This invention relates to a medical applicator for applying an occlusive plug to a fallopian tube of a female.
For female sterilization the known Filshie procedure using the known Filshie clip system is recognised as the leading surgical procedure worldwide, accounting for over 80% of female sterilisations in England and Canada, and having a low failure rate of around 0.27%. The Filshie clip system involves making an incision in the patient's abdomen and fitting a removable clip around each of the patient's fallopian tubes and therefore requires post operative care and a hospital stay.
As an alternative to the Filshie clip, the plugging of fallopian tubes as a medical procedure has been known both in principle and in practice for some years as a means of sterilisation. These procedures avoid abdominal surgery and involve the use of a medical applicator inserted in to the patient's womb via the vagina, and are therefore less traumatic than abdominal surgery. Examples of the techniques are known in WO 97/12569, and WO2007/072004.
WO97/12569 discloses a hysteroscope used for insertion of a self tapping screw occlusive plug into the fallopian tubes, and using a flexible tube applicator having an octagonal head connector for attaching to an occlusive plug.
However, the fitting of a plug into a fallopian tube is not without its difficulties despite the availability of hysteroscopic vision to aid the medical practitioner.
An object of the present invention is the provision of an improved applicator for use in the fitting of an occlusive plug of the screw-in kind to a fallopian tube.
According to one aspect of the present invention, there is provided a medical applicator for use in female sterilisation of a fallopian tube, said applicator comprising:
a body member;
an elongate probe carried by, and projecting from one end of the body member;
a viewing means extending along the probe to an end of the probe distal from the body member;
a connector piece movably mounted at said distal end of the probe;
means for varying the position of the connector with respect to a main length of said probe; and
a rotational drive means extending between the body member and the connector to apply rotational movement to said connector.
According to a second aspect there is provided an applicator for use in the fitting of an occlusive plug of the screw in type to a fallopian tube, said applicator comprising:
an elongate probe member, said probe member comprising:
an elongate hollow tubular member;
an elongate flexible drive shaft extending along said tubular member to a distal end of said probe;
wherein said hollow tubular member, comprises at a distal end, a deflectable nose portion which can be controllably directed in a direction making an angle in the range 0 to 60 degrees to a main length direction of said probe.
According to a third aspect there is provided an applicator for use in the fitting of an occlusive plug of the screw in type to a fallopian tube, said applicator comprising:
an elongate probe member;
a drive shaft extending along said probe member;
an electric stepper motor connected to said drive shaft; and
a controller for controlling operation of said stepper motor;
wherein said electric stepper motor is configured to drive said drive shaft in a clockwise or an anti-clockwise direction.
According to a fourth aspect there is provided an applicator for use in the fitting of an occlusive plug said applicator comprising:
an elongate probe;
a connector at a distal end of said probe, for connecting to an occlusive plug;
a fluid tube extending along said probe for carrying fluid to a distal end of said probe;
a fibre optic viewing cable extending along said probe for viewing at a distal end of said probe from a viewing position at a near end of said probe;
an fibre optic light transmission cable for conducting light from said near end of the probe to said distal end of the probe for illuminating said distal end of said probe;
wherein said fluid channel, said fibre optic viewing cable and said fibre optic light transmitting cable are all formed into a single unitary flexible cable extending along a length of said probe.
According to a fifth aspect there is provided a method of using an applicator, said applicator comprising:
a body member;
an elongate probe carried by, and projecting from one end of the body member;
a viewing means extending along the probe to an end of the probe distal from the body member;
a connector piece movably mounted at said distal end of the probe;
means for varying the position of the connector with respect to a main length of said probe; and
a rotational drive means extending between the body member and the connector to apply rotational movement to said connector,
said method comprising:
fitting an occlusive plug to said connector;
inserting said probe into a neck of a womb;
deflecting said distal end of said probe to point towards a cornu region;
using said viewing means to view a region around said distal end of said probe;
locating a forward end of said occlusive plug at an ostium;
operating said rotational drive means to rotate said connector a predetermined number of revolutions to drive said occlusive plug into said ostium; and
detaching said connector from said occlusive plug.
According to a sixth aspect there is provided a method of female sterilisation using an elongate uterine probe, said uterine probe comprising:
(i) a viewing means extending along the probe to a distal end of the probe;
(ii) a connector piece movably mounted at said distal end of the probe for connecting to an occlusive plug;
(iii) means for varying the position of the connector with respect to a main length of said probe; and
(iv) a rotational drive means operable to apply rotational movement to said connector;
said method comprising:
fitting an occlusive plug to said connector at said distal end of said probe;
inserting said probe into a neck of a womb;
deflecting said distal end of said probe within a uterine cavity, to point towards a cornu region;
using said viewing means to view a region around said distal end of said probe;
locating a forward end of said occlusive plug at an ostium;
operating said rotational drive means to rotate said connector to drive said occlusive plug into said ostium; and
detaching said connector from said occlusive plug.
According to a seventh aspect there is provided a method of reversing a female sterilisation caused by an occlusive plug positioned in a fallopian tube of a female, using a uterine probe, said probe comprising:
(i) a viewing means extending along the probe to a distal end of the probe;
(ii) a connector piece movably mounted at said distal end of the probe for connecting to an occlusive plug;
(iii) means for varying the position of the said distal end of the probe with respect to a main length of said probe; and
(iv) a rotational drive means operable to apply rotational movement to said connector;
said method comprising:
inserting said probe into a neck of a womb;
deflecting said distal end of said probe within a uterine cavity, to point said distal end towards a cornu region;
using said viewing means to view a region around said distal end of said probe to locate an end of an occlusive plug protruding from an ostium;
locating said connector at said protruding end of said occlusive plug and attaching said connector to said protruding end;
operating said rotational drive means to rotate said connector to withdraw said occlusive plug from said ostium.
The invention includes an applicator for use in the fitting of an occlusive plug of the screw-in kind to a fallopian tube comprising:
Other aspects are as set out in the claims herein.
Specific embodiment applicators disclosed herein may provide a single instrument with which a practitioner may, aided by hysteroscopic vision, accurately locate a leading end of a screw type occlusive plug in the lumen of a fallopian tube, by firstly applying any angular adjustment of the plug that may be necessary to locate the nose of a plug at an ostium, and when so located, by rotating the plug to screw it further into the fallopian tube, for example by a distance of up to 20 mm, so that the plug effects a self-retaining engagement of the lumen.
For a better understanding of the invention and to show how the same may be carried into effect, there will now be described by way of example only, specific embodiments, methods and processes according to the present invention with reference to the accompanying drawings in which:
There will now be described by way of example a specific mode contemplated by the inventors. In the following description numerous specific details are set forth in order to provide a thorough understanding. It will be apparent however, to one skilled in the art, that the present invention may be practiced without limitation to these specific details. In other instances, well known methods and structures have not been described in detail so as not to unnecessarily obscure the description.
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Casing
The casing 1 is formed of two approximately mirror image shell halves 13, 14 which surround the front end of the eyepiece, and other internal components such as the switch 9, stepper motor 7, stepper motor printed circuit board, and part of the fluid tubes and fibre optic cables. At the rear of the casing is provided a cover portion 15 for covering the optics at the front of the eyepiece, which is removable separate from the casing shell halves 13, 14 for inspection of the front end of the eye piece, and the end of the viewing fibre optic. The casing shell halves 13, 14 may be provided with slots or apertures 16, to allow air to flow through the casing for cooling of the step motor 7.
A front portion 17 of the outer casing 1 may provide a curved trough shaped recess which allows viewing of the near or proximal end of the probe, and in particular to allow viewing of the flexible drive shaft, and an elongate spring which extends along the length of the probe for bending the nose end of the probe 6. The flexible drive shaft 8 protrudes through an aperture in the trough portion of the casing, before entering an open end of the tubular probe 4. This allows the operator to visually check that the drive shaft is rotating, without the need to remove the probe from the patient's body.
In other embodiments, the trough 16 at the front end of the casing may be covered with a transparent see through plastics cover.
In a preferred embodiment, the casing has a length, excluding eye piece and excluding the probe member in the range 200 mm to 280 mm, and preferably of the order of 267 mm; a maximum width in the range 40 mm to 60 mm, and preferably of the order of 50 mm; and a maximum height in the range 58 mm to 78 mm, and preferably of the order of 68 mm.
Preferably the two shell halves of the casing are connected together by a plurality of screws. Similarly, the rear cover 15 is retained to the casing shell halves by a pair of small screws.
Probe
The probe 4 comprises an elongate rigid tubular member 8, having a rotatable drive rod passing there through, which can rotate relative to the rigid tube 8. A distal end of the drive member is fitted with a bayonet fitting type socket connector 9, comprising a substantially cylindrical hollow tubular member having a pair of diametrically opposed slots, for engaging with a substantially cylindrical end of the plug, where the end of the plug has a pair of radially extending bayonet type protrusions, which engage with the slots in the hollow cylindrical end of the bayonet connector of the probe. In use, the plug can be inserted into a fallopian tube on the end of the probe, rotated in a first direction to drive the plug along the fallopian tube, for example by distance of up to 20 mm, and then the rotational direction of the drive means is reversed, to disengage the bayonet socket from the end of the plug, thereby leaving the plug in situ within the fallopian tube. Subsequently, the probe member can be removed from the patient's body.
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The tubular wall 600 of the probe is substantially rectangular in cross section, but having rounded corners 601. At the distal end of the tube comprising the nose portion of the probe, the tube has a window portion 602 whereby 3 sides of the tube are removed over a distance of around 15 mm to 35 mm, and leaving only one side 603 of the tube present. At the distal end of the tube, the tube provides a loop 604, through which the drive shaft 8 and multi-function cable 6 pass.
Secured to the end loop 604 of the tube 600, a strip 605 is provided, being preferably a leaf spring which is flexible enough to bend to allow the nose to bend to an angle of up to 60°, but rigid enough to be able to push or pull the loop 604 on the end of the probe so that the end loop 604 can be deflected, either side of a straight ahead or axial direction of the main probe tubular body. The leaf spring is located substantially parallel with and spaced apart from the exposed tube side 603, so that the leaf spring faces opposite the sidewall 603 across a gap.
Both the multi-function cable 607, and the flexible drive rod 8 pass through the hollow tube 600 and protrude from the distal end of the tube. As shown in
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The probe comprises a hollow tube 600, manufactured from a bendable material, for example medical grade polycarbonate, or a metal alloy, the material being selected such that when the tube is fully integral having a solid tubular surface, the tube is substantially rigid, but will allow a slight degree of flexing by a few degrees over its length, and such that at a distal end of the tube, with a section of tube wall removed such that only one side wall portion 603 remains, the material will flex enough to bend over an angle of up to 60° with respect to the inline position, without the material of the tube fracturing.
Multi-Function Cable
In a best mode, running in parallel inside the rigid tubular member, there is provided a multi function cable 609 which consists of a tubular passage for transporting fluid from the fluid flush inlet 13 to the distal end of the probe such that a clear fluid can be inserted into a patient's womb at the end of the probe, thereby giving expansion of the womb cavity and enabling the end of the probe to be more easily moved around within the womb; a light conducting fibre optic cable or cable bundle 610,611, for transmitting light from the light source to the end of the probe and illuminating the area of the womb within the immediate vicinity of the probe nose; and a fibre optic viewing cable 612 arranged to view in a direction along the end of the nose, so as to see the occlusive plug and the womb wall in the immediate area in front of the plug via the eye piece 3.
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Slideable Insertion Sheath
Along the probe, and surrounding the probe is provided a slidable protective sheath 700 comprising a hollow tube surrounding the outside of the probe. The function of the tubular sheath is to aid insertion of the probe into the patient's womb, whilst at the same time providing a covering for the nose portion of the probe which holds the occlusive plug. Since the occlusive plug is relatively small and held in place by a connector, the sheath protects the plug against detachment from the end of the probe during the initial insertion of the probe through the cervix and through towards the ostium of the patient. The distal end of the tubular sheath has a chamfered end to aid insertion and removal, and so as to provide a relatively blunt end to the probe during initial insertion of the applicator.
The sheath can be slid back to expose the nose of the probe when the probe is in situ in the womb, and sliding the sheath back then allows deflection of the nose portion relative to the main elongate axis direction of the probe.
The end of the sheath nearest or proximal to the body 2 of the applicator is provided with a plate 18 which allows the medical practitioner to grasp the end of the sheath and either withdraw or extend the sheath relative to the end of the probe, that is, to slide the sheath backwards or forward along the probe.
The plate 18 also allows the medical practitioner to judge the depth of the probe within the patient's body, and to judge the position of the probe relative to the length of the probe.
On withdrawal of the probe from the patient's body, once the nose end of the probe is straightened, the sheath can be slid back over the probe end, whilst the end of the probe is still in the uterine cavity, and this protects the end of the probe against snagging on removal, and if a plug is attached, prevents the plug detaching from the probe end and becoming loose in the uterine cavity.
Drive Mechanism
The drive mechanism for rotating the bayonet socket and rotating the plug comprises the electric stepper motor 7, operated by a forward-off-reverse switch 9 located on the underside of the body; the electric motor 7 being connected via a gearbox to the flexible torsional drive rod 8 which passes through the rigid tubular member 600, and at a distal end of which is fitted the bayonet socket 608. The electric motor can be driven in a forward or a reverse direction by operation of the forwards/backwards switch, and its speed may be reduced by gearing in the optional gearbox. Preferably a gear ratio of 1:6 is provided to reduce the motor speed.
The drive electronics to the stepper motor incorporates a means to induce step wise rotation of the drive shaft so as to induce vibration at the nose assembly, so as to vibrate the bayonet fixing end of the plug from the bayonet socket end of the drive mechanism, when in situ in the fallopian tube. Hence, the medical practitioner, by using the touch switch 9 can effect various modes of operation of the drive shaft as follows:
In the general case, the electric drive to the stepper motor may be programmable by the practitioner to achieve a set of drive speeds and angular rotational movement profiles to best suit the medical conditions of patients, and optimized for accuracy and controllability of the plug rotation and manipulation within the body.
Eye Piece and Optics
Eye piece 3 comprises a substantially tubular molding of synthetic plastics material, having a plurality of lenses arranged to focus on one end of the fibre optic cable. Within the optics inside the eye piece housing, is provided a light splitter, to allow light from the light source to be either passed down the fibre optic viewing cable to illuminate the end of the nose assembly, or through one or more separate light conducting fibre optic cables. The fibre optic viewing cable preferably comprises one or more multi-mode fibres, through which an image can be viewed at the end of the nose assembly, as magnified by the lenses and prisms within the optics set within the eye piece housing.
The tubular eye piece 3 is aligned with the end of the viewing fibre optic, by fitment into the rear end of the casing 1, which holds a near end of the fibre optic viewing cable. The fibre optic viewing cable itself comprises one or a plurality of multi-mode glass or plastics fibre optic cables as are known in the art. The viewing fibre optic cable has a near end which is positioned at a focal point of the eye piece 3, and a distal end positioned at the end of the probe behind the end of the flexible drive shaft, so as to allow viewing of the end of the flexible drive shaft through the eye piece. Since the optical fibre has a degree of flexibility, this allows the viewing optical fibre to bend along with the end of the nose of the probe. The distal end of the viewing optical fibre may be provided with a small dimension lens on the end of the fibre to allow light from the region around the nose portion to be focused on the end of the optical fibre for viewing.
The eye piece is optionally detachable so that a camera can be attached to the end of the optics tube instead of the eye piece, allowing the view to be seen on a monitor screen.
In some embodiments the eye piece may be removable.
Illumination System
The illumination system comprises a universal connector or socket and a focusing lens or mirror. The connector can accept either a detachable battery pack 5, which is provided at one end with a light emitting diode or incandescent light filament light source, or a known dedicated surgical theatre light source.
The light source 5 attaches to the eye piece 3 so that the light couples with the light splitter, which can be for example a prism.
In one embodiment, the light can be split by a prism and sent down the viewing fibre optic cable, so that the same fibre optic cable is used both for viewing, and for delivery of illumination to the end of the probe.
However, in a preferred embodiment and best mode of the invention, the light source is coupled to one or more independent optical fibres the specific function of which is to transmit light from the light source, along the probe member and to illuminate the end of the probe at the nose 6. In the best mode, one or more light conducting optical fibres, and a viewing optical fibre are incorporated into a single multi-function cable which extends from the eye piece to a position immediately rear of the end of the drive shaft at the end of the nose 6 of the probe 4.
Fluid Delivery
The applicator can be connected to an external fluid source via the luer type fluid connector 10 which comprises part of the housing of the optics assembly. In the best mode, where a multi-function cable is used, the cable comprises a hollow tubular passage through which a fluid, for example de-ionized water, or other clear transparent medical grade fluid can be injected. Pressurized fluid flows through the connector 10, into the tubular fluid passage of the multi-function cable and is delivered to the nose or the probe 6. When the probe is inside the body, enough fluid can be delivered to expand the womb cavity, so that the walls of the womb in the region of the ostium are expanded, thereby allowing greater freedom of movement of the end of the probe 6 within the womb cavity. Fluid may be delivered under pressure, for example using an electric pump, or under gravity pressure, for example from a drip feed bag.
Angular Adjustment of the Probe
The nose assembly can be moved angularly with respect to a main length of the probe, so as to deflect the nose assembly within the patient's body by an angle in the range 0° to 60° with respect to an inline position along the main length direction of the probe.
A mechanism for adjusting the angle of the nose comprises an actuation wire, preferably in the form of a nylon filament, which is attached to the nose piece and which extends along the tube 8, and can be pulled by means of a hand operated adjustment wheel 13. Operation of the wheel in a first rotational direction causes tension on the cable and pulls the cable so as to deflect the end of the probe from its normal straight ahead bias position, when under no tension from the cable. Rotation of the wheel in an opposite direction causes the cable to pay out and move back along the probe, so the end of the probe can move back towards its normal unbiased straight ahead position. The position of the wheel can be locked using a friction pad, latch or ratchet, to allow the nose to be kept ant any angular deflection of the nose relative to the main probe length, within its maximum range of deflection, so once set, the operator can leave the probe at a selected angle of deflection. Typically there may be markings on the wheel to indicate angles of deflection of the probe end of 0°, 30°, 40°, 50° and 60°.
In other embodiments, the angular adjustment wheel may be replaced by a cam or pulley attached to a filament, wire or cable.
In other embodiments there may be is provided a rack located internally of the body member which is adapted to be displaced manually to and fro along the body member to allow for angular displacement of the end of the nose relative to the inline or co-axial direction of the probe.
The leaf spring 606 biases the bayonet socket to remain in an inline or co-axial position, unless the angle is deflected via the manually operated nose adjuster wheel.
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Operation of the Applicator
The applicator is deployed as follows. The applicator is prepared for use by inserting new batteries into the light source 5, checking operation of the probe adjuster 10 by turning the thumb wheel, connecting power to the power socket 11, and connecting a fluid supply to the fluid connector 12. The practitioner also checks sliding of the sheath backwards and forwards along the probe, and fits an occlusive plug into the connector at the end of the probe. The sheath is slid over the nose of probe, protecting the occlusive plug.
The practitioner inserts the probe into the female patient's vagina, and at the same time may view the end of the probe through the eye piece 3 and optics, under illumination from the light source. The end of the probe is inserted through the neck of the womb, which needs to be dilated. The sheath of sleeve 700 protects plug on the end of the probe. The practitioner may inject fluid via the fluid connector, which flows out of the end of the fluid pipe in the region around the nose. The fluid distends the uterine cavity so that the operator can see inside the cavity and identify for example the left ostium.
Preferably, the eye piece is adapted so that a television camera can be fitted to the eye piece, allowing the practitioner to see the view through the end of the probe on a known close circuit television system, which is ergonomically more efficient for the surgeon, allowing the surgeon to stand upright whilst manipulating the applicator.
The operator may draw back the sheath, exposing the end of the nose whilst the end of the probe is inside the patient's womb, and may deflect the end of the probe using the deflection control thumb wheel 10, (or in other embodiments, a motor driven preset deflection). Rotation of the thumb wheel in one direction causes deflection of the nose from its straight ahead position, and rotation of the thumb wheel in an opposite direction causes the end of the probe to move towards its normal un-deflected straight ahead position.
The operative identifies the ostium through the viewing system and can manipulate the whole body of the applicator, and deflect the end of the probe to align the occlusive plug with the ostium. The geometry of the probe is designed such that the end of the probe lines up correctly in a direction pointing at the ostium, after insertion through the neck of the womb. The tip of the plug can then be manipulated into the ostium and the medical practitioner can drive the plug in a clockwise direction so that the tip of the plug, which has a self-tapping thread, drives into the end of the fallopian tube whilst being rotated by the rotatable drive shaft 8. Depending on the type of lug used, a predetermined number of rotations may be applied by a single activation of the motor control switch.
In other variants, the speed of rotation may be continuously variable, and the practitioner may drive the plug either in the forward or reverse direction as appropriate under fine speed control of the motor control switch 9.
Once fully inserted, the operative must then detach the plug from the connector 608. However first the practitioner may slightly over-tighten the plug within the fallopian tube, so that the tissue around the ostium compresses at the collar at the end of the plug, and then slightly relax the rotation of the plug before removing the connector. This helps stop any trivial bleeding which may have occurred during insertion of the plug.
Removal of the connector from the end of the plug should be by straight forward withdrawal or pulling of the end of the applicator away from the plug, the plug being retained in the fallopian tube. The dimensions of the connector relative to the dimensions of the end of the plug are selected so that the plug normally stays in place in the connector 608, when being driven clockwise or anti-clockwise, but can easily be slid out of the connector, when the connector is withdrawn in a direction along a main central axis of the plug. However, if there is any sticking of the plug, the operator can apply either clockwise or anti-clockwise rotation of the drive shaft, or in a further mode of operation, the stepper motor is driven to make a series of small angle rotations on a stop-start cycle, with a stop-start duty cycle in the range 5 Hz to 20 Hz, which has the effect of vibrating or shaking the plug free of the end connector 608. A variety of preset rotational or shake cycles are as described herein above.
In the best mode, a single operation of the switch 9 in the forwards direction may be preprogrammed to make between 6 and 9 and preferably 7.5 clockwise revolutions of the drive shaft, followed by one anticlockwise revolution, followed by a shake function to detach the connector from the rear of the plug, (alternate back/forwards step rotations).
The applicator can also be used to reverse a sterilized patient who has a pair of occlusive plugs fitted. Reversal of the sterilization operation is achieved by inserting the applicator into the uterine cavity of the womb, as herein above described, but without any plug attached to the applicator, sliding back the protective sheath once the probe end is in the uterine cavity, deflecting the end of the probe to align with the ostium, identifying the end of the plug protruding from the ostium and attaching the connector 608 of the applicator to the protruding plug end by sliding the connector on to the plug end.
The motor control 9 is operated to rotate the drive shaft 8 in an anticlockwise direction so that the rotational movement of the plug within the fallopian tube urges the plug in a direction out of the tube into the lumen. There will be a certain amount of trauma to the cornu where the plug was fitted at the end of the fallopian tube, however this part of the womb has good regenerative capacity, and will heal up, resulting in a patent lumen capable of conducting sperm and fertilized egg, so a return to fertility can be expected.
The probe end is then withdrawn slightly, and straightened whilst still in the uterine cavity, and the previously retracted protective sheath is slid over the distal end of the probe to cover the occlusive plug on the end of the probe and prevents the plug becoming detached and loose in the uterine cavity. The plug, attached to the end of the drive shaft and the connector 608 can then be removed by withdrawal of the probe through the neck of the womb. The fallopian tube on the other side of the womb is treated similarly.
Preferred/Optional Features
Other specific embodiments and/or variations of the best mode embodiment may comprise any one or more of the following features.
The eye-piece is a generally tubular moulding in a synthetic plastic.
The synthetic plastic is of medical grade polycarbonate.
The eye-piece is provided in a first mounting socket/spigot for the mounting of a light source attachment e.g. of stainless steel, and a second mounting socket/spigot for the mounting of a flushing attachment e.g. of stainless steel.
The eye-piece is provided at its end adjacent the body member with a flanged nose moulding e.g. of rubber, attached to the eye-piece by a screw-on end cap.
The eye-piece is attached to the body member as a push-fit, by inserting a leading end of the eye piece into a rear end portion of the body member.
The nose-piece is movably mounted by attachment to the carrier tube via the sidewall portion 603. A leaf spring arrangement biases the nose-piece to an in-line, co-axial location.
An actuation wire is attached to the nose-piece via a bayonet screw, and extends along the carrier to a spool having an integral spur wheel in engagement with a rack located internally of the body member, which rack is adapted to be displaced manually to and fro along the body member by the practitioner e.g. using a thumb to deflect the spring and hence to rotate the plug to a different angular position from in-line, if such deflection is required to assist in locating the leading end of the plug, as a pilot nose, in the fallopian tube.
The rack is provided with an integral thumb piece located externally of the body member.
From its in-line position, the leaf spring may be deflected by the practitioner, such that the plug is at 30°, 40°, 50° or 60° with respect to the in-line position.
For a plug having an hexagonal trailing end e.g. as disclosed in WO/2007/072004, the nose-piece includes an hexagonal drive socket connected by a flexible drive cable housed in a carrier tube extending along the probe to the manually operable drive system for translating linear or arcuate movement of a trigger, into rotational movement via a step-up gearing.
As an alternative to a bayonet type fixing, a hexagonal trailing end and complementary drive socket may be provided to connect the releasable plug-to-the-nose piece.
Irrespective of the drive connection to the plug at the nosepiece, the applicator also incorporates means, operable by the practitioner, to induce a vibration at the drive connection, to aid disconnection after the plug has been successfully inserted.
In an alternative embodiment, the vibration means may comprise a rotatable, out-of-balance body, which could be drivable by a drive shaft or by electric induction. In the best mode, vibration is achieved by drive of the stepper motor.
In one embodiment, a manually operable drive system comprises a gearbox housing at least two spur gearwheels, with a bevel friction drive to a drive head in which an end of a flexible drive cable is secured.
Preferably, the gearwheels provide a 1:6 ratio, whereby translational movement of the trigger from a start position to a stop position produces six revolutions of the flexible drive cable and hence six revolutions of the plug which, if the plug is as described in PCT/GB2009/002450, would advance the plug by some 20 mm along the lumen of the fallopian tube.
The optional gearbox preferably comprises a casing e.g. of medical grade polycarbonate, with integral pivot pins for receiving the gearwheels e.g. of Nylon (delrin), with a closure cover e.g. of medical grade polycarbonate, secured to the casing by two stainless steel screws.
Preferably, the trigger comprises a ‘C’-shaped loop able to receive a finger of the practitioner, and an integral lever operable to rotate the gearing to rotate the drive cable.
In one embodiment, the probe also houses a flushing tube extending back to the eye-piece.
The mechanical connection between the body member and the nose piece may be manually operable.
The mechanical connection between the body member and the nose piece may be power operable.
The rotatable drive means extending between the body member and the nose piece may be manually operable.
The rotatable drive means extending between the body member and the nose piece may be power operable.
Power operation is preferably by a battery with electronic controls.
Embodiments of the applicator may be designed to be single use disposable, or engineered to be sterilisable for repeated use in an autoclave.
Number | Date | Country | Kind |
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1203994.7 | Mar 2012 | GB | national |
Filing Document | Filing Date | Country | Kind |
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PCT/GB2013/000094 | 3/6/2013 | WO | 00 |