomy burr.

Alternatively or additionally, the atherectomy system may further include a pumping section that is disposed within the gear housing.

Alternatively or additionally, the atherectomy system may further include a pump rotor that is operably secured to the drive shaft and is disposed within the pumping section.

Alternatively or additionally, the single use assembly may further include a translation handle coupled to the gear housing such that translating the translation handle causes the gear housing to translate relative to the spline shaft.

In another example, an atherectomy system includes a housing and a drive motor that is disposed within the housing. The drive motor includes an output shaft that extends to an exterior of the housing. A controller is disposed within the housing and is adapted to control operation of the drive motor. The atherectomy system includes a magnetic coupling segment that is rotatably coupled to the output shaft exterior to the housing and is adapted to releasably and rotatably engage a single use assembly in order to rotate an atherectomy burr forming part of the single use assembly, the drive motor adapted to rotate the atherectomy burr at rotational speeds exceeding <NUM>,<NUM> revolutions per minute.

Alternatively or additionally, the single use assembly includes a second magnetic coupling segment adapted to rotatably engage the first magnetic coupling segment, a spline shaft that is rotatably coupled with the second magnetic coupling segment, a drive gear assembly that is translatable along the spline shaft and a drive shaft that is operably coupled with the drive gear assembly and is adapted to rotatably engage the atherectomy burr.

Alternatively or additionally, the single use assembly may further include a translation handle that is coupled to the gear housing, such that translating the translation handle causes the gear housing to translate relative to the spline shaft.

Alternatively or additionally, the single use assembly may further include a pump rotor that is operably secured to the drive shaft.

The invention may be more completely understood in consideration of the following detailed description of various embodiments of the invention in connection with the accompanying drawings, in which:.

On the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the scope of the disclosure.

Cardiovascular disease and peripheral arterial disease may arise from accumulation of atheromatous material on the inner walls of vascular lumens, resulting in a condition known as atherosclerosis. Atheromatous and other vascular deposits may restrict blood flow and can cause ischemia in a heart of a patient, vasculature of a patient's legs, a patient's carotid artery, etc. Such ischemia may lead to pain, swelling, wounds that will not heal, amputation, stroke, myocardial infarction, and/or other conditions.

Atheromatous deposits may have widely varying properties, with some deposits being relatively soft and others being fibrous and/or calcified. In the latter case, the deposits may be referred to as plaque. Atherosclerosis occurs naturally as a result of aging, but may also be aggravated by factors such as diet, hypertension, heredity, vascular injury, and the like. Atherosclerosis may be treated in a variety of ways, including drugs, bypass surgery, and/or a variety of catheter-based approaches that may rely on intravascular widening or removal of the atheromatous or other material occluding the blood vessel. Atherectomy is a catheter-based intervention that may be used to treat atherosclerosis.

Atherectomy is an interventional medical procedure performed to restore a flow of blood through a portion of a patient's vasculature that has been blocked by plaque or other material (e.g., blocked by an occlusion). In an atherectomy procedure, a device on an end of a drive shaft that is used to engage and/or remove (e.g., abrade, grind, cut, shave, etc.) plaque or other material from a patient's vessel (e.g., artery or vein). In some cases, the device on an end of the drive shaft may be abrasive and/or may otherwise be configured to remove plaque from a vessel wall or other obstruction in a vessel when the device is rotating and engages the plaque or other obstruction. In some cases, atherectomy involves using an abrasive atherectomy burr that is rotated at high speeds exceeding <NUM>,<NUM> revolutions per minute (RPM) in order to abrade plaque and other hardened materials from within the patient's vessel. Atherectomy burrs may be rotated at speeds exceeding <NUM>,<NUM> RPM, and even at speeds as high as <NUM>,<NUM> RPM.

<FIG> is a schematic block diagram of an illustrative atherectomy system <NUM>. In some cases, the atherectomy system <NUM> may be considered as including a multiple use assembly <NUM> and a single use assembly <NUM>. As will be discussed, the multiple use assembly <NUM> may include some of the more expensive components such as a drive motor and the electronics necessary to control operation of the drive motor. The multiple use assembly <NUM> may include a user interface, for example. The multiple use assembly <NUM> may be considered as being intended to be used over and over again. Being able to use the multiple use assembly <NUM> a plurality of times can provide cost savings. Because the multiple use assembly <NUM> is sealed against contaminants, a plurality of single use assemblies <NUM> may be used with the multiple use assembly <NUM>, one after the other.

As an example, a particular single use assembly <NUM> may include a drive shaft having a particular length, and an operator may discover in the middle of an atherectomy procedure that the drive shaft is either too short or too long. The operator may withdraw the drive shaft of that particular single use assembly <NUM> from the patient's vasculature and that particular single use assembly <NUM> may be thrown away, and a new single use assembly <NUM> having a drive shaft of more appropriate length may be coupled with the multiple use assembly <NUM> and the atherectomy procedure may continue. It will be appreciated that this is merely illustrative, as there are any variety of reasons to change to a different single use assembly <NUM> during an atherectomy procedure.

In some cases, for example, a first single use assembly <NUM> may be used for a first patient and then disposed of, and a second single use assembly <NUM> may be used for an atherectomy procedure performed on a second patient. One way to consider the illustrative atherectomy system <NUM> is that the multiple use assembly <NUM>, may be considered as the "dry" part of the atherectomy system <NUM>. Conversely, the single use assembly <NUM> may be considered as the "wet" part of the atherectomy system <NUM>. The single use assembly <NUM> may, for example, include saline that is provided within a drive shaft. There is no fluid transfer between the "wet" part of the atherectomy system <NUM> and the "dry" part of the atherectomy system <NUM>. Moreover, it will be appreciated that the "dry" part of the atherectomy system <NUM>, may be re-sterilized and re-used with a subsequent patient. This can provide cost savings, as the components within the "dry" part don't have to be replaced with each atherectomy process.

The multiple use assembly <NUM> may be sterilized and subsequently re-sterilized after use, via any of a variety of different sterilization processes. For example, the multiple use assembly <NUM> may be exposed to an ethylene oxide atmosphere in order to sterilize the multiple use assembly <NUM>. It will be appreciated that it is only necessary to sterilize the outer surfaces of the multiple use assembly <NUM>. In some instances, the multiple use assembly <NUM> may be subjected to a radiative sterilization process such as e beam radiation or gamma radiation.

As will be discussed, the atherectomy system <NUM> may include a magnetic coupling between the multiple use assembly <NUM> and the single use assembly <NUM> such that the drive motor within the multiple use assembly <NUM> may easily and cleanly rotatably engage the drive shaft provided as part of the single use assembly <NUM>. In some cases, use of a magnetic coupling permits contactless torque transmission from the drive motor to an atherectomy burr. Use of a magnetic coupling seals the drive motor against fluid ingress. Because the multiple use assembly <NUM> is sealed against fluid ingress, the multiple use assembly <NUM> remains cleaner and is easily re-sterilized before subsequent re-use.

<FIG> is a schematic block diagram of the multiple use assembly <NUM>. The multiple use assembly <NUM> includes a drive motor <NUM> that includes an output shaft <NUM>. The output shaft <NUM> may be operably coupled to a rotor (not shown) within the drive motor <NUM>, such that the output shaft <NUM> rotates in response to the rotor rotating within the drive motor <NUM>. In some cases, the drive motor <NUM> is an electric drive motor, but this is not required in all cases. A first magnetic coupling segment <NUM> is rotatably coupled to the output shaft <NUM>. As a result, the first magnetic coupling segment <NUM> can rotate when the output shaft <NUM> rotates. It will be appreciated that by including a second magnetic coupling segment (to be discussed) as part of the single use assembly <NUM>, the drive shaft of the single use assembly <NUM> can be operably coupled with the drive motor <NUM>. Using a magnetic coupling that includes the first magnetic coupling segment <NUM> and the second magnetic coupling segment provides an easy way to provide a repeatable connection between the drive motor <NUM> and ultimately an atherectomy burr. Using a magnetic coupling also enables a "clean" connection between the multiple use assembly <NUM> and each of the single use assemblies <NUM> used with the multiple use assembly <NUM> as any possible contaminants are kept well away from the multiple use assembly <NUM>.

The multiple use assembly <NUM> includes a controller <NUM> that is adapted to control operation of the drive motor <NUM>. In some cases, the controller <NUM> may be a PID controller that utilizes a Proportional (P) gain, an Integral (I) gain and a Derivative (D) gain as well as one or more feedback and/or reference signals in generating an output signal to the drive motor <NUM>. In some instances, the multiple use assembly <NUM> may include a user interface <NUM> that is operably coupled with the controller <NUM>. The user interface <NUM> may be used to input settings and other information, for example. In some cases, the user interface <NUM> may include a display that is adapted to display information provided by the controller <NUM>.

In some cases, the multiple use assembly <NUM> may be considered as including a multiple use assembly housing <NUM>. The first magnetic coupling segment <NUM> may extend through a side wall of the multiple use assembly housing <NUM> so that it is easy to see where to couple the single use assembly <NUM>. In some instances, if the multiple use assembly housing <NUM> is polymeric, the first magnetic coupling segment <NUM> may remain just inside of the multiple use assembly housing <NUM>. In such cases, the multiple use assembly housing <NUM> may include a marking indicating where the single use assembly <NUM> should be located in order to magnetically couple with the first magnetic coupling segment <NUM>. It will be appreciated that the drive motor <NUM> and the controller <NUM> are both disposed within the multiple use assembly housing <NUM>.

<FIG> is a schematic block diagram of the single use assembly <NUM>. The single use assembly <NUM> is releasably engageable with the multiple use assembly <NUM>. The single use assembly <NUM> includes a second magnetic coupling segment <NUM> that is adapted to rotatably engage the first magnetic coupling segment <NUM> such that the second magnetic coupling element <NUM> rotates as the first magnetic coupling segment <NUM> rotates. It will be appreciated that the first magnetic coupling segment <NUM> and the second magnetic coupling segment <NUM> should have relative magnetic polarities that cause the first magnetic coupling segment <NUM> to be magnetically drawn towards the second magnetic coupling segment <NUM>, and for the second magnetic coupling segment <NUM> to be magnetically drawn towards the first magnetic coupling segment <NUM>, rather than the first magnetic coupling element <NUM> and the second magnetic coupling element <NUM> repelling each other. A North magnetic pole will attract a South magnetic pole and will repel a North magnetic pole. Similarly, a South magnetic pole will attract a North magnetic pole and will repel a South magnetic pole.

A spline shaft <NUM> is operably coupled with the second magnetic coupling segment <NUM> such that the spline shaft <NUM> rotates when the second magnetic coupling segment <NUM> rotates. A drive gear assembly <NUM> is translatable along the spline shaft <NUM>, as indicated by arrows <NUM> and <NUM>. The drive gear assembly <NUM> may be adapted to rotate in response to rotation of the spline shaft <NUM>. As the drive gear assembly <NUM> rotates, a drive shaft <NUM> that is operably coupled with the drive gear assembly <NUM> is driven into rotation. The drive shaft <NUM> may be considered as being adapted to rotatably engage an atherectomy burr <NUM>. In some cases, the drive shaft <NUM> may be adapted to rotatably engage any of a variety of different atherectomy burrs. For example, each of the variety of different atherectomy burrs may have a different diameter, for use in a variety of different sized blood vessels. In some cases, some of the atherectomy burrs <NUM> may vary in what is used as an abrasive material on a surface of the atherectomy burrs <NUM>. In some instances, an atherectomy burr <NUM> may include one or more cutting elements formed in a surface of the atherectomy burr <NUM>.

<FIG> is a schematic illustration of an illustrative atherectomy system <NUM>. The illustrative atherectomy system <NUM> may be considered as being an example of the illustrative atherectomy system <NUM>. Features described as part of the atherectomy system <NUM> may be considered as being applicable to the atherectomy system <NUM>, and features attributed to the atherectomy system <NUM> may be considered as being applicable to the atherectomy system <NUM>. The atherectomy system <NUM> may be considered as including a multiple use assembly <NUM> and a single use assembly <NUM>. As illustrated, the multiple use assembly <NUM> includes a drive motor <NUM> having an output shaft <NUM>. A first magnetic coupling segment <NUM> is secured to the output shaft <NUM>. The multiple use assembly <NUM> includes a Printed Circuit Board Assembly (PCBA) <NUM>. It will be appreciated that the PCBA <NUM> may provide the functionality of the controller <NUM>, for example.

The single use assembly <NUM> includes a second magnetic coupling segment <NUM> that magnetically engages the first magnetic coupling segment <NUM> such that the second magnetic coupling segment <NUM> rotates when the first magnetic coupling segment <NUM> rotates. A spline shaft <NUM> is coupled to the second magnetic coupling segment <NUM>. A drive gear assembly <NUM> is adapted to translate along the spline shaft <NUM>. As shown, the single use assembly <NUM> includes a translation handle <NUM> that can be grasped by an operator in order to translate the drive gear assembly <NUM> back and forth relative to the spline shaft <NUM>, thereby moving a drive shaft <NUM> back and forth, thereby causing an atherectomy burr to translate back and forth without having to move the entirety of the atherectomy system <NUM>.

The drive gear assembly <NUM> extends into a gear housing <NUM>, where the drive gear assembly <NUM> engages a driven gear <NUM>. Rotation of the drive gear assembly <NUM> causes rotation of the driven gear <NUM>, which itself is coupled with and thus causes rotation of the drive shaft <NUM>. It will be appreciated that each of the geared elements, including the spline shaft <NUM>, components of the drive gear assembly <NUM> and the driven gear <NUM> are all supported by appropriate bearings <NUM>. It will be appreciated that by changing relative gear diameters and other gear parameters, it is possible to provide a speed increase, a speed decrease or no change in speed to the drive shaft <NUM>.

The gear housing <NUM> defines a pumping section <NUM>. The pumping section <NUM> defines a pumping chamber <NUM> in which a rotor <NUM> is able to rotate as a result of being secured to the drive shaft <NUM>. While not illustrated, it will be appreciated that there may be a saline source fluidly coupled with the gear housing <NUM> and hence with the pumping chamber <NUM>. Rotation of the rotor <NUM> within the confines of the pumping chamber <NUM> causes fluid (saline) to be pumped through an interior of a hollow shaft <NUM> surrounding the drive shaft <NUM>. The fluid pumped through the hollow shaft <NUM> serves to reduce heat that may be caused by rotation of the drive shaft <NUM> within the hollow shaft <NUM> and to reduce heat caused by rotation of the atherectomy burr as the atherectomy burr rotates against a vessel blockage. The fluid pumped through the hollow shaft <NUM> also serves to flush debris away from the atherectomy burr as the atherectomy burr rotates.

Claim 1:
An atherectomy system (<NUM>, <NUM>), comprising:
a multiple use assembly (<NUM>, <NUM>) including:
a drive motor (<NUM>, <NUM>) having an output shaft (<NUM>, <NUM>);
a first magnetic coupling segment (<NUM>, <NUM>) operably rotatably coupled to the output shaft; and
a controller (<NUM>) adapted to control operation of the drive motor; and
a single use assembly (<NUM>, <NUM>) releasably engageable with the multiple use assembly, the single use assembly including:
a second magnetic coupling segment (<NUM>, <NUM>) adapted to rotatably engage the first magnetic coupling segment;
a spline shaft (<NUM>, <NUM>) rotatably coupled with the second magnetic coupling segment;
a drive gear assembly (<NUM>, <NUM>) translatable along the spline shaft; and
a drive shaft (<NUM>, <NUM>) operably coupled with the drive gear assembly, the drive shaft adapted to rotatably engage an atherectomy burr (<NUM>).