JP2005144085A - Safety device for syringe needle melting apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an apparatus for safely and rapidly melting a syringe needle, which solves the following problem that a dangerous situation occurs by the generation of an ultraviolet ray by sparks and arc when a syringe needle is melted with a current. <P>SOLUTION: When the syringe needle is inserted from the conical hole of an upper electrode, the upper electrode and a lower electrode is short-circuited, so as to melt the needle by Joule heat. A syringe needle melter includes a circuit for allowing the current to intermittently flow when the current is enlarged by a battery and a protecting circuit between both the electrodes. Since the needle is inserted from the conical hole in the upper electrode, the electrodes have a structure to prevent the sparks and the UV ray from leaking outside. A spring is arranged in the lower part of the upper electrode, so that the upper electrode is vertically moved. Thus, melt is performed even to the base of the syringe needle. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

Detailed Description of the Invention

Industrial application fields

When throwing away needles and injection needles, if the tip is sharp, it can be dangerous to the operator. It is safe to melt the tip before throwing it away.

Conventional methods and problems

When the needle thickness is changed, the conventional injection needle dissolution apparatus is dangerous because the dissolution time is too long or sparks are generated.
In addition, when a DC arc is generated, it is dangerous if ultraviolet rays enter the user's eyes.

Problems that the device tries to solve

Even if the thickness of the needle changes, the generation of sparks is reduced, ultraviolet rays are not emitted to the outside, and the melting time is shortened as much as possible.

Means to solve the problem

This will be explained with reference to the drawings. (A) The main part of FIG. 2 is contained in the case of FIG. 1 (b) One upper electrode and two lower electrodes are arranged below the hole in the upper part of the case. The material is a good conductor. (In this case copper).
1 When an injection needle is inserted from a conical hole in the center of the upper electrode, both electrodes are electrically short-circuited by the same needle and dissolved.
(C) A DC voltage is supplied to these both electrodes through 3 protection circuits by 4 batteries.
(D) The 3 protection circuit includes the 7MOSFET, 6MOSFET control circuit, and 5 voltage detection circuit of FIG.

Action

In FIG. 2, when the needle is inserted, 1 upper electrode and 2 lower electrode are short-circuited by the needle. Since the needle has a large specific resistance, it is melted by Joule heat, and the 6MOSFET control circuit is continuous when the drain-source voltage of the 7MOSFET is large by utilizing the fact that the drain-source voltage when the MOSFET is ON is inversely proportional to the drain current. When it is on and small, it is controlled to repeat on and off at a high speed of several hundred Hz to several kHz (see FIG. 4).
That is, the circuit does not continuously flow a large current. Therefore, the arc disappears immediately. In addition, since sparks and arcs are generated below the upper electrode, ultraviolet rays do not come out.

Effect of device

When a large current flows, the generation of the arc is large, but since the arc is turned off immediately, the arc disappears immediately and the generation of the spark is limited to the minimum.
Further, 7MOSFET does not limit the maximum value of current, so the dissolution rate is only slightly reduced when a thick needle is used.
Therefore, even if the thickness of the needle changes, the change is detected and controlled by the five-voltage detection circuit, so that the generation of sparks is minimized and can be safely processed.
In addition, since the current is turned on and off, power consumption is low, and the number of treatments per charge is doubled.

Dimensions Detailed view of the main part Internal configuration of FIG. Protection circuit configuration diagram 3 protection circuit details of FIG. Current of electrode Current waveform flowing through protection circuit of FIG. 3 1 Upper electrode 2 Lower electrode 3 Protection circuit 4 Battery 5 Voltage detection circuit 6 MOSFET control circuit 7 MOSFET

Claims (2)

As shown in FIG. 2, a switching circuit using a MOSFET is added between 4 batteries, 1 upper electrode, and 2 lower electrode, and when a large current flows when a needle is inserted into the electrode, the current is turned on and off at high speed. Needle dissolver In FIG. 2, when a conical hole is made in the copper plate of the upper electrode 1 and an injection is inserted into the hole, the needle contacts the lower electrode 2 and the needle melts due to Joule heat.
The lower part of the cone has a slightly larger hole than the injection needle, so the needle itself closes the hole so that sparks and arcs are not visible to the operator's eyes

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