GB2593977A - An umbilical cord clamp - Google Patents

Abstract

An umbilical cord clamp includes a pair of tapered jaw beams 5 (or arms) connected by a hinge 1. The hinge 1 is flexible, directly connecting the clamp arms such that little or no distance exists between them when the clamp is open. As there is no C-loop or accompanying hinge gate at the hinge, the umbilical cord is less likely to get trapped or punctured. The tapered clamp arms are preferably arranged to undergo proportional deflection along two-thirds their length from the hinge. This allows the clamp to apply a uniform force across an umbilical cord and accommodate a range of umbilical cord diameters. An irreversible locking latch 3 may be provided to hold the jaws arms 5 closed. Ideally, a viewing aperture 6 and a click provide visual and audible confirmation of clamp closure. A soft elastomeric surface may be moulded over the clamp to round-off angular edges and to enhance grip.

Description

An Umbilical Cord Clamp

Field of the Invention

This invention relates to single use disposable umbilical cord clamps and has for its object the provision of a single use disposable umbilical cord clamp having enhanced features which significantly improve functionality, intraoperative performance and patient safety.

Immediately following birth, the new-born baby's umbilical cord is clamped on the infant side with a single use disposable umbilical cord clamp and on the maternal side typically with an artery forceps, occasionally with a further umbilical cord clamp. The cord is then surgically sectioned with an umbilical cord scissor. The timing of umbilical cord sectioning has been the subject of much research, and the traditional practice of "immediate" cord clamping has been superseded by "deferred" clamping, as this practice has been shown to significantly increase the storage of iron in the new-born infant, as well as providing other physiological benefits.

Clamping of the umbilical cord with traditional design single-use, disposable cord clamps can be associated with significant clinical complications, which include: Unforeseen cord clamp displacement, typically due to inadequate cord clamp closure, which will result in significant infant blood loss, and rapid onset of neonatal shock. Inadequate clamp closure can be caused by the cord clamp not providing positive audible and/or visual confirmation of secure clamp closure.

The clamp may not be applied tightly enough, which can result in significant infant blood loss, and rapid onset of neonatal shock. This complication can also be caused by the cord clamp not providing positive audible and/or visual confirmation of secure clamp closure, The clamp may be applied too tightly, which can result in an umbilical cord tear, with associated sudden significant infant blood loss, and rapid onset of neonatal shock.

Perforation or tearing of the umbilical cord by the flexible plastic cord clamp "hinge gate" mechanism. This is most likely to occur when the umbilical cord is located too close to the clamp hinge prior to clamp closure, whereby the cord is forced into the C-Loop hinge present in clamps of traditional design (umbilical cord clamps of traditional design typically incorporate a "C-Loop" hinge mechanism which assists with accommodating a range of umbilical cord diameters). However, should the clamp be opened too widely prior to clamping a large diameter umbilical cord, the hinge gate mechanism can fracture, with the potential to perforate or tear the cord upon subsequent clamp closure.

Umbilical cord clamps of traditional design are typically manufactured from a hard and unyielding polymer with an inherently angular geometry to their external surfaces. Such geometry can traumatise the new-born infant's abdominal skin as a direct result of the continuous rubbing movement which occurs between the clamp and the infant's skin, particularly when the clamp is located at or below the nappy (diaper) line.

Cord clamps are applied across the umbilical cord by a clinician using gloved fingers which are typically slippery from contact with blood and other tissue exudates associated with the birthing process. This can result in significant difficulties with the clinician's ability to rapidly and effectively apply the required compressive force to securely close the cord clamp.

Cord clamp jaws are manufactured with a series of teeth on those surfaces which approximate with the cord itself. If such teeth are designed with acutely angled pointed profiles, they can potentially perforate or tear the cord during clamp closure.

Traditional single use disposable umbilical cord clamps are typically manufactured with a "C-Loop" hinge and "hinge gate" mechanism, which assists with accommodating a range of umbilical cord diameters. Such traditional designs are associated with two significant clinical shortcomings: : Firstly, to prevent the inadvertent entry of the umbilical cord wall into the C-Loop hinge (causing significant cord haemorrhage), a flexible plastic "hinge gate" mechanism is provided. Such inadvertent entry of the umbilical cord wall into the C-Loop hinge is most likely to occur when the umbilical cord is located too close to the clamp hinge prior to clamp closure.

Secondly, should the clamp be opened too widely, prior to clamping a large diameter cord, the flexible plastic hinge gate mechanism can fracture, with the resultant fractured hinge gate ends presenting a significant risk of cord perforation or tearing upon subsequent clamp closure, and thereby potentially leading to significant umbilical cord haemorrhage.

Two variants of an injection moulded polymeric single use disposable umbilical cord clamp designed to specifically overcome the clinical and design shortcomings associated with traditional design single use disposable umbilical cord clamps are the subject of the present invention.

The novel single use disposable umbilical cord clamp described hereafter is designed to significantly enhance the functionality, intra operative performance and safety of such products, thereby providing a significantly optimised and fit-for-purpose medical device.

Summary of the Invention

According to the present invention there is provided a single use disposable umbilical cord clamp which includes a pair of tapered beams connected by a hinge mechanism which enables the cord clamp jaws to accommodate the required range of umbilical cord diameters by utilising the principle of a tapered beam jaw profile.

The tapered beam jaw profile is preferably so designed that it produces proportional deflection along two thirds of the beam length, projected from the hinge point, thereby ensuring an even application of compressive force across the entire width of the umbilical cord during closure, with no risk of compressing the cord into the hinge mechanism.

The hinge mechanism of the present invention is designed to eliminate both of the two major clinical risks detailed above, and which are specifically associated with traditional "C-Loop Hinge" and "Hinge Gate" umbilical cord clamp designs Single use disposable umbilical cord clamps of traditional design are also associated with additional adverse design issues, which are also specifically addressed by the present invention.

Said traditional adverse design issues include insecure clamp closure caused by the lack of a robust and reliable irreversible jaw locking mechanism with meaningful audible and/or visual indications of clamp closure, trauma to the new-born infant's abdominal skin caused by continuous movement/rubbing of the inherently angular external geometry of traditional design cord clamps, significant difficulties with the clinician's ability to rapidly and effectively apply the required compressive force to close the cord clamp securely when wearing wet medical examination gloves and potential perforation or tearing of the cord during clamp closure as a direct consequence of the cord clamp jaws being manufactured with a series of teeth with excessively pointed profile on those surfaces which approximate with the cord upon final closure.

Brief Description of the Drawings

Fig. 1 is a side elevation of the device detailing its principal inventive step, i.e. a "no trap" hinge mechanism, Fig. 2 is a perspective view detailing the radiused teeth moulded within the gripping surfaces of the cord jaws, Fig. 3 is a side elevation detailing the locking latch mechanism in the fully "engaged" closed position, the locking latch viewing aperture, curved opposing thumb grip surfaces in the engaged closed position, and raised thumb/finger grips, Fig. 4 is a plan view detailing the moulded raised thumb/finger grips and the ergonomic thumb/finger grip platform, Fig. 5 is a side elevation detailing an alternative clamp design variant which includes a soft polymeric external, preferably over-moulded, surface, which provides for a smooth friction grip soft surface covering for the thumb/finger grip platform, Fig. 6 is a perspective view detailing the alternative clamp design variant which includes a soft polymeric external, preferably over-moulded, surface, including the thumb/finger grip platform, and Fig. 7 is a plan view detailing the alternative clamp design variant which includes a soft polymeric external, preferably over-moulded, surface, including the thumb/finger grip platform.

Description of the Preferred Embodiments

Figure 1 of the drawings shows the single use disposable umbilical cord clamp having a "no trap" hinge mechanism 1 which provides for the cord clamp jaws to accommodate the required anatomical range of umbilical cord diameters, utilising the principle of a tapered beam jaw profile 5. The tapered beam jaw profile 5 produces proportional deflection along two thirds of the beam length, projected from the hinge point, thereby ensuring an even application of compressive force across the entire width of the umbilical cord during closure, with no risk of compressing the cord into the "no-trap" hinge mechanism.

The single use disposable umbilical cord clamp is preferably injection-moulded using a bio-compatible, sterilisable high strength low friction polymer, preferably, but not exclusively, Nylon 66, Polyoxymethylene ("Acetal") or Polypropylene.

The single use disposable cord clamp is preferably injection moulded using a biocompatible sterilisable high strength low friction polymer, which is either of natural (non-pigmented) colour or alternatively coloured with a biocompatible, preferably but not exclusively, pastel shade pigment to provide a calming and soothing appearance for the clamp.

Figure 1 of the drawings also contains details of moulded radiused teeth 2 on the gripping surface of the clamp jaws, an irreversible locking latch 3, raised thumb/finger grips 4, a tapered beam profile 5, a locking latch viewing aperture 6 and curved opposing thumb grip surfaces 7.

Figures 1 and 3 of the drawings also show the novel curved opposing thumb grip surfaces 7. A concave surface is shown at the inferior (lower) surface of the superior (upper) jaw thumb grip, and a convex surface is shown at the superior (upper) surface of the inferior (lower) jaw thumb grip. Said curved opposing profile is specifically designed to accommodate the tapered beam deflection during clamp closure, and to ensure that the upper and lower beams engage into full apposition during and after the process of closing the clamp into its fully locked position, regardless of the varying anatomically diverse range of umbilical cord diameters which the device is required to accommodate.

Figure 2 of the drawings shows details of the configuration of the moulded atraumatic radiused teeth 2 on the gripping surface of the clamp jaws, which are designed to securely retain the umbilical cord in position during and after cord clamp placement, at the same time minimising the risk of inadvertent cord puncture or tearing upon final clamp closure (which is a known complication of cord clamps traditionally designed with acutely angled, pointed teeth).

Figure 3 of the drawings shows the irreversible locking latch 3 in its fully closed position and the locking latch viewing aperture 6 located on the lateral aspects of the lower ("inferior") clamp beam, designed specifically to provide the clinician with visual confirmation of clamp closure when in its fully locked position, in addition to the positive audible click which can be heard when the locking latch 3 is fully engaged. This combined visual and audible confirmation of secure clamp closure is an important safety feature of the present invention.

Figures 3 and 4 of the drawings contain details of the moulded raised thumb/finger grips 4, designed to reduce slippage when closing the clamp with wet surgical gloves and the novel ergonomic thumb/finger grip platform 8, designed to maximise the area of surface contact with the clinician's gloved fingers, and thereby assured security, when closing the clamp into the fully locked position. The platform 8 is additionally designed to accommodate a wide range of thumb and finger sizes from small to large, an important safety consideration for this type of device.

Figures 5, 6 and 7 of the drawings detail a second clinically significant alternative variant of the present invention, which provides for an over-moulded soft elastomeric surface 9 which covers the entire external aspect of the cord clamp beams, hinge and thumb/finger grip platforms 8. This additional novel feature is designed to overcome a significant adverse clinical consequence associated with cord clamps of traditional design, which are typically manufactured from a hard and unyielding polymer with an inherently angular geometry to their external surfaces. Such geometry can traumatise the new-born infant's abdominal skin as a direct result of the continuous rubbing movement which occurs between the clamp and the infant's skin, particularly when the clamp is located at or below the nappy (diaper) line.

The over-moulded soft elastomeric surface is preferably manufactured from a high performance biocompatible sterilisable soft thermoplastic elastomer, such as, but not restricted to, TPU (TPU),TPS (WE-s), TPO (TPE-o), TPV (TPE-v or TPV), TPC (TPE-E), TPA (TPE-A), TPZ or alternatively silicone rubber, preferably but not exclusively, within the Shore A hardness range 50 to 60, using an over-moulding or twin-shot co-injection moulding technique.

Furthermore, the over-moulded soft elastomeric surface may be alternatively manufactured from a high performance biocompatible sterilisable soft thermoplastic elastomer, which is either of natural colour, i.e. non-pigmented, or alternatively coloured with a biocompatible, preferably but not exclusively, pastel shade pigment to provide a calming and soothing appearance for the device.

The present invention thus provides a single-use disposable umbilical cord clamp comprising a novel 'no trap' hinge mechanism which utilises the principle of a tapered beam jaw profile, which provides for proportional deflection along two thirds of the beam length, projected from the hinge point, thereby ensuring an even application of compressive force across the entire width of the umbilical cord during final closure of the cord clamp.

The cord clamp is preferably injection moulded using a biocompatible, sterilisable high strength low friction polymer, preferably, but not exclusively natural or alternatively pastel colour Nylon 66, Polyoxymethylene ("Acetal") or Polypropylene.

The cord clamp may be over-moulded with an external soft elastomeric surface covering which is preferably manufactured from a high performance biocompatible, sterilisable, preferably but not exclusively pastel shade soft thermoplastic elastomer using either an over-moulding or twin-shot co-injection moulding technique.

The cord clamp typically comprises a novel 'no trap' hinge mechanism, radiused teeth on the gripping surface of the clamp jaws, an irreversible locking latch, raised thumb/finger grips, a tapered beam profile, a locking latch viewing aperture, curved opposing thumb grip surfaces, ergonomic thumb/finger grip platforms or alternatively, a soft elastomeric external over-moulded surface.

Claims (4)

1. Claims:- 1. A single use disposable umbilical cord clamp which includes a pair of tapered beams connected by a hinge mechanism which enables the cord clamp jaws to accommodate the required range of umbilical cord diameters by utilising the principle of a tapered beam jaw profile.
2. 2. A single use disposable umbilical cord clamp as claimed in Claim 1, in which the tapered beam jaw profile is so designed that it produces proportional deflection along two thirds of the beam length, projected from the hinge point, thereby ensuring an even application of compressive force across the entire width of the umbilical cord during closure, with no risk of compressing the cord into the hinge mechanism.
3. 3. A single use disposable umbilical cord as claimed in either of the preceding claims, which includes an irreversible locking latch for holding the clamp jaws in their closed positon.
4. 4. A single use disposable umbilical cord clamp as claimed in any one of the preceding claims, which includes a locking latch viewing aperture.