Patent Application
20210023354
This invention relates to an apparatus and methods for fluid injection into tissue. Particular embodiments provide apparatus and methods for fluid injection into tissue by inserting one or more microneedles into tissue.
Microneedles may be employed to deliver treatment such as fluid (e.g. drugs), electrical signals, or the like into tissue. Microneedles may also be employed for sensing particular compounds (e.g. biological fluid assays, drug concentration sensors, etc.) or extracting matter from tissue.
Various methods and apparatus have been disclosed for inserting microneedles into tissue. For example, see:
With some microneedle-insertion methods and apparatus, the microneedle is prone to “bounce-back” off of (i.e. away from) the tissue due to the elasticity of the tissue after insertion. In some cases, such “bounce-back” can result in ejection of the microneedle from the tissue in a direction generally opposing the insertion direction. Attempts have been made to counter such bounce-back by applying continuous force on the microneedle after insertion (i.e. in the insertion direction). However, when the microneedle is used for fluid injection, a wheal typically forms at or near the surface of the skin (e.g. to accommodate the volume of injected fluid). Application of continuous pressure in the insertion direction may prevent the tissue from expanding (e.g. may prevent a wheal from forming) and may therefore reduce effectiveness of the microneedle. For example, the rate of fluid injection may be reduced when pressure is applied against the formation of a wheal. In other situations (e.g. where microneedles are used for sensing or material extraction applications), application of force by the microneedle and/or parts of its insertion apparatus to the tissue may change one or more characteristics of the tissue and it may be desirable to reduce the force applied to the tissue after insertion of the microneedle to prevent or reduce such change to the one or more characteristics of the tissue. It may be generally desirable to reduce the force that is applied to the tissue by the microneedle and/or parts of its insertion apparatus after insertion of the microneedle, whether the microneedle is used for injection of fluid, a sensing application, a material extraction application and/or otherwise.
There is a general desire for simple, effective methods and apparatus for effective controlled insertion of needles and microneedles into tissue that reduce bounce-back of the microneedle upon insertion and , once inserted, minimize or reduce force that would tend to, undesirably affect characteristics of the tissue and/or counteract expansion of the tissue (e.g. wheal formation) upon the injection of fluid into the tissue.
The foregoing examples of the related art and limitations related thereto are intended to be illustrative and not exclusive. Other limitations of the related art will become apparent to those of skill in the art upon a reading of the specification and a study of the drawings.
One aspect of the invention provides an apparatus for inserting a microneedle into tissue. The apparatus may comprise a microneedle supported by a backing to move therewith, a forcer selectably operable between a retracted state and an extended state and a releasable locking mechanism. Upon operation of the forcer from the retracted state to the extended state, the forcer applies force to the backing which causes the backing to travel in an insertion direction toward the tissue. The releasable locking mechanism, in a locking state, permits one-way motion of the backing in the insertion direction toward the tissue and lockingly engages the backing to prevent motion of the backing in a reverse direction opposed to the insertion direction. The releasable locking mechanism is releasable, to a released state, which permits motion of the backing in the reverse direction. The forcer is disengaged from the backing when the locking mechanism lockingly engages the backing.
Another aspect of the invention provides an apparatus for inserting a microneedle into tissue. The apparatus comprises a housing for housing a microneedle, a backing for supporting a microneedle and moveable therewith relative to the housing, a forcer selectably operable between a retracted state and an extended state, and a forcer withdrawal mechanism. Upon operation of the forcer from the retracted state to the extended state, the forcer applies force to the backing which causes the backing to travel in an insertion direction toward the tissue and to thereby insert the microneedle into the tissue. At least a portion of the forcer withdrawal mechanism is couplable to the forcer after the microneedle is inserted into the tissue to move with the forcer and independently of the backing relative to the housing, to thereby disengage the forcer from the backing by movement of the portion of the forcer withdrawal mechanism and the forcer away from the backing in a reverse direction opposed to the insertion direction.
Another aspect of the invention provides an apparatus for inserting a microneedle into tissue. The apparatus comprises a microneedle supported by a backing to move therewith, a forcer selectably operable between a retracted state and an extended state, and an activator. Upon operation of the forcer from the retracted state to the extended state, the forcer applies force to the backing which causes the backing to travel in an insertion direction toward the tissue. When the activator is actuated, the activator enables the forcer to operate from the retracted state to the extended state wherein actuation of the activator comprises applying force to the activator in a transverse direction having at least a component orthogonal to the insertion direction.
Another aspect of the invention comprises an apparatus for inserting a microneedle into tissue. The apparatus comprises a housing for housing a microneedle, a backing for supporting a microneedle and moveable therewith relative to the housing, a forcer selectably operable between a retracted state and an extended state and wherein, upon operation of the forcer from the retracted state to the extended state, a proximal end of the forcer applies force to the backing which causes the backing to travel in an insertion direction toward the tissue and to thereby insert the microneedle into the tissue, and a forcer release mechanism, the forcer release mechanism releasable to allow movement of a distal end of the forcer, opposite to the proximal end, relative to the housing in a reverse direction opposed to the insertion direction to thereby reduce the force applied to the backing by the proximal end of the forcer to permit motion of the backing in the reverse direction.
In some embodiments, the locking mechanism comprises a lock that, in the locking state of the releasable locking mechanism, permits motion of at least a portion of the backing in the insertion direction from a location on a first side of the lock to a location on a second side of the lock and wherein interaction between the lock and the backing prevents motion of the at least a portion of the backing in the reverse direction from the location on the second side of the lock to the location on the first side of the lock. In some embodiments, the interaction comprises physical contact between the lock and the backing
In some embodiments, the locking mechanism is spaced apart from the backing when the forcer is in the retracted state and, wherein, the locking mechanism lockingly engages the backing as the backing travels in the insertion direction in response to the forcer operating from the retracted state to the extended state
In some embodiments, the backing comprises at least one concavity and the locking mechanism comprises at least one pawl which extends into the at least one concavity to lockingly engage the backing as the backing travels in the insertion direction in response to the forcer operating from the retracted state to the extended state.
In some embodiments, the backing comprises a plurality of transversely extending teeth, each transversely extending tooth comprising an insertion-direction face and a reverse-direction face and wherein each concavity is defined by the insertion-direction face and the reverse-direction face of a pair of adjacent teeth.
In some embodiments, the insertion-direction face of each tooth is shaped such that contact between the pawl and the insertion-direction face of each tooth causes movement (e.g. translation and/or rotation) of at least part of the pawl as the backing travels in the insertion direction in response to the forcer operating from the retracted state to the extended state.
In some embodiments, the insertion-direction face of each tooth is shaped such that contact between the pawl and the insertion-direction face of each tooth causes deformation of a bias mechanism that biases the pawl toward the backing as the backing travels in the insertion direction in response to the forcer operating from the retracted state to the extended state.
In some embodiments, the reverse-direction face of each tooth is shaped to guide the pawl into a corresponding concavity and thereby prevent reverse direction movement of the backing.
In some embodiments, the pawl is shaped to extend transversely and in the insertion direction when the locking mechanism lockingly engages the backing.
In some embodiments, at least a portion of the pawl is biased in a transverse direction toward the backing when the locking mechanism lockingly engages the backing.
In some embodiments, the pawl is pivotally mounted and wherein the portion of the pawl is pivotally biased toward the backing when the locking mechanism lockingly engages the backing.
In some embodiments, at least a portion of the pawl is deformed in a transverse direction away from the backing when the locking mechanism lockingly engages the backing
In some embodiment, the apparatus comprises a pawl release which is actuatable to withdraw the pawl from engagement with the concavity.
In some embodiments, the pawl release is actuatable to withdraw the pawl from engagement with the concavity by pivotal motion of the pawl.
In some embodiments, the locking mechanism is releasable by applying force to the housing in a transverse direction nonparallel to the insertion and reverse directions.
In some embodiments, the locking mechanism is releasable by applying force to the housing in the insertion direction.
In some embodiments, the housing comprises a first section having a first beveled surface and a second section having a second beveled surface and application of force to the housing in the insertion direction causes the first beveled surface of the first section of the housing to contact the second beveled surface of the second section of the housing thereby deforming and/or otherwise moving at least a portion of the second section of the housing to release the locking mechanism.
In some embodiments, deforming and/or otherwise moving at least a portion of the second section of the housing to release the locking mechanism comprises deforming and/or otherwise moving the at least a portion of the second section of the housing in a transverse direction nonparallel to the insertion and reverse directions.
In some embodiments, deforming and/or otherwise moving at least a portion of the second section of the housing to release the locking mechanism release comprises deforming and/or otherwise moving the at least a portion of the second section of the housing until one or more stops projecting from the second section of the housing disengage the backing.
In some embodiments, deforming and/or otherwise moving at least a portion of the second section of the housing to release the locking mechanism comprises deforming and/or otherwise moving the at least a portion of the second section of the housing until one or more stops projecting from the backing disengage the second section of the housing.
In some embodiments, deforming and/or otherwise moving at least a portion of the second section of the housing to release the locking mechanism comprises deforming and/or otherwise moving the at least a portion of the second section of the housing until one or more teeth projecting from the second section of the housing disengage the backing.
In some embodiments, the forcer applies force to the backing which causes the backing to travel in the insertion direction toward the tissue as a projectile which is disengaged from the forcer during at least a portion of the travel of the backing in the insertion direction.
In some embodiments, the apparatus comprises a catch which prevents the forcer from operating from the retracted state to the extended state.
In some embodiments, the catch is releasable to allow the forcer to operate from the retracted state to the extended state by applying force to the housing in a transverse direction nonparallel to the insertion and reverse directions.
In some embodiments, the catch is releasable to allow the forcer to operate from the retracted state to the extended state by applying force to the housing in the insertion direction.
In some embodiments, applying force to the housing in the insertion direction comprises forcing a third beveled surface of a first section of the housing to contact a fourth beveled surface of a second section of the housing thereby deforming and/or otherwise moving at least a portion of the second section of the housing to release the catch.
In some embodiments, deforming and/or otherwise moving at least a portion of the second section of the housing to release the catch comprises deforming and/or otherwise moving the at least a portion of the second section of the housing in a radially outward direction nonparallel to the insertion and reverse directions.
In some embodiments, deforming and/or otherwise moving at least a portion of the second section of the housing to release the catch comprises deforming and/or otherwise moving the at least a portion of the second section of the housing until the catch projecting from the second section of the housing disengages the backing thereby enabling the forcer to operate from the retracted state to the extended state.
In some embodiments, deforming and/or otherwise moving at least a portion of the second section of the housing to release the catch comprises deforming and/or otherwise moving the at least a portion of the second section of the housing until the catch projecting from backing disengages the second section of the housing thereby enabling the forcer to operate from the retracted state to the extended state.
In some embodiments, the apparatus comprises a fluid conduit connected to transport fluid to or from the microneedle when the forcer is in the retracted state and when the forcer is in the extended state.
In some embodiments, the forcer withdrawal mechanism is free to move relative to the forcer when the forcer is in the retracted state.
In some embodiments, the forcer is located within the housing.
In some embodiments, the apparatus comprises a catch which prevents the forcer from operating from the retracted state to the extended state.
In some embodiments, the catch is releasable to allow the forcer to operate from the retracted state to the extended state by applying force to the housing in a transverse direction nonparallel to the insertion and reverse directions.
In some embodiments, the catch is releasable to allow the forcer to operate from the retracted state to the extended state by applying force to the housing in the insertion direction.
In some embodiments, the portion of the forcer withdrawal mechanism is coupleable to the forcer by abutting the portion of the forcer withdrawal mechanism against the forcer.
In some embodiments, the forcer comprises a store of potential energy and wherein at least some of the potential energy remains in the store after insertion of the microneedle into the tissue.
In some embodiments, the apparatus comprises a forcer locking mechanism for lockingly engaging the portion of the forcer withdrawal mechanism in a location where the forcer is spaced apart from the backing and for preventing movement of the forcer in the insertion direction.
In some embodiments, a force applied to the backing by the forcer in the insertion direction after the microneedle is inserted into the tissue is greater than any bounce-back force associated with restoring deformation of the tissue that may have occurred as a result of insertion of the microneedle into the tissue.
In some embodiments, applying force to the activator in a transverse direction comprises applying force to a housing in the transverse direction.
In some embodiments, the backing comprises an adhesive surface contactable with the tissue when the microneedle is inserted into the tissue.
In some embodiments, the apparatus comprises an activator which, when actuated, enables the forcer to operate from the retracted state to the extended state.
In some embodiments, actuation of the activator comprises applying force to the housing in the insertion direction.
In some embodiments, releasing the forcer release mechanism comprises applying force to the housing in the insertion direction.
In some embodiments, a force applied to the backing by the forcer in the insertion direction after the microneedle is inserted into the tissue is greater than any bounce-back force associated with restoring deformation of the tissue that may have occurred as a result of insertion of the microneedle into the tissue. In some embodiments, the catch is releasable to allow the forcer to operate from the retracted state to the extended state by applying force to the housing in a transverse direction nonparallel to the insertion and reverse directions. In some embodiments, the catch is releasable to allow the forcer to operate from the retracted state to the extended state by applying force to the housing in the insertion direction. In some embodiments, applying force to the housing in the insertion direction comprises forcing a third beveled surface of a first section of the housing to contact a fourth beveled surface of a second section of the housing thereby deforming and/or otherwise moving at least a portion of the second section of the housing to release the catch. In some embodiments, deforming and/or otherwise moving at least a portion of the second section of the housing to release the catch comprises deforming and/or otherwise moving the at least a portion of the second section of the housing in a radially outward direction nonparallel to the insertion and reverse directions. In some embodiments, deforming and/or otherwise moving at least a portion of the second section of the housing to release the catch comprises deforming and/or otherwise moving the at least a portion of the second section of the housing until the catch projecting from the second section of the housing disengages the backing thereby enabling the forcer to operate from the retracted state to the extended state. In some embodiments, deforming and/or otherwise moving at least a portion of the second section of the housing to release the catch comprises deforming and/or otherwise moving the at least a portion of the second section of the housing until the catch projecting from backing disengages the second section of the housing thereby enabling the forcer to operate from the retracted state to the extended state.
Another aspect of the invention provides a method for inserting a microneedle into tissue. The method comprises supporting a microneedle by a backing to move therewith, selectably operating a forcer between a retracted state and an extended state, lockingly engaging the backing with a releasable locking mechanism and disengaging the forcer from the backing. Force is applied to the backing via the forcer by selectably operating the forcer from the retracted state to the extended state to thereby cause the backing to travel in an insertion direction toward the tissue. The releasable locking mechanism lockingly engages the backing to, in a locking state, prevent motion of the backing in a reverse direction opposed to the insertion direction while still permitting one-way motion of the backing in the insertion direction toward the tissue, the releasable locking mechanism releasable, to a released state, which permits motion of the backing in the reverse direction.
In some embodiments, selectably operating the forcer comprises applying a first force to the housing in a first transverse direction having at least a component orthogonal to the insertion direction.
In some embodiments, releasing the locking mechanism from the backing.
In some embodiments, releasing the locking mechanism from the backing by withdrawing the first force.
In some embodiments, lockingly engaging the backing comprises applying a second force to the locking mechanism in a second transverse direction having at least a component orthogonal to the insertion direction.
In some embodiments, applying the second force to the locking mechanism comprises applying the first force to the housing.
Another aspect of the invention provides a method for inserting a microneedle into tissue. The method comprises housing a microneedle in a housing, supporting a microneedle by a backing to move therewith, selectably operating a forcer between a retracted state and an extended state, applying force to the backing via the forcer by operating the forcer from the retracted state to the extended state to cause the backing to travel in an insertion direction toward the tissue to thereby insert the microneedle into the tissue, withdrawing the forcer using a forcer withdrawal mechanism. Withdrawing the forcer using the forcer withdrawal mechanism comprises coupling at least a portion of the forcer withdrawal mechanism to the forcer after the microneedle is inserted into the tissue and moving the forcer by moving of the portion of the forcer withdrawal mechanism and the forcer away from the backing and relative to the housing in a reverse direction opposed to the insertion direction to thereby disengage the forcer from the backing.
In some embodiments, selectably operating the forcer comprises applying a first force to the housing in a first transverse direction having at least a component orthogonal to the insertion direction.
In some embodiments, after moving the forcer by moving the portion of the forcer withdrawal mechanism, locking the forcer withdrawal mechanism relative to the housing to prevent the forcer from applying force to the backing.
In some embodiments, locking the forcer withdrawal mechanism comprises twisting the forcer withdrawal mechanism relative to the housing.
Another aspect of the invention provides a method for inserting a microneedle into tissue. The method comprises supporting a microneedle by a backing to move therewith, selectably operating a forcer between a retracted state and an extended state, applying force to the backing via the forcer by operating the forcer from the retracted state to the extended state to thereby cause the backing to travel in an insertion direction toward the tissue, and actuating an actuator to enable the forcer to operate from the retracted state to the extended state.
In some embodiments, actuating the activator comprises applying force to the activator in a transverse direction having at least a component orthogonal to the insertion direction.
In some embodiments, the method comprises contacting an adhesive surface of the backing to the tissue to adhere the backing to the tissue.
Another aspect of the invention comprises a method for inserting a microneedle into tissue. The method comprises housing a microneedle in a housing, supporting a microneedle by a backing to move therewith, selectably operating a forcer between a retracted state and an extended state, applying force to the backing via the forcer by operating the forcer from the retracted state to the extended state to cause the backing to travel in an insertion direction toward the tissue to thereby insert the microneedle into the tissue, and releasing a distal end of the forcer, opposite to the proximal end, to allow movement of the distal end of the forcer relative to the housing in a reverse direction opposed to the insertion direction thereby reducing the force applied to the backing by the proximal end of the forcer to permit motion of the backing in the reverse direction.
Other aspects of the invention are provided in the detailed description that follows.
Exemplary embodiments are illustrated in referenced figures of the drawings. It is intended that the embodiments and figures disclosed herein are to be considered illustrative rather than restrictive.
Throughout the following description specific details are set forth in order to provide a more thorough understanding to persons skilled in the art. However, well known elements may not have been shown or described in detail to avoid unnecessarily obscuring the disclosure. Accordingly, the description and drawings are to be regarded in an illustrative, rather than a restrictive, sense.
Particular aspects of the invention provide methods and apparatus for microneedle insertion into tissue. In particular embodiments, an apparatus is provided comprising a microneedle supported by a backing such that the microneedle may move with the backing. A forcer is selectively operable between a retracted state and an extended state. In its extended state, the forcer causes the backing to travel in a first direction toward the tissue. A locking mechanism is provided which permits one-way motion of the backing in a first direction toward the tissue. The locking mechanism lockingly engages the backing to prevent motion of the backing in a reverse direction away from the tissue.
In another particular embodiment, a housing is provided for housing a microneedle. A backing is provided for supporting the microneedle. The backing is moveable with the microneedle relative to the housing. A forcer is selectively operable between a retracted state and an extended state. In its extended state, the forcer causes the backing to travel in a first direction toward the tissue. A forcer withdrawal mechanism is provided and is free to move relative to the forcer prior to insertion of the microneedle. The forcer withdrawal mechanism is couplable to the forcer after the microneedle is inserted. When coupled to the forcer, the forcer withdrawal mechanism moves with the forcer relative to the housing to thereby disengage the forcer from the backing by movement of the forcer away from the tissue.
In another particular embodiment, an apparatus is provided comprising a microneedle supported by a backing such that the microneedle may move with the backing. A forcer is selectively operable between a retracted state and an extended state. In its extended state, the forcer causes the backing to travel in a first direction toward the tissue. An adhesive is provided on a surface of the backing such that upon contact with a tissue surface, the adhesive adheres the backing to the tissue surface to prevent motion of the backing in a reverse direction away from the tissue.
In some embodiments, the forcer switches from the retracted state to the extended state when a force is applied to the housing or an activator in a third direction that is non-parallel to the first direction.
Microneedle 25 may comprise any suitable needle known in the art. In currently preferred embodiments, microneedle 25 is a microneedle having a length of less than 3 mm or less than 2 mm and a cross-section of less than 250 μm at its distal (away from its point) end. This is not mandatory. Microneedle 25 may be solid or hollow. Microneedle 25 may be metallic. Microneedle 25 may be configured to deliver fluid to the tissue via a conduit 35 which may be in fluid communication with a fluid reservoir. In some embodiments, conduit 35 comprises a piston or other suitable mechanism for forcing fluid through conduit 35 and out the tip 25A of microneedle 25. In some embodiments, conduit 35 is unnecessary and microneedle 25 is connected directly to a fluid reservoir that may or may not move with microneedle 25.
In the
Forcer 30 may comprise any suitable forcer capable of applying force against backing 20 in insertion direction 75. For example, forcer 30 may comprise a spring, as depicted in
Various methods and mechanisms may be employed to change the state of forcer 30 from the retracted state to the expanded state. In some embodiments, the state of forcer 30 may be changed by activating forcer 30. For example, an electrical current may be supplied to a solenoid actuator causing the solenoid actuator to apply force to backing 20 such that backing 20 travels in insertion direction 75 (e.g. toward the tissue).
In some embodiments, forcer 30 is naturally biased toward its extended state and is held in the retracted state by one or more stops or stop-mechanisms (also referred to herein as a catch). For example, in the
Stops 50 may comprise any suitable stopping mechanism. In some embodiments, stops 50 comprise one or more protrusions or flanges extending from an interior surface of housing 15 (or another part of apparatus 10). Stops 50 may physically engage (e.g. abut against) backing 20 or forcer 30. Stops 50 may be physically disengaged from backing 20 or forcer 30 using any suitable technique. In the illustrated embodiment of
In the
Stops 50 may also serve to limit extension of forcer 30 in insertion direction 75. For example, as can be seen from
Once stops 50 have released backing 20 and/or forcer 30 has been activated, forcer 30 applies force against backing 20 in insertion direction 75, thereby causing backing 20 (and microneedle 25) to move in insertion direction 75 toward the tissue. In the
In the
Gravitational forces and frictional forces may also impact the motion of backing 20 and microneedle 25. Once microneedle 25 and/or backing 20 contacts the tissue, the tissue will also exert force on microneedle 25 and/or backing 20. Such forces exerted by the tissue may include a friction-like resistance to insertion of microneedle 25 into the tissue and may also include a “bounce-back” force associated with restoring any deformation of the tissue caused by the impact of microneedle 25 and/or backing 20. Such forces exerted by the tissue tend to be oriented in reverse direction 80, opposed from insertion direction 75. In some embodiments, it may be desirable to adjust the projection parameters of forcer 30 to ensure sufficient insertion of microneedle 25 and/or to reduce bounce-back.
As backing 20 travels in insertion direction 75 toward the tissue, locking mechanism 40 may engage backing 20 to mitigate against bounce-back. In the illustrated embodiment of
Locking mechanism 40 may comprise any suitable locking mechanism for effecting such one-way motion of backing 20 and microneedle 25. For example, locking mechanism 40 may comprise an electrically driven solenoid that activates when the presence of backing 20 is sensed by one or more sensors and permits motion of backing 20 in insertion direction 75 while preventing motion of backing 20 in reverse direction 80. In another example, locking mechanism 40 may comprise one or more magnets or electromagnets which permit motion of backing 20 in insertion direction 75 and prevent motion of backing 20 in reverse direction 80. In some embodiments like the
The concavities on sides 20A, 20B of backing 20 may be formed by one or more teeth on sides 20A, 20B. To allow backing 20 to travel in insertion direction 75, surfaces of the one or more teeth that face at least partially in insertion direction 75 (e.g. have normal vectors with components in insertion direction 75) may be beveled such that the first and second pawls 40A, 40B slide relatively easily (e.g. without significant decelerating force in reverse direction 80) along the beveled portion of the one or more teeth as backing 20 travels in insertion direction 75. In some embodiments, such motion of backing 20 in insertion direction 75 may comprise deformation of one or both of pawls 40A, 40B and/or the deformation of the biasing mechanisms associated with one or both of pawls 40A, 40B.
In some embodiments, the bevel angle of the surface of pawls 40A, 40B may additionally or alternatively be shaped to permit motion of backing 20 relative to pawls 40A, 40B in insertion direction 75.
On the other hand, to prevent backing 20 from travelling in reverse direction 80 opposed to insertion direction 75, surfaces of the one or more teeth that face at least partially in reverse direction 80 (e.g. have normal vectors with components in reverse direction 80) may be beveled such that backing 20 is incapable of sliding relative to first and second pawls 40A, 40B to travel in reverse direction 80. In some embodiments, the bevel angle of the surface of pawls 40A, 40B may additionally or alternatively be shaped to prevent motion of backing 20 relative to pawls 40A, 40B in reverse direction 80.
In the locked configuration, locking mechanism 40 permits motion of at least a portion of backing 20 in insertion direction 75 from a location on a first side of pawls 40A, 40B to a location on a second side (opposing the first side) of pawls 40A, 40B and interaction between pawls 40A, 40B and backing 20 prevents motion of the at least a portion of backing 20 in reverse direction 80 from a location on the second side of pawls 40A, 40B to a location on the first side of pawls 40A, 40B.
In practice, as forcer 30 extends from its retracted configuration (
After microneedle 25 is inserted into the tissue as desired, microneedle 25 may be used to, for example, inject fluid into the tissue, apply electrical current to the tissue, extract matter from the tissue, sensing and monitoring interstitial fluid (ISF), blood, skin composition etc. In the
Locking mechanism 40 may be released by any suitable mechanism or using any suitable method. In some embodiments, locking mechanism 40 may be released by withdrawing forces applied to housing 15 in directions 85, to thereby allow housing 15 to restoratively deform to its un-deformed shape or to a shape similar to its un-deformed state.
In some embodiments, with housing 15 in an un-deformed state, first and second pawls 40A, 40B of locking mechanism 40 are sufficiently close together to lockingly engage backing 20. In some embodiments, first and second pawls 40A, 40B are only close enough to one another to lockingly engage backing 20 upon deformation of housing 15. Such deformation may be caused by force applied to housing 15 in directions 85. In some embodiments, the force applied to portion 15A of housing 15 to release stops 50 from backing 20 may be sufficient to allow first and second pawls 40A, 40B to lockingly engage backing 20.
In such embodiments, a user may squeeze portion 15A of housing 15 (e.g. in transverse directions 85) to release stops 50 from backing 20 (causing forcer 30 to extend to its extended configuration and to move backing 20 in insertion direction 75) and may continue to squeeze portion 15A until after microneedle 25 is inserted into the tissue as desired and until any bounce-back forces have subsided. Then, by removing the force applied to portion 15A and allowing housing 15 to at least partially restoratively deform (i.e.
return to its un-deformed shape), pawls 40A, 40B may move apart from one another such that locking mechanism 40 is released from backing 20 and backing 20 is free to move in reverse direction 80 as the tissue expands, and/or as wheal, W, forms.
In some embodiments, to ensure that sufficient transverse direction 85 force is applied to housing 15 to engage locking mechanism 40, housing 15 may be constructed such that it may elastically deform upon application of force in directions 85 until a certain point wherein a rigid (or semi-rigid) stop prevents additional deformation. In this way, a user may discern that sufficient force has been applied to housing 15 to engage locking mechanism 40 when it is no longer possible (or becomes noticeably more difficult) to deform housing 15 in directions 85. Such a rigid (or semi-rigid) stop may be achieved in various ways, such as with an internal skeleton, a rigid internal stop, or through material choice. In some embodiments, the same amount of deformation of housing 15 may be used to release stops 50 and to engage locking mechanism 40.
Locking mechanism 40 may be released in other ways. For example, in the case that locking mechanism 40 comprises one or more solenoid actuators, the actuators may be caused to release by the push of a button or in response to information from one or more sensors.
Once locking mechanism 40 is released, backing 20 is permitted to move in reverse direction 80. Fluid may be injected into the tissue and the tissue may be allowed to expand in reverse direction 80 (e.g. form a wheal W), as depicted in
A biasing member (e.g. a spring, torsion spring, elastomeric element, or the like) may apply force to first and second locking members 141, 142 (e.g. torque around pivots 141B, 142B), such that ends 141D, 142D of locking members 141, 142 are biased toward each other and ends 141E, 142E of locking members 141, 142 are biased apart from one another.
In some embodiments, ends 141D, 142D may function as first and second stops 150A, 150B (similar to stops 50). In such embodiments, first and second stops 150A, 150B are biased toward backing 120 such that a portion of backing 120 abuts each of first and second stops 150A, 150B thereby preventing movement of backing 120 in direction 75.
First and second locks 141, 142 comprise first and second pawls 141A, 142A. In some embodiments, first and second pawls 141A, 142A are provided by ends 141 E, 142E of first and second locks 141, 142. In other embodiments, first and second pawls 141A, 142A are provided by other projecting members, such as, for example, is depicted in the
As ends 141D, 142D are biased toward each other (e.g. toward backing 120), first and second pawls 141A, 142A are biased apart from one another (e.g. away from backing 120). The biasing force at pivots 141B, 142B may be overcome by applying force in transverse directions 85 to portions 141C, 142C of locks 141, 142. Portions 141C, 142C are located on opposite sides of pivots 141B, 142B as compared to ends 141 D, 142D. As the biasing force at pivots 141 B, 142B is overcome, stops 150A, 150B move apart from one another thereby allowing backing 120 to move in insertion direction 75 due to the force applied by forcer 130. Meanwhile, as stops 150A, 150B move apart, pawls 141A, 142A move together such that pawls 141A, 142A engage sides 120A, 120B of backing 120 as backing 120 travels in insertion direction 75 (as shown in
In particular, as shown in
As pawls 141A, 142A contact teeth 121, 122 while backing 120 is moving in insertion direction 75, pawls 141A, 142A first contact beveled insertion-direction faces 121C, 122C. Insertion-direction faces121C, 122C may be beveled with bevel angles which cause pawls 141A, 142A to move away from each other (either by movement/deformation of pawls 141A, 142A or by movement/deformation of other elements locks 141, 142), thereby allowing backing 120 to continue to travel in insertion direction 75.
On the other hand, if a net force applied to backing 120 was directed in second direction 80, pawls 141A, 142A protrude into, and are lockingly engaged in, concavities 121B, 122B. When pawls 141A, 142A project into concavities 121B, 122B, reverse-direction faces 121A, 122A may be shaped (e.g. relative to the extension directions of pawls 141A, 142A) to prevent movement of backing 120 in reverse direction 80. Accordingly, pawls 141A, 142A allow backing 120 to travel in insertion direction 75 such that microneedle 125 may be inserted into the tissue and pawls 141A, 142A (in conjunction with teeth 121, 122) prevent backing 120 from travelling in reverse direction 80, thereby mitigating against bounce-back which could cause microneedle 125 to withdraw from the tissue.
Once microneedle 125 is inserted into the tissue as desired, the applied force in directions 85 on portions 141C, 142C of locks 141, 142 may be released, thereby allowing the biasing members to cause pawls 141A, 142A to move apart from one another as shown in
Similar to apparatus 10 described above, backing 220, microneedle 225 and/or at least some of forcer 230 may be contained in a housing 215. Housing 215 may be substantially similar to housing 15.
Forcer 230 may comprise any suitable forcer capable of applying force against backing 220 in direction 75. Forcer 230 may be substantially similar to forcer 30. Forcer 230 may comprise a store of potential energy wherein at least a portion of the potential energy stored in forcer 230 is released as forcer 230 operates from its retracted configuration to its extended configuration. In some embodiments, at least some of the potential energy of forcer 230 remains in the store after insertion of microneedle 225 in the tissue.
Apparatus 200 may differ from apparatus 10 in that forcer 230 does not “fire” backing 220 (as a projectile) in insertion direction 75. Instead, forcer 230 remains in contact with, and continues to apply force in insertion direction 75 to, backing 220 until, and for at least a period of time after, microneedle 225 is inserted into the tissue. In this way, forcer 230 may continue to apply force to backing 220 in insertion direction 75 to mitigate bounce-back of microneedle 225 upon impact with the tissue, thereby ensuring that microneedle 225 does not undesirably withdraw from the tissue in reverse direction 80.
Once microneedle 225 is inserted into the tissue as desired and after any associated bounce-back forces have subsided, forcer 230 may be disengaged from backing 220 by forcer withdrawal mechanism 240, as depicted in
For example, in the illustrated embodiment, forcer withdrawal mechanism 240 comprises a collar 240A. Collar 240A has an internal diameter that is greater than the external diameter of backing 220, so that collar 240A and backing 220 can move freely relative to one another in insertion direction 75 or reverse direction 80. Collar 240A may be co-axial or substantially co-axial with backing 220 such that collar 240A does not interfere with backing 220 as backing 220 travels in insertion direction 75 to insert microneedle 225 into the tissue as depicted in
Collar 240A may have a height hc that is less than a height hb of backing 220 such that forcer 230 does not contact collar 240A when microneedle 225 is inserted into the tissue (see
Collar 240A may be caused to move in reverse direction 80 by applying force to one or more tabs 240B attached to collar 240A. In some embodiments, the tabs 240B may protrude through housing 215. Collar 240A may be moved in reverse direction 80 by applying force to tabs 240B, for example, manually, by magnetic force, by one or more motors, by one or more pulleys, by a wind-up mechanism, etc. Once collar 240A is moved in reverse direction 80 such that forcer 230 no longer engages backing 220, and backing 220 is free to move with the expansion of the tissue in reverse direction 80 (e.g. as a wheal is formed in response to injection of fluid through microneedle 225).
A locking mechanism may be provided to hold collar 240A in place after forcer 230 is moved in reverse direction 80 and disengaged from backing 220. The locking mechanism may comprise one or more protrusions or bumps that may deform (or that may be supported by a deformable material) such that collar 240A is allowed to engage the protrusions or bumps and is then prevented from moving back in insertion direction 75 by such protrusions or bumps. In some embodiments, tabs 240B of collar 240A be lockingly engaged by housing 215 (e.g. by rotation of collar 240A about the needle axis). In some embodiments, an actuator applies continuous force against collar 240A to prevent collar 240A from moving back in insertion direction 75. In some embodiments, an additional forcer is provided to restrain collar 240A. In some embodiments, collar 240A is restrained manually.
Forcer 330 may comprise any suitable forcer capable of applying force against backing 320 by extending in direction 75 and capable of withdrawing force from backing 320 by retracting in reverse direction 80. For example, forcer 330 may comprise an electromechanical forcer capable of moving in insertion direction 75 and in reverse direction 80, or may be manually operated. In this way, forcer 330 may apply force in insertion direction 75 against backing 320 and then disengage from backing 320 by moving in reverse direction 80, as needed.
Apparatus 300 may also be similar to apparatus 200 in that forcer 230 may remain in contact with, and continue to apply force in insertion direction against, backing 320 until and for at least a period of time after microneedle 325 is inserted into the tissue and any bounce-back forces have subsided. In this way, forcer 330 may continue to apply force to backing 320 in insertion direction 75 to reduce bounce-back of microneedle 325 upon impact with the tissue, thereby ensuring that microneedle 325 does not undesirably withdraw from the tissue.
Once microneedle 325 is inserted into the tissue as desired, forcer 330 may be disengaged from backing 320, as depicted in
As can be seen from
To allow forcer 430 to go from its retracted state to its extended state and to apply force which causes backing 420 to move in insertion direction 75, force may be applied in X-axis transverse directions 85 to portion 415A of housing 415. As can be seen by comparing
In some embodiments, the deformation of housing 415 is elastic and after the forces applied to housing 415 in direction-axis transverse directions 85 are released, housing 415 restoratively deforms to (or close to) its original shape. This is not necessary. In other embodiments, housing 415 plastically deforms and might only be used once.
As forcer 430 extends in insertion direction 75, forcer 430 forces backing 420 in insertion direction 75 toward the tissue until microneedle 425 contacts and is inserted into the tissue, as depicted in
Once microneedle 425 is inserted into the tissue as desired, forcer withdrawal mechanism 440 may be employed to disengage forcer 430 from backing 420. In the illustrated embodiment, forcer withdrawal mechanism 440 comprises a collar 440A that is translatable in insertion direction 75 and in reverse direction 80. Collar 440A is substantially similar to collar 240A described herein. Collar 440A comprises a pair of tabs 440B for applying force to collar 440A in reverse direction 80. Collar 440 comprises a shoulder 440C that can abut a portion of forcer 430. By applying force to collar 440A in reverse direction 80, shoulder 440C abuts forcer 430 and moves forcer 430 in reverse direction 80 to disengage forcer 430 from backing 420. Collar 440A may be held in place (e.g. prevented from moving back in insertion direction 75) by one or more features, such as those discussed in relation to collar 240A. By disengaging forcer 430 from backing 420, backing 420 and microneedle 425 become free to move in directions 75, 80 as the tissue expands or contracts due to the injection of fluid via conduit 435 and the corresponding formation of a wheal or due to the extraction of matter from the tissue.
Adhesive surface 540 may be a surface of backing 520 or may be attached to backing 20 in any suitable manner such that adhesive surface 540 contacts the tissue when microneedle 525 is inserted into the tissue, as shown in
Adhesive surface(s) 540 may surround or partially encircle (although this does not require that adhesive surface(s) 540 are circular in shape) microneedle 525 (e.g. in a plane extending into and out of the page in
After microneedle 525 is inserted into the tissue as desired, microneedle 525 may be used to, for example, inject fluid into the tissue, sense and/or monitor interstitial fluid (ISF), blood, skin composition, etc., apply electrical current to the tissue, extract matter from the tissue etc. In the
Forcer 630 is selectably operable between a retracted state (as depicted in
Forcer 630 may comprise any suitable forcer capable of applying force against backing 620 by extending in direction 75 and capable of being released, as discussed further below. For example, in the depicted embodiment, forcer 630 comprises a spring.
Forcer 630 may be naturally biased toward its extended state and may be held in the retracted state by one or more stops or stop-mechanisms (also referred to as a “catch”). For example, in the
Stops 650 may comprise any suitable stopping mechanism. In some embodiments, stops 650 comprise one or more protrusions or flanges extending from an interior surface of housing 615 (or another part of apparatus 600). Stops 650 may physically engage (e.g. abut against) backing 620 and/or forcer 630. Stops 650 may be physically disengaged from backing 620 or forcer 630 using any suitable technique. In the illustrated embodiment of
In the
While the
In other embodiments, backing 620 may be released from stops 650 by rotating backing 620 relative to second section 619 of housing 615. For example, backing 620 may be configured such that if backing 620 is rotated sufficiently in relation to section portion 619, stops 650 no longer engage backing 620 and backing 620 is free to move relative to second section 619 of housing 615. In some embodiments, backing 620 is rotated relative to second section 619 of housing 615 by rotating first section 617 of housing 615. In some embodiments, insertion direction 75 movement of first section 617 relative to second section 619 may cause rotation of backing 620 due to, for example, abutment of one or more beveled surfaces of backing 620 with one or more beveled surfaces of first section 617 and/or second section 619.
Apparatus 600 may also be similar to apparatus 200 in that forcer 630 may remain in contact with, and continue to apply force in insertion direction against, backing 620 until and for at least a period of time after microneedle 625 is inserted into the tissue and any bounce-back forces have subsided. In this way, forcer 630 may continue to apply force to backing 620 in insertion direction 75 to reduce bounce-back of microneedle 625 upon impact with the tissue, thereby ensuring that microneedle 625 does not undesirably withdraw from the tissue.
Once microneedle 625 is inserted into the tissue as desired, forcer 630 may be released. In some embodiments, releasing forcer 630 may comprise disengaging a proximal end 630A of forcer 630 from backing 620. In other embodiments, releasing forcer 630 may comprise releasing a distal end 630B of forcer 630. For example, in the
Referring now to
In the
First and second flanges 632A, 632B may be forced out of slots 617C, 617D in a radially inward direction 85 to allow relative movement in the forward direction 75 and/or reverse direction 80 between forcer support 632 and housing 615 to thereby release forcer 630. Forcing first and second flanges 632A, 632B out of slots 617C, 617D may comprise deforming support 632 or pivoting one or more portions of support 632 (not depicted). In some embodiments, first and second flanges 632A, 632B are manually forced out of first and second slots 617C, 617D in a radially inward direction by applying a force to each of first and second flanges 632A, 632B in radially inward direction 85. In other embodiments, applying force to first section 617 of housing 615 in the forward direction 75 may cause first and second flanges 632A, 632B to move in radial inward direction 85 and out of first and second slots 617C, 617D. In some embodiments, first and second flanges 632A, 632B may be disengaged from first and second slots 617C, 617D if force applied to housing 615 in insertion direction 75 after backing 620 disengages from stops 650. In this way, a single application of force to first section 617 may cause backing 620 to disengage from stops 650 (to thereby allowing forcer 630 to cause microneedle 625 to penetrate the tissue) and may cause flanges 632A, 632B to disengage slots 617C, 617D (to thereby release forcer 630 and allow backing 620 to move with the tissue and/or allow a wheal to form).
Once flanges 632A, 632B move radially inwardly and out of slots 617C, 617D, reverse direction 80 force applied by distal end 630B of forcer 630 may cause support 632 to continue to move in reverse direction 80 relative to first section 617 of housing 615. In some embodiments, to guide movement of flanges 632A, 632B in radially inward direction 85 while support 632 continues to move in reverse direction 80 relative to first section 617 of housing 615, edges 617E, 617F may be beveled so as to face at least partially in a radially inward direction 85. As first and second flanges 632A, 632B abut against edges 617E, 617F due to the reverse direction 80 forcer of forcer 630, first and second flanges 632A, 632B may be caused to move radially inwardly until first and second flanges 632A, 632B disengage (e.g. cease to abut) edges 617E, 617F. Such movement of flanges 632A, 632B may comprise, for example, deformation of at least a portion of forcer support 632 or pivoting of one or more pivotable arms of support 632 attached to flanges 632A, 632B (not depicted).
In other embodiments, flanges 632A, 632B may be released from slots 617C, 617D by rotating first section 617 of housing 615 relative to second section 619 of housing 615.
For example, in some embodiments, a portion of second section 619 of housing 615 may prevent forcer support 632 from rotating relative to second section 619 which may cause flanges 632A, 632B to rotate (relative to first section 617C) out of slots 617C, 617D when first section 617 of housing 615 is rotated relative to second section 619 of housing 615. Flanges 632A, 632B may be beveled to facilitate such movement. In some embodiments, insertion direction 75 movement of first section 617 relative to second section 619 may cause backing support 632 to rotate (e.g. due to abutting beveled surfaces of support plate 632 and first and/or second sections 617, 619) which may cause flanges 632A, 632B to rotate out of slots 617C, 617D.
When flanges 632A, 632B are disengaged from slots 617C, 617D, forcer support 632 is free to move in reverse direction 80, thereby allowing forcer 630 to achieve its extended state, reduce the force applied to backing 620 and allow backing 620 to move with the tissue and/or a wheal as it forms, as shown in
Like the
As in the
As backing 720 travels in insertion direction 75 toward the tissue, locking mechanism 740 may engage backing 720 to mitigate against bounce-back. In the illustrated embodiment of
Locking mechanism 740 may comprise any suitable locking mechanism for effecting such one-way motion of backing 720 and microneedle 725. In some embodiments like the
The concavities 740A, 740B of locking mechanism 740 may be formed by one or more teeth 740C, 740D on an inner surface of second section 719 of housing 715. To allow backing 720 to travel in insertion direction 75, surfaces of the prongs 720B, 720C that face at least partially in insertion direction 75 (e.g. have normal vectors with components in insertion direction 75) may be beveled such that the teeth 740C, 740D slide relatively easily (e.g. without significant decelerating force in reverse direction 80) along the beveled portion of the prongs 720C, 720D as backing 720 travels in insertion direction 75. In some embodiments, such motion of backing 720 in insertion direction 75 may comprise deformation of one or more of prongs 720C, 720D, sides 720A, 720B of backing 720, teeth 740C, 740D of locking mechanism 740 and second section 719 of housing 715. In some embodiments, the bevel angle of the surface of teeth 740C, 740D may additionally or alternatively be shaped to permit motion of backing 720 relative to teeth 740C, 740D in insertion direction 75.
On the other hand, to prevent backing 720 from travelling in reverse direction 80 opposed to insertion direction 75, surfaces of prongs 720C, 720D that face at least partially in reverse direction 80 (e.g. have normal vectors with components in reverse direction 80) may be beveled such that prongs 720C, 720D are guided into concavities 740A, 740B and backing 720 is incapable of sliding relative to teeth 740C, 740D to travel in reverse direction 80. In some embodiments, the bevel angle of the surface of teeth 740C, 740D may additionally or alternatively be shaped to guide prongs 720C, 720D into concavities 740A, 740B and prevent motion of backing 720 prongs 720C, 720D in reverse direction 80. In the locked configuration, locking mechanism 740 permits motion of at least a portion of backing 720 in insertion direction 75 from a first side one or more teeth 740C, 740D to a second side of the one or more teeth 740C, 740D and interaction between one or more teeth 740C, 740D and backing 720 prevents motion of the at least a portion of backing 720 in reverse direction 80 from the second side of one or more teeth 740C, 740D to the first side of the one or more teeth 740C, 740D.
In practice, as forcer 730 extends from its retracted configuration (
After microneedle 725 is inserted into the tissue as desired, microneedle 725 may be used to, for example, inject fluid into the tissue, apply electrical current to the tissue, extract matter from the tissue etc. In the
Locking mechanism 740 may be released by any suitable mechanism or using any suitable method. In some embodiments, a locking mechanism release 745 allows locking mechanism 740 to be released by applying force to housing 715 in insertion direction 75, to thereby cause at least a portion of housing 715 to deform (elastically or plastically) disengage prongs 720C, 720D from concavities 740A, 740B and teeth 740C, 740D to allow reverse direction 80 movement of backing 720.
Locking mechanism release 745 may function in a substantially similar way to how stops 650, 750 are released. For example, In the
In other embodiments, locking mechanism 740 may be released by rotating first section 717 relative to second section 719 and/or by rotation backing 720 relative to second section 719. In some embodiments, backing 720 may be configured such that if backing 720 is rotated sufficiently in relation to section portion 719, prongs 720C, 720D no longer engage 740A, 740B and teeth 740C, 740D of locking mechanism 740 and backing 720 is free to move relative to second section 719. In some embodiments, applying force to first section 717 in insertion direction 75 may cause backing 720 to rotate relative to second section 719 thereby releasing backing 720 from locking mechanism 740. In such embodiments, backing 720 and one or more of first and second sections 717, 719 may comprise abuttable beveled portions that are arranged to translate linear motion of first section 717 relative to second section 719 into rotational motion of backing 720 and prongs 720C, 720D.
Once locking mechanism 740 is released, backing 720 is permitted to move in reverse direction 80. Fluid may be injected into the tissue and the tissue may be allowed to expand in reverse direction 80 (e.g. form a wheal), as depicted in
Where a component is referred to above, unless otherwise indicated, reference to that component (including a reference to a “means”) should be interpreted as including as equivalents of that component any component which performs the function of the described component (i.e. that is functionally equivalent), including components which are not structurally equivalent to the disclosed structure which performs the function in the illustrated exemplary embodiments of the invention.
Unless the context clearly requires otherwise, throughout the description and any accompanying claims (where present), the words “comprise,” “comprising,” and the like are to be construed in an inclusive sense, that is, in the sense of “including, but not limited to.” As used herein, the terms “connected,” “coupled,” or any variant thereof, means any connection or coupling, either direct or indirect, between two or more elements; the coupling or connection between the elements can be physical, logical, or a combination thereof. Additionally, the words “herein,” “above,” “below,” and words of similar import, shall refer to this document as a whole and not to any particular portions. Where the context permits, words using the singular or plural number may also include the plural or singular number respectively. The word “or,” in reference to a list of two or more items, covers all of the following interpretations of the word: any of the items in the list, all of the items in the list, and any combination of the items in the list.
As will be apparent to those skilled in the art in the light of the foregoing disclosure, many alterations and modifications are possible in the practice of this invention without departing from the spirit or scope thereof. For example:
While a number of exemplary aspects and embodiments have been discussed above, those of skill in the art will recognize certain modifications, permutations, additions and sub-combinations thereof. It is therefore intended that the following appended claims and claims hereafter introduced are interpreted to include all such modifications, permutations, additions and sub-combinations as are consistent with the broadest interpretation of the specification as a whole.
This application is a continuation of Patent Cooperation Treaty (PCT) application No. PCT/CA2018/051307 having an international filing date of 17 Oct. 2018, which in turn claims priority from US application No. 62/573570 filed 17 Oct. 2017. Both PCT application No. PCT/CA2018/051307 and US application No. 62/573570 are hereby incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| 62573570 | Oct 2017 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/CA2018/051307 | Oct 2018 | US |
| Child | 16845053 | US |
