Medical device including unitary, continuous portion of varying durometer

A medical device (110) comprising a unitarily and continuously formed portion (108) having a varying durometer;

• a catheter shaft (211) having an outer catheter shaft (114) and an inner catheter shaft (112) received in the outer catheter shaft (114), the outer catheter shaft (114) comprising the unitarily and continuously formed portion (108);
• and an inflatable balloon (18) connected to the outer catheter shaft (114) and the inner catheter shaft (112), although not unitarily and continuously formed with the unitarily and continuously formed portion (108);
• wherein the inflatable balloon (18) and the unitarily and continuously formed portion (108) have different durometers;
• and wherein the unitarily and continuously formed portion (108) comprises an irradiation cross-linkable mixture of a nylon block copolymer including polyether blocks separated by polyamide blocks, about 3 percent by weight triallyl isocyanurate and about 10 percent by weight nylon.

A process for assembling a medical device (110), the medical device (110) comprising a unitarily and continuously formed portion (108) having a varying durometer, and the process comprising:

• creating an irradiation cross-linkable mixture of a polyamide elastomer and at least one additional cross-linking reactant;
• forming the mixture into a unitarily and continuously formed portion (108);
• and
• exposing the unitarily and continuously formed portion (108), at least in part, to cross-linking irradiation.

A process for assembling a medical device (110), the medical device (110) comprising a unitarily and continuously formed portion (108) having a varying durometer, and the process comprising:

• creating an irradiation cross-linkable mixture of a polyamide elastomer and at least one additional cross-linking reactant;
• forming the mixture into a unitarily and continuously formed portion (108);
• and
• exposing the unitarily and continuously formed portion (108), at least in part, to cross-linking irradiation;
• wherein the step of forming the portion (108) comprises forming the mixture into a tubular portion (106);
• wherein the forming step is carried out so as to yield a unitarily and continuously formed portion (108) comprising at least first and second parts (102 and 104) unitarily and continuously formed with one another, and the exposing step comprises exposing at least one of the first and second parts (102 or 104) to cross-linking irradiation;
• wherein the exposing step comprises irradiating the mixture with an electron beam at a total fluence of about 0.5 to about 60 megarads;
• wherein the mixing of the polyamide elastomer and the at least one additional reactant is carried out by compounding, and wherein the tubular portion (106) is formed by extruding the mixture of the polyamide elastomer and the at least one additional reactant;
• and
• wherein the process is carried out with a mixture comprising:
• a nylon block copolymer including polyether blocks separated by polyamide blocks, about 3 percent by weight triallyl isocyanurate and about 10 percent by weight nylon.