Patent Publication Number: US-2022233820-A1

Title: Systems, apparatus and methods for supporting and driving elongated medical devices in a robotic catheter-based procedure system

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is based on, claims priority to, and incorporates herein by reference in its entirety U.S. Ser. No. 62/874,222, filed Jul. 15, 2019, and entitled “Systems, Apparatus and Methods for Supporting and Driving Elongated Medical Devices in a Robotic Catheter-Based Procedure System.” 
    
    
     FIELD 
     The present invention relates generally to the field of robotic medical procedure systems and, in particular, to systems, apparatus and methods for supporting and driving elongated medical devices in a robotically controlled interventional procedure using a catheter-based procedure system. 
     BACKGROUND 
     Catheters and other elongated medical devices (EMDs) may be used for minimally invasive medical procedures for the diagnosis and treatment of diseases of various vascular systems, including neurovascular intervention (NVI) also known as neurointerventional surgery, percutaneous coronary intervention (PCI) and peripheral vascular intervention (PVI). These procedures typically involve navigating a guidewire through the vasculature, and via the guidewire advancing a catheter to deliver therapy. The catheterization procedure starts by gaining access into the appropriate vessel, such as an artery or vein, with an introducer sheath using standard percutaneous techniques. Through the introducer sheath, a sheath or guide catheter is then advanced over a diagnostic guidewire to a primary location such as an internal carotid artery for NVI, a coronary ostium for PCI, or a superficial femoral artery for PVI. A guidewire suitable for the vasculature is then navigated through the sheath or guide catheter to a target location in the vasculature. In certain situations, such as in tortuous anatomy, a support catheter or microcatheter is inserted over the guidewire to assist in navigating the guidewire. The physician or operator may use an imaging system (e.g., fluoroscope) to obtain a cine with a contrast injection and select a fixed frame for use as a roadmap to navigate the guidewire or catheter to the target location, for example, a lesion. Contrast-enhanced images are also obtained while the physician delivers the guidewire or catheter so that the physician can verify that the device is moving along the correct path to the target location. While observing the anatomy using fluoroscopy, the physician manipulates the proximal end of the guidewire or catheter to direct the distal tip into the appropriate vessels toward the lesion or target anatomical location and avoid advancing into side branches. 
     Robotic catheter-based procedure systems have been developed that may be used to aid a physician in performing catheterization procedures such as, for example, NVI, PCI and PVI. Examples of NVI procedures include coil embolization of aneurysms, liquid embolization of arteriovenous malformations and mechanical thrombectomy of large vessel occlusions in the setting of acute ischemic stroke. In an NVI procedure, the physician uses a robotic system to gain target lesion access by controlling the manipulation of a neurovascular guidewire and microcatheter to deliver the therapy to restore normal blood flow. Target access is enabled by the sheath or guide catheter but may also require an intermediate catheter for more distal territory or to provide adequate support for the microcatheter and guidewire. The distal tip of a guidewire is navigated into, or past, the lesion depending on the type of lesion and treatment. For treating aneurysms, the microcatheter is advanced into the lesion and the guidewire is removed and several embolization coils are deployed into the aneurysm through the microcatheter and used to block blood flow into the aneurysm. For treating arteriovenous malformations, a liquid embolic is injected into the malformation via a microcatheter. Mechanical thrombectomy to treat vessel occlusions can be achieved either through aspiration and/or use of a stent retriever. Depending on the location of the clot, aspiration is either done through an aspiration catheter, or through a microcatheter for smaller arteries. Once the aspiration catheter is at the lesion, negative pressure is applied to remove the clot through the catheter. Alternatively, the clot can be removed by deploying a stent retriever through the microcatheter. Once the clot has integrated into the stent retriever, the clot is retrieved by retracting the stent retriever and microcatheter (or intermediate catheter) into the guide catheter. 
     In PCI, the physician uses a robotic system to gain lesion access by manipulating a coronary guidewire to deliver the therapy and restore normal blood flow. The access is enabled by seating a guide catheter in a coronary ostium. The distal tip of the guidewire is navigated past the lesion and, for complex anatomies, a microcatheter may be used to provide adequate support for the guidewire. The blood flow is restored by delivering and deploying a stent or balloon at the lesion. The lesion may need preparation prior to stenting, by either delivering a balloon for pre-dilation of the lesion, or by performing atherectomy using, for example, a laser or rotational atherectomy catheter and a balloon over the guidewire. Diagnostic imaging and physiological measurements may be performed to determine appropriate therapy by using imaging catheters or fractional flow reserve (FFR) measurements. 
     In PVI, the physician uses a robotic system to deliver the therapy and restore blood flow with techniques similar to NVI. The distal tip of the guidewire is navigated past the lesion and a microcatheter may be used to provide adequate support for the guidewire for complex anatomies. The blood flow is restored by delivering and deploying a stent or balloon to the lesion. As with PCI, lesion preparation and diagnostic imaging may be used as well. 
     When support at the distal end of a catheter or guidewire is needed, for example, to navigate tortuous or calcified vasculature, to reach distal anatomical locations, or to cross hard lesions, an over-the-wire (OTW) catheter or coaxial system is used. An OTW catheter has a lumen for the guidewire that extends the full length of the catheter. This provides a relatively stable system because the guidewire is supported along the whole length. This system, however, has some disadvantages, including higher friction, and longer overall length compared to rapid-exchange catheters (see below). Typically to remove or exchange an OTW catheter while maintaining the position of the indwelling guidewire, the exposed length (outside of the patient) of guidewire must be longer than the OTW catheter. A 300 cm long guidewire is typically sufficient for this purpose and is often referred to as an exchange length guidewire. Due to the length of the guidewire, two operators are needed to remove or exchange an OTW catheter. This becomes even more challenging if a triple coaxial, known in the art as a tri-axial system, is used (quadruple coaxial catheters have also been known to be used). However, due to its stability, an OTW system is often used in NVI and PVI procedures. On the other hand, PCI procedures often use rapid exchange (or monorail) catheters. The guidewire lumen in a rapid exchange catheter runs only through a distal section of the catheter, called the monorail or rapid exchange (RX) section. With a RX system, the operator manipulates the interventional devices parallel to each other (as opposed to with an OTW system, in which the devices are manipulated in a serial configuration), and the exposed length of guidewire only needs to be slightly longer than the RX section of the catheter. A rapid exchange length guidewire is typically 180-200 cm long. Given the shorter length guidewire and monorail, RX catheters can be exchanged by a single operator. However, RX catheters are often inadequate when more distal support is needed. 
     SUMMARY 
     In accordance with an embodiment, an apparatus for providing support to an elongated medical device between a first device module and a second device module coupled to a linear member of a robotic drive for a catheter. The second device module is located in a position along the linear member distal to the first device module. The apparatus incudes a device support having a distal end and a proximal end. A section of the device support is positioned within the first device module. The apparatus also includes a connector attached to the distal end of the device support. The connector including an attachment mechanism for engaging a proximal end of the second device module. The proximal end of the device support is configured to be coupled to the second device module. 
     In accordance with another embodiment, a cassette for use in a robotic drive of a catheter-based procedure system includes a housing having a distal end and a proximal end, a device support having a lengthwise slit, a distal end and a proximal end, a connector attached to a distal end of the device support and a splitter positioned at the distal end of the housing of the cassette at an entry point for an elongated medical device into the device support. A section of the device support is positioned within the housing. In a first position, the connector is located proximal to the entry point and in a second position, the connector is located distal to the entry point. 
     In accordance with another embodiment, a device support for providing support to an elongated medical device between a first device module and a second device module coupled to a linear member of a robotic drive of a catheter-based procedure system includes a first tube having a lengthwise slit configured to move between a first position and a second position and a second tube having a lengthwise opening, an inner diameter and an outer diameter. The first tube has an inner diameter and an outer diameter. The second tube is disposed around the outer diameter of the first tube and is configured to provide a force on the first tube to hold the first tube in the first position. 
     In accordance with another embodiment, a cassette for use in a robotic drive of a catheter-based procedure system includes a housing having a distal end and a proximal end, an entry point to a device support on the distal end of the housing; and a modular section of the housing located between the proximal end and the entry point on the distal end. The modular section is configured to receive a plurality of different adapters configured to support different elongated medical devices. 
     In accordance with another embodiment, an apparatus for providing support for an elongated medical device in a catheter-based procedure system, the apparatus includes a cassette and an elongated medical device adapter. The cassette includes a housing having a distal end and a proximal end, an entry point to a device support on the distal end of the housing and a modular section of the housing located between the proximal end and the entry point on the distal end. The modular section includes a midsection and a recess positioned off-axis from a longitudinal axis of the cassette. The elongated medical device adapter includes a first section configured to receive a first elongated medical device and a second section configured to receive a second elongated medical device. The second section is positioned at an angle from a longitudinal axis of the first section. The first section of the elongated medical device adapter is positioned in the midsection of the modular section and the second section of the elongated medical device adapter is positioned in the recess of the modular section. 
     In accordance with another embodiment, a cassette for use in a robotic drive of a catheter-based procedure system includes a rigid support including an opening and an isolated interface positioned within the opening. The isolated interface includes a cradle for an elongated medical device. The recess and the isolated interface may allow a limited range of motion of the isolated interface in the x, y, and z directions relative to the rigid support. 
     In accordance with another embodiment, a cassette for use in a robotic drive of a catheter-based procedure system includes a rigid support portion, an interface portion configured to support a hemostasis valve having a port and an apparatus for anchoring a fluid connection to the hemostasis valve. The apparatus for anchoring a fluid connection includes a flexible tube having a first end and a second end a clip attached to the rigid support portion and the second end of the flexible tube. The first end of the flexible tube is configured to connect to the port of the hemostasis valve. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention will become more fully understood from the following detailed description, taken in conjunction with the accompanying drawings, wherein the reference numerals refer to like parts in which: 
         FIG. 1  is a perspective view of an exemplary catheter procedure system in accordance with an embodiment; 
         FIG. 2  is a schematic block diagram of an exemplary catheter procedure system in accordance with an embodiment; 
         FIG. 3  is a perspective view of a drive assembly for a catheter procedure system in accordance with an embodiment; 
         FIG. 4  is a perspective view of device supports with fixed front (or distal) and rear (or proximal) points to provide tension in accordance with an embodiment; 
         FIG. 5  is a diagram showing a top view of a cassette with a device support in a withdrawn position to facilitate exchange of an elongated medical device in accordance with an embodiment; 
         FIG. 6  is a diagram showing a top view of a cassette with a device support in an extended position constrained at two ends in accordance with an embodiment; 
         FIG. 7  is a top view of two device modules with device supports in accordance with an embodiment; 
         FIG. 8  is a top view illustrating forward translation of a device module linearly relative to a device support in accordance with an embodiment; 
         FIG. 9  is a top view illustrating reverse translation of a device module linearly relative to a device support in accordance with an embodiment; 
         FIG. 10  is a top view illustrating reverse translation of a device module linearly relative to a device support in accordance with an embodiment; 
         FIG. 11  shows a simplified top view of four device modules and four device supports for a robotic drive in accordance with an embodiment; 
         FIG. 12  shows a simplified top view illustrating movement of a device module relative to a device support in accordance with an embodiment; 
         FIG. 13  shows a simplified top view illustrating the four device modules of  FIG. 11  in a forward position relative to their respective device support in accordance with an embodiment; 
         FIG. 14  shows a simplified top view illustrating the four device modules of  FIG. 11  in a withdrawn position relative to their respective device support in accordance with an embodiment; 
         FIG. 15  is a side view of a proximal end of a device support that is extended and a rear constraint for a rear (or proximal) fixed point to which the device support is connected in accordance with an embodiment; 
         FIG. 16  is a side view of a proximal end of a device support that is partially retracted and a rear constraint for a rear (or proximal) fixed point to which the device support is connected in accordance with an embodiment; 
         FIG. 17  shows a simplified top view of device modules with device supports stored on a reel in accordance with an embodiment; 
         FIG. 18  shows an exemplary spooled tensioner in accordance with an embodiment; 
         FIG. 19  shows a simplified top view of device modules with drive device supports in accordance with an embodiment; 
         FIG. 20  shows an exemplary geared tensioner in accordance with an embodiment; 
         FIG. 21  shows a simplified top view of device modules with device supports formed with accordions or springs in accordance with an embodiment; 
         FIG. 22  illustrates a compressed accordion/spring in accordance with an embodiment; 
         FIG. 23  illustrates a stretched accordion/spring in accordance with an embodiment; 
         FIGS. 24 ( a )-( c )  are perspective views of exemplary slit shapes for a device support flexible tube in accordance with an embodiment; 
         FIG. 25  is an exploded view of a device module and an elongated medical device in accordance with an embodiment; 
         FIG. 26 a    is a perspective view of a cassette with a device support installed and in a retracted position in accordance with an embodiment; 
         FIG. 26 b    is a perspective view of a cassette with a device support installed and in a retracted position in accordance with an embodiment; 
         FIG. 27  is a top view of a device support and connector extended from a cassette ahead of an EMD entry point in accordance with an embodiment; 
         FIG. 28  is a top view of a device support and connector withdrawn behind an EMD entry point in accordance with an embodiment; 
         FIG. 29  is an end view of a splitter holding open a device support in accordance with an embodiment; 
         FIG. 30  is a top view of cassette with a device support connector withdrawn and off of a device axis to facilitate loading of an EMD in accordance with an embodiment; 
         FIG. 31  is a perspective view of a forward constraint and a connector in accordance with an embodiment; 
         FIG. 32  is a perspective view of a forward constraint with a lid in accordance with an embodiment; 
         FIG. 33  is a perspective view of a distal support arm and distal support connection in accordance with an embodiment; 
         FIG. 34  is a perspective view of a distal support connection coupled to a device support and connector in accordance with an embodiment; 
         FIG. 35  is a side view of a distal support arm, distal support connection and an introducer interface support in accordance with an embodiment; 
         FIG. 36  is a perspective view of an introducer interface support connected to an introducer sheath in accordance with an embodiment; 
         FIG. 37  is a perspective view of a movable distal support arm in a first position in accordance with an embodiment; 
         FIG. 38  is a perspective view of a moveable distal support arm in a second position in accordance with an embodiment; 
         FIG. 39  is a top view of a moveable distal support arm and movable support arm in a first position in accordance with an embodiment; 
         FIG. 40  is a top view of a moveable distal support arm and movable support arm in a second position in accordance with an embodiment; 
         FIG. 41  is a top view illustrating movement of a distal support arm and a support arm from the second position to the first position in accordance with an embodiment; 
         FIG. 42  is a perspective view of a catheter with an on-device adapter in accordance with an embodiment; 
         FIG. 43  is a perspective view of a guidewire with an on-device adapter in accordance with an embodiment; 
         FIG. 44  is a perspective view of a cassette with an installed elongated medical device with an on-device adapter in accordance with an embodiment; 
         FIG. 45  is a exploded view of a cassette and an elongated medical device with an on-device adapter that is removed from the cassette in accordance with an embodiment; 
         FIG. 46  s a top view of a cassette in accordance with an embodiment; 
         FIG. 47  is an exploded view of an elongated medical device (EMD) adapter and a lid in accordance with an embodiment; 
         FIG. 48  is a perspective view of an EMD adapter and EMD installed in a cassette in accordance with an embodiment; 
         FIG. 49  is a top view of s cassette with a floating interface and a rigid support section in accordance with an embodiment; 
         FIG. 50 a    is an end cross-sectional view of an floating (or isolated) interface and rigid support section of a cassette in accordance with an embodiment; 
         FIG. 50 b    is an exploded isometric view of a cassette showing a first component and a second component of a floating (or isolated) interface in accordance with an embodiment; 
         FIG. 51  is a bottom view of the floating (or isolated) interface of a cassette in accordance with an embodiment; 
         FIG. 52  shows cradle supporting a rotational drive gear with rollers in accordance with an embodiment; and 
         FIG. 53  illustrates a cassette with a support assembly for anchoring tubing and fluid connections in accordance with an embodiment; 
         FIG. 54  is an end cross-sectional view of a device support in accordance with an embodiment; and 
         FIG. 55  is an end cross-sectional vie of a device support and splitter in accordance with an embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     The following definitions will be used herein. The term elongated medical device (EMD) refers to, but is not limited to, catheters (e.g. guide catheters, microcatheters, balloon/stent catheters), wire-based devices (guidewires, embolization coils, stent retrievers, etc.), and devices that have a combination of these. Wire-based EMD includes, but is not limited to, guidewires, microwires, a proximal pusher for embolization coils, stent retrievers, self-expanding stents, and flow divertors. Typically wire-based EMD&#39;s do not have a hub or handle at its proximal terminal end. In one embodiment the EMD is a catheter having a hub at a proximal end of the catheter and a flexible shaft extending from the hub toward the distal end of the catheter, wherein the shaft is more flexible than the hub. In one embodiment the catheter includes an intermediary portion that transitions between the hub and the shaft that has an intermediate flexibility that is less rigid than the hub and more rigid than the shaft. In one embodiment the intermediary portion is a strain relief. 
     The terms distal and proximal define relative locations of two different features. With respect to a robotic drive the terms distal and proximal are defined by the position of the robotic drive in its intended use relative to a patient. When used to define a relative position, the distal feature is the feature of the robotic drive that is closer to the patient than a proximal feature when the robotic drive is in its intended in-use position. Within a patient, any vasculature landmark further away along the path from the access point is considered more distal than a landmark closer to the access point, where the access point is the point at which the EMD enters the patient. Similarly, the proximal feature is the feature that is farther from the patient than the distal feature when the robotic drive in its intended in-use position. When used to define direction, the distal direction refers to a path on which something is moving or is aimed to move or along which something is pointing or facing from a proximal feature toward a distal feature and/or patient when the robotic drive is in its intended in-use position. The proximal direction is the opposite direction of the distal direction. 
     The term longitudinal axis of a member (e.g., an EMD or other element in the catheter-based procedure system) is the direction of orientation going from a proximal portion of the member to a distal portion of the member. By way of example, the longitudinal axis of a guidewire is the direction of orientation from a proximal portion of the guide wire toward a distal portion of the guidewire even though the guidewire may be non-linear in the relevant portion. The term axial movement of a member refers to translation of the member along the longitudinal axis of the member. When a distal end of an EMD is axially moved in a distal direction along its longitudinal axis into or further into the patient, the EMD is being advanced. When the distal end of an EMD is axially moved in a proximal direction along its longitudinal axis out of or further out of the patient, the EMD is being withdrawn. The term rotational movement of a member refers to change in angular orientation of the member about the local longitudinal axis of the member. Rotational movement of an EMD corresponds to clockwise or counterclockwise rotation of the EMD about its longitudinal axis due to an applied torque. 
     The term axial insertion refers to inserting a first member into a second member along the longitudinal axes of the second member. The term lateral insertion refers to inserting a first member into a second member along a direction in a plane perpendicular to the longitudinal axis of the second member. This can also be referred to as radial loading or side loading. The term pinch refers to releasably fixing an EMD to a member such that the EMD and member move together when the member moves. The term unpinch refers to releasing the EMD from a member such that the EMD and member move independently when the member moves. The term clamp refers to releasably fixing an EMD to a member such that the EMD&#39;s movement is constrained with respect to the member. The member can be fixed with respect to a global coordinate system or with respect to a local coordinate system. The term unclamp refers to releasing the EMD from the member such that the EMD can move independently. 
     The term grip refers to the application of a force or torque to an EMD by a drive mechanism that causes motion of the EMD without slip in at least one degree of freedom. The term ungrip refers to the release of the application of force or torque to the EMD by a drive mechanism such that the position of the EMD is no longer constrained. In one example, an EMD gripped between two tires will rotate about its longitudinal axis when the tires move longitudinally relative to one another. The rotational movement of the EMD is different than the movement of the two tires. The position of an EMD that is gripped is constrained by the drive mechanism. The term buckling refers to the tendency of a flexible EMD when under axial compression to bend away from the longitudinal axis or intended path along which it is being advanced. In one embodiment axial compression occurs in response to resistance from being navigated in the vasculature. The distance an EMD may be driven along its longitudinal axis without support before the EMD buckles is referred to herein as the device buckling distance. The device buckling distance is a function of the device&#39;s stiffness, geometry (including but not limited to diameter), and force being applied to the EMD. Buckling may cause the EMD to form an arcuate portion different than the intended path. Kinking is a case of buckling in which deformation of the EMD is non-elastic resulting in a permanent set. 
     The terms top, up, and upper refer to the general direction away from the direction of gravity and the terms bottom, down, and lower refer to the general direction in the direction of gravity. The term inwardly refers to the inner portion of a feature. The term outwardly refers to the outer portion of a feature. The term sterile interface refers to an interface or boundary between a sterile and non-sterile unit. For example, a cassette may be a sterile interface between the robotic drive and at least one EMD. The term sterilizable unit refers to an apparatus that is capable of being sterilized (free from pathogenic microorganisms). This includes, but is not limited to, a cassette, consumable unit, drape, device adapter, and sterilizable drive modules/units (which may include electromechanical components). Sterilizable Units may come into contact with the patient, other sterile devices, or anything else placed within the sterile field of a medical procedure. 
     The term on-device adapter refers to sterile apparatus capable of releasably pinching an MED to provide a driving interface. For example, the on-device adapter is also known as an end-effector or EMD capturing device. In one non-limiting embodiment, the on-device adapter is a collet that is operatively controlled robotically to rotate the EMD about its longitudinal axis, to pinch and/or unpinch the EMD to the collet, and/or to translate the EMD along its longitudinal axis. In one embodiment the on-device adapter is a hub-drive mechanism such as a driven gear located on the hub of an EMD. The term hub driving or proximal driving refers to holding on to and manipulating an EMD from a proximal position (e.g., geared adapter on catheter hub). In one embodiment, hub driving refers to imparting a force or torque to the hub of a catheter to translate and/or rotate the catheter. In hub driving, often applying typical clinical loads causes the EMD to buckle and thus hub driving often requires anti-buckling features in the driving mechanism. For devices that do not have hubs or other interfaces (e.g., a guidewire), device adapters may be added to the device to act as a temporary hub. In one embodiment, an EMD handle includes mechanisms to manipulate features within the catheter such as wires that extend from the handle to the distal end of the catheter to deflect the distal end of the catheter. In contrast, the hub is the rigid portion of the EMD at the proximal end that does not include control mechanisms to manipulate features within the catheter. The term shaft (distal) driving refers to holding on to and manipulating an EMD along its shaft. For example, an on-device adapter may be placed just proximal of the hub or Y-connector the device is inserted into. If the location of the on-device adapter is at the proximity of an insertion point (to the body or another catheter or valve), shaft driving does not typically require anti-buckling features (it may include anti-buckling features to improve drive capability). 
       FIG. 1  is a perspective view of an exemplary catheter-based procedure system  10  in accordance with an embodiment. Catheter-based procedure system  10  may be used to perform catheter-based medical procedures, e.g., percutaneous intervention procedures such as a percutaneous coronary intervention (PCI) (e.g., to treat STEMI), a neurovascular interventional procedure (NVI) (e.g., to treat an emergent large vessel occlusion (ELVO)), peripheral vascular intervention procedures (PVI) (e.g., for critical limb ischemia (CLI), etc.). Catheter-based medical procedures may include diagnostic catheterization procedures during which one or more catheters or other elongated medical devices (EMDs) are used to aid in the diagnosis of a patient&#39;s disease. For example, during one embodiment of a catheter-based diagnostic procedure, a contrast media is injected onto one or more arteries through a catheter and an image of the patient&#39;s vasculature is taken. Catheter-based medical procedures may also include catheter-based therapeutic procedures (e.g., angioplasty, stent placement, treatment of peripheral vascular disease, clot removal, arterial venous malformation therapy, treatment of aneurysm, etc.) during which a catheter (or other EMD) is used to treat a disease. Therapeutic procedures may be enhanced by the inclusion of adjunct devices  54  (shown in  FIG. 2 ) such as, for example, intravascular ultrasound (IVUS), optical coherence tomography (OCT), fractional flow reserve (FFR), etc. It should be noted, however, that one skilled in the art would recognize that certain specific percutaneous intervention devices or components (e.g., type of guidewire, type of catheter, etc.) may be selected based on the type of procedure that is to be performed. Catheter-based procedure system  10  can perform any number of catheter-based medical procedures with minor adjustments to accommodate the specific percutaneous intervention devices to be used in the procedure. 
     Catheter-based procedure system  10  includes, among other elements, a bedside unit  20  and a control station  26 . Bedside unit  20  includes a robotic drive  24  and a positioning system  22  that are located adjacent to a patient  12 . Patient  12  is supported on a patient table  18 . The positioning system  22  is used to position and support the robotic drive  24 . The positioning system  22  may be, for example, a robotic arm, an articulated arm, a holder, etc. The positioning system  22  may be attached at one end to, for example, a rail on the patient table  18 , a base, or a cart. The other end of the positioning system  22  is attached to the robotic drive  24 . The positioning system  22  may be moved out of the way (along with the robotic drive  24 ) to allow for the patient  12  to be placed on the patient table  18 . Once the patient  12  is positioned on the patient table  18 , the positioning system  22  may be used to situate or position the robotic drive  24  relative to the patient  12  for the procedure. In an embodiment, patient table  18  is operably supported by a pedestal  17 , which is secured to the floor and/or earth. Patient table  18  is able to move with multiple degrees of freedom, for example, roll, pitch, and yaw, relative to the pedestal  17 . Bedside unit  20  may also include controls and displays  46  (shown in  FIG. 2 ). For example, controls and displays may be located on a housing of the robotic drive  24 . 
     Generally, the robotic drive  24  may be equipped with the appropriate percutaneous interventional devices and accessories  48  (shown in  FIG. 2 ) (e.g., guidewires, various types of catheters including balloon catheters, stent delivery systems, stent retrievers, embolization coils, liquid embolics, aspiration pumps, device to deliver contrast media, medicine, hemostasis valve adapters, syringes, stopcocks, inflation device, etc.) to allow the user or operator  11  to perform a catheter-based medical procedure via a robotic system by operating various controls such as the controls and inputs located at the control station  26 . Bedside unit  20 , and in particular robotic drive  24 , may include any number and/or combination of components to provide bedside unit  20  with the functionality described herein. A user or operator  11  at control station  26  is referred to as the control station user or control station operator and referred to herein as user or operator. A user or operator at bedside unit  20  is referred to as bedside unit user or bedside unit operator. The robotic drive  24  includes a plurality of device modules  32   a - d  mounted to a rail or linear member  60  (shown in  FIG. 3 ). The rail or linear member  60  guides and supports the device modules. Each of the device modules  32   a - d  may be used to drive an EMD such as a catheter or guidewire. For example, the robotic drive  24  may be used to automatically feed a guidewire into a diagnostic catheter and into a guide catheter in an artery of the patient  12 . One or more devices, such as an EMD, enter the body (e.g., a vessel) of the patient  12  at an insertion point  16  via, for example, an introducer sheath. 
     Bedside unit  20  is in communication with control station  26 , allowing signals generated by the user inputs of control station  26  to be transmitted wirelessly or via hardwire to bedside unit  20  to control various functions of bedside unit  20 . As discussed below, control station  26  may include a control computing system  34  (shown in  FIG. 2 ) or be coupled to the bedside unit  20  through a control computing system  34 . Bedside unit  20  may also provide feedback signals (e.g., loads, speeds, operating conditions, warning signals, error codes, etc.) to control station  26 , control computing system  34  (shown in  FIG. 2 ), or both. Communication between the control computing system  34  and various components of the catheter-based procedure system  10  may be provided via a communication link that may be a wireless connection, cable connections, or any other means capable of allowing communication to occur between components. Control station  26  or other similar control system may be located either at a local site (e.g., local control station  38  shown in  FIG. 2 ) or at a remote site (e.g., remote control station and computer system  42  shown in  FIG. 2 ). Catheter procedure system  10  may be operated by a control station at the local site, a control station at a remote site, or both the local control station and the remote control station at the same time. At a local site, user or operator  11  and control station  26  are located in the same room or an adjacent room to the patient  12  and bedside unit  20 . As used herein, a local site is the location of the bedside unit  20  and a patient  12  or subject (e.g., animal or cadaver) and the remote site is the location of a user or operator  11  and a control station  26  used to control the bedside unit  20  remotely. A control station  26  (and a control computing system) at a remote site and the bedside unit  20  and/or a control computing system at a local site may be in communication using communication systems and services  36  (shown in  FIG. 2 ), for example, through the Internet. In an embodiment, the remote site and the local (patient) site are away from one another, for example, in different rooms in the same building, different buildings in the same city, different cities, or other different locations where the remote site does not have physical access to the bedside unit  20  and/or patient  12  at the local site. 
     Control station  26  generally includes one or more input modules  28  configured to receive user inputs to operate various components or systems of catheter-based procedure system  10 . In the embodiment shown, control station  26  allows the user or operator  11  to control bedside unit  20  to perform a catheter-based medical procedure. For example, input modules  28  may be configured to cause bedside unit  20  to perform various tasks using percutaneous intervention devices (e.g., EMDs) interfaced with the robotic drive  24  (e.g., to advance, retract, or rotate a guidewire, advance, retract or rotate a catheter, inflate or deflate a balloon located on a catheter, position and/or deploy a stent, position and/or deploy a stent retriever, position and/or deploy a coil, inject contrast media into a catheter, inject liquid embolics into a catheter, inject medicine or saline into a catheter, aspirate on a catheter, or to perform any other function that may be performed as part of a catheter-based medical procedure). Robotic drive  24  includes various drive mechanisms to cause movement (e.g., axial and rotational movement) of the components of the bedside unit  20  including the percutaneous intervention devices. 
     In one embodiment, input modules  28  may include one or more touch screens, joysticks, scroll wheels, and/or buttons. In addition to input modules  28 , the control station  26  may use additional user controls  44  (shown in  FIG. 2 ) such as foot switches and microphones for voice commands, etc. Input modules  28  may be configured to advance, retract, or rotate various components and percutaneous intervention devices such as, for example, a guidewire, and one or more catheters or microcatheters. Buttons may include, for example, an emergency stop button, a multiplier button, device selection buttons and automated move buttons. When an emergency stop button is pushed, the power (e.g., electrical power) is shut off or removed to bedside unit  20 . When in a speed control mode, a multiplier button acts to increase or decrease the speed at which the associated component is moved in response to a manipulation of input modules  28 . When in a position control mode, a multiplier button changes the mapping between input distance and the output commanded distance. Device selection buttons allow the user or operator  11  to select which of the percutaneous intervention devices loaded into the robotic drive  24  are controlled by input modules  28 . Automated move buttons are used to enable algorithmic movements that the catheter-based procedure system  10  may perform on a percutaneous intervention device without direct command from the user or operator  11 . In one embodiment, input modules  28  may include one or more controls or icons (not shown) displayed on a touch screen (that may or may not be part of a display  30 ), that, when activated, causes operation of a component of the catheter-based procedure system  10 . Input modules  28  may also include a balloon or stent control that is configured to inflate or deflate a balloon and/or deploy a stent. Each of the input modules  28  may include one or more buttons, scroll wheels, joysticks, touch screen, etc. that may be used to control the particular component or components to which the control is dedicated. In addition, one or more touch screens may display one or more icons (not shown) related to various portions of input modules  28  or to various components of catheter-based procedure system  10 . 
     Control station  26  may include a display  30 . In other embodiments, the control station  26  may include two or more displays  30 . Display  30  may be configured to display information or patient specific data to the user or operator  11  located at control station  26 . For example, display  30  may be configured to display image data (e.g., X-ray images, MRI images, CT images, ultrasound images, etc.), hemodynamic data (e.g., blood pressure, heart rate, etc.), patient record information (e.g., medical history, age, weight, etc.), lesion or treatment assessment data (e.g., IVUS, OCT, FFR, etc.). In addition, display  30  may be configured to display procedure specific information (e.g., procedural checklist, recommendations, duration of procedure, catheter or guidewire position, volume of medicine or contrast agent delivered, etc.). Further, display  30  may be configured to display information to provide the functionalities associated with control computing system  34  (shown in  FIG. 2 ). Display  30  may include touch screen capabilities to provide some of the user input capabilities of the system. 
     Catheter-based procedure system  10  also includes an imaging system  14 . Imaging system  14  may be any medical imaging system that may be used in conjunction with a catheter based medical procedure (e.g., non-digital X-ray, digital X-ray, CT, MRI, ultrasound, etc.). In an exemplary embodiment, imaging system  14  is a digital X-ray imaging device that is in communication with control station  26 . In one embodiment, imaging system  14  may include a C-arm (shown in  FIG. 1 ) that allows imaging system  14  to partially or completely rotate around patient  12  in order to obtain images at different angular positions relative to patient  12  (e.g., sagittal views, caudal views, anterior-posterior views, etc.). In one embodiment imaging system  14  is a fluoroscopy system including a C-arm having an X-ray source  13  and a detector  15 , also known as an image intensifier. 
     Imaging system  14  may be configured to take X-ray images of the appropriate area of patient  12  during a procedure. For example, imaging system  14  may be configured to take one or more X-ray images of the head to diagnose a neurovascular condition. Imaging system  14  may also be configured to take one or more X-ray images (e.g., real time images) during a catheter-based medical procedure to assist the user or operator  11  of control station  26  to properly position a guidewire, guide catheter, microcatheter, stent retriever, coil, stent, balloon, etc. during the procedure. The image or images may be displayed on display  30 . For example, images may be displayed on display  30  to allow the user or operator  11  to accurately move a guide catheter or guidewire into the proper position. 
     In order to clarify directions, a rectangular coordinate system is introduced with X, Y, and Z axes. The positive X axis is oriented in a longitudinal (axial) distal direction, that is, in the direction from the proximal end to the distal end, stated another way from the proximal to distal direction. The Y and Z axes are in a transverse plane to the X axis, with the positive Z axis oriented up, that is, in the direction opposite of gravity, and the Y axis is automatically determined by right-hand rule. 
       FIG. 2  is a block diagram of catheter-based procedure system  10  in accordance with an exemplary embodiment. Catheter-procedure system  10  may include a control computing system  34 . Control computing system  34  may physically be, for example, part of control station  26  (shown in  FIG. 1 ). Control computing system  34  may generally be an electronic control unit suitable to provide catheter-based procedure system  10  with the various functionalities described herein. For example, control computing system  34  may be an embedded system, a dedicated circuit, a general-purpose system programmed with the functionality described herein, etc. Control computing system  34  is in communication with bedside unit  20 , communications systems and services  36  (e.g., Internet, firewalls, cloud services, session managers, a hospital network, etc.), a local control station  38 , additional communications systems  40  (e.g., a telepresence system), a remote control station and computing system  42 , and patient sensors  56  (e.g., electrocardiogram (ECG) devices, electroencephalogram (EEG) devices, blood pressure monitors, temperature monitors, heart rate monitors, respiratory monitors, etc.). The control computing system is also in communication with imaging system  14 , patient table  18 , additional medical systems  50 , contrast injection systems  52  and adjunct devices  54  (e.g., IVUS, OCT, FFR, etc.). The bedside unit  20  includes a robotic drive  24 , a positioning system  22  and may include additional controls and displays  46 . As mentioned above, the additional controls and displays may be located on a housing of the robotic drive  24 . Interventional devices and accessories  48  (e.g., guidewires, catheters, etc.) interface to the bedside system  20 . In an embodiment, interventional devices and accessories  48  may include specialized devices (e.g., IVUS catheter, OCT catheter, FFR wire, diagnostic catheter for contrast, etc.) which interface to their respective adjunct devices  54 , namely, an IVUS system, an OCT system, and FFR system, etc. 
     In various embodiments, control computing system  34  is configured to generate control signals based on the user&#39;s interaction with input modules  28  (e.g., of a control station  26  (shown in  FIG. 1 ) such as a local control station  38  or a remote control station  42 ) and/or based on information accessible to control computing system  34  such that a medical procedure may be performed using catheter-based procedure system  10 . The local control station  38  includes one or more displays  30 , one or more input modules  28 , and additional user controls  44 . The remote control station and computing system  42  may include similar components to the local control station  38 . The remote  42  and local  38  control stations can be different and tailored based on their required functionalities. The additional user controls  44  may include, for example, one or more foot input controls. The foot input control may be configured to allow the user to select functions of the imaging system  14  such as turning on and off the X-ray and scrolling through different stored images. In another embodiment, a foot input device may be configured to allow the user to select which devices are mapped to scroll wheels included in input modules  28 . Additional communication systems  40  (e.g., audio conference, video conference, telepresence, etc.) may be employed to help the operator interact with the patient, medical staff (e.g., angio-suite staff), and/or equipment in the vicinity of the bedside. 
     Catheter-based procedure system  10  may be connected or configured to include any other systems and/or devices not explicitly shown. For example, catheter-based procedure system  10  may include image processing engines, data storage and archive systems, automatic balloon and/or stent inflation systems, medicine injection systems, medicine tracking and/or logging systems, user logs, encryption systems, systems to restrict access or use of catheter-based procedure system  10 , etc. 
     As mentioned, control computing system  34  is in communication with bedside unit  20  which includes a robotic drive  24 , a positioning system  22  and may include additional controls and displays  46 , and may provide control signals to the bedside unit  20  to control the operation of the motors and drive mechanisms used to drive the percutaneous intervention devices (e.g., guidewire, catheter, etc.). The various drive mechanisms may be provided as part of a robotic drive  24 .  FIG. 3  is a perspective view of a robotic drive for a catheter-based procedure system  10  in accordance with an embodiment. In  FIG. 3 , a robotic drive  24  includes multiple device modules  32   a - d  coupled to a linear member  60 . Each device module  32   a - d  is coupled to the linear member  60  via a stage  62   a - d  moveably mounted to the linear member  60 . A device module  32   a - d  may be connected to a stage  62   a - d  using a connector such as an offset bracket  78   a - d . In another embodiment, the device module  32   a - d  is directly mounted to the stage  62   a - d . Each stage  62   a - d  may be independently actuated to move linearly along the linear member  60 . Accordingly, each stage  62   a - d  (and the corresponding device module  32   a - d  coupled to the stage  62   a - d ) may independently move relative to each other and the linear member  60 . A drive mechanism is used to actuate each stage  62   a - d . In the embodiment shown in  FIG. 3 , the drive mechanism includes independent stage translation motors  64   a - d  coupled to each stage  62   a - d  and a stage drive mechanism  76 , for example, a lead screw via a rotating nut, a rack via a pinion, a belt via a pinion or pulley, a chain via a sprocket, or the stage translation motors  64   a - d  may be linear motors themselves. In some embodiments, the stage drive mechanism  76  may be a combination of these mechanisms, for example, each stage  62   a - d  could employ a different type of stage drive mechanism. In an embodiment where the stage drive mechanism is a lead screw and rotating nut, the lead screw may be rotated and each stage  62   a - d  may engage and disengage from the lead screw to move, e.g., to advance or retract. In the embodiment shown in  FIG. 3 , the stages  62   a - d  and device modules  32   a - d  are in a serial drive configuration. 
     Each device module  32   a - d  includes a drive module  68   a - d  and a cassette  66   a - d  mounted on and coupled to the drive module  68   a - d . In the embodiment shown in  FIG. 3 , each cassette  66   a - d  is mounted to the drive module  68   a - d  in a vertical orientation. In other embodiments, each cassette  66   a - d  may be mounted to the drive module  68   a - d  in other mounting orientations. Each cassette  66   a - d  is configured to interface with and support a proximal portion of an EMD (not shown). In addition, each cassette  66   a - d  may include elements to provide one or more degrees of freedom in addition to the linear motion provided by the actuation of the corresponding stage  62   a - d  to move linearly along the linear member  60 . For example, the cassette  66   a - d  may include elements that may be used to rotate the EMD when the cassette is coupled to the drive module  68   a - d . Each drive module  68   a - d  includes at least one coupler to provide a drive interface to the mechanisms in each cassette  66   a - d  to provide the additional degree of freedom. Each cassette  66   a - d  also includes a channel in which a device support  79   a - d  is positioned, and each device support  79   a - d  is used to prevent an EMD from buckling. A support arm  77   a ,  77   b , and  77   c  is attached to each device module  32   a ,  32   b , and  32   c , respectively, to provide a fixed point for support of a proximal end of the device supports  79   b ,  79   c , and  79   d , respectively. The robotic drive  24  may also include a device support connection  72  connected to a device support  79 , a distal support arm  70  and a support arm  77   o . Support arm  77   o  is used to provide a fixed point for support of the proximal end of the distal most device support  79   a  housed in the distal most device module  32   a . In addition, an introducer interface support (redirector)  74  may be connected to the device support connection  72  and an EMD (e.g., an introducer sheath). The configuration of robotic drive  24  has the benefit of reducing volume and weight of the drive robotic drive  24  by using actuators on a single linear member. 
     To prevent contaminating the patient with pathogens, healthcare staff use aseptic technique in a room housing the bedside unit  20  and the patient  12  or subject (shown in  FIG. 1 ). A room housing the bedside unit  20  and patient  12  may be, for example, a cath lab or an angio suite. Aseptic technique consists of using sterile barriers, sterile equipment, proper patient preparation, environmental controls and contact guidelines. Accordingly, all EMDs and interventional accessories are sterilized and can only be in contact with either sterile barriers or sterile equipment. In an embodiment, a sterile drape (not shown) is placed over the non-sterile robotic drive  24 . Each cassette  66   a - d  is sterilized and acts as a sterile interface between the draped robotic drive  24  and at least one EMD. Each cassette  66   a - d  can be designed to be sterile for single use or to be re-sterilized in whole or part so that the cassette  66   a - d  or its components can be used in multiple procedures. 
     As mentioned, the robotic drive  24  may include a device support  79   a - d  between each device module  32   a - d  and between the most distal device module  32   a  and the device support connection  72 . Each device support  79   a - d  is configured to prevent elongated medical devices from buckling as they are advanced outside of a patient and prior to being advanced into a more distal EMD. In an embodiment, each device support  79   a - d  may be a flexible tube with a lengthwise slit and used in connection with a splitter on a cassette. Each device support  79   a - d  is fixed or constrained at both ends so that the device support may be kept in tension so that the flexible tube is limited in the amount of displacement it can buckle. Buckling the elongated medical device limits the amount of force that can be applied and can permanently damage the elongated medical device. The compressive load can be caused by several factors, which may include friction between the EMD and device support, friction between the device support and a cassette (e.g. a splitter in the cassette (discussed below with respect to  FIGS. 27-29 )), etc. Maintaining the device support under tension may eliminate the need for extra column strength and allow for smaller, more flexible device supports. In one embodiment where the device support is a flexible tube, tension may be provided by fixing or constraining a front (or distal) and rear (or proximal) point or location of the flexible tube. The device supports  79   a - d  shown in  FIG. 3  are one embodiment of a device support with fixed front and rear points. In another embodiment, the device support may be an accordion or spring type support that provides appropriate tension. Each of these different embodiments of a device support are discussed further below. 
       FIG. 4  is a perspective view of device supports with fixed front (or distal) and rear (or proximal) points to provide appropriate tension in accordance with an embodiment.  FIG. 4  illustrates the device support embodiment shown in  FIG. 3 . In  FIG. 4 , a first device module  102  includes a first cassette  106  that has a first device support  128 , e.g., a flexible tube, positioned in a channel  124  of the cassette  106 . The first cassette  106  and the first device support  128  are moveable relative to one another. In  FIG. 4 , the first device support  128  extends out from the distal end of the first cassette  106  and a first end of the first device support  128  connects to a proximal end of a second device module  104  at a first front (or distal) fixed point  110 . The second device module  104  is located distal to the first device module  102 . The second device module  104  includes a second cassette  108  and a support arm  116  that extends from the second device module  104  in a proximal direction towards the first cassette  106 . A second end of the first device support  128  extends out from the proximal end of the first cassette  106  and connects to a first rear (or proximal) fixed point  112  on a proximal end of the support arm  116  of the second device module  104 . The first device support  128  is held in place by fixed (or constrained) first front  110  and rear  112  points. The first front and rear fixed points  110  and  112  are kept a constant distance from one another. The first front and rear fixed points  110  and  112  may be rigid or may have some elasticity to account for manufacturing and assembly tolerance. The first device module  102  also includes a support arm  114  that may be used to provide a rear (or proximal) fixed point for a device support for a cassette (not shown) located proximal to the first cassette  106 . 
     The second device module  104  is the most distal module and closest to the patient (not shown). The second cassette  108  of the second device module  104  includes a second device support  130 , e.g., a flexible tube, positioned in a channel  126  of the second cassette  108 . The second cassette  108  and the second device support  130  are moveable relative to one another. Since there is no device module or cassette in front of the second device module  104 , a distal support connection  132  mounted to a distal support arm  134  is used to provide a second front (or distal) fixed point  120  for the distal end of the second device support  130 . The distal support connection  132  and distal support arm  134  are described in further below with regard to  FIGS. 33-41 . A second end of the second device support  130  extends out from the proximal end of the second cassette  108  and connects to a second rear (or proximal) fixed point  122  on a proximal end of the support arm  118  connected to the distal support arm  134 . The second device support  130  is held in tension by fixed second front  120  and rear  122  points. The second front and rear points  120  and  122  are kept a constant distance from one another. The second front and rear fixed points  120  and  122  may be rigid or may have some elasticity to account for manufacturing and assembly tolerance. 
     In one embodiment, the distal end of the first device support  128  connected to the first front fixed point  110  and the distal end of the second device support  130  connected to the second front fixed point  120  may be detached or disconnected, as discussed further below, to facilitate loading and unloading of EMDs before, during and after a procedure.  FIG. 5  is a diagram showing a top view of a cassette with a device support in a withdrawn position to facilitate exchange of an elongated medical device in accordance with an embodiment. In  FIG. 5 , a device support  142  of a cassette  140  has been detached from a front (or distal) fixed point  150  and is in a retracted position which exposes an EMD  148  to facilitate loading and unloading of the EMD. As discussed above, the front fixed point  150  is located on a device module distal to the cassette  140 . The device support  142  is shown over the cassette  140  cover in  FIG. 5  for clarity. A first (or distal) end  144  of the device support  142  is located at the distal end of the cassette  140 . A second (or proximal) end  146  of the device support  142  has moved past a rear (or proximal) fixed point  152 . As discussed above, the rear fixed point  152  is located on a support arm of, for example, cassette, drive module or stage, distal to the cassette  140 . Additionally, the fixed rear point  152  may be attached to the frame of the robotic drive.  FIG. 6  is a diagram showing a top view of a cassette with a device support in an extended position constrained at two ends in accordance with an embodiment. When the device support  142  is pulled over the EMD  148 , the first end  144  is attached to the front fixed point  150  and the second end  146  is constrained by the rear fixed point  152 . As discussed above, the front fixed point  150  and the rear fixed point  152  are fixed relative to a device module the distal end of the EMD  148  is entering. The device support  142  is shown over the cassette  140  cover in  FIG. 6  for clarity. 
     Constraining (fixing) each device support on both ends allows for relative motion between all of the device modules in a robotic drive.  FIG. 7  is a top view of two device modules with device supports in accordance with an embodiment. A first device module  160  has a first device support  168  constrained at a first front (or distal) fixed point  172  at the proximal end of a second device module  162  and at a first rear (or proximal) fixed point  174  located on a proximal end of a support arm  171  of the second device module  162 . The second device module  162  has a second device support  170  that is constrained at a second front (or distal) fixed point (not shown) and a second rear (or proximal) fixed point  175  located in the proximal end of a support arm  173  of a device module (not shown) distal to the second device module  162 . The first device module  160  may be translated forward from a first position  164 . The second device module  162  is at a first position  176 .  FIG. 8  is a top view illustrating forward translation of a device module linearly relative to a device support in accordance with an embodiment. When the first device module  160  moves forward towards the patient (as indicated by arrow  177 ) from the first position  164  to a second position  166 , the first rear fixed point  174  takes the load developed as a cassette of the first device module  160  (and the device module) moves along the first device support  168  (e.g., friction between the cassette and the first device support  168 ). Accordingly, the first device support  168  will not buckle between the distal end of the cassette on the first device module  160  and the proximal end or rear of a cassette on the second device module  162 . As the first device module  160  advances distally toward the second device module  162  (which is stationary at its first position  176  in this example) it moves relative to the first device support  168  as illustrated by reference points A and B located along the length of the first device support  168 . When the first device module  160  is at the first position  164 , reference point A and reference point B are located proximate to the distal end of the first device module  160 . As the first device module  160  advances along the first device support  168 , the first device support  168  remains stationary because the second device module  162  to which it is coupled via the first front fixed point  172  and the first rear fixed point  174  is also stationary. When the first device module  160  is located at the second position  166 , reference point A and reference point B are located off axis and proximal to the first device module  160 . The first device module  160  may also be translated backwards from the second position  166  to the first position  164 . 
       FIG. 9  is a top view illustrating reverse translation of a device module linearly relative to a device support in accordance with an embodiment. When the first device module  160  moves backwards (retracts) away from the patient (as indicated by arrow  179 ) from the second position  166  to the first position  164 , the first front fixed point  172  takes the load developed as a cassette of the first device module  160  (and the device module) moves along the first device support  168  (e.g., friction between the cassette and the first device support  168 ). Accordingly, the first device support  168  will not buckle between the cassette on the first device module  160  and the first rear fixed point  174 . As the first device module  160  moves proximally away from the second device module  162  (which is stationary at its first position  176  in this example) it moves relative to the first device support  168  as illustrated by reference points A and B located along the length of the first device support  168 . When the first device module  160  is at the second position  166 , reference point A and reference point B are located off axis and proximal to the first device module  160 . As the first device module  160  moves proximally (retracts) along the first device support  168 , the first device support  168  remains stationary because the second device module  162  to which it is coupled via the first front fixed point  172  and the first rear fixed point  174  is also stationary. When the first device module  160  is at the first position  164 , reference point A and reference point B are the located proximate to the distal end of the first device module  160   
       FIG. 10  is a top view illustrating reverse translation of a device module linearly relative to a device support in accordance with an embodiment. When the second device module  162  moves backwards away from the patient (as indicated by arrow  169 ) from a first position  176  to a second position  178 , the second front fixed point (not shown) distal to the second device module  162  takes the load developed as a cassette of the second device module  162  (and the device module) moves along the second device support  170  (e.g., friction between the cassette and the second device support  170 ). Accordingly, the second device support  170  will not buckle between the cassette on the second device module  162  and the second rear fixed point  175 . Since the device supports  168  and  170  are each being supported between two known points, the length of each device support does not need to change. As the second device module  162  moves proximally towards the first device module  160  (which is stationary at its first position  164  in this example) the second device module  162  moves relative to the second device support  170 . In addition, the first device support  168  (coupled to the second device module  162  via first front  172  and rear  174  fixed points) moves relative to the first device module  160  as illustrated by reference points A and B located along the length of the first device support  168 . When the second device module  162  is at the first position  176 , reference point A and reference point B are located proximate to the distal end of the first device module  160  as shown in  FIG. 7 . As the second device module  162  moves proximally (retracts) along the second device support  170 , the second device support  170  remains stationary because it is coupled to a more distal device module (not shown) which is stationary in this example. However, the first device support  168  moves proximally with the second device module  162  to which it is coupled via the first front fixed point  172  and the first rear fixed point  174 . At the second position  178  of the second device module  162 , reference point A and reference point B are located off axis and proximal to the first device module  160 . 
       FIG. 11  shows a simplified top view of four device modules and four device supports for a robotic drive in accordance with an embodiment. A first device module  202  includes a first device support  204  with one end connected to a support arm  218  and one end connected to a distal support point. A second device module  206  includes a second device support  208  with one end connected to a support arm  220  and one end connected to the first device module  202 . A third device module  210  includes a third device support  212  with one end connected to a first front (or distal) fixed point  226  on the second device module  206  and another end connected to a first rear (or proximal) fixed point  228  on a support arm  222 . A fourth device module  214  includes a fourth device support  216  with one end connected to a second front (or distal) fixed point  230  on the third device module  210  and another end connected to a second rear (or proximal) fixed point  232  on a support arm  224 . In various embodiments, the support arms  218 ,  220 ,  222  and  224  may be connected to the device module or the cassette of a drive module. In another embodiment, the support arms  218 ,  220 ,  222  and  224  may be foldable, telescoping or use other methods to shorten the length of the support arm when not in operation.  FIG. 12  shows a simplified top view illustrating movement of a device module relative to a device support in accordance with an embodiment. The third device module  210  starts at a first position  234  (shown with dotted lines) and moves to a second position  236  (as indicated by arrow  246 ). As the third device module  210  moves forward (toward a patient), it moves along the third device support  212  that is fixed to second device module  206  at the first front fixed point  226  and is fixed to the support arm  222  extending from the second device module  206  at the first rear fixed point  228 . As the third device module translates, the portion of the device support  212  moving through the third device module  210  changes, while the first front  226  and first rear  228  fixed points do not move. The length of a first section  242  of the device support  212  spanning between the second device module  206  and the third device module  210  decreases while the length a second section  244  of the device support  212  spanning between the third device module  210  and the rear fixed point  228  increases. This allows the third device module  210  (and the associated EMDs) to remain fully supported between the span between the third device module  210  and the second device module  206  during linear motion. Another relative motion occurring during the movement of the third device module  210  between the first position  234  and the second position  236  involves the fourth device support  216  of the fourth device module  214  and the second front (or distal)  230  and second rear (or proximal)  232  fixed points for the fourth device support  216 . The fourth device support  214  is fixed to the third device module  210  at the second front fixed point  230  and is fixed to the support arm  224  extending from the third device module  210  at a second rear fixed point  232 . Because the third device module  210  is moving, the second front  230  and second rear  232  fixed points are moving as well. A first section  238  of the fourth device support  216  slides through the fourth device module  214 , increasing in length in the span between the forth device module  214  and the third device module  210  while a second section  240  of the fourth device support  216  decreases in length in the span between the fourth device module  214  and the rear fixed point  232 . 
       FIG. 13  shows a simplified top view illustrating the four device modules of  FIG. 11  in a forward position relative to their respective device support in accordance with an embodiment. In  FIG. 13 , the first device module  202 , the second device module  206 , the third device module  210  and the fourth device module  214  are each shown in the maximum forward position along their respective device support  204 ,  208 ,  212  and  216 .  FIG. 14  shows a simplified top view illustrating the four device modules of  FIG. 11  in a withdrawn position relative to their respective device support in accordance with an embodiment. In  FIG. 14 , the first device module  202 , the second device module  206 , the third device module  210  and the fourth device module  214  are shown in a maximum extended (rear) position along their respective device support  204 ,  208 ,  212  and  216 . In an embodiment, the device support length is determined by the straight length of the device support and the S-shaped spline that takes the device support off the longitudinal device axis of a device module and directs it towards the support arm longitudinal axis. In one embodiment, each device support  204 ,  208 ,  212  and  214  may include compliance to pretention the device support to help with slack when transitioning between forward and reversed directions. 
     As discussed above, each device support is constrained at a rear (or proximal) fixed point that is connected to a support arm extending from a device module in front (e.g., distal to) the device module associated with the device support. In an embodiment, the rear (or proximal) fixed point includes a rear constraint that may be configured to only react tensile forces.  FIG. 15  is a side view of a proximal end of a device support that is extended and a rear constraint for a rear (or proximal) fixed point to which the device support is connected in accordance with an embodiment and  FIG. 16  is a side view of a proximal end of a device support that is partially retracted and a rear (or proximal) constraint for a rear fixed point to which the device support is connected in accordance with an embodiment. A proximal end  252  of a support arm includes a retaining clip  254  which holds the proximal end of the device support  250 . A hard stop  256  is positioned on the end of the device support and is configured to hold the device support in tension when the device support moves forward and allowing the device support to be retracted for device loading (as described above with respect to  FIGS. 5 and 6 ). Forward motion and retraction of the device support  250  is indicated with arrow  258 . An operator may pull back on the device support  250  without removing it from the retaining clip  254 . The rear constraint formed from the retaining clip  254  and the hard stop  256  only reacts tensile forces. The device support will not buckle because the retaining clip  254  cannot react compressive forces. 
     In another embodiment, the tension on the device support provided by front (or distal) fixed point that connects the device support to a more distal device module and a rear (or proximal) fixed point is created by storing the proximal end of the device support on a reel or spool at each cassette. In this embodiment, support arms would not be required to provide the fixed point on the proximal end of the device support.  FIG. 17  shows a simplified top view of device modules with device supports stored on a reel in accordance with an embodiment and  FIG. 18  shows an exemplary spooled tensioner in accordance with an embodiment. In  FIG. 17 , each device module  260  includes a reel or spool  262  on which the device support may be wound. An exemplary spooled tensioner is shown in  FIG. 18  that includes a spool  262  on which the flexible tube of the device support  264  is wound. The proximal end of the device support is fixed to the spool  262 . The distal or “free” end of the device support may be pulled out by an operator or robotically actuated by the robotic drive and attached to a front fixed point on a distal cassette. A torque may be applied to the spool to apply tension to the device support  264 . The torque could be applied by a solely mechanical apparatus such as a constant torque spring or a rack and pinion. In another embodiment, the torque may be applied by, for example, a motor (not shown) which is controlled by the control computing system  34  (show in  FIG. 2 ).  FIG. 19  shows a simplified top view of device modules with driven device supports in accordance with an embodiment and  FIG. 20  shows an exemplary geared tensioner in accordance with an embodiment. In  FIG. 19 , each device module  270  includes a drive mechanism  274  which interacts with or engage a device support  272  to provide tension on the device support and allow the device support  272  to move forward and backwards. The drive mechanism may be, for example, a wheel or gear. In one embodiment, the drive mechanism  274  may engage the device support via friction on the walls of the flexible tube of the device support  272 . In another embodiment, the device support may have radial holes along a side which are then engaged by a pin-drive gear, also called a tractor feed. In another embodiment, the device support is a ribbed or convoluted tube and the drive mechanism is a toothed gear that engages and tensions the ribbed or convoluted tube. An exemplary geared tensioner  276  is shown in  FIG. 20  that engages a convoluted flexible tube  278 . 
     In another embodiment, the device support may be an accordion or spring.  FIG. 21  shows a simplified top view of device modules with device supports formed with accordions or springs in accordance with an embodiment. In  FIG. 21 , a device support between the device modules  280  is formed from an accordion element  286  and two linear guides  284  which are positioned in parallel to one another on opposite sides of the accordion element  286 . An EMD  282  is positioned through openings  292  (shown in  FIG. 23 ) in each segment  294  (shown in  FIG. 23 ) of the accordion element  286 . The accordion based device support is always in tension. In one embodiment, the accordion device support has compliance built in such that is capable of handling the relative translational motion between two device modules  280 . Even though the accordion member acts as a tensile spring and typically stays in tension, it may still deflect from the device axis when axial load is applied. The linear guides (or guiding rails)  284  shown in  FIG. 21  constrain the accordion so it is limited in deflection away from the device axis. In one embodiment, the linear guides  284  of a first device module mount to the proximal end of the more distal second device module and the other end of the linear guides  284  are free to slide through the accordion and the first device module. An embodiment where four accordions exist to support four device modules can have the accordion linear guides offset so that the linear guides for not interfere with one another when the device module are close.  FIG. 22  illustrates a compressed state  288  of the accordion element  286 . The linear guides are not shown in  FIG. 22  for clarity.  FIG. 23  illustrates a stretched state  280  of the accordion element  286 . The linear guides are not shown for clarity. The accordion element  286  includes multiple segments  294  that each include an opening  292  through which an EMD may be positioned. The number of segments  294  and the lengths of the segments  294  may be optimized so that the unsupported distance between discrete segments  294  is such that an EMD will not buckle at maximum loads experienced during a procedure. The accordion device support has multiple flexures which auto-balance to give equal spacing regardless of the overall tension so that no single gap across the length of a segment  294  becomes large enough for buckling. In other words, the gaps across each segment  294  length want to be the same across all segments  294 . This helps minimize the unsupported distance an EMD needs to travel, which allows the accordion element  286  to reach higher loads before buckling. 
     The profile of a device support formed from a flexible tube should support being opened and closed, for example, to allow EMDs to be loaded into the device support. When the slit at the distal end of the device support flexible tube is forced apart (e.g., using a splitter as discussed further below, the device support may be advanced to encapsulate the EMD and when, closed, the EMD is adequately supported and retained so as to not pop out and buckle.  FIGS. 24 ( a )-( c )  are perspective views of exemplary slit shapes for a device support flexible tube in accordance with an embodiment. In  FIG. 24( a ) , a device support flexible tube  300  is shown with a straight slit  302  lengthwise along the tube. In another example, a device support flexible tube  300  may have a serrated shaped slit  304  lengthwise along the tube as shown in  FIG. 24( b ) . In yet another example, a device support flexible tube  300  may have a wave shaped slit  306 , similar to a sine wave, lengthwise along the tube as shown in  FIG. 24( c ) . The slit of the device support  300  may be opened by a wedge or splitter (shown in  FIGS. 27-29  and discussed further below) that is positioned close to an entry point for an EMD to the device support. The wedge or splitter spreads the opening wide enough to clear the EMD. The elasticity of the flexible tube causes the slit to recover and close on the other side of the EMD, encapsulating and retaining the EMD. The serrated shape and shape similar to a sine may be used so that the material in the area of the slit overlaps so as to improve EMD retention in the device support. 
     The EMDs utilized in a robotic drive for an interventional procedure may vary in size, for example, the various EMDs that may be used may vary from 9FR to 2FR or even a 0.010″ guidewire. For example, in a multi-axial robotic drive configured for an endovascular therapy procedure treat acute ischemic stroke, it can be expected that the first EMD in the device stack-up is between 6 and 9 FR. The second and third EMDs in the device stack-up may be between 2.5 to 6 FR. The fourth EMD may be a wire-based EMD with a diameter between 0.010″ to 0.038″. In order to properly support and retain EMDs with different sizes, different device supports may be provided for each EMD where the device support for each EMD is designed to work with the corresponding size of EMD. For example, by minimizing the diametrical clearance between the EMD and the device support tube, any device buckling inside the tube will store less energy and have less linear motion hysteresis. In an embodiment, the device support of each cassette may be designed to be modular so that the correctly sized device support may be added to a cassette based on the EMD being supported by the cassette. In addition, a splitter and device support connector (both discussed further below with respect to  FIGS. 27-29 ) that are designed to work with a specific size of EMD may also be modular and switched based on the specific size of EMD being supported by a cassette. In another embodiment, different versions of a cassette may be provided for each subset of device sizes, where the cassette has an appropriately sized device support pre-installed. The appropriate cassette design for the specific size or range of sizes of an EMD may be mounted to a drive of the robotic drive and removed when a different design is needed for a different size of EMD or a different size range. For example, a cassette may be designed to support a range of sizes of the wire-based EMD which can vary between 0.010″ and 0.38″. 
     As discussed above with respect to  FIG. 3 , a device module  32  of a robotic drive  24  includes a drive module  68  and a cassette  66  mounted on and releasably coupled to the drive module  68 .  FIG. 25  is an exploded view of a device module and an elongated medical device in accordance with an embodiment. A drive module  310  includes a mounting surface  312  and a coupler  314 . A motor and a drive belt (not shown) may be housed in the drive module  310  and connected to the coupler  314 . The motor and belt are used to control a rotational position of the coupler  314 . Drive module  310  may include an encoder (not shown) for device position feedback. The drive module  310  shown in  FIG. 25  has one coupler  314 , however, it should be understood that the drive module  310  may have more than one coupler  314  and more than one motor. (for example, one motor for each coupler or one motor driving multiple couplers) The rotation of the coupler  314  may be used to provide another degree of freedom for an EMD positioned in a cassette  316  that may be mounted on the mounting surface  312  so as to interface with the coupler  314 . For example, the coupler  314  may be used to rotate an EMD  324  when the EMD is positioned in the cassette  316 . If the drive module  310  has two or more couplers  314 , each coupler may be used to provide a degree of freedom for an EMD. 
     As mentioned, a cassette  316  may be positioned on the mounting surface  312  of the drive module  310  and used to interface with an EMD  324  positioned in the cassette  316 . The cassette  316  includes a housing  318 . In an embodiment, the cassette housing  318  may be releasably attached to the drive module  310 . The drive module  310  may also include one or more additional elements  313  on the mounting surface  312  such as, for example, positioning pins, alignment pins, etc. to interact with elements on a cassette  316  (e.g., connection points, slots, channels, etc.) to enable a releasable attachment of the cassette  316  to the drive module  310 . In one embodiment, cassette housing  318  is releasably connected to the drive module  310  using a quick release mechanism  321 . In one embodiment, the quick release mechanism  321  includes a spring-biased member in cassette housing  318  that is actuated by a latch release  323  that releasably engages with a quick release locking pin  315  secured to the drive module  1010 . 
     The cassette housing  318  includes a cradle  320  configured to receive the EMD  324 . A bevel gear  322  is used to interface with the coupler  314  of the drive module  310  and to interface with the EMD  324  to rotate the EMD  324 . In one embodiment, EMD  324  is provided with an on-device adapter  326  (discussed further below with respect to  FIGS. 42-44 ) to interface the EMD  324  to the cassette  316 , for example, an interface to bevel gear  322 . In the example shown in  FIG. 25 , the EMD is a guidewire and the on-device adapter  326  is a collet with a gear  327 . When power is transferred from the device module  310  to the gear  322  in the cassette  316  (e.g., via the coupler  314 ), the gear  322  in the cassette interacts with the gear  327  on the collet to rotate the guidewire  324 . A device support  328  is positioned in the cassette in a channel  342  which may be covered by the housing  318 . As discussed above, the device support  328  and the cassette  316  are configured to move relative to one another. The device support  328  includes a connector  330  which is used to connect to a device module (e.g., to a cassette, to other elements of the device module, or to elements positioned in the device module) distal (or in front of) the cassette  316  in a robotic drive. Connector  330  includes a recess  332 . In a withdrawn or retracted position, the connector  330  is positioned in a recess  336  in the housing  318  on a distal end  334  of the cassette  316 . As discussed above, the connector  330  and device support  328  may be pulled outward from the cassette  316  so the connector may be attached to a more distal device module (e.g., a cassette of the device module) in the robotic drive. In one embodiment, a forward constraint  340  is provided on a proximal end  338  of the cassette  316  and is used to connect to a connector of a device support on another cassette proximal to (or behind) the cassette  316  in a robotic drive.  FIG. 26 a    is a perspective view of a cassette with a device support installed and in a retracted position in accordance with an embodiment. In the retraced position, the connector  330  is positioned in the recess  336  in the housing  318  at the distal end  334  of the cassette  316 .  FIG. 26 b    is a perspective view of a cassette with a device support installed and in a retracted position in accordance with an embodiment. The device support  328  is positioned in a channel  342  of the cassette. The cassette  316  incudes a proximal support member  331  positioned on the proximal end  338  of the cassette  316 . The proximal support member  331  includes an opening and is configured to provide support to the device support  328 . Device support  328  is positioned in and passes through the opening  333 . The opening  333  is sized so that the device support can move through the opening  333  as the device support  328  is advanced and retracted. 
       FIG. 27  is a top view of a device support and connector extended from a cassette ahead of an EMD entry point in accordance with an embodiment. A device support  328  and connector  330  are extended out from the recess in the distal end  334  of the cassette housing. A guide  344  and a splitter  348  are positioned in the recess  336  on opposite sides of the path of the device support  328  as it is moved into and out of the recess  336  and channel  342 . In the extended position, the device support encapsulates an EMD  324 . The EMD enters the device support  328  at an EMD entry point  346  which is located between a proximal section and a distal section of the splitter  348 . The proximal and distal sections of the splitter are shown with dotted lines. As mentioned above, the device support  328  includes a lengthwise slit so the device support may be forced apart (e.g., by using splitter as described below) and closed to allow the device support to encapsulate an EMD as the device support is advanced. The connector  330  holds open an end of the device support tube allowing it to pass over the splitter  348  as shown in  FIG. 29 . Referring to  FIGS. 27 and 29 , the splitter  348  holds the slit in the device support  328  open as the EMD  324  is encapsulated by the device support  328  as the connector  330  and device support  328  pass over the splitter  348  and EMD entry point  346 . The end of the device support tube  328  is positioned in a recess  332  of the connector  330 . Using the splitter  348  to hold open the device support  328  on both sides of EMD entry point  346  reduces or eliminates friction forces on the EMD  324 . For example, this prevents the walls of the device support  328  tube from rubbing the EMD  324  which can cause damage to the EMD  324  at the entry point  346  and would introduce noise to a load sensing system (not shown) which may be used to read the force or torque the EMD is subjected to. The EMD  324  passes through a cavity  352  in the center of the splitter  348 . The connector  330  and the splitter  348  are designed so that the device support  328  is held open as it passes over a gap between the proximal and distal section of the splitter  348 . Splitter  348  is also designed such that the unsupported length of the EMD  324  at any point is not such that it can catastrophically buckle. Guide  344  is configured to guide the device support  328  over the gap and retain the device support  328  on the splitter  348 . As mentioned above, the splitter  348  may be designed for specific EMD and device support size ranges.  FIG. 28  is a top view of a device support and connector withdrawn behind an EMD entry point in accordance with an embodiment and  FIG. 30  is a top view of cassette with a device support connector withdrawn and off of a device axis to facilitate loading of an EMD in accordance with an embodiment. To facilitate loading of an EMD  324  in a cassette  316  (shown in  FIG. 25 ), the device support  328  and connector  330  are retracted into the recess  336  before an EMD  324  is loaded. As shown in  FIGS. 28 and 30 , the connector  330  may be retracted onto the splitter  348  and guide  344  and behind (or proximal to) the EMD entry point  346 . In addition, the retracted (or withdrawn) position of the connector  330  is off of a longitudinal EMD axis  350 . This allows for EMD placement into cassette  316 , for example, loading a side loading EMD. Retracting the connector  330  behind the EMD entry point also reduces the unsupported EMD length and reduces working length loss. 
     As discussed above, the connector  330  and device support  328  may be pulled outward from the cassette  316  so the connector may be attached to a more distal device module (e.g., a cassette of the device module) in the robotic drive. In an embodiment, a forward constraint  340  (shown in  FIG. 25 ) may be provided on a proximal end  338  of a first cassette and is used to connect to a connecter of a device support on a second cassette proximal to (or behind) the first cassette in the robotic drive.  FIG. 31  is a perspective view of a forward constraint and a connector in accordance with an embodiment. Forward constraint  340  includes a latching mechanism  354 , for example, a spring latch. A connector  330  of a device support  328  from a proximal cassette (not shown) is attached to the spring latch  354 . In one embodiment, the connector  330  connects to the latching mechanism  354  by pushing the connector  330  into the foreword constraint  340 . In an embodiment, the latching mechanism  354  may require no secondary motion other than axial translation to engage the latching mechanism  354 , but may require one or more additional movements to disengage the latching mechanism  354  and remove the connector from the forward constraint  340 . For example, there may be buttons, levers or knobs which may need to be released before the connector  330  becomes disengaged. The connector  330  may be manually disengaged or disengaged using a control computing system  34  (shown in  FIG. 2 ). The connector  330  attaches to the forward constraint  340  approximately along the longitudinal EMD axis  350  of an EMD (not shown) contained in the device support  328 . This prevents shearing of the EMD by moving perpendicular to the latching mechanism  354 . In another embodiment, a secondary latch or tightening mechanism may be provide to further secure the connector  330  and reduce play.  FIG. 32  is a perspective view of a forward constraint with a lid in accordance with an embodiment. In  FIG. 32 , a lid  356  is connected to the forward constraint  340 , for example using a pivot. The lid  356  may be closed over the connector  330  and latched to further constrain the connector  330  in the forward constraint  340 . 
     As discussed above with respect to  FIG. 4 , a distal support connection mounted to a distal support arm may be used to provide a front (or distal) fixed point to support the distal end of the device support in the cassette of the most distal device module in the robotic drive, i.e., the device module closest to the patient.  FIG. 33  is a perspective view of a distal support arm and distal support connection in accordance with an embodiment. A cassette  362  is mounted to a drive module  364  which is connected to a stage  366  using an offset bracket  368 . The stage  366  is movably mounted to a rail or linear member  360  and may be moved linearly along the rail  360 . A distal support arm  370  may be attached to a frame of the robotic drive, for example, a frame of the rail  360 . In one embodiment, the distal support arm  370  may be rigidly attached to the frame. In another embodiment, the distal support arm  370  may be attached to a patient table or the patient. The distal support arm  370  extends away from the robotic drive and is connected to a device support connection  372  to provide a distal fixed point for the device support at an introduced sheath hub. In one embodiment, the distal support arm  370  may also be used to provide a distal define for the cassette  362  and drive module  364 . A distal define is used to define the most distal aspect of the most distal device (e.g., cassette  362  and drive module  364 ) of the robotic drive. In another embodiment, the distal define may be provided using a separate distal define arm (not shown) that may be coupled to, for example, the frame of the robotic drive. The distal support connection  372  may also be coupled to an introducer sheath hub. An introducer interface support  376  may be connected to the device support connection  372 . A connector  374 , for example, a connector on a distal end of a device support as described above with respect to  FIGS. 27-30  may be attached to the device support connection  372  to provide a front (or distal) fixed point and support for the distal end of the device support. A device support is not shown in  FIG. 33 , but would be positioned in by the cassette  362  as shown in  FIG. 34 .  FIG. 34  is a perspective view of a distal support connection coupled to a device support and connector in accordance with an embodiment. A device support  378  is shown as a dotted line encapsulating an EMD  379  and extending between the cassette  362  and the device support connection  372 . The connector  374  is attached to the device support connection  372 . The device support connection  372  may be, for example, a forward constraint such as described above with respect to  FIGS. 31 and 32 . The device support connection  1072  is mounted to a distal support arm  370  and may be connected to an introducer interface support  376 .  FIG. 35  is a side view of a distal support arm, distal support connection and an introducer interface support in accordance with an embodiment. The introducer interface support  376  is configured to support an EMD  379  (shown in  FIG. 34 ) between the device support  378  (shown in  FIG. 34 ) and an introducer sheath  375  connected to a distal end of the introducer interface support  376  as discussed further below. The introducer interface support  376  ensures that the EMD  379  does not buckle or prolapse between the distal end of the device support  378  and the hub of an introducer sheath  375 . In an embodiment, the introducer interface support  376  may also be used to redirect an EMD from a position that is axially aligned with the robotic drive device axis  365  to a position that is axially aligned with the introducer sheath  375  or other supporting member. 
     The introducer sheath  375  is inserted at an access point (e.g., the femoral artery) into a patient&#39;s vasculature that will lead the EMD to the target location in the patient (e.g., a lesion). The introducer sheath  375  should be held in place so that it does not come out of the patient. In one embodiment, the distal support arm  370  and the device support connection  372  may be used to fix the position of the introducer sheath  375  and may react forces on the introducer sheath  375  created from the friction between the introducer sheath  375  and the EMD moving inside of the introducer sheath  375 . In another embodiment the introducer sheath  375  may be supported by a separate structure than the distal support arm  370  and device support connection  372 , for example, the introducer sheath  375  may be attached to the patient or a patient table using known methods. 
       FIG. 36  is a perspective view of an introducer interface support connected to an introducer sheath in accordance with an embodiment. The introducer interface support  376  is connected at its proximal end  380  to a device support connection  372  that is connected to a distal support arm  370 . An introducer sheath  375  is connected to a distal end  382  of the introducer interface support  376 . The introducer interface support  376  may be configured to receive the introducer sheath  375  with a side port (not shown). The side port and its tubing (not shown) can allow for administration of medicine, contrast or saline injection or drawing blood samples. An EMD (not shown) enters the body of a patient through the introducer sheath  375  which is inserted into a vessel (typically an artery). In one embodiment, the introducer interface support  376  opens to allow the EMD to be placed in the introducer interface support  376 . In another embodiment, an EMD may be inserted axially into the introducer interface support  376 . In another embodiment, the EMD and introducer interface support  376  may be frictionally fit so that the introducer interface support  376  does not need to open or have the EMD inserted axially. As mentioned above, the introducer interface support  376  may be configured to redirect an EMD from a position that is axially aligned with the robotic drive device axis  365  (shown in  FIG. 35 ) to a position that is axially aligned with the introducer sheath  375  or other supporting member. The introducer interface support  376  also provides support to the EMD in the distance between the connector  372  and the introducer sheath  375 . The introducer interface support  376  may be rigid (as shown in  FIG. 36 ) or flexible. For example, the introducer interface support  376  may be made of flexible material or the introducer interface support  376  may have a joint near the device support connection  372  which allows for a limited range of motion of the distal end  382  (where the introducer sheath  375  is held) to account for perturbation of the robotic drive or movement of the patient. 
     In another embodiment, the distal support arm  370  may be movably connected to the robotic drive. A moveable distal support arm  370  may have one or more degrees of freedom to account for excess exposed EMD length that may not need to be actuated. For example, with shorter patients and/or less tortuously, more of the first guide catheter may be exposed because it will never need to enter the patient. If the distal support arm (and therefore the device support connection  372 ) can move forward, it can account for the excess length of the guide catheter that does not need to be actuated. This may also help reduce the overall length of the rail or linear member  361  (and rail  360  shown in  FIGS. 33 and 35 ).  FIG. 37  is a perspective view of a movable distal support arm in a first position in accordance with an embodiment. A distal support arm  370  may be moveable connected to a rail or linear member  361  using a stage  390 . In  FIG. 37 , the distal support arm  370  is in a first position  394  where the distal support connection  372  is located proximate to with the distal end of a device module  392 . The stage  390  may be manually or robotically moved along the rail  361  to change the position of the distal support arm  370 .  FIG. 38  is a perspective view of a moveable distal support arm in a second position in accordance with an embodiment. In  FIG. 38 , the stage  390  and the distal support arm  370  have been moved linearly to a second more distal position  396  from the device module  392 . Accordingly, the device support connection  372  and the device module  392  are separated by a distance  395 . In the embodiment shown in  FIGS. 37 and 38 , the distal support arm  370  has one degree of freedom. In another embodiment, the distal support arm  370  may be an articulating or driven arm with multiple degrees of freedom. 
     As discussed above, each end of the device support may be connected to fixed point (front (or distal) and rear (or proximal)) to provide appropriate tension to the device support between device modules or between most distal device module and a device support connection to prevent an EMD from buckling. The device support connection  372  described above provides a front (or distal) fixed point for the device support of the most distal cassette in the robotic drive. The device support of the most distal cassette may be provided with a rear (or proximal) fixed point using a support arm (e.g., support arm  118  shown in  FIG. 4 ) that is connected to the distal support arm  370 . For a moveable distal support arm, the support arm will also be moveable.  FIG. 39  is a top view of a moveable distal support arm and movable support arm in a first position in accordance with an embodiment. In  FIG. 39 , a distal support arm  410  is in a first position  414 . A device module  406  is connected to a rail or linear member  400  using a first stage  402 . A device support  408  is positioned in the device module  406  (e.g., in a cassette of the device module) and a distal end of the device support  408  is connected to a device connection point  411  (front (or distal) fixed point) connected to the distal support arm  410 . A proximal end of the device support  408  is connected to a proximal end of a support arm  412  at a rear (or proximal) fixed point  409 . A second stage  403  is connected to the rail  400  (or a different rail (not shown) in the system) and may be manually or robotically moved along the rail  400  to change the position of the distal support arm  410  and the support arm  412 .  FIG. 40  is a top view of a moveable distal support arm and movable support arm in a second position in accordance with an embodiment. In  FIG. 40 , the second stage  403 , the distal support arm  410  and the support arm  412  have been moved linearly to a second more distal position  416  from the device module  406 . The support arm  412  moves with the device support connection  411  so there is always the same length of the device support  408  between the device support connection  411  and the rear fixed point  409 .  FIG. 41  is a top view illustrating movement of a distal support arm and a support arm from the second position to the first position in accordance with an embodiment. In  FIG. 41 , the device support connection  411 , the support arm  412 , the distal support arm  410  and the second stage  403  start at the second position  416  (indicated by dotted lines). The second stage  403  may be actuated to move linearly along the rail  400  to the first position  414  as indicated by arrow  418 . The first position of the device support connection, the support arm, the distal support arm, rear fixed point, and the second stage are indicated by the reference numbers  411 ′,  412 ′,  410 ′,  409 ′, and  403 ′, respectively. 
       FIG. 42  is a perspective view of a catheter with an on-device adapter in accordance with an embodiment and  FIG. 43  is a perspective view of a guidewire with an on-device adapter in accordance with an embodiment. As used herein, an on-device adapter is a sterile apparatus capable of releasably clamping to an EMD to provide a driving interface. In  FIG. 42 , a catheter  420  includes a hemostasis valve or hub (e.g., a rotating hemostasis valve)  424  on the proximal end  426  of the catheter  420 . An on-device adapter  422  is positioned on the catheter  420  distal to the hemostasis value  424  on the proximal end  426  of the catheter. In the embodiment of  FIG. 42 , the external surface of the on-device adapter is formed as a gear. The gear feature of the on-device adapter  422  is configured to interact with a gear  322  (shown in  FIG. 26 a   ) of a cassette, for example, cassette  316  shown in  FIG. 26 a   . When power is transferred from a device module (not shown) to the gear in the cassette (e.g., via a coupler), the gear in the cassette interacts with the gear  422  on the catheter  420  to rotate the catheter. In another embodiment, rotation of the on-device adapter  422  may be configured to pinch/unpinch the catheter  420 . In an embodiment, an internal surface of the on-device adapter  422  is firmly attached to a standard luer section of the elongated medical device (e.g., catheter  420 ). In another embodiment, the internal surface of the on-device adapter is clamped to a lateral surface it the proximal end of the elongated medical device. In another embodiment, the on-device adapter is attached to a cylindrical section (shaft) of the EMD. In yet another embodiment, the on-device adapter is not directly attached to the EMD, by is attached to the EMD via an interface. The power can transfer from the cassette to the on-device adapter in different ways such as, for example, gears (as mentioned above), or friction surface (e.g., tire and roller), belt, pneumatic, or magnetic/electromagnetic coupling. 
     In  FIG. 43 , a guidewire  430  is shown with an on-device adapter  432 . In the embodiment of  FIG. 43 , the on-device adapter  432  is a collet with a gear  434  on the proximal end  436  of the collet. The collet  432  is configured to grip the guidewire  430 . The term collet as used herein is a device to releasably fix a portion of an EMD thereto. In one embodiment the collet includes at least two members that move relative to each other to releasably fix the EMD to at least one of the two members. Fixed means no intentional relative movement of the collet and EMD during operation parameters. The gear  434  is configured to interact with a gear  322  (shown in  FIG. 26 a   ) of a cassette, for example, cassette  316  shown in  FIG. 26 a   . When power is transferred from a device module (not shown) to the gear in the cassette (e.g., via a coupler), the gear in the cassette interacts with the gear  434  on the guidewire  430  to rotate the guidewire  430 . In another embodiment, rotation of the on-device adapter  432  via gear  436  may be configured to pinch/unpinch the guidewire  430 . The elongated medical device and on-device adapter may be positioned in the cassette as shown in  FIG. 44 . In  FIG. 44 , a guide wire  430  and collet  432  are positioned in a cradle  442  of the cassette  440 . The elongated medical device and the on-device adapter may be removed from one cassette and moved to another unpopulated cassette.  FIG. 45  shows a guide wire  430  and collet  432  with a gear  434  removed from the cassette  440 . When the cassettes are similar and an on-device adapter is used to interface an elongated medical device to the cassette, the device and on-device adapter may be moved between unpopulated cassettes enabling the number of devices and configuration of the robotic drive to be changed. 
       FIG. 46  is a top view of a cassette in accordance with an embodiment. The cassette  450  has a distal end  452  and a proximal end  454  and is typically used to interface with an EMD such as a guidewire or a catheter. The area between the distal end  452  and the proximal end  454  includes a cradle  456 , a midsection  458  and an off-axis recess  460  that is positioned angled away from the cassette longitudinal device axis  461 . The midsection  458  and off-axis recess  460  may be configured to receive an EMD adapter to interface the cassette with EMDs with atypical proximal ends, for example, a balloon guide catheter (which includes an integrated y-connector) or a rapid exchange device such as a rapid exchange balloon.  FIG. 47  is an exploded view of an elongated medical device (EMD) adapter and a lid in accordance with an embodiment. The EMD adapter  462  shown in  FIG. 47  is a rapid exchange EMD adapter. The EMD adapter includes a lid  464 , a first section  466  and a second section  468 . The first section is configured to receive a guidewire. The second section is configured to receive an EMD, e.g. a rapid exchange EMD  470 . In one example, the EMD  470  is a rapid exchange balloon. The second section  468  is positioned at an angle from the longitudinal axis of the first section  466 . The second section also includes a clip  472  that is used to retain a proximal end of the EMD  470 .  FIG. 48  is a perspective view of an EMD adapter and EMD installed in a cassette in accordance with an embodiment. The first section  466  of the EMD adapter  462  is positioned in the cradle  456  and midsection  458  of the cassette  450 . The second section  468  of the END adapter  462  is positioned in the off-axis recess  460 . A rapid exchange EMD  470  (e.g., a rapid exchange balloon) is positioned in the second section of the EMD adapter  462  and the proximal end of the EMD  470  is clipped into place using clip  472 . The first section  466  of the EMD adapter  462  may be used to receive a guidewire (not shown) from a proximal device module (not shown). The guidewire may pass through the cassette  450  and be driven by the more proximal device module. The EMD adapter  462  provides buckling support for the guidewire. In another embodiment, an EMD adapter may be configured to interface with a balloon guide catheter. For a balloon guide catheter, an EMD adapter may be configured to constrain the proximal end of the balloon guide catheter for linear motion, but not to allow the balloon guide catheter to be rotated. 
     It may be desirable to measure the load applied to an EMD as it is hub driven using a device module in a robotic drive by using a load sensing system. To accurately sense the linear force on an EMD hub, the components in the device module (e.g., the EMD and EMD hub) to be sensed should be isolated from external forces. A device support, as it is tensioned, redirected through the cassette and split, imparts forces on the cassette. The connection of a connector of a device support and a forward constraint of another cassette also imparts forces. In an embodiment, the cassette of a device module may be configured separate the portion of the cassette that supports an EMD from the rest of the cassette to isolate linear forces on the EMD hub.  FIG. 49  is a top view of s cassette with a floating (or isolated) interface and a rigid support section in accordance with an embodiment. Cassette  500  includes a floating (or isolated) interface (or component)  506  located in the cassette so as to provide support for an EMD  502  positioned in the floating interface  506 . The remainder of the cassette  500  (e.g., the housing) forms a rigid support  508 . The EMD  502  includes a rotational drive element  504  (e.g., an on-device adapter such as a gear) configured to interface with the drive mechanisms e.g., a bevel gear (not shown) in the floating interface  506 . The rotational drive element  504  is supported in a rotational drive element cradle  510  of the floating interface  506 . The floating interface  506  is floating with respect to the rigid support  508  portion of the cassette  500 . For example, the floating (or isolated) interface  506  is moveable within and/or relative to the rigid support  508 . In an embodiment, the floating interface  506  is isolated from the rigid support such that the floating interface  506  is not fixed to the rigid support  508 . As discussed further below, the floating interface  506  is configured to be isolated from loads other that the actual load acting on the EMD  502 . The rigid support  508  reacts forces such as, for example, forces from a device support connected to the cassette. To reduce measurement noise for rotational forces, a cradle  510  supporting the rotational drive element  504  (e.g., a gear) of an EMD  502  may be formed from low friction static material. In another embodiment, the cradle  510  may include rollers  534  as shown in  FIG. 52 . For example, the rollers  534  may be sliding or rolling bearings. 
       FIG. 50 a    is an end cross-sectional view of a floating (or isolated) interface and rigid support section of a cassette in accordance with an embodiment. The floating (or isolated) interface  506  is positioned within a recess or opening  536  (shown in  FIG. 50 b   ) in the cassette  500  housing and is separated from the rigid support  508  by a first slot  514  and a second slot  515  and confined to a limited range of motion. In an embodiment, the floating interface  506  includes a first component  506   a  and a second component  506   b  as discussed further below with respect to  FIG. 50 b   . The floating interface  506  is loosely contained within the recess  536  (shown in  FIG. 50 b   ). The range of motion of the floating interface  506  allows the floating interface  506  to be mounted to a drive module (e.g., drive module  310  shown in  FIG. 25 )), in particular, a load sensing portion of a drive module while giving allowances for tolerances between interfacing components. The first slot  514  and the second slot are configured to allow limited movement of the floating interface  506  in the X and Y directions. The floating interface  506  is also floating (or isolated) but captive in the first slot  514  and the second slot  515  in the z-direction due to a first tab  522  on a first side  518  of the rigid support  508  proximate the first slot and a second tab  523  on a second side  520  of the rigid support  508  proximate the second slot  515 . The floating interface  506  includes a first recess  524  on a first side  526  of the floating interface  506  and a second recess  525  on a second side  528  of the floating interface  506 . The tabs  522  are loosely positioned in the recesses  524  of the floating interface  506 . First tab  522  is loosely positioned on the first recess  524  of floating interface  506  and the second tab  523  is loosely positioned in the second recess  525  of the floating component  506 . In one embodiment, the floating interface  506  and the rigid support  508  exist as a single unit, rather than two completely independent pieces which can aid in the usability and setup of a robotic drive. A contactless, frictionless interface between the floating interface  506  and the rigid support  508  is enabled by having the floating interface  506  floating in the z-direction. A contactless interface is achieved when the floating interface  506  is mounted to a drive module (e.g. drive module  310  shown in  FIG. 25 ). For example, the positioning pins  313  (shown in  FIG. 25 ) on the drive module  310  lift the floating interface  506  to a height relative to the rigid support  508  where a contactless interface is achieved as shown in  FIG. 50 . In one embodiment, the height is 1 mm. In other embodiments, the height is less than 1 mm and in other embodiments the height is greater than 1 mm. 
     A bottom surface  516  of the floating (or isolated) interface  506  is configured to couple to a drive module.  FIG. 51  is a bottom view of the floating interface of a cassette in accordance with an embodiment. The bottom surface  516  of the floating (or isolated) interface  506  includes a connector  530  to receive a coupler (e.g., coupler  314  shown in  FIG. 25 ) of a drive module and connection points  532  configured to receive various types of connection members of the drive module. For example, positioning pins  313  (shown in  FIG. 25 ) may fit into a series of holes and slots in the bottom surface  516  of the floating interface  506 . Positioning pins  313  may be used to constrain the floating interface  506  and the drive module in the X and Y directions. In an embodiment, the floating interface  506  may also be constrained in the Z direction by using magnets positioned in one or more connection point  532 . In another embodiment, floating interface  506  is constrained in the z direction by friction with the connection points  532 . In one embodiment, slots are used to interact with the positioning pins  313  of the drive module to constrain floating interface  506 . 
     As mentioned, the floating (or isolated) interface  506  includes a first component  506   a  and a second component  506   b .  FIG. 50 b    is an exploded isometric view of a cassette showing a first component and a second component of a floating (or isolated) interface in accordance with an embodiment. The first component  506   a  is placed within a recess  536  of the rigid support portion (or cassette housing)  508  of the cassette in a direction toward a drive module  310  (shown in  FIG. 25 ) when the cassette is in the in-use position secured to the drive module  310 . The second component  506   b  is placed within the recess  536  from a direction away from the drive module  310  toward the first component  560   a . The floating (or isolated) interface  506  is positioned within and separate from the rigid support  508  in at least one direction when the floating interface  506  is connected to the drive module. The rigid support (or cassette housing)  508  include two longitudinally oriented rails  507  located within the recess  536 . In an embodiment, the rails  507  act as the tabs  522  and  523  (discussed above with respect to  FIG. 50 a   ). The first component  506   a  is located on the top surface of the rails  507  closer to the top surface with the rigid support  508  and the second component  506   b  is located proximate to the bottom surface e of the rails  507  closest to the drive module (e.g., drive module  310  shown in  FIG. 25 ). Note that although the direction of assembly of the first component  506   a  and the second component  506   b  of the floating interface  506  is described in relation to the in-use position, the first and second components  506   a ,  506   b  of the floating component  506  are installed away from the drive module. Stated another way, the first component  506   a  of the floating interface  506  is inserted into the recess  536  in a direction from a top surface of the cassette to the bottom surface of the cassette in a direction generally perpendicular to a longitudinal axis of the cassette housing. 
     The first component  506   a  and the second component  506   b  of the floating interface  506  are secured to one another. In one embodiment, a mechanical fastener or a plurality of fasteners may be used to secure the first component  506  to the second component  506   b  of the floating interface  506 . In other embodiment, the first component  506   a  and the second component  506   b  may be secured together using for example, magnets or adhesive. The first component  506   a  and the second component  506   b  may be releasably secured to one another or non-releasably secured to one another. 
     In an in-use position where the second component  506   b  of the floating interface  506  is releasably secured to a drive module (e.g., drive module  310  shown in  FIG. 25 ), the first component  506   a  and the second component  506   b  are spaced from the rails  507  of the rigid support  508  such that the first component  506   a  and the second component  506   b  are in a non-contact relationship with the rigid support  508 . In one embodiment, the cassette includes a cassette cover  505  pivotally coupled by a hinge  503  to the floating interface  506  separate from and in non-contact with the rigid support  508 . For example, the cover  505  may be pivotally coupled by hinge  503  to the first component  506   a . In another embodiment, the cover  505  may be connected to the first component  506   a  by other connection mechanism, such as snap fits. 
     Often, an EMD (e.g., a catheter) in a cassette may be connected via a side port of a hemostasis valve connected to the EMD to various tubing to, for example, supply a saline drip, to allow for contrast injection, to allow for aspiration, etc. In a robotic drive that manipulates EMDs linearly it would be advantageous to account for tubing connections, in particular, to provide a support assembly so that the tubing does not snag or pull on the hemostasis valve.  FIG. 53  illustrates a cassette with a support assembly for anchoring tubing and fluid connections in accordance with an embodiment. The support assembly for tubing and fluid connection includes a flexible section of tube  544  attached at one end to a side port  542  of a hemostasis value positioned in a cassette  540 . A second end of the flexible section of tube  544  is attached to a clip  548  which is mounted to a support  546 . The support  546  is connected to the cassette  540 . The second end of the tube  544  and the clip  548  may be configured to provide a connector (e.g., a female port) to be attached to a tube or other fluid connection. The support assembly creates strain relief so that if the tubing  544  were tugged, the force would be reacted by the connection to the support  546  and not the hemostasis valve  542 . In another embodiment, the strain relief tube  544  may also terminate in a multi-port stopcock manifold, which would allow for multiple tubing connections to remain in place during a procedure. 
     As mentioned above, the profile of a device support formed from a flexible tube with a longitudinal slit should support being opened and closed, for example, to allow EMDs to be loaded into the device support and retained in the device support so as to not pop out and buckle.  FIG. 54  is an end cross-sectional view of a device support in accordance with an embodiment. In  FIG. 54 , a device support  550  includes a first (or inner) flexible tube  552  and a second (or outer) flexible tube  556 . The inner tube  552  includes a lengthwise slit  554 , an outer diameter  558  and an inner diameter  560 . In an embodiment, inner tube  552  is a thin-walled tube to allow the lengthwise slit  554  to be more easily spread apart and closed. The outer tube  556  includes an outer diameter  562  and an inner diameter  564 . In addition, the outer tube  556  includes a lengthwise opening defined by a first side  566  and a second side  568 . The outer tube  556  is disposed around the outer diameter  558  of the inner tube  552 . The outer tube  556  may be formed using a material that provides sufficient force to hold the slit  554  of the inner tube  552  in a “closed” position, for example, so the sides of the slit  554  are in contact and an EMD  570  positioned in the inner tube  552  is retained in the inner tube  552 . The material used to form the outer tube  556  should also be configured to allow the slit of the inner tube to be forced apart when a force from, for example, a splitter is applied. In an embodiment, the inner diameter  564  of the outer tube  556  is smaller than the outer diameter  558  of the inner tube  552 . 
     As discussed above, a splitter or wedge may be used to spread apart the lengthwise slit of a device support to allow the device support to encapsulate an EMD.  FIG. 55  is an end cross-sectional view of a device support and splitter in accordance with an embodiment. In  FIG. 55 , a device support  580  includes a first (or inner) flexible tube  572  and a second (or outer) flexible tube  574 . The inner tube  572  includes a lengthwise slit  582 , a first arm element  576  and a second arm element  578 . In an embodiment, inner tube  572  is a thin-walled tube to allow the lengthwise slit  582  to be more easily spread apart and closed. The outer tube  574  includes a lengthwise opening defined by a first side  588  and a second side  590 . The outer tube  574  is disposed around an outer diameter of the inner tube  572 . The first arm  576  and the second arm  578  of the inner tube  572  are disposed within the opening of the outer tube  574 . In the embodiment shown in  FIG. 55 , the first arm  576  is in contact with the first side of the opening and the second arm  578  is in contact with the second side  590  of the opening. The first  576  and second arm  578  provide a surface that may run over a splitter, for example, splitter  584 , as the device support is advanced over the splitter  584  to force apart the slit  582  of the inner tube  572  to encapsulate an EMD  586 . The first  576  and second  578  arms prevent the splitter  584  from making contact (e.g., rubbing) with the EMD  586  as the device support  580  is advanced over the splitter  584 . Accordingly, the first  576  and second  578  arms may reduce or eliminate friction forces on the EMD  586  which can cause damage to the EMD  586 . 
     Computer-executable instructions for supporting and driving elongated medical devices in a robotic catheter-based procedure system in according to the above-described methods may be stored on a form of computer readable media. Computer readable media includes volatile and nonvolatile, removable, and non-removable media implemented in any method or technology for storage of information such as computer readable instructions, data structures, program modules or other data. Computer readable media includes, but is not limited to, random access memory (RAM), read-only memory (ROM), electrically erasable programmable ROM (EEPROM), flash memory or other memory technology, compact disk ROM (CD-ROM), digital versatile disks (DVD) or other optical storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other medium which can be used to store the desired instructions and which may be accessed by system  10  (shown in  FIG. 1 ), including by internet or other computer network form of access. 
     A control computing system as described herein may include a processor having a processing circuit. The processor may include a central purpose processor, application specific processors (ASICs), circuits containing one or more processing components, groups of distributed processing components, groups of distributed computers configured for processing, etc. configured to provide the functionality of module or subsystem components discussed herein. Memory units (e.g., memory device, storage device, etc.) are devices for storing data and/or computer code for completing and/or facilitating the various processes described in the present disclosure. Memory units may include volatile memory and/or non-volatile memory. Memory units may include database components, object code components, script components, and/or any other type of information structure for supporting the various activities described in the present disclosure. According to an exemplary embodiment, any distributed and/or local memory device of the past, present, or future may be utilized with the systems and methods of this disclosure. According to an exemplary embodiment, memory units are communicably connected to one or more associated processing circuit. This connection may be via a circuit or any other wired, wireless, or network connection and includes computer code for executing one or more processes described herein. A single memory unit may include a variety of individual memory devices, chips, disks, and/or other storage structures or systems. Module or subsystem components may be computer code (e.g., object code, program code, compiled code, script code, executable code, or any combination thereof) for conducting each module&#39;s respective functions. 
     This written description used examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to make and use the invention. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal language of the claims. The order and sequence of any process or method steps may be varied or re-sequenced according to alternative embodiments. 
     Many other changes and modifications may be made to the present invention without departing from the spirit thereof. The scope of these and other changes will become apparent from the appended claims.