Pinch clamp

Abstract

A pinch clamp is provided that provides positive displacement while preventing springback. To provide positive displacement while preventing springback, upper and lower clamping surfaces can be configured to form a pinch profile along which the catheter is compressed, wherein a pinch point is formed at the distal end of the pinch profile. To further prevent springback, the lower arm of the pinch clamp can include a barrier rib that interfaces with the upper clamping surface, thereby preventing the pinch point from traveling distally even if the upper arm is forced into an over-engaged position.

Description

[0001] This divisional application is a divisional application based on the patent application with Chinese invention patent application number 201980070676.9 (international application number PCT / US2019 / 051850), invention name “Pinch-type clip” and application date September 19, 2019. Background Art

[0002] Pinch clamps are commonly used to occlude catheters in veins or other medical systems. Pinch clamps often have a clamshell design, with an upper arm connected to a lower arm by a living hinge. The lower arm is typically configured to hold the upper arm in a closed position, in which the catheter is clamped between the two arms.

[0003] Conventional pinch clip designs have various drawbacks. For example, due to the molding process, pinch clips often have sharp edges, which can cause patient discomfort. The molding process also makes pinch clips relatively bulky. Many pinch clip designs also cause the two arms to move laterally when in the closed position, which can lead to accidental disengagement of the pinch clip. Even when lateral disengagement features are incorporated into these designs, the asymmetry in these features can lead to failure in one direction.

[0004] Many pinch clip designs also make it possible for over-engagement to occur, which can result in springback. Figures 1 and 1A-1C show an example of how springback can occur when a pinch clip 100 is over-engaged. The pinch clip 100 includes an upper arm 110 connected to a lower arm 120 by a living hinge 130. A distal portion 140 (where "distal" means the distal end of the distal portion 140 relative to the living hinge 130 toward the patient or catheter 190) extends upward from the lower arm 120 opposite the living hinge 130. An engagement structure 141 is formed at an upper end of the distal portion 140. The engagement structure 141 forms an engagement surface 141 that is oriented downwardly to enable the front end 111 of the upper arm 110 to be retained below the engagement surface 141, thereby engaging the pinch clip 100. In the engaged position, the lower clamping surface 151 and the upper clamping surface 152 are positioned sufficiently close together to block a conduit 190 extending through the pinch clip 100 .

[0005] FIG1A shows the pinch clamp 100 in an engaged position. To move the pinch clamp 100 to this engaged position, the clinician typically squeezes the upper arm 110 and the lower arm 120 until the front end 111 of the upper arm 110 drops below the engagement surface 141. At this point, the offset end portion 140 will hold the front end 111 below the engagement surface 141. However, this can be difficult because the upper arm 110 can unnecessarily move downward beyond the amount required to reach the engaged position. For example, FIG1B shows the upper arm 110 being subjected to a downwardly applied force such that the front end 111 has moved substantially beyond the engagement surface 114a. As such, the upper clamping surface 152 has contacted the lower clamping surface 151 and has moved in a forward direction (i.e., toward the end portion 140) relative to the lower clamping surface 151.

[0006] This forward movement of upper clamping surface 152 relative to lower clamping surface 151 causes a "positive displacement" of the fluid within catheter 190, as indicated by the arrows in FIG. 1B . In other words, overengagement of pinch clamp 100 causes the fluid within catheter 190 to flow into, or at least toward, the patient. Positive displacement is generally desirable. However, in this case, because the positive displacement is caused by overengagement, rebound occurs, as shown in FIG. 1C . In FIG. 1C , it is assumed that the clinician is no longer squeezing pinch clamp 100, and therefore upper arm 110 has pivoted upward back to the engaged position (i.e., until front end 111 contacts engagement surface 141 a). This upward movement of upper arm 110 relative to lower arm 120 causes upper clamping surface 152 to also travel in an upward and slightly rearward direction. This upward and rearward movement increases the internal volume of catheter 190 downstream of the "pinch point" (i.e., the point where lower and upper clamping surfaces 151, 152 occlude catheter 190). In this way, fluid, which may include blood, will be drawn into the conduit of another device connected to conduit 190. The term "rebound" refers to the transition from the overengaged position shown in FIG IB to the engaged position shown in FIG1C.

[0007] Backflow caused by the recoil of a pinch clip presents a number of problems. For example, backflow of blood can increase the risk of obstruction (e.g., due to intraluminal thrombosis within the catheter), which can prevent the infusion of fluids or the withdrawal of blood through the catheter. Even if no obstruction occurs, backflow can increase the risk of infection. Summary of the Invention

[0008] The present disclosure generally relates to pinch clips designed to provide positive displacement while preventing rebound. Thus, these pinch clip designs minimize the occurrence of backflow. In addition to preventing rebound, the pinch clip design also prevents lateral disengagement, minimizing the force required for engagement and improving patient comfort.

[0009] To prevent springback while providing positive displacement, the upper and lower clamping surfaces can be configured to form a pinching profile along which the catheter is compressed, wherein a pinch point is formed at the distal end of the pinching profile. To further prevent springback, the lower arm of the pinch clip can include a barrier rib that engages the upper clamping surface, thereby preventing the pinch point from traveling distally even if the upper arm is forced into an over-engaged position.

[0010] In some embodiments, the present invention is implemented as a pinch clamp, which includes an upper arm having a proximal end and a distal end and a lower arm having a proximal end and a distal end, wherein the proximal end of the lower arm is connected to the proximal end of the upper arm by a hinge. The pinch clamp also includes a terminal end extending upward from the distal end of the lower arm. The terminal end includes an engagement structure, which forms an engagement surface that intersects with the distal end of the upper arm to maintain the pinch clamp in an engaged position. An upper clamping surface is formed on the upper arm and has a proximal portion and a distal portion. Moreover, a lower clamping surface is formed on the lower arm and has a proximal portion and a distal portion. When the pinch clamp is in the engaged position, the distance between the distal portion of the upper clamping surface and the distal portion of the lower clamping surface is less than the distance between the proximal portion of the upper clamping surface and the proximal portion of the lower clamping surface.

[0011] In other embodiments, the present invention is implemented as a pinch clamp, which includes an upper arm having a proximal end and a distal end and a lower arm having a proximal end and a distal end, wherein the proximal end of the lower arm is connected to the proximal end of the upper arm by a hinge. The pinch clamp also includes a terminal end extending upward from the distal end of the lower arm. The terminal end includes an engagement structure, which forms an engagement surface that intersects with the distal end of the upper arm to hold the pinch clamp in an engaged position. An upper clamping surface is formed on the upper arm and has a proximal portion and a distal portion. Moreover, a lower clamping surface is formed on the lower arm and has a proximal portion and a distal portion. The pinch clamp also includes blocking ribs, which are arranged on opposite sides of the lower arm and extend distally from the distal portion of the lower clamping surface.

[0012] In other embodiments, the present invention is implemented as a pinch clamp, which includes an upper arm having a proximal end and a distal end and a lower arm having a proximal end and a distal end, wherein the proximal end of the lower arm is connected to the proximal end of the upper arm by a hinge. The pinch clamp also includes a terminal end extending upward from the distal end of the lower arm. The terminal end includes an engagement structure that forms an engagement surface that intersects with the distal end of the upper arm to maintain the pinch clamp in an engaged position. An upper clamping surface is formed on the upper arm and has a flat proximal portion and a distal portion that protrudes downward from the flat proximal portion. A lower clamping surface is formed on the lower arm and is flat.

[0013] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory and do not limit the invention, as claimed. It should be understood that the various embodiments are not limited to the devices and apparatus shown in the accompanying drawings. It should also be understood that the embodiments may be combined, or other embodiments may be used, and that structural changes may be made without departing from the scope of the various embodiments of the invention, except as claimed. Therefore, the following detailed description should not be construed as limiting. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The exemplary embodiments will be described and explained through the use of the accompanying drawings and with additional specificity and detail, in which:

[0015] 1 and 1A-1C illustrate a prior art pinch clamp, including how the pinch clamp can cause backflow when the pinch clamp is over-engaged;

[0016] Figure 2A A front perspective view of a pinch clip constructed in accordance with an embodiment of the present invention is provided;

[0017] Figure 2B Provided Figure 2A A front view of a pinch clamp;

[0018] Figure 2C Provided Figure 2A A side view of a pinch clamp;

[0019] Figure 2D Provided Figure 2A a cross-sectional front view of the pinch clamp when in a disengaged position;

[0020] Figure 2E Provided Figure 2A a cross-sectional front view of the pinch clamp when in an engaged position;

[0021] Figure 3 A pinch clamp constructed according to another embodiment of the present invention is shown;

[0022] Figure 4 shows a pinch clamp constructed according to another embodiment of the present invention; and

[0023] Figure 5 A pinch clamp constructed in accordance with another embodiment of the present invention is shown. DETAILED DESCRIPTION

[0024] A pinch clamp constructed in accordance with the present invention can provide positive displacement while preventing rebound, thereby minimizing the occurrence of backflow. The pinch clamp of the present invention can produce positive displacement relative to a single pinch point by configuring the upper and lower clamping surfaces to provide a pinch profile. Additionally, the upper and lower clamping surfaces can be configured to form a pinch point toward the distal end of the pinch profile. By positioning the pinch point toward the distal end, the likelihood of rebound can be minimized if the pinch clamp is over-engaged. Alternatively or additionally, the pinch clamp may include a barrier rib that intersects the upper clamping surface to prevent the pinch point from traveling distally even if the upper arm is forced into an over-engaged position.

[0025] Figures 2A-2E Various views of a pinch clip 200 constructed in accordance with an embodiment of the present invention are provided. The pinch clip 200 includes an upper arm 210, a lower arm 220, a movable hinge 220 coupling the proximal ends of the upper and lower arms 210, 220, and a distal end 240 extending upward from the distal end of the lower arm 220. The movable hinge 230 and distal end 240 form openings 230a and 240a, respectively, through which a catheter (not shown) extends. An upper portion of the distal end 240 forms an engagement structure 241 having a downwardly facing engagement surface 241a. The upper arm 210 pivots relative to the lower arm 220 such that a front end 211 of the upper arm 210 is secured below the engagement surface 241a, thereby maintaining the pinch clip 200 in an engaged position. In some embodiments, the front end 211 may include a protrusion 212 extending outward from a side of the upper arm 210. To facilitate gripping, the upper and lower arms 210, 220 may include a series of ridges 213 and 222, respectively, spanning the width of the respective arms.

[0026] To prevent lateral disengagement, the lower arm 220 may include protrusions 221 extending upward from opposite sides of the lower arm 220, thereby forming a gap between the protrusions. The upper arm 210 may include a rib 214 extending downward from the underside of the upper arm 210 and configured to be inserted into the gap between the protrusions 221. The intersection between the rib 214 and the protrusion 221 will prevent the upper arm 210 from moving laterally relative to the lower arm 220 when in the engaged position, thereby preventing the front end 211 from lateral disengagement from the engagement surface 241a. Figure 2B As best shown, the ribs 214 and protrusions 221 can be positioned toward the distal end 240. In addition to preventing lateral disengagement, the protrusions 221 also serve to center the catheter between the lower arm 210 and the upper arm 220. In other embodiments, such as Figure 5As shown, the pinch clip 200 may not include the ribs 214. In these embodiments, the pinch clip 200 may be disengaged by lateral movement, yet still provide positive displacement and allow for catheter centering.

[0027] like Figure 2B As best shown, the pinch clamp 200 can be configured such that when the lower arm 220 is horizontal and the pinch clamp 220 is in the disengaged position, the upper arm 210 will be oriented at an upward angle. Figure 2C As best shown, the outer edges 231 of the upper and lower arms 210, 220 are rounded to eliminate sharp edges, thereby improving patient comfort.

[0028] The upper arm 210 forms an upper clamping surface 252 that is positioned proximal to the rib 214 and extends downwardly beyond the rib 214. Figures 2A-2E In some embodiments, including the illustrated embodiment, the upper clamping surface 252 includes a generally flat proximal portion 252b and a protruding distal portion 252a. In other embodiments, the upper clamping surface 252 may not include the protruding distal portion 252a, such that the upper clamping surface 252 is generally flat from its proximal end to its distal end. The lower arm 220 forms a generally flat lower clamping surface 251. The barrier ribs 253 extend distally along opposite sides of the lower arm 220 beyond the distal end of the lower clamping surface 251. Thus, gaps 253a are formed between the barrier ribs 253 distal to the lower clamping surface 251. In some embodiments, the protrusion 221 comprises a raised extension of the barrier ribs 253.

[0029] Both the upper clamping surface 252 and the lower clamping surface 251 are elongated to create a pinching profile when the pinch clamp 200 is in the engaged position. Figure 2D and 2E , the upper clamping surface 252 can be configured such that when the pinch clip is in the disengaged position, the upper clamping surface 252 is angled in a distal direction relative to the lower clamping surface 251. Then, once the pinch clip 200 is transitioned to the engaged position, the upper clamping surface 252 pivots in a downward direction relative to the lower clamping surface 251. As part of this transition, the proximal portion 252b will initially contact the catheter and compress the catheter toward the proximal end of the lower clamping surface 251. This compression of the catheter will produce a positive displacement. When the pinch clip 200 is fully transitioned to the engaged position and due to the downwardly angled orientation of the upper clamping surface 252, the distal portion 252a will contact, compress, and occlude the catheter toward the distal end of the lower clamping surface 251 (i.e., create a pinch point). Thus, the pinching profile includes compressing the catheter toward the proximal end of the clamping surfaces 251 / 252 and occluding the catheter distally of the clamping surfaces 251 / 252.

[0030] The provision of the protruding distal portion 252a minimizes the force required to occlude the catheter. More specifically, the protruding distal portion 252a minimizes the length of the catheter that is occluded, thereby minimizing the squeezing force required to reach the engagement position. In contrast, if the upper clamping surface 252 were flat, a longer length of the catheter would be compressed and occluded, thereby increasing the squeezing force required to reach the engagement position.

[0031] Refer again Figure 2E Due to the positioning of the barrier ribs 253, if an excessive engagement force is applied to the pinch clip 200, the upper clamping surface 252 is blocked from moving in a downward direction relative to the lower clamping surface 251. In other words, the barrier ribs 253 prevent the pinch point from moving in a distal direction, thereby preventing springback once the excessive engagement force is removed. The generally flat orientation of the lower clamping surface 251 and the barrier ribs 253, along with the downwardly angled orientation of the upper clamping surface 252, also converts the excessive engagement force on the upper arm 220 into a pivoting force about the distal portion 252a. This pivoting force minimizes the likelihood that the upper clamping surface 252 will slide in a distal direction relative to the lower clamping surface 251.

[0032] Figure 3 An alternative configuration of the lower and upper clamping surfaces 251, 252 is shown that also provides a pinching profile. In this embodiment, similar to that described above, the upper clamping surface 252 includes a generally flat proximal portion 252b and a protruding distal portion 252a. However, the lower clamping surface 251 also includes a protruding distal portion 251b that is generally aligned with, but elongated relative to, the distal portion 252a. In this configuration, the generally flat proximal portions of the upper and lower clamping surfaces 252, 251 will compress the catheter, while the distal portions 252a / 251a will form a pinch point.

[0033] Figure 4 Another alternative configuration of lower and upper clamping surfaces 251, 252 is shown, which also provides a pinching profile. In this embodiment, lower clamping surface 251 is not flat, but includes a protruding proximal portion 251b in addition to a protruding distal portion 251a. Proximal portion 251b protrudes upward further than distal portion 251a. Upper clamping surface 252 includes protruding distal portion 252a and proximal portion 252b. A recess 252c is formed between distal portion 252a and proximal portion 252b and has a curved shape corresponding to the curved shape of proximal portion 251b. Proximal portion 251b is inserted into recess 252c, which in turn prevents the pinching clamp from overengaging.

[0034] like Figure 4As shown, when in the engaged position, a generally constant spacing is formed between the proximal portion 251b and the recess 252c, and between the proximal portion 251b and the proximal portion 252b. This constant spacing creates a channel in which the catheter will be compressed but not blocked. In contrast, in the engaged position, the spacing between the distal portion 252a and the distal portion 25a is less than the constant spacing between the other portions, thereby forming a pinch point between the distal portions 252a / 251a.

[0035] exist Figure 3 and Figure 4 In the embodiment shown, the elongated upper and lower clamping surfaces will provide positive displacement and will also prevent springback. Springback is prevented because the pinching profile positions the pinch point at the distal end of the clamping surfaces.

[0036] In summary, the pinch clamp of the present invention includes upper and lower clamping surfaces configured to provide a pinching profile that provides positive displacement by compressing the catheter toward the proximal end of the clamping surfaces and prevents recoil by positioning the pinch point toward the distal end of the clamping surfaces.

Claims

1. A pinching clip for clamping a medical catheter, the pinching clip comprising: a lower arm comprising a lower clamping surface, wherein the lower clamping surface comprises an upwardly projecting proximal portion and an upwardly projecting distal portion, wherein the upwardly projecting proximal portion projects upwardly further than the upwardly projecting distal portion; an upper arm comprising an upper clamping surface, wherein the upper clamping surface includes a downwardly projecting proximal portion, a downwardly projecting distal portion, and a recess between the downwardly projecting proximal portion and the downwardly projecting distal portion, wherein the upwardly projecting proximal portion is configured to be inserted into the recess when the pinch clip is in an engaged position, and wherein the upwardly projecting distal portion is configured to align with the downwardly projecting distal portion when the pinch clip is in the engaged position; a tip extending upwardly from the distal end of the lower arm, the tip including an engagement structure forming an engagement surface that interfaces with the distal end of the upper arm to retain the pinch clip in an engaged position; and a hinge disposed between a proximal end of the lower arm and a proximal end of the upper arm; Wherein, when the pinching clip is in the engaged position, a distance between the downwardly protruding distal portion and the upwardly protruding distal portion is smaller than a distance between the upwardly protruding proximal portion and the recess.

2. The pinch clip according to claim 1, wherein: The upper arm is configured to pivot relative to the lower arm and is configured to be secured below the engagement surface when the pinch clip is in the engaged position.

3. The pinch clamp of claim 1 , further comprising a pinch profile formed by the upper clamping surface and the lower clamping surface, the medical catheter being compressed along the pinch profile, wherein A pinch point is formed at the distal end of the pinch profile.

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