Aspiration and infusion needle

Abstract

An aspiration and infusion needle which comprises a substantially cylindrical body tapering at one end, which has an axial through-bore diverging from axiality in the region of the point to open out at a lateral surface of the body, the curvature of the surface of the body opposite to said lateral surface extending, at the point of the body, over the axial part of the through-bore. This needle does not cause the formation of splinters when penetrating elastomeric materials.

Description

Background of the Invention

1. Field of the Invention

This invention relates to an improved aspiration and infusion needle which may particularly, but not exclusively, be used in the clinical field.

2. Description of the Prior Art

It is known in the medical art that it is often necessary to draw solution from small receptacles or bottles which are sealed by plugs made of rubber or a similar material, by using an aspiration needle which is caused to penetrate the said plug into the inner part of the receptacle or container.

However, the shape of the pointed end with which these needles are provided is such as to often cause the shearing off of splinters of elastomeric material from the plug which are likely to partially or completely obstruct the aspiration channel of the needle, thus preventing or slowing down the aspiration of the solution which is consequently subjected to contamination. If the same needle used for aspiration of the solution is subsequently employed for the injection of the solution, there is the risk of injecting, along with the solution, the splinters of elastomeric material which are likely to be present in the needle channel.

Summary of the Invention

It is therefore an object of the present invention to provide an improved aspiration and infusion needle having a shape such as not to form splinters when penetrating elastomeric materials.

According to the present invention there is provided a needle for use in the aspiration and infusion of solutions comprising a substantially cylindrical body which tapers at one end to form a point and which comprises a substantially axial through-bore which diverges from axiality in the region of the point to open out at a lateral surface of the body and wherein the curvature of the surface of the body opposed to said lateral surface is such that at the point, the body extends over the substantially axial part of the through-bore.

In order that the invention may be more clearly understood an embodiment thereof will now be described by way of example with reference to the accompanying drawings.

Brief Description of the Drawings

FIG. 1 is a longitudinal cross-section of the improved needle in accordance with this invention; and

FIG. 2 is an elevation of the needle in accordance with this invention, rotated through 90.degree. with respect to axis II--II of FIG. 1.

Description of the Preferred Embodiment

Referring now to the accompanying drawing, needle 1 comprises an essentially cylindrical body 2, an axial bore 3, a bevel 5, and a curved point 8.

The point 8 of needle 1 is curved at its end wall 4 so that the minimum areas of cross-section of the bore 3 at the point 8 are inclined to an axis which is at right angle to axis II--II. In particular, end section 6 of bore 3 of needle 1 lies on a plane substantially parallel to axis II--II. Consequently, the penetration of needle 1, for instance through articles made of elastomeric material, suitable for sealing closing receptacles and small bottles containing solutions, cannot cause the shearing off of shreds of this material and their conveyance up into the bore, because the cross sectional area of bore 3 abutting the seal is zero when penetrating a plane surface perpendicular to axis II--II of FIG. 1.

The bevel 5 comprises a notch in the wall adjacent end section 6. The bevel 5 is needed to allow the sharpening of the point surface 7.

Claims

What we claim is:

1. In a needle for use in the aspiration and infusion of solutions comprising a tubular cylindrical body and a pointed end integral therewith, said body having an axial through-bore that diverges from axiality in the region of the pointed end and terminates in an opening lying in a lateral plane and wherein the curvature of the surface of the body opposite to said opening is such that at the pointed end the body extends over the axis of the tubular body, the improvement wherein the opening and the surface surrounding the opening lie in the same lateral plane located substantially midway between and parallel to the axis of the tubular body and a plane tangent to the tubular body's outer cylindrical surface, and wherein a beveled surface is provided between the end of the surface surrounding the opening opposite from the pointed end and the tubular body's outer cylindrical surface so that the entire opening of the needle lies in the substantially lateral plane.