Laser cutting of stents and other medical devices
A desired pattern may be cut into a stent preform by impinging a laser beam onto the stent preform. The laser beam is formed using a laser system comprising a resonator cavity for resonating laser radiation, a gain medium contained in the resonator cavity, a pump for periodically pumping the gain medium and an electro-optical modulator in communication with the resonator cavity. The laser system produces a radiation pulse for each pump period. Each radiation pulse is conditioned by suppressing at least a portion of the pulse. The pulse may also be modulated with an electro-optical modulator to produce a pulse train of ordered pulses of radiation. Each pulse train is output from the optical cavity as an output laser beam which is directed at the stent preform to cut a desired pattern in the stent preform.
1 . A method of processing a stent preform comprising the steps of:
providing a stent preform;
providing a laser system comprising:
a) a resonator cavity for resonating laser radiation
b) a gain medium contained in the resonator cavity
c) a pump for periodically pumping the gain medium, the laser system producing a radiation pulse for each pump period;
d) conditioning the radiation pulse by suppressing a portion of, but not the entirety of the radiation pulse to produce conditioned radiation;
e) outputting the conditioned radiation in the form of a laser beam
f) directing the laser beam at the stent preform; and
g) impinging the laser beam onto the stent preform to cut a desired pattern in the stent preform.
2 . The method of claim 1 wherein the stent preform is a tube.
3 . The method of claim 2 wherein the tube is made of Nitinol.
4 . The method of claim 2 wherein the tube is made of at least one polymeric material.
5 . The method of claim 1 wherein the stent preform is a sheet of material, the method further comprising the step of forming the sheet into a tube subsequent to the impinging step.
6 . The method of claim 2 wherein the tube is made of stainless steel.
7 . The method of claim 1 wherein only the beginning of the pulse is suppressed.
8 . The method of claim 1 wherein only the beginning of the pulse and the end of the pulse are suppressed, a portion of the pulse between the beginning and the end not being suppressed.
9 . The method of claim 1 wherein only the end of the pulse is suppressed.
10 . The method of claim 9 wherein the laser beam is entrained in a column of water prior to being impinged against the stent perform.
11 . The method of claim 1 wherein the conditioning step further comprises conditioning each radiation pulse to produce a pulse train of ordered pulses of radiation for each radiation pulse.
12 . The method of claim 11 wherein the stent preform is formed of Nitinol.
13 . The method of claim 1 wherein during the impinging step the stent preform is moved relative to the laser beam.
14 . The method of claim 11 wherein during the impinging step the stent preform is moved relative to the laser beam.
15 . A method of processing a medical device preform comprising the steps of:
providing a medical device preform;
providing a laser system comprising:
a) a resonator cavity for resonating laser radiation
b) a gain medium contained in the resonator cavity
c) a pump for periodically pumping the gain medium, the laser system producing a radiation pulse for each pump period;
d) conditioning the radiation pulse by suppressing a portion of, but not the entirety of the radiation pulse to produce conditioned radiation;
e) outputting the conditioned radiation in the form of a laser beam
f) directing the laser beam at the medical device preform; and
g) impinging the laser beam onto the medical device preform to modify the surface of the medical device preform.
16 . The method of claim 15 wherein the medical device preform is a stent preform.
17 . The method of claim 16 wherein the stent preform is tubular.
18 . The method of claim 17 wherein during the impinging step, a desired pattern is cut into the stent preform.
19 . The method of claim 15 wherein only the beginning of the pulse is suppressed.
20 . The method of claim 15 wherein only the beginning of the pulse and the end of the pulse are suppressed, a portion of the pulse between the beginning and the end not being suppressed.
21 . The method of claim 15 wherein only the end of the pulse is suppressed.
22 . The method of claim 15 wherein the conditioning step further comprises conditioning each radiation pulse to produce a pulse train of ordered pulses of radiation for each radiation pulse.
23 . The method of claim 18 wherein the conditioning step further comprises conditioning each radiation pulse to produce a pulse train of ordered pulses of radiation for each radiation pulse.