in the following detailed description , reference is made to the accompanying drawings which form a part hereof , and in which is shown by way of illustration specific embodiments in which the invention may be practiced . these embodiments are described in sufficient detail to enable those skilled in the art to practice the invention , and it is to be understood that other embodiments may be utilized and that structural changes may be made without departing from the scope of the present invention . therefore , the following detailed description is not to be taken in a limiting sense , and the scope of the present invention is defined by the appended claims and their equivalents . a catheter having an adjustable shape is provided . the adjustable catheter is used for cannulating complex locations within a body , for instance , within the coronary sinus ostium for the purpose of acute deployment of drugs or acute and chronic deployment of medical instrumentation or devices such as a pacing lead . fig1 illustrates a catheter assembly 100 constructed in accordance with one embodiment . the catheter assembly generally includes an outer catheter member 110 and an inner catheter member 120 which is movably received by the outer catheter member 110 . the outer catheter member 110 extends from a first distal end 112 to a first proximal end 114 , and has a first lumen 116 therein , as shown in fig2 and 3 . the first lumen 116 extends from the first distal end 112 to the first proximal end 114 of the outer catheter member 110 . the first distal end 112 of the outer catheter member 110 is flexible . optionally , the entire outer catheter member 110 is more flexible than the inner catheter member 120 . in one embodiment , the first distal end 112 of the outer catheter member 110 has a preformed curve 118 therein . the first lumen 116 of the outer catheter member 110 receives therein the inner catheter member 120 . the inner catheter member 120 extends from a second distal end 122 to a first proximal end 124 , and optionally has a second lumen 126 therein , as shown in fig2 and 3 . the second lumen 126 extends from the second distal end 122 to the second proximal end 124 of the inner catheter member 120 . in another option , the inner catheter member 120 does not have a lumen , such as an electrode catheter . the user optionally can open the hemostasis mechanism , discussed further below , and extend the electrode catheter out of the outer catheter member to use the electrodes thereon to sense and / or pace tissue . in one option , the inner catheter member 120 has a preformed curve 128 therein . the preformed curve 128 of the inner catheter member 120 is provided in addition to the preformed curve 118 of the outer catheter member 110 . alternatively , the preformed curve 128 of the inner catheter member 120 is provided in alternative to the preformed curve 118 of the outer catheter member 110 . fig4 - 6 illustrate other options for the catheter assembly 100 . in one option , the catheter assembly 100 includes a braid 130 of material , where the braid 130 is disposed between the outer catheter member 110 and the inner catheter member 120 , as shown in fig4 . optionally , the braid 130 of material is secured to the inner catheter member 120 or the outer catheter member 110 , for example by providing the braid 130 of material within the wall construction of the inner and / or outer catheter member . it should be noted that providing the braid 130 of material within the wall construction also includes , but is not limited to , forming the braid in the center of the wall , the outer portion of the wall , or the inner portion of the wall of the inner or outer catheter member . in yet another option , the inner catheter member 120 is releasably attached to the inner handle , using a luer style hub . the braid 130 of material includes a braid 130 of stainless steel material , although sleeves of other types of materials would be suitable as well , such as flat or round wire , rigid polymeric material such as ptfe , polyurethane , or polyesters . in one embodiment , the braid 130 of material has a length which is less than that of the outer catheter member 110 , as shown in fig5 . fig6 illustrates another embodiment of the catheter assembly 100 , where the first distal end 112 of the outer catheter member 110 includes two or more segments 108 of material . the two or more segments include , but are not limited to , a first segment 104 and a second segment 106 . in one option , the first segment 104 is comprised of a different material than the second segment 106 . in another option , the first segment 104 is comprised of a material having a different durometer than the material of the second segment 106 . fig7 illustrates another embodiment of a catheter assembly 200 . the catheter assembly 200 includes the outer catheter member 110 and the inner catheter member 120 , and the variations thereto , as discussed above in reference to fig1 - 6 . in addition , the catheter assembly 200 includes a handle assembly 250 which is adapted to move the inner catheter member 120 relative to the outer catheter member 110 . the handle assembly 250 includes an outer handle member 260 and an inner handle member 280 . the inner handle member 280 is slidably received by the outer handle member 260 . the outer handle member 260 , as shown in more detail in fig8 and 9 , has a first passage 262 for receiving the inner handle member 280 therein . the first passage 262 extends from a distal end 266 to a proximal end 264 of the outer handle member 260 , and allows for fluids and / or instrumentation to be disposed therethrough . the outer handle member 260 further includes a cut out 268 therein , which optionally , extends only partially from the distal end 266 to the proximal end 264 . the cut out 268 , as shown in cross - section in fig9 , is adapted to receive therethrough a portion of the inner handle member 280 , as discussed further below . referring again to fig7 , the outer handle member 260 is coupled with the outer catheter member 110 , and is optionally coupled with a luer style hub 261 . the inner handle member 280 is shown in more detail in fig1 . the inner handle member 280 includes an inner passage 282 therein . the inner passage 282 extends from a distal end 286 to a proximal end 284 of the inner handle member 280 , and allows for fluids and / or instrumentation to be disposed therethrough . the inner handle member 280 further includes a projection 288 . the projection 288 is optionally integral with the inner handle member 280 . alternatively , the projection 288 is a separate component which is coupled with the inner handle member 280 . the inner handle member 280 is coupled with the inner catheter member 120 , in one embodiment , with an adjustable grommet and hub mechanism , for instance , a hemostasis - like mechanism 290 . the hemostasis - like mechanism 290 allows for different inner catheter members to be interchanged within the catheter assembly 200 . for instance , inner catheter members having differing amounts of stiffness and / or varying shapes can be used to achieve further complex movements through the vasculature . as a user advances the projection 288 which is slidingly received in the cut out 268 , for example , by using a thumb , the inner catheter member 120 is moved within the outer catheter member 110 , thereby altering the distal end 112 of the outer catheter member 110 . as the distal end 112 of the outer catheter member 110 is modified , a change results in the curve of the distal end 112 to modify the geometry and the position of the catheter assembly 200 . fig1 - 13 illustrate another embodiment of the catheter assembly 100 ′. similar to the previously discussed embodiment , the handle assembly 250 includes an outer handle member 260 and an inner handle member 280 . the inner handle member 280 is slidably received by the outer handle member 260 . the outer handle member 260 , as shown in more detail in fig1 and 13 has a first passage 262 for receiving the inner handle member 280 therein . the first passage 262 extends from a distal end 266 to a proximal end 264 of the outer handle member 260 , and allows for fluids and / or instrumentation to be disposed therethrough . the outer handle member 260 further includes a sprocket 294 movably coupled with the outer handle member 260 . for instance , in one option , the sprocket 294 is rotatably coupled with the outer handle member 260 . the sprocket 294 includes a lever 292 which allows for the sprocket to be rotated along 296 . it should be noted that the lever 292 is usable to implement other motions of movement , such as linear movement . the sprocket 294 further includes sprocket teeth 278 , which are configured to engage with a portion of the inner handle member 280 , as further discussed below . the inner handle member 280 is shown in more detail in fig1 . the inner handle member 280 includes an inner passage 282 therein . the inner passage 282 extends from a distal end 286 to a proximal end 284 of the inner handle member 280 , and allows for fluids and / or instrumentation to be disposed therethrough . the inner handle member 280 further includes inner member teeth 270 projecting from a surface of the inner handle member 280 . the inner member teeth 270 are configured to engage the sprocket teeth 278 . as a user manipulates the sprocket 294 , for example by using the lever 292 , the inner handle member 280 is moved relative to the outer handle member 260 . as the sprocket teeth 278 engage the inner member teeth 270 , the inner catheter member 120 ( fig7 ) is moved within the outer catheter member 110 ( fig7 ), thereby altering the distal end 112 ( fig1 ) of the outer catheter member 110 ( fig7 ). as the distal end 112 ( fig1 ) of the outer catheter member 110 ( fig7 ) is modified , a change results in the curve of the distal end 112 ( fig1 ) to modify the geometry and the position of the catheter assembly 200 ( fig7 ). the sprocket 294 and the lever 292 facilitates single - handed manipulation of the instrument , freeing the physicians other hand for other types of catheter manipulation or for manipulation of other medical instruments . during use of the catheter assembly , a method includes disposing an inner catheter member within an outer catheter member , to form one of the several catheter assemblies discussed above , where the outer catheter member extends from a first distal end to a first proximal end , and the first distal end is flexible . as mentioned above , the outer catheter member has a first lumen , and the inner catheter member has a second lumen . the inner catheter member is disposed within the first lumen of the outer catheter member . the method further includes inserting the outer catheter member and the inner catheter member within a body , for instance , of a human patient . the inner catheter member is moved relative to the outer catheter member , for instance , by sliding the inner catheter member within the outer catheter member . optionally , as discussed above , a handle assembly is used to slide the inner catheter member relative to the outer catheter member . the first distal end of the outer catheter member , in one option , is flexed in a two dimensional motion as shown in fig1 along “ a .” in another option , as shown in fig1 , the first distal end of the outer catheter member is flexed in a three dimensional motion , for example , by rotating the shaped inner catheter member . flexing of the outer catheter member allows positioning of the catheter assembly within complex locations of a patient . once the catheter assembly is positioned within the body , or at least partially positioned within the body , fluid and / or a medical device is disposed through the second lumen of the inner catheter member . the medical device , for example , comprises a cardiac lead or alternatively , a guidewire . the fluid includes , but is not limited to , saline or medicine , or radiopaque dye . optionally , the inner catheter member is removed from the catheter assembly , and fluid and / or a medical device is disposed through the first lumen of the outer catheter member . the implanting physician or technician has more options since the various lumens accommodate various types and sizes of medical instruments , or rates of introduction of fluids . in yet a further option , torque is applied to the inner catheter member , which is particularly beneficial , for instance , when the inner catheter is shaped in conjunction with the outer catheter . applying torque to the inner catheter having a preformed shape provides a three - dimensional geometry at the tip . in yet another option , a stiff guide wire , either straight or preformed , is advanced down the central lumen of the inner catheter , which allows for additional shape control . advantageously , the catheter assembly is easily manipulatable by the medical technician into complex shapes , which allows for the assembly to be positioned in to complex areas within a patient , for instance , within the coronary sinus ostium . since the catheter assembly is able to be positioned within many different areas , regardless of their complexity in shape , a medical technician or physician has more available options when treating a patient . a further benefit of the catheter assembly is that the device is easy to use , easy to manufacture , and provides a cost benefit in both assembly and in its use . it is to be understood that the above description is intended to be illustrative , and not restrictive . many other embodiments will be apparent to those of skill in the art upon reading and understanding the above description . it should be noted that embodiments discussed in different portions of the description or referred to in different drawings can be combined to form additional embodiments of the present invention . the scope of the invention should , therefore , be determined with reference to the appended claims , along with the full scope of equivalents to which such claims are entitled .
a catheter assembly for cannulating an ostium of a coronary sinus of a heart comprises an outer catheter member and an inner catheter member . the outer catheter member has a distal end portion including a deflectable distal end and a lumen extending through the deflectable distal end , wherein the distal end portion includes regions of varying stiffness and has a pre - formed curvature . the inner catheter member is slidably and rotatably disposed within the lumen of the outer catheter member , and has a distal end portion including a distal end , and a lumen extending through the distal end . the distal end portion of the inner catheter member has regions of varying stiffness and a pre - formed curvature . the outer and inner catheter members are configured such that relative translation and rotation of the outer and inner catheter members causes the distal end of the outer catheter member to assume a plurality of two and three dimensional shapes .