fig1 - 3 illustrate a guide wire 10 having features of the invention that generally include an elongated core member 11 , with a proximal core section 12 and a distal core section 13 and a distal , highly flexible helical coil 14 disposed about and secured to the distal extremity of the core member . a shaping ribbon 15 ( optional ) extends from the distal end of the core member 11 and is secured to the mass of solder or weldment forming the rounded distal tip 16 of the guide wire . the proximal end of the shaping ribbon 15 is secured to the distal end of the core member 11 by suitable means such as solder , brazement , weldment or adhesive . the coil 14 will be secured to the core member 11 differently depending on the length of the coil . for example , a 3 . 0 cm long coil 14 would be secured between distal tip 16 and mass 17 which may be solder , brazement , weldment or adhesive . in another embodiment , the coil 14 would be 30 cm long and have two radiopaque coils , one 3 cm long and another 27 cm long . the 3 cm long coil would be attached between tip 16 and mass 17 while the 27 cm long coil would be secured between a first taper 21 and mass 17 . the core member 11 of the guide wire 10 , as shown in fig1 , generally may have conventional features with conventional dimensions . the proximal core section has a relatively constant or uniform transverse cross - sectional dimensions and the distal core section 13 has a first taper 21 , a second taper 22 and a third taper 23 which taper in the distal direction to smaller transverse cross - sectional dimensions . an first intermediate uniform dimensioned core portion 24 extends between the first and second tapers 21 and 22 and a second intermediate uniform dimensioned core portion 25 extends between the second taper 22 and the third taper 23 . generally , the overall length of the guide wire may range from about 80 to about 320 cm , preferably about 160 to about 200 for coronary use . as is know in the art , there are different length guide wires for endovascular and peripheral use . typically , commercial guide wire products of the invention will come in standard lengths of 175 , 190 and 300 cm . the distal section of the guide wire is about 1 to about 10 cm , preferably about 2 to about 5 cm in length , the intermediate section is about 15 to about 50 , preferably about 25 to about 40 cm in length . the outer diameter of the guide wire may vary depending upon use , but typically is about 0 . 008 to about 0 . 035 inch ( 0 . 2 - 0 . 9 mm ). the lengths and diameters of the tapers may vary as well as the number of tapers and their shapes . the composite wire forming the proximal and distal coils will typically have a diameter of about 0 . 002 to about 0 . 006 inch ( 0 . 051 - 0 . 15 mm ). a 0 . 002 inch diameter composite wire is typically used for forming a coil of about 0 . 010 to about 0 . 014 inch ( 0 . 25 - 0 . 36 mm ) in diameter , a 0 . 0025 inch ( 0 . 063 mm ) wire for a coil with an od of 0 . 0014 inch and a wire of 0 . 0055 inch ( 0 . 14 mm ) for larger od coils . to the extent not otherwise described herein , the dimensions , constructions and materials of the guide wire may be conventional . referring to fig1 - 4 , the guide wire 10 includes a highly flexible helical coil 14 comprised of two different metals . in one embodiment , the helical coil 14 has a first wire 30 wound into helical first coils 32 and a second wire 34 wound into helical second coils 36 . the first wire is formed from a metallic material take from the group of metallic materials that include any of stainless steel , tantalum , cobalt - chromium , titanium , nickel - titanium , and alloys thereof . the first wire 30 has a substantially lower radiopacity than the second wire 34 , but the material of the first wire generally is much less expensive than that of the second wire . with respect to the second wire 34 , it is formed from a metallic material taken from the group of metallic materials including platinum , gold , palladium , iridium , silver , bismuth , and tungsten , and alloys thereof . the second wire metallic materials are highly radiopaque and can be seen under x - ray and fluoroscopy for the purpose of positioning the distal end of the guide wire . the second wire 34 is substantially more radiopaque than the first wire 30 , however second wire 34 is made from materials that are substantially higher cost than the metallic materials forming the first wire . in one aspect of the invention , in order to reduce the cost of forming the helical coil 14 , the first wire 30 and the second wire 34 are wound into helical coils in an alternating fashion , with first coils 32 alternating with second coils 36 . in this embodiment , the radiopacity of the helical coil 14 will be less than if the helical coil were made solely of the second wire metallic materials . in other words , if helical coil 14 were formed solely of platinum , it would be very expensive yet highly radiopaque . in the present invention , the helical coil 14 would have half the amount of platinum coils since the second wire 34 formed of the platinum material alternates with the first coils 32 of the first wire 30 which is made of a different material such as stainless steel . in another embodiment , as shown in fig4 , the helical coil 14 includes a first wire 30 having first coils 32 and a second wire 34 having second coils 36 . in this embodiment , the first wire 30 is wound into the first coils 32 and the second wire is wound into the second coils 36 so that there is one first coil 32 wound in between every two second coils 36 . the radiopacity of this embodiment of helical coil 14 is less than if the helical coil were made purely of just the second wire material , but it has a higher radiopacity than the previous embodiment in fig3 because there are twice as many second coils 36 in this embodiment . thus , the helical coil of this embodiment is still highly radiopaque and is less expensive than if the helical coil were made solely of the more expensive radiopaque materials . other combinations are contemplated , such as three second coils alternating with every one first coil , two first coils alternating with every two second coils , and three first coils alternating with every one second coil . with respect to any of the embodiment disclosed herein , the pitch and dimensions of the first wire 30 and the second wire 34 coils can vary as needed . in fact , the outer diameters of the first coils 34 and the second coils 36 do not need to be the same , although it is preferable that they be close in their dimensions for a multi - filer coil winder to be able to wind the first wire 30 and the second wire 34 into coils at the same time . the metallic material forming the first wire 30 typically is more solderable than the metallic material forming the second wire 34 , so the first wire coils 32 can be soldered and assist in holding the second coils 36 together . as is known in the art , helical coils may have a polymer coating on the wires , either on the outside or the inside of the coil , or any variation thereof . such polymer coatings assist in holding the coils in place without unduly decreasing the flexibility of the helical coil . although individual features of embodiments of the invention may be shown in some of the drawings and not in others , those skilled in the art will recognize that individual features of one embodiment of the invention can be combined with any or all the features of another embodiment . various modification may be made to the invention without departing from the scope thereof .
a guide wire includes a distal flexible member , such as a helical coil , which is formed with at least one highly radiopaque component and at least one component that is less radiopaque . a first wire is wound into first coils and a second wire is wound into second coils so that the first coils alternate between the second coils to form a distal helical coil . the second wire is highly radiopaque to assist a physician in positioning the distal end of the guide wire in a patient &# 39 ; s vasculature , such as a coronary artery .