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Claims  |
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What is claimed is:
1. A variable shape guide apparatus comprising
a temperature-activated memory element moving in a first direction to
assume a predetermined shape when heated to a predetermined temperature,
spring means housing the memory element for yieldably urging the memory
element in a second direction away from the first direction upon cooling
of the memory element to a temperature less than the predetermined
temperature so that the memory element is moved to assume a shape other
than the predetermined shape, the spring means having an original shape
alterable by movement of the memory element in its first direction toward
its predetermined shape,
insulation means for preventing electrically conductive contact between the
memory element and the spring means, and
control means for selectively heating the memory element so that the memory
element is moved in the first direction against the urging of the spring
means to permit an operator to alter the shape of the spring means
automatically by heating the memory element, whereby the spring means is
allowed to resume its original shape upon cooling of the memory element
housed in the spring means, the spring means being an elongated coil
spring formed to include a longitudinal cavity and the memory element
being positioned in the longitudinal cavity.
2. The apparatus of claim 1, wherein the insulation means includes a
tubular sleeve positioned in the longitudinal cavity and the memory
element is positioned in the tubular sleeve.
3. The apparatus of claim 1, further comprising an end cap coupled to a
distal end of the elongated coil spring, the insulation means including
means for preventing electrically conductive contact between the memory
element and the end cap.
4. A variable shape guide apparatus comprising
a temperature-activated memory element moving in a first direction to
assume a predetermined shape when heated to a predetermined temperature,
spring means housing the memory element for yieldably urging the memory
element in a second direction away from the first direction upon cooling
of the memory element to a temperature less than the predetermined
temperature so that the memory element is moved to assume a shape other
than the predetermined shape, the spring means having an original shape
alterable by movement of the memory element in its first direction toward
its predetermined shape,
insulation means for preventing electrically conductive contact between the
memory element and the spring means, and
control means for selectively heating the memory element so that the memory
element is moved in the first direction against the urging of the spring
means to permit an operator to alter the shape of the spring means
automatically by heating the memory element, whereby the spring means is
allowed to resume its original shape upon cooling of the memory element
housed in the spring means, the control means including power supply
means, first electrical lead means for coupling the power supply means and
the spring means in electrical communication, second electrical lead means
for coupling the power supply means and the memory element in electrical
communication, and circuit means interconnecting the spring means and the
memory element for establishing an electrical circuit electrically
connecting the spring means, the memory element, and the control means in
series.
5. The apparatus of claim 4, wherein the memory element is made of an
electrically conductive shape-memory alloy, the memory element includes
one end coupled to the second electrical lead means and an opposite end,
and the spring means includes an electrically conductive coil spring
having one end coupled to the first electrical lead means and an opposite
end, an electrically conductive end cap, first means for coupling the
opposite end of the coil spring and the end cap in electrical
communication, and second means for coupling the end cap and the opposite
end of the memory element in electrical communication.
6. A variable shape guide apparatus comprising
a temperature-activated memory element moving in a first direction to
assume a predetermined shape when heated to a predetermined temperature,
spring means housing the memory element for yieldably urging the memory
element in a second direction away from the first direction upon cooling
of the memory element to a temperature less than the predetermined
temperature so that the memory element is moved to assume a shape other
than the predetermined shape, the spring means having an original shape
alterable by movement of the memory element in its first direction toward
its predetermined shape,
insulation means for preventing electrically conductive contact between the
memory element and the spring means, and
control means for selectively heating the memory element so that the memory
element is moved in the first direction against the urging of the spring
means to permit an operator to alter the shape of the spring means
automatically by heating the memory element, whereby the spring means is
allowed to resume its original shape upon cooling of the memory element
housed in the spring means, the spring means including a longitudinal
axis, the memory element being positioned along the longitudinal axis to
apply a bending force to the spring means upon movement of the memory
element to assume its predetermined shape, and the spring means being
configured to provide means for converting bending forces to
rotation-inducing forces so that the spring means rotates about its
longitudinal axis in response to movement of the memory element to assume
its predetermined shape.
7. A variable shape guide apparatus comprising
a temperature-activated memory element moving in a first direction to
assume a predetermined shape when heated to a predetermined temperature,
spring means housing the memory element for yieldably urging the memory
element in a second direction away from the first direction upon cooling
of the memory element to a temperature less than the predetermined
temperature so that the memory element is moved to assume a shape other
than the predetermined shape, the spring means having an original shape
alterable by movement of the memory element in its first direction toward
its predetermined shape,
insulation means for preventing electrically conductive contact between the
memory element and the spring means, and
control means for selectively heating the memory element so that the memory
element is moved in the first direction against the urging of the spring
means to permit an operator to alter the shape of the spring means
automatically by heating the memory element, whereby the spring means is
allowed to resume its original shape upon cooling of the memory element
housed in the spring means, the spring means including spaced-apart distal
and proximal portions, and further comprising first means for anchoring
one end of the memory element to the distal portion and second means for
anchoring the other end of the memory element to the proximal portion.
8. The apparatus of claim 7, wherein the spring means is an elongated coil
spring formed to include a longitudinal cavity, the memory element is
positioned in the longitudinal cavity, the first anchor means includes an
end cap coupled to the distal portion and means for coupling said one end
of the memory element to the end cap, and the second anchor means includes
a plug disposed in the longitudinal cavity and fixed to the proximal
portion, and means for coupling said other end of the memory element to
the fixed plug.
9. The apparatus of claim 8, wherein the plug provides means for
interconnecting the control means and said other end of the memory
element.
10. A variable shape guide apparatus comprising
a temperature-activated memory element moving in a first direction to
assume a predetermined shape when heated to a predetermined temperature,
spring means housing the memory element for yieldably urging the memory
element in a second direction away from the first direction upon cooling
of the memory element to a temperature less than the predetermined
temperature so that the memory element is moved to assume a shape other
than the predetermined shape, the spring means having an original shape
alterable by movement of the memory element in its first direction toward
its predetermined shape,
insulation means for preventing electrically conductive contact between the
memory element and the spring means, and
control means for selectively heating the memory element so that the memory
element is moved in the first direction against the urging of the spring
means to permit an operator to alter the shape of the spring means
automatically by heating the memory element, whereby the spring means is
allowed to resume its original shape upon cooling of the memory element
housed in the spring means, the guide member being an elongated, tubular
coil spring formed to provide the cavity and the control means including
means for supporting the memory element within the cavity for movement
relative to the coil spring so that the memory element applies a
displacement force to the coil spring as the memory element moves to
assume its predetermined shape causing the guide member to change shape
and impart the biasing force to the memory element.
11. The apparatus of claim 10 wherein the support means includes at least
one electrical lead coupled to the memory element.
12. The apparatus of claim 10, wherein the coil spring includes
spaced-apart distal and proximal portions, the support means includes a
plug disposed in the interior cavity provided by the tubular coil spring
and rigidly fixed to the proximal portion of the coil spring, the memory
element is coupled at opposite ends to the distal portion and the plug.
13. A variable shape guide apparatus comprising
a flexible guide member having an original shape and being formed to
include an interior cavity,
a temperature-activated memory element within the interior cavity of the
flexible guide member, the memory element moving against the flexible
guide member to assume a predetermined shape when heated to a
predetermined temperature, thereby altering the shape of the flexible
guide member, the guide member providing spring means for yieldably
applying a biasing force to the memory element so that the memory element
is moved to assume a shape other than the predetermined shape upon cooling
of the memory element to a temperature less than the predetermined
temperature, thereby allowing the flexible guide member to resume its
original shape, and
control means for selectively heating the memory element so that the memory
element is moved to assume its predetermined shape and alter the shape of
the flexible guide member, whereby the guide member is allowed to resume
its original shape upon cooling of the memory element, the control means
including power supply means, first electrical lead means for coupling the
power supply means and the guide member in electrical communication, and
second electrical lead means for coupling the power supply means and the
memory element in electrical communication, circuit means interconnecting
the guide member and the memory element for establishing an electrical
circuit electrically connecting the guide member, the memory element, and
the control means in series.
14. A variable shape guide apparatus comprising
a temperature-activated memory element, the memory element moving to assume
a predetermined shape when heated to a predetermined temperature,
a guide member formed to include an interior cavity, the memory element
being positioned within the interior cavity and movable therein to engage
the guide member and alter the shape of the guide member upon movement of
the memory element to assume its predetermined shape, the guide member
including a tip member having an initial position, the tip member normally
occupying the initial position while the temperature of the memory element
is less than the predetermined temperature, and rotating means for moving
the tip member along a path orbiting the initial position in response to
movement of the memory element to assume its predetermined shape and to
apply a shape-altering force to the guide member, and
control means for selectively heating the memory element so that the memory
element moves to assume its predetermined shape and activates the rotating
means.
15. The apparatus of claim 14, wherein the rotating means is an elongated
coil formed to include a cavity and the memory element is positioned in
the cavity to engage the elongated coil during movement to assume its
predetermined shape.
16. The apparatus of claim 15, wherein the elongated coil includes a distal
end configured to provide an opening into the cavity and the tip member is
positioned in the distal end to close the cavity opening.
17. The apparatus of claim 15, wherein the elongated coil is made of a
spring material and configured to provide spring means for yieldably
applying a biasing force to the memory element so that the memory element
is moved to assume a shape other than the predetermined shape upon cooling
of the memory element to temperature less than the predetermined
temperature.
18. The apparatus of claim 17, wherein the guide member has a longitudinal
axis and the spring material helically winds about the longitudinal axis
to provide the elongated coil.
19. An apparatus comprising
a base member formed to include an interior chamber and an exterior opening
communicating with the interior chamber, the base member being insertable
into a body cavity,
guide means for selectively steering and aiming the base member along a
path through the body cavity, the guide means having a proximal portion
anchored in the interior chamber to the base member and a distal portion
extending through the exterior opening in a direction away from the base
member, at least the distal portion of the guide means being movable
relative to the base member and including a tubular coiled spring formed
to include a longitudinally extending chamber having an open mouth, a
temperature-activated memory element positioned within the longitudinally
extending chamber, the memory element moving to assume a predetermined
shape when heated to a predetermined position so that the distal portion
of the guide means is moved relative to the base member, the tubular
spring being configured to provide spring means for yieldably applying a
biasing force to the memory element so that the memory element is moved to
assume a shape other than the predetermined shape upon cooling of the
memory element to a temperature less than the predetermined temperature to
permit the distal portion of the guide member to be moved relative to the
base member, and insulation means for preventing electrically conductive
contact between the memory element and the tubular spring, and
control means for selectively heating the memory element so that the memory
element moves to assume its predetermined shape, thereby moving the distal
portion of the guide means relative to the base member.
20. The apparatus of claim 19, wherein the memory element includes opposite
ends, the guide means further includes an end cap coupled to the tubular
spring to close the open mouth, first means for anchoring one end of the
memory element to the end cap, and second means for anchoring the other
end of the memory element to a portion of the coiled spring situated in
spaced-apart relation to the portion coupled to the end cap so that the
memory element is fixed at its opposite ends to spaced-apart portions of
the coiled spring.
21. The apparatus of claim 20, wherein the second anchor means includes a
plug disposed in the longitudinally extending chamber in spaced relation
to the end cap and fixed to the coiled spring, and the memory element is
arranged to interconnect the end cap and the plug.
22. The apparatus of claim 21, wherein the control means includes power
supply means, first electrical lead means for coupling the power supply
means and the coiled spring in electrical communication, second electrical
lead means for coupling the power supply means and the plug in electrical
communication, the end cap and the plug being electrical conductors, and
insulation means for preventing electrically conductive contact between
the plug and the coiled spring.
23. An apparatus comprising
a base member insertable into a body cavity,
guide means within the base member for selectively steering and aiming the
base member along a path within the body cavity, the guide means including
a tubular coiled spring made of a resilient shape-memory alloy, the
tubular coiled spring moving from an initial shape to assume a
predetermined shape when heated to a predetermined temperature, and
control means for selectively heating the tubular coiled spring so that the
tubular coiled spring moves from its initial shape to assume its
predetermined shape, the tubular coiled spring returning toward its
initial shape upon being cooled to a temperature less than the
predetermined temperature.
24. An apparatus comprising
an elongated coiled spring formed to include a longitudinal cavity and
spaced-apart distal and proximal portions,
an elongated temperature-activated memory element moving in a first
direction to assume a predetermined shape and shortening in length when
heated to a predetermined temperature, the memory element being disposed
in the longitudinal cavity and including opposite ends,
first means for anchoring one end of the memory element to the distal
portion of the coiled spring,
second means for anchoring the other end of the memory element to the
proximal portion of the coiled spring, and
control means for selectively heating the memory element so that the memory
element is moved in the first direction to apply a movement-inducing
transverse shear load to the coiled spring and shortened to apply a
movement-inducing axial compression load to assume a shape corresponding
to the predetermined shape of the memory element, the first means
including an end cap interconnecting the distal portion of the coiled
spring and said one end of the memory element, the control means including
power supply means, first electrical lead means for coupling the power
supply means and the coiled spring in electrical communication, second
electrical lead means for coupling the power supply means and the plug in
electrical communication, the end cap and the plug being electrical
conductors, and insulation means for preventing electrically conductive
contact between the plug and the coiled spring.
25. An apparatus comprising
an elongated coiled spring formed to include a longitudinal cavity and
spaced-apart distal and proximal portions, the coiled spring being
preformed to assume a predetermined curved shape,
an elongated temperature-activated memory element moving in a first
direction to assume a predetermined straight shape and shortening in
length when heated to a predetermined temperature, the memory element
being disposed in the longitudinal cavity and including opposite ends,
first means for anchoring one end of the memory element to the distal
portion of the coiled spring,
second means for anchoring the other end of the memory element to the
proximal portion of the coiled spring, and
control means for selectively heating the memory element so that the memory
element is moved in the first direction to apply a movement-inducing
transverse shear load to the coiled spring and shortened to apply a
movement-inducing axial compression load to the coiled spring, thereby
moving the coiled spring from its predetermined curved shape to assume a
straight shape corresponding to the predetermined straight shape of the
memory element.
26. The apparatus of claim 25, wherein the coiled spring, first means, and
second means cooperate to provide means for yieldably urging the memory
element in a second direction away from the first direction upon cooling
of the memory element to a temperature less than the predetermined
temperature so that the memory element is moved to assume a shape other
than the predetermined shape and lengthened.
27. The apparatus of claim 25, wherein the second anchor means includes a
plug disposed in the longitudinal cavity and fixed to the proximal
portion.
28. The apparatus of claim 27 wherein the control means includes power
supply means, first electrical lead means for coupling the power supply
means and said one end of the memory element in electrical communication
at a point adjacent the first anchor means, and second electrical lead
means for coupling the power supply means and said other end of the memory
element in electrical communication at a point adjacent the second anchor
means.
29. The apparatus of claim 27 wherein the plug is formed to include
longitudinally extending passageway and the memory element extends through
the passageway to provide an exposed distal end disposed in the
longitudinal cavity. |
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Claims |
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Description |
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BACKGROUND AND SUMMARY OF THE INVENTION
The present invention relates to guide apparatus, probes, and the like, and
particularly to guide apparatus that are steerable through body cavities
and aimable at obstructions, organs, or tissue within the body from a
position external to the body. More particularly, the present invention
relates to maneuverable guide apparatus including spring means for biasing
a temperature-activated memory element to alter the shape of the memory
element upon cooling of the memory element to a temperature below its
martensitic transformation temperature.
Some attempts have been made in the past to provide catheters having distal
ends which, when inserted into a body, are manipulatable to advance the
catheter through body cavities. See for example, U.S. Pat. Nos. 3,674,014
and 3,773,034. The catheter disclosed in Pat. No. 3,674,014 includes
permanent magnets and employs a magnetic field to bend the distal end of
the catheter. The catheter disclosed in Pat. No. 3,773,034 includes fluid
conduits and employs a fluid to bend the distal end of the catheter. Other
controlled devices are disclosed in U.S. Pat. Nos. 3,605,725 and
4,176,662. However, these prior devices are quite difficult to control and
manipulate.
Some work has previously been done to produce a catheter which is readily
insertable while being effectively anchorable in a body cavity. See, for
example, U.S. Pat. Nos. 3,729,008 and 3,890,977.
In U.S. Pat. No. 3,890,977 to Wilson, the distal end of the catheter is
formed into a desired shape by using a material exhibiting mechanical
memory that is triggered by heat. By heating the mechanical memory
material, the distal end of the catheter is shaped to anchor the catheter
within the body. However, the change of the shape or other movement of the
distal end in these prior devices is limited to a single direction. Once
the memory material has been heated causing the distal end to move in said
single direction to assume its characteristic anchoring shape, it becomes
necessary to deform the distal end manually at a temperature below the
transition temperature of the mechanical memory material in order to
change the shape of the distal end. The need for manual manipulation of a
catheter once it is inserted into a body limits the steerability and
aimability of the catheter.
Other devices are known for guiding a catheter to a particular location
within the body. See for example U.S. Pat. No. 3,043,309.
One object of the present invention is to provide a steerable guide
apparatus, probe, and the like which is easy to operate and steerable in a
plurality of different directions within the body.
Another object of the present invention is to provide an aimable guide
apparatus, probe, and the like which is easy to operate and which | | |
