RU2000103444A

RU2000103444A - IMPLANTED MEDICAL DEVICES FROM ALLOY WITH MEMORY MEMORY

Info

Publication number: RU2000103444A
Application number: RU2000103444/02A
Authority: RU
Inventors: Джозеф ФЛОМЕНБЛИТ; Натали БУДИДЖИНА
Original assignee: Литана Лтд
Priority date: 1997-07-15
Filing date: 1998-04-29
Publication date: 2001-12-10

Claims

1. A medical device comprising a part from a shape-memory alloy (SPF) having an austenitic and martensitic state with a different configuration in each of these states, and the SPF is capable of transitioning from martensitic to austenitic state using an austenitic transition occurring in a temperature range from a _s, the initial temperature of the austenitic transformation, to a _f, a final austenite transition temperature, and is able to transition from the austenitic state to a martensitic state by a martensitic transition proish dyaschego in the temperature range below body temperature by M _s, the initial martensitic transition temperature to M _f, a final martensitic transition temperature, wherein A _s below body temperature in an undeformed state, characterized in that: the SMA portion is deformable from an undeformed first configuration adopted in the austenitic state, into a deformed second configuration so that the deformation turns it into a martensitic or partial martensitic state caused by mechanical stress with an increase in A _s from its the initial temperature And _s ^o to the temperature A ' _s , and the fact that when the part of the NWF located in the specified second configuration is heated to a temperature higher than A' _s , it goes into an at least partial austenitic state, and the transition leads to a configuration change from the deformed second configuration in the direction of the undeformed first configuration and to a decrease in A _s from A ' _s to A _s ^o so that part of the NWP is stable in at least partial austenitic state at body temperature.

2. The medical device according to claim 1, characterized in that the shape memory alloy is nitinol.

3. The medical device according to claim 1, characterized in that at least one part of the SPF can be deformed to a higher mechanical stress than the rest of the SPF so that the specified at least one part has a temperature A ' _s t ₂ , which is higher than the temperature A ' _{s of the} rest of the NWF, t ₁ .

4. The medical device according to claim 3, characterized in that it must be placed in the body by heating the NWF to a temperature exceeding t ₁ but lower than t ₂ , whereby said at least one part remains in a martensitic state in placement time, and the rest of the NWF goes into an austenitic state.

5. The medical device according to paragraphs. 1-4, characterized in that A ' _{s is} higher than body temperature.

6. The medical device according to paragraphs. 1-4, characterized in that A ' _{s is} lower than body temperature, and A' _{f is} higher than body temperature.

7. A method of placing a medical device inside a person’s body, the medical device comprising a shape memory alloy (SPF) part having an austenitic and martensitic state with a different configuration in each of these conditions and having interconnected temperatures M _s , M _f , A _s and A _f , which are respectively the initial and final temperatures of the martensitic transition of the NWP and the initial and final temperatures of the austenitic transition of the NWF, and A _s has the value A

\binom{°}{s}

which is lower than the body temperature when the medical device is in an undeformed state, in which the medical device is deformed by transferring it from the undeformed first configuration, which it accepts in the austenitic state, to the deformed second configuration, and this deformation leads to an increase in A _s from A

\binom{°}{s}

to A ' _s , where part of the NWP is in a state caused by mechanical stress martensite or partial martensitic state after said deformation, the medical device is placed in the target location inside the body, and part of the NWF remains in the specified state induced by mechanical stress martensite or partial martensitic state during said placement, and transfer part of the NWF from said martensitic or partial martensitic state to at least a partial austenitic state by heating to a temperature greater than A _'s, wherein said transition leads to a change in the configuration of the portion SEF deformed second configuration towards the undeformed first configuration, wherein the configuration change results in a decrease in A _s from A' _s to A

\binom{°}{s}

so that the medical device is stable in at least partially austenitic state when placed in the body.

8. A method of placing a medical device inside the human body, the medical device comprising a shape memory alloy (SPF) part having an austenitic and martensitic state with a different configuration in each of these conditions and having interconnected temperatures M _s , M _f , A _s and A _f , which are respectively the initial and final temperatures of the martensitic transition of the NWP and the initial and final temperatures of the austenitic transition of the NWF, and A _s has the value A

\binom{°}{s}

which is lower than body temperature when the medical device is in an undeformed state, a M _{s is} less than A _s , in which: the SZF is heated to a temperature higher than A _s , whereby the SZP is placed in at least a partial austenitic state, cooled the medical device to a temperature between A _s and M _s , the medical device is deformed from the undeformed first configuration, which it receives in the austenitic state, into the deformed second configuration, and this deformation leads to an increase A _s from A

\binom{°}{s}

to A ' _s , where part of the NWF is in a martensitic or partial martensitic state after said deformation, the medical device is placed in the target location inside the body, and some of the NWF remains in the martensitic or partial martensitic state during the indicated placement, and a part of the NWF is transferred from martensitic or partial martensitic state to at least a partial austenitic state by heating it to a temperature greater than a _'s, wherein said transition leads to a change confi uracil SMA portion from the deformed second configuration towards the undeformed first configuration, wherein the configuration change results in a decrease in A _s from A _'s to A

\binom{°}{s}

9. The method according to claim 8, characterized in that the shape memory alloy is nitinol.

10. The method according to claim 8 or 9, characterized in that at least one part of the SZF can be deformed to a higher mechanical stress than the rest of the SEF during the specified deformation so that the specified at least one part has a temperature A ' _s t ₂ , which is higher than the temperature A' _{s of the} rest of the NWF, t ₁ .

11. The method according to claim 10, characterized in that the NWP is heated to a temperature exceeding t ₁ but lower than t ₂ , so that at least one part remains in the martensitic state, and the rest of the NWF is converted to austenite.

12. The method according to claim 11, characterized in that it further includes heating the NWP to a temperature exceeding t ₂ after the indicated transition step, thus translating at least one part from the martensitic state to the austenitic state.

13. The method according to claim 11, characterized in that it further includes removing the medical device from the body by capturing at least one part having a higher mechanical stress, which was converted during heating to a temperature of approximately t ₂ .

14. The medical device according to any one of claims 1 to 6, characterized in that it is a medical stent.

15. The medical device according to any one of claims 1 to 6, characterized in that it is a dental implant.

16. A medical device according to any one of claims 1 to 6, characterized in that it is a device for splicing bone fractures.

17. The medical device according to any one of claims 1 to 6, characterized in that it is a heart implant.

18. The medical device according to any one of claims 1 to 6, characterized in that it is a bone plate.

19. A medical device according to any one of claims 1 to 6, characterized in that it is an intrauterine contraceptive device.