Foetal vacuum extractor

Abstract

The foetal vacuum extractor comprises a proximal handle, a distal suction cup, and a traction member that pulls the suction cup from the handle to provide assistive traction during childbirth. The proximal handle includes a distal portion reciprocally accommodating a proximal portion, with the distal portion defining a neck interfacing the traction member. Shoulders adjacent to the neck provide a gripping surface for opposing forefingers. The handle is manually pumped to operate a mechanical pump that induces suction in the suction cup via a pneumatic tube. A force gauge in the handle, with haptic protrusions extending through the shoulders, provides tactile force feedback to monitor applied tension. The extractor may also include a flexion point marker along the traction member, allowing precise alignment of the suction cup with the foetus's flexion point, and monitoring traction progress.

Description

Foetal Vacuum ExtractorField of the Invention

[0001] The present invention relates to medical devices, specifically to foetal vacuum extractors used during childbirth to assist in the delivery of a baby by providing assistive or corrective traction during childbirth traction to the foetal head.Background of the Invention

[0002] During vaginal childbirth, the foetus must pass through the birth canal after the mother's cervix is fully dilated. This process can be physically demanding due to the relatively large size of the foetal head compared to the dimensions of the birth canal, requiring significant stretching of the vaginal tissues. While natural forces, such as the mother's efforts and uterine contractions, facilitate this process, there are cases where these forces prove insufficient or inappropriate for a safe and timely delivery.

[0003] In particular, difficulties can arise in cases of prolonged or obstructed labour, uterine inertia, maternal exhaustion, foetal distress, or malposition of the foetal head, which can inhibit the progress of labour. These situations may require additional assistance to deliver the foetus safely. Traditional forceps are often used to provide the necessary traction; however, they present certain risks. Forceps, due to their rigid structure, can cause injuries to both the mother and the foetus, including damage to the foetal head and discomfort for the mother.

[0004] To address these risks, alternative methods such as vacuum-assisted deliveries have been developed. However, conventional vacuum extractors come with their own challenges, including difficulties in controlling the amount of force applied, leading to the potential for overtensioning and associated complications. Other difficulties may also include accurately monitoring the progress of the procedure or accurate positioning of the cup at the foetus's flexion point, further complicating the delivery process.

[0005] As such, a need exists for improved methods and devices that can assist with foetal delivery in a controlled and safe manner, minimising risks of injury while ensuring effectiveness in cases where natural forces alone are insufficient.Summary of the Disclosure

[0006] The described foetal vacuum extractor includes a proximal handle, a distal suction cup, and a traction member. The traction member connects the suction cup to the handle and facilitates assistive traction during childbirth by pulling the suction cup from the handle. The proximal handle consists of a distal portion that reciprocally accommodates a proximal portion, with the distal portion defining a neck that interfaces with the traction member. This neck structure provides a robust connection, while the shoulders adjacent to the neck offer a gripping surface for the operator's opposing forefingers, allowing secure handling during use.

[0007] The handle is designed to allow for both pulling and pumping with one hand. The distal and proximal portions are configured to be manually pumped, operating a mechanical pump that interfaces with a pneumatic tube in the traction member to induce suction in the suction cup. This design provides the advantage of ease of operation, enabling the operator to both maintain the grip and create the necessary suction with a single hand, freeing the other hand for additional tasks if needed.

[0008] A feature of the extractor is the inclusion of a force gauge in the handle. The force gauge is displaced by the traction member under tension and includes haptic protrusions that extend through the shoulders of the handle. These protrusions provide tactile feedback to the operator, alerting them to excessive tension without requiring visual confirmation. This is particularly advantageous in vacuum -assisted deliveries, where overtensioning can lead to scalp injuries or complications. The non visual cues allow the operator to focus on the procedure itself, adjusting force intuitively and reducing the risk of injury to the foetus.

[0009] The combined features of the handle design and force gauge enable controlled application of traction while facilitating safety through feedback mechanisms, making the extractor efficient and safe for use in assisted deliveries.

[0010] The foetal vacuum extractor preferably includes a flexion point slider marker positioned along the pneumatic tube of the traction member. It allows the operator to visually track the insertion distance of the suction cup to ensure correct alignment with the foetus's flexion point. Proper alignment of the suction cup with the flexionpoint is critical for effective and safe traction during delivery, as it reduces the risk of incorrect positioning, which can lead to failed vacuum extraction attempts or injury to the foetus. The marker helps the operator measure and monitor the progress of the foetus through the birth canal, providing a reliable visual reference for accurate suction cup placement and traction progress assessment during the procedure. The foetal vacuum extractor preferably also includes a timer which provides a clear indication of the elapsed time during the vacuum-assisted delivery. This is especially beneficial given the recommended time limits for vacuum-assisted deliveries, typically to avoid complications such as prolonged stress on the foetus. The timer is designed to help the operator adhere to these time limits, thus reducing the likelihood of adverse outcomes. The timer may involve a dye wick system, which progresses over a predetermined period, allows for continuous visual monitoring of the procedure's duration without requiring additional external devices.

[0011] According to one aspect, a foetal vacuum extractor is provided, comprising a proximal handle, a distal suction cup, and a traction member. The traction member is configured to pull the suction cup from the proximal handle to provide assistive traction during childbirth. The proximal handle includes a distal portion reciprocally accommodating a proximal portion, with the distal portion defining a neck that interfaces with the traction member. Shoulders adjacent to the neck provide a gripping surface for opposing forefingers, enabling secure handling during the procedure. The distal and proximal portions are manually pumped to operate a mechanical pump, which interfaces with a pneumatic tube in the traction member to generate suction in the suction cup. A force gauge is incorporated into the handle, connected to the traction member, and includes haptic protrusions that extend through the shoulders to provide tactile feedback to the operator's fingers when sufficient force is applied. This arrangement allows the operator to monitor and control the applied force without needing constant visual confirmation, promoting safety and efficiency during delivery.

[0012] Optionally, the force gauge may comprise a wishbone structure having a pair of side slide rails connected to a pneumatic tube engagement. This engagement pneumatically interfaces with the pneumatic tube, and the force gauge provides tactilefeedback when sufficient force displaces both the pneumatic tube engagement and the wishbone. This arrangement ensures reliable force monitoring through a robust mechanical configuration, enhancing the safety of the procedure through detection of excessive force.

[0013] Preferably, a traction cord extends through the pneumatic tube, and cup and gauge beads may be used to secure respective ends of the traction cord. The use of a traction cord in combination with these beads ensures that the traction force is securely transferred through the pneumatic tube, reducing the risk of system failure during use.

[0014] The traction cord may optionally be looped back between the suction cup and the handle, providing a doubled length of the cord within the pneumatic tube. This configuration enhances the durability of the traction system. In another preferable embodiment, the cup bead may include a barb that is configured to receive the traction cord and pneumatically seal within the distal end of the pneumatic tube. This ensures that the vacuum created in the suction cup is maintained without leakage, reducing the likelihood of procedural failure due to a loss of suction.

[0015] Additionally, the cup bead may comprise a distal retainer to engage the distal end of the traction cord, further securing the traction system and ensuring that the applied force is reliably transferred from the handle to the suction cup.

[0016] Preferably, the gauge bead may be retained entirely within the proximal end of the pneumatic tube, allowing it to interface with the force gauge. This positioning ensures that the force applied through the traction cord is accurately measured by the force gauge, contributing to the safety and effectiveness of the device.

[0017] The gauge bead may include an engagement portion that secures the traction cord and is shaped to interfere with a corresponding profile of the surrounding cylinder of the force gauge. This feature ensures that the traction force is transferred directly from the cord to the force gauge, providing precise feedback on the force being applied. Optionally, the gauge bead may include air passage stand-offs to ensure unobstructed airflow through the pneumatic tube, preserving the integrity of the vacuum system during use.

[0018] A compression spring may be included to bias the cylinder in a proximal direction. This feature provides a counterforce to the traction, ensuring that the system returns to its neutral position when traction is not applied, improving control and ease of use.

[0019] The pneumatic tube may include a slack portion between the gauge bead and the pump, allowing relative movement of the gauge bead under tension. This design facilitates smooth operation of the traction system while maintaining accurate force measurement and vacuum integrity.

[0020] In a preferable embodiment, the extractor may include a vacuum gauge operably coupled to the pump. The vacuum gauge may feature an elongate bellow mechanically interfacing with an indicator, wherein the bellow contracts longitudinally at a working vacuum pressure to offset the indicator. This provides the operator with a clear visual indication of when sufficient vacuum pressure is achieved, facilitating proper suction during the procedure. The bellow may optionally include a series of convolutions with a pitch configured to cause the bellow to contract at the working vacuum pressure. This enhances the accuracy of the vacuum gauge, providing reliable feedback on vacuum pressure levels.

[0021] Alternatively, the vacuum gauge may be operably coupled to the pump, wherein markings on the handle and pump align at the working vacuum pressure. This may provide a simple and reliable means of allowing the appropriate vacuum level to be maintained during use.

[0022] The mechanical pump may further include a manifold pneumatically interfacing with a cylinder of the proximal portion, allowing efficient transfer of pressure between the pump and the suction cup. This configuration ensures that suction is generated reliably and efficiently.

[0023] Compression springs may be included to bias the proximal portion in a proximal direction, for reciprocal operation of the mechanical pump and maintaining system stability during use.

[0024] The manifold may interface with an exhaust valve and an intake valve, facilitating the controlled intake and expulsion of air from the system to maintain thevacuum. The intake valve may optionally be a diaphragm valve that seals against radially offset offtake ports, providing required airflow control within the system.

[0025] One of the offtake ports may interface with the pneumatic tube, ensuring consistent vacuum pressure is delivered to the suction cup.

[0026] Another offtake port may interface with a vacuum release mechanism, allowing the operator to safely and efficiently release the vacuum after the procedure.

[0027] Preferably, the vacuum release mechanism may include a trigger that is operative in a distal direction, preventing accidental release when pulling the handle in a proximal direction.

[0028] The vacuum release mechanism may further comprise a pneumatically sealing plunger, with the trigger interfacing with the plunger to pneumatically release it. This ensures safe and controlled release of the vacuum for removal of the suction cup.

[0029] A travel delay coupling may optionally be included between the trigger and the plunger, ensuring that the vacuum is only released after the trigger has travelled a sufficient distance. This feature prevents accidental vacuum release during use.

[0030] A biasing mechanism, such as a living hinge compression spring, may be used to reset the trigger after vacuum release.

[0031] The trigger may be exposed through the neck of the handle, providing easy access for the operator and enabling efficient release of the vacuum at the appropriate time.

[0032] Preferably, the underside of the handle may include a muscle memory formation indicative of the location of the flexion point for memorising the proper placement of the suction cup relative to the foetal head, improving alignment accuracy during the procedure.

[0033] The muscle memory formation may be approximately 3 cm in length, representing the typical distance from the posterior fontanelle to the flexion point. This ensures that the suction cup is correctly positioned to provide optimal traction during delivery.

[0034] According to another aspect, a method of using a foetal vacuum extractor is provided. The method involves positioning the suction cup on a foetus's head andmanually pumping the proximal and distal portions of the handle to create a vacuum within the suction cup via the pneumatic tube. This vacuum secures the suction cup to the foetus’s head. The operator applies traction via the traction member to assist in delivery, with tactile force feedback provided by haptic protrusions in the force gauge to indicate excessive applied tension without the need for visual monitoring. This aids the operator to adjust the force as necessary during the delivery process, enhancing control and reducing the risk of overtensioning.

[0035] Optionally, the method may include using a flexion point marker along the traction member to ensure the suction cup is correctly aligned with the foetus’s flexion point. This ensures precise positioning of the suction cup, optimising the effectiveness of the applied traction.

[0036] Preferably, the method includes monitoring the progress of the suction cup while assessing the amount of force applied without needing to constantly observe the handle through the force gauge’s haptic feedback, providing a safer and more intuitive method of force application during delivery.

[0037] Additionally, the method may involve releasing the vacuum by operating the vacuum release mechanism. The operator can pull the trigger to disengage the plunger, releasing the vacuum from the suction cup and allowing it to be safely removed from the foetus's head. The inclusion of the travel delay coupling ensures that the vacuum is only released when the trigger is intentionally pulled beyond a certain threshold, preventing accidental vacuum release.

[0038] This method provides a safe and efficient means of applying assistive traction during childbirth, with feedback mechanisms and visual markers to aid precision and safety of the procedure.

[0039] Other aspects of the invention are also disclosed.Brief Description of the Drawings

[0040] Notwithstanding any other forms which may fall within the scope of the present invention, preferred embodiments of the disclosure will now be described, by way of example only, with reference to the accompanying drawings in which:

[0041] Figure 1 shows a top perspective view of a foetal vacuum extractor 100.

[0042] Figure 2 illustrates a bottom perspective view of the extractor 100.

[0043] Figure 3 is an exploded representation of the extractor 100 showing its parts.

[0044] Figure 4 is an exploded representation of a handle 101 of the extractor 100.

[0045] Figure 5 details the structure of the suction cup 102 and its components, including the lower and upper cup portions and the opening.

[0046] Figure 6 depicts a flexion point marker 164 and its frictional engagement with the pneumatic tube 103.

[0047] Figure 7 shows the internal protrusions 166 of the marker 164 engaging the pneumatic tube 103.

[0048] Figure 8 shows an alternative embodiment of the marker 164 with a starshaped cross-section bore.

[0049] Figure 9 illustrates the traction cord 120 and its arrangement through the pneumatic tube 103.

[0050] Figure 10 displays an underside of a cup bead 121 for securing the traction cord.

[0051] Figure 1 1 shows a top view of the cup bead 121.

[0052] Figure 12 shows a perspective view of gauge bead 122.

[0053] Figure 13 shows a front view of the gauge bead 122.

[0054] Figure 14 portrays the engagement of the gauge bead by a force gauge 1 12 of the extractor 100.

[0055] Figure 15 shows the force gauge 1 12.

[0056] Figure 16 depicts the vacuum gauge 135 with an elongate bellow 136 and indicator 137 in an embodiment.

[0057] Figure 17 shows a vacuum release mechanism 157 with a trigger portion 159 interfacing a plunger 160.

[0058] Figure 18 shows a front perspective view of a manifold 144 which interfaces a pneumatic cylinder of a proximal portion 110.

[0059] Figure 19 shows a rear perspective view of the manifold 144.

[0060] Figure 20 shows an alternative embodiment of the of gauge bead 122.

[0061] Figure 21 shows an alternative embodiment of the flexion point marker 164.Description of Embodiments

[0062] Figure 1 shows a foetal vacuum extractor 100 comprising a proximal handle 101 , a distal suction cup 102, and a traction member 179 between them. The traction member 179 comprises a pneumatic tube 103, which facilitates the suction function. Throughout this description, "distal" refers to being toward the suction cup 102, and "proximal" refers to being toward the handle 101 .

[0063] The suction cup 102 may include an interior sponge 104, which may be secured with adhesive backing . With reference to Figure 5, the suction cup 102 may comprise a lower cup portion 102A that interfaces with an upper cup portion 102B, the latter defining an opening 105. The lower cup portion 102A may feature an integrally formed channel 106, which connects to the distal end of the pneumatic tube 103, ensuring vacuum transmission between the pump and the suction cup 102.

[0064] The handle 101 houses a manual pneumatic pump that interfaces with the pneumatic tube 103. The handle 101 includes a distal portion 107, narrowing into a neck 108 that interfaces with the traction member 179, and shoulders 109 adjacent to the neck 108 defining a gripping surface for gripping between two of the operator's forefingers, typically the index finger and middle finger. The proximal portion 1 10 of the handle 101 reciprocates within the housing 1 1 1 and is manually pumped with the palm to create the necessary vacuum in the suction cup 102, securing it to the foetus's head. The handle 101 is then pulled to apply assistive or corrective traction during childbirth.

[0065] With reference to Figure 3, the housing 1 1 1 may comprise a lower housing portion 1 1 1 A and an upper housing portion 1 1 1 B. The extractor 100 further includes a force gauge 1 12, shown in Figure 15, which features haptic protrusions 1 13 that extend through the shoulders 109 of the handle 101 to provide tactile feedback. The force gauge 1 12 may also include a visual force marker 173, which extends distally through a preview cutout 174 in the handle 101 to provide a visible indication of applied force, as shown in Figure 1. Under high force, the marker 173 may extend concentrically from the distal end of the handle 101 , alerting the operator to high excessive force.

[0066] In this embodiment, the force gauge 1 12 comprises a wishbone 1 14 that slides along a pair of side rails 1 15. The wishbone 1 14 connects to a pneumatic tube engagement 1 16 that houses a cylinder 1 17, which pneumatically interfaces with the pneumatic tube 103. When tension is applied to the handle 101 , the housing 1 1 1 moves proximally relative to the pneumatic tube engagement 1 16, displacing the wishbone 1 14 via a pickup aperture 175 and hook 178. The haptic protrusions 1 13 then extend through ports 1 18 (shown in Figure 2) on the shoulder portions 109, providing tactile feedback to the operator's fingers during use.

[0067] The pneumatic tube engagement 1 16 may be counterbalanced by a compression spring 1 19. When sufficient traction force is applied, it overcomes the resistance of the compression spring 1 19, causing the pneumatic tube engagement 1 16 to pull the wishbone 1 14, projecting the haptic protrusions 1 13 through the ports 1 18 on the handle 101. This feedback allows the operator to reduce the pulling force without looking at the handle 101. Additionally, the visual force marker 173 may provide additional visual confirmation of the applied force for the operator or an assistant.

[0068] The extractor 100 may include a traction cord 120, as shown in Figure 9, which runs through the pneumatic tube 103. While the pneumatic tube 103 may stretch slightly, the traction cord 120 does not. In a preferred embodiment, the traction cord 120 is a steel wire rope, and which may have a diameter of 0.6 mm, coated with transparent polyamide (PA) to a total diameter of 0.8 mm . The proximal end of the pneumatic tube 103 may have a larger orifice to accommodate a gauge bead 122.

[0069] Additionally, the extractor 100 may features a cup bead 121 and a gauge bead 122, each securing an end of the traction cord 120. The traction cord 120 may be looped, creating two strands within the pneumatic tube 103. With reference to Figures 10 and 1 1 , the cup bead 121 may have a barb 123 that receives the traction cord 120 and seals it within the distal end of the pneumatic tube 103. The barb 123 may include a proximal termination annulus 124 that secures the distal end of the pneumatic tube 103 through the integrally formed channel 106.

[0070] The cup bead 121 may also have a distal retainer 126. As shown in Figure 5, a toggle 127 may be tied to the end of the traction cord 120. With reference to Figure 9, the traction cord 120 may be looped over the distal retainer 126, and the toggle 127 secures the cord to the cup bead 121 or the gauge bead 122.

[0071] As shown in Figure 14, the gauge bead 122 may be entirely housed within the proximal portion of the pneumatic tube 103. The cylinder 1 17 of the force gauge 112 surrounds the gauge bead 122 within the proximal portion of the pneumatic tube 103. The gauge bead 122 includes an engagement portion 128 that secures the traction cord 120. The engagement portion 128 is shaped to fit within a constriction 131 of the surrounding cylinder 117 to transfer traction force from the traction cord 120 to the force gauge 1 12.

[0072] The engagement portion 128 may feature longitudinal channels 129 and a through aperture 130, through which a loop of the traction cord 120 is guided. The engagement portion 128 and the constriction 131 of the cylinder 117 may both taper distally, ensuring a secure engagement. To maintain proper airflow, the gauge bead 122 may include pneumatic stand-offs 132. These stand-offs may include minor stand-offs 132A on the engagement portion 128 and major stand-offs 132B at the proximal end of an alignment stem 133.

[0073] Figure 20 shows an alternative embodiment of the gauge bead 122 having a generally elongate body 188 designed to fit within the proximal end of the pneumatic tube 103 which defines a lumen 191 for air flow therethrough and which defines a conical distal end 189 that wedges into the constriction 131 when within the pneumatic tube 103. The body 188 may define proximal side slots 190 which may engage respective ends of a toggle 127 engaging a proximal end of the traction cord 120. The slot 190 may further define stand-offs therebetween which prevent collapsing of the pneumatic tube 103 under suction. The body 188 may have a 4.9 mm outer diameter and be constructed from polycarbonate.

[0074] Figure 14 further illustrates a proximal annulus 134 that interfaces with the proximal end of the compression spring 1 19. The proximal portion of the pneumatic tube 103 may have a slackened configuration, such as a curve or S-bend, to facilitatemovement of the gauge bead 122 during traction. The proximal portion of the pneumatic tube 103 may comprise an inner spring to mitigate against tube collapse or obstruction which may be caused by suction, tensile load or movement of the force gauge 1 17.

[0075] Figure 20 illustrates an alternative embodiment of the gauge bead 122, described as having a 4.9 mm outer diameter and constructed from polycarbonate (PC) in a feed-through design.

[0076] With reference to Figure 16, the extractor 100 may also include a vacuum gauge 135 operably connected to the pump. The vacuum gauge 135 may consist of an elongate bellow 136, made from rubber, which mechanically interfaces with an indicator 137. The bellow 136 contracts longitudinally when the pressure inside falls below a threshold, causing the indicator 137 to move. The distal end of the bel low 136 may include an aperture 138 that engages a barbed hook 139 on the indicator 137. The indicator 137 may have two coloured portions: a first coloured portion 140A and a second coloured portion 1406. These coloured portions are visible through a window 141 on the handle 101 , as shown in Figure 4. Typically, the second coloured portion 1406 is visible when the vacuum is insufficient, but as the bellow 136 contracts, the first coloured portion 140A becomes visible.

[0077] The bellow 136 may feature convolutions 143, pitched to cause contraction at a working vacuum pressure. The clinician pumps the proximal portion 1 10 until the vacuum gauge 135 indicates that sufficient vacuum has been created. In alternative embodiments, the vacuum gauge 135 may be facilitated by the pump and springs, with alignment markings on the handle 101 to indicate when working vacuum pressure is achieved.

[0078] With reference to Figures 18 and 19, the extractor 100 may include a manifold 144 that interfaces with the pneumatic cylinder of the proximal portion 1 10. The proximal portion 1 10 may be biased proximally by compression springs 145, which act through cylindrical posts 146 of the manifold 144. The manifold 144 may contain a piston 147 sealed within the pneumatic cylinder by an O-ring 148. The piston 147features an intake valve 149, which takes the form of a diaphragm valve secured by a central aperture 150 on the piston.

[0079] On the distal side, the piston 147 may include an exhaust valve 155 within an exhaust valve port 156. In some embodiments, the extractor 100 may feature a hybrid intake and exhaust valve combining elements of both the intake valve 149 and the exhaust valve 155. The intake valve 149 seals against radially offset offtake ports 151. As the proximal portion 1 10 moves proximally, the intake valve 149 allows air to enter the pneumatic cylinder via the offtake ports 151. When the proximal portion 1 10 moves distally, the intake valve 149 blocks the offtake ports 151 , while the exhaust valve 155 expels air to create the necessary vacuum.

[0080] With reference to Figure 19, one of the offtake ports 151 may connect to a pneumatic tube connector 152, another to a vacuum gauge connector 153, and another to a vacuum release connector 154.

[0081] With reference to Figure 17, the extractor 100 may feature a vacuum release mechanism 157, which includes a trigger portion 159 and a trigger 158. As shown in Figure 2, the trigger 158 may be exposed on the undersurface of the neck 108. The trigger 158 operates distally, preventing accidental activation when the handle 101 is pulled proximally.

[0082] The vacuum release mechanism 157 may also include a plunger 160 with a seal 161 , secured by an O-ring 176 within the vacuum release connector 154. The plunger 160 is biased into the vacuum release connector 154 by default, maintaining a pneumatic seal. When the trigger 158 is pulled, it disengages the plunger 160 from the O-ring 176, releasing the vacuum created by the pneumatic pump.

[0083] The vacuum release mechanism 157 may be designed to prevent accidental release, requiring the trigger 158 to be pulled beyond a certain distance. The mechanism 157 may include a travel delay coupling between the trigger portion 159 and the plunger 160. The trigger portion 159 features a larger aperture 162 through which a hook on the plunger 160 is inserted. By default, the hook 163 rests at the distal end of the aperture 162. When the trigger 158 is pulled, the hook 163 travels across the aperture 162 until it strikes the proximal wall, engaging the plunger 160.The trigger portion 159 is biased proximally by integrally formed side-living compression springs 177.

[0084] The extractor 100 may also include a flexion point marker 164, as shown in Figure 1 , which slides along the pneumatic tube 103. This marker 164 may be positioned to indicate the distance to the flexion point, facilitating alignment of the centre of the suction cup 102 with the flexion point. The flexion point marker 164 may also be used to visually track the foetuses’ progress through the birth canal.

[0085] In an alternative embodiment, the extractor 100 features two sliders 164: a first marker indicating the starting point and a second marker tracking progress. The clinician positions both markers at the diagnosed insertion distance, facilitating correct placement of the suction cup 102 over the flexion point. As the procedure progresses, the second marker 164 is moved to the mother's fourchette after each traction to denote the baby’s progress through the birth canal.

[0086] With reference to Figures 6 and 7, the marker 164 comprises a cylinder 165 with internal protrusions 166 that frictionally engage the pneumatic tube 103. Figure 8 shows an alternative embodiment where the marker 164 features a star-shaped bore 167 to similarly engage the pneumatic tube 103.

[0087] Figure 21 shows a disassembled view of the flexion point marker 164 in accordance with a further embodiment. The marker 164 is operable in a compressed configuration to release the pneumatic tube 103 for sliding along it, and in a released configuration, where it grips the pneumatic tube 103 in position. Accordi ng to the embodiments shown, the marker 164 comprises a main body 180, preferably spherical to facilitate gripping between the forefingers, and a button 181 slidably retained within it. The main body 180 defines a major through-aperture 182A, while the button 181 defines a minor through-aperture 182B. A compression spring 183 biases the button 181 to the released configuration, and the button 181 may comprise side rails 184 that slidably engage corresponding slots in the main body 180. Catches 186 on the button 181 may engage corresponding inner catches 187 within the main body 180 to prevent disconnection of the button 181 from the main body 180 under compressive force from the compression spring 183.

[0088] When the button 181 is pushed into the main body 180, the apertures 182 align coaxially with the pneumatic tube 103, allowing the marker 164 to slide along the pneumatic tube 103. An internal buttress 188 may limit the travel of the button 181 to prevent over-insertion and may be positioned and configured so that the apertures182 align exactly when the undersurface of the button 181 contacts the buttress 188. In the compressed state, the marker 164 can be placed at the desired position along the pneumatic tube 103. Once the button 181 is released, the compression spring183 displaces it out from the main body 180, causing the apertures 182 to misalign and grip the pneumatic tube 103, thereby resisting movement along it.

[0089] With reference to Figure 3, the extractor 100 may include a single-use wick timer 168, which is adhered to the handle 101. The timer 168 is initiated by pressing a button 169, which ruptures to release dye along a wick 170. The dye reaches a marker junction after a predetermined time interval, such as 20 minutes.

[0090] In some embodiments, the pneumatic tube 103 may feature measurement markings to gauge the distance from the mother’s posterior fourchette to the flexion point when the suction cup 102 is correctly positioned. These markers may indicate common flexion point intervals, such as 6 cm for occiput anterior (OA) and 9 cm for occiput transverse (OT) and occiput posterior (OP) positions. The markings may be printed circumferentially around the entire pneumatic tube 103 to ensure visibility, regardless of rotation.

[0091] With reference to Figure 2, the underside of the housing 1 1 1 A may include a muscle memory formation 172, which simulates the distance from the posterior fontanelle to the flexion point, typically 3 cm. This formation 172 allows the operator to practise the diagnostic movement before beginning the procedure. The formation 172 represents the relative positions of the posterior fontanelle 172A, sagittal suture 172B, and flexion point 172C.

[0092] An exemplary method of use of the foetal vacuum extractor 100 during a vacuum-assisted delivery will now be described with reference to the accompanying figures.

[0093] The clinician begins by positioning the suction cup 102 on the foetus's head, facilitating alignment with the flexion point to optimise traction. To facilitate this alignment, the clinician uses the flexion point marker 164, which is positioned along the traction member 179 to indicate the distance to the flexion point. This ensures that the centre of the suction cup 102 is correctly aligned with the flexion point of the foetus’s head.

[0094] Once the suction cup 102 is correctly positioned, the clinician manually pumps the proximal portion 1 10 and distal portion 107 of the handle 101 to generate suction, while maintaining cup position on the foetal head with the non-pumping hand. The mechanical pump, interfacing with the pneumatic tube 103 of the traction member 179, induces suction in the suction cup 102, securing it to the foetus’s head.

[0095] As the clinician pulls the handle 101 to apply traction, the traction member 179 transmits force to the foetus, assisting in correcting any malposition and guiding it through the birth canal. The force gauge 1 12, connected to the traction member, monitors the tension in the traction cord 120 and provides feedback. If the applied force exceeds a safe level, the haptic protrusions 1 13 extend through the shoulders 109 of the handle, offering continuous tactile feedback to the clinician’s fingers without the need for visual confirmation. The haptic feedback from the force gauge 1 12 allows the clinician to adjust the applied force as needed, facilitating safe traction. The clinician can monitor the flexion point slide marker at any stage to track the baby's descent through the birth canal, enabling them to assess progress or lack of progress, and adjust the procedure accordingly to mitigate risks associated with failure to progress. Additionally, if the device includes the timer 168, the clinician can track the duration of the procedure, adhering to recommended time limits to reduce the risk of complications from prolonged use.

[0096] After the required traction is applied and the foetus has safely progressed, the clinician releases the vacuum by activating the vacuum release mechanism 157. By pulling the trigger 158, the plunger 160 disengages from the vacuum seal, releasing the suction in the suction cup 102, allowing it to be safely removed from the foetus's head.

[0097] This method ensures controlled and safe application of traction during childbirth, using the flexion point marker 164 for precise alignment and to monitor progress, tactile feedback from the force gauge 1 12 for monitoring force application, and a vacuum release mechanism 157 for safe removal of the suction cup.

[0098] The foregoing description, for purposes of explanation, used specific nomenclature to provide a thorough understanding of the invention. However, it will be apparent to one skilled in the art that specific details are not required in order to practise the invention. Thus, the foregoing descriptions of specific embodiments of the invention are presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed as obviously many modifications and variations are possible in view of the above teachings. The embodiments were chosen and described in order to best explain the principles of the invention and its practical applications, thereby enabling others skilled in the art to best utilize the invention and various embodiments with various modifications as are suited to the particular use contemplated. It is intended that the following claims and their equivalents define the scope of the invention.

Claims

Claims1 . A foetal vacuum extractor comprising: a proximal handle, a distal suction cup, and a traction member, wherein the distal suction cup is pulled by the traction member from the proximal handle to provide assistive traction during childbirth, wherein the proximal handle comprises a distal portion reciprocally accommodating a proximal portion, the distal portion defining a neck interfacing the traction member, wherein shoulders adjacent the neck define a gripping surface for opposing forefingers, wherein the distal and proximal portions are configured to be manually pumped to operate a mechanical pump between them, the mechanical pump interfacing a pneumatic tube of the traction member to induce suction in the suction cup, and wherein the proximal handle further comprises a force gauge connected to the traction member having haptic protrusions which protrude through the gripping surface when sufficient force applied by the traction member displaces the force gauge to provide tactile force feedback to the opposing forefingers.

2. The extractor as claimed in claim 1 , wherein the force gauge comprises a wishbone having a pair of side slide rails connected to a pneumatic tube engagement which pneumatically interfaces the pneumatic tube, wherein the force gauge provides tactile feedback when sufficient force displaces the pneumatic tube engagement and the wishbone.

3. The extractor as claimed in claim 1 , further comprising a traction cord extending through the pneumatic tube, and wherein the traction cord is secured by cup and gauge beads at respective ends.

4. The extractor as claimed in claim 3, wherein the traction cord is looped back between the suction cup and the handle.

5. The extractor as claimed in claim 3, wherein the cup bead comprises a barb configured to receive the traction cord therethrough and to pneumatically seal within a distal end of the pneumatic tube.

6. The extractor as claimed in claim 3, wherein the cup bead comprises a distal retainer to engage a distal end of the traction cord.

7. The extractor as claimed in claim 3, wherein the gauge bead is retained entirely within a proximal end of the pneumatic tube.

8. The extractor as claimed in claim 7, wherein the gauge bead comprises an engagement portion securing the traction cord, wherein the engagement portion is shaped to interfere with a corresponding profile of a surrounding cylinder of the force gauge within the pneumatic tube to transfer traction force from the traction cord to the force gauge.

9. The extractor as claimed in claim 7, wherein the gauge bead comprises air passage stand-offs.

10. The extractor as claimed in claim 8, further comprising a compression spring biasing the cylinder in a proximal direction.1 1 . The extractor as claimed in claim 7, wherein a proximal portion of the pneumatic tube between the gauge bead and a pump of the extractor is slack to facilitate movement of the gauge bead under traction force with respect to the pump.

12. The extractor as claimed in claim 1 , further comprising a vacuum gauge operably coupled to the pump, wherein the vacuum gauge comprises an elongate bellow mechanically interfacing with an indicator, wherein the elongate bellow is configured to contract longitudinally at a working vacuum pressure to offset the indicator.

13. The extractor as claimed in claim 12, wherein the elongate bellow comprises a plurality of convolutions having a pitch configured to cause the bellow to contract at the working vacuum pressure.

14. The extractor as claimed in claim 1 , further comprising a vacuum gauge operably coupled to the pump, wherein markings on the handle and pump align at a working vacuum pressure.

15. The extractor as claimed in claim 1 , wherein the mechanical pump comprises a manifold pneumatically interfacing a cylinder of the proximal portion.

16. The extractor as claimed in claim 15, wherein the proximal portion is biased in a proximal direction by compression springs.

17. The extractor as claimed in claim 15, wherein the manifold interfaces with an exhaust valve and an intake valve.

18. The extractor as claimed in claim 17, wherein the intake valve is a diaphragm valve which seals against radially offset offtake ports.

19. The extractor as claimed in claim 18, wherein one of the offtake ports interfaces with the pneumatic tube.

20. The extractor as claimed in claim 18, wherein one of the offtake ports interfaces with a vacuum release mechanism.

21. The extractor as claimed in claim 18, wherein one of the offtake ports interfaces with a vacuum gauge.

22. The extractor as claimed in claim 1 , further comprising a vacuum release mechanism comprising a trigger.

23. The extractor as claimed in claim 22, wherein the trigger is operative in a distal direction.

24. The extractor as claimed in claim 22, wherein the vacuum release mechanism comprises a pneumatically sealing plunger, and wherein the trigger interfaces the plunger to pneumatically release the plunger.

25. The extractor as claimed in claim 24, wherein the vacuum release mechanism comprises a travel delay coupling interfacing the trigger and the plunger, wherein the trigger offsets the plunger after travelling more than a distance threshold.

26. The extractor as claimed in claim 22, wherein the trigger comprises a biasing mechanism to reset the trigger.

27. The extractor as claimed in claim 26, wherein the biasing mechanism comprises a living hinge compression spring.

28. The extractor as claimed in claim 22, wherein the trigger is exposed through the neck of the handle.

29. The extractor as claimed in claim 1 , wherein an underside of the housing comprises a muscle memory formation indicative of the location of the flexion point.

30. The extractor as claimed in claim 29, wherein the muscle memory formation is approximately 3 cm in length to represent the distance from a posterior fontanelle position along a sagittal suture position to a flexion point position.31 . A method of using a foetal vacuum extractor as claimed in claim 1 , comprising: positioning the suction cup on a foetus's head; manually pumping the proximal and distal portions of the handle to create a vacuum within the suction cup via the pneumatic tube; and applying traction via the traction member to assist in delivery, wherein tactile force feedback is provided by haptic protrusions of the force gauge to indicate applied tension without visual monitoring.

32. The method as claimed in claim 31 , further comprising using a flexion point marker along the traction member to indicate the distance to a flexion point on the foetus's head, facilitating alignment of a centre of the suction cup with the flexion point.

33. The method as claimed in claim 31 , further comprising using a flexion point marker along the traction member to indicate traction progress.

34. The method as claimed in claim 31 , wherein the force gauge comprises a wishbone and pneumatic tube engagement and wherein applying traction further comprises receiving tactile feedback when the wishbone and the pneumatic tube engagement of the force gauge are displaced, indicating that a predetermined force threshold has been reached.

35. The method as claimed in claim 31 , further comprising releasing the vacuum by operating a vacuum release mechanism comprising a trigger, wherein the trigger interfaces with a plunger to pneumatically release the vacuum from the suction cup.

36. The method as claimed in claim 35, further comprising pulling the trigger beyond a travel delay threshold to ensure intentional release of the vacuum, preventing accidental vacuum release during the procedure.

37. The method as claimed in claim 31 , further comprising observing a vacuum gauge comprising an elongate bellow interfacing with an indicator, wherein the elongate bellow contracts longitudinally at a working vacuum pressure to offset the indicator, providing visual confirmation that sufficient vacuum pressure has been achieved.

38. The method as claimed in claim 31 , wherein the extractor comprises a vacuum gauge comprising markings on the handle and pump, and the method further comprises aligning the markings to confirm the working vacuum pressure has been reached before applying traction.

39. The method as claimed in claim 35, further comprising resetting the trigger after vacuum release by means of a biasing mechanism comprising a living hinge compression spring.

40. The method as claimed in claim 31 , wherein applying traction further comprises using a traction cord extending through the pneumatic tube, and wherein the traction cord is secured by cup and gauge beads positioned at respective ends of the traction member to transfer traction force from the handle to the suction cup.41 . The method as claimed in claim 31 , further comprising using a wick timer to monitor the duration of the vacuum-assisted delivery, providing visual indication of elapsed time.

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