LED Lamps
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Illuminated Instrumental Insemination Tips

I am currently looking at using high brightness white LEDs directly within specially made insemination tips.

If light is introduced axially into the glass tube that forms the tip, this light will be transmitted along the parallel portion by "total internal reflection" and will result in little loss, when the light reaches the drawn down tapered portion it will "spill out" to a certain degree... Thus illuminating the area immediately surrounding the tip. Because this light is exactly where you need it, the fact that the rest of the area is not illuminated (or only marginally illuminated) is unimportant, in fact it may help to focus your attention, as the queen's back end will be strongly illuminated within a darker field.

I have thought of making a tip that had a right angle bend in it and melting a solid glass rod of 5 mm dia that had been tapered down to 1.5 mm and melted (fused) onto the right angle bend so that it was axially in line with the business end of the tip. This would have the disadvantage that the blob of the union would disrupt light passage and disperse stray light everywhere.

However I persevered with thoughts on this approach and decided that a plain 2 mm diameter glass rod could be grafted on to the end of a short tip to get the light transmitted axially.

First stage, welding tip to rod To start with we need to fuse a piece of rod of the same outside diameter as the tube coaxially onto it's end. as per above right (squares represent 1 mm). The bulge caused at the fusing junction of tube and rod should be as insignificant as possible, otherwise the excess may need grinding of and the surface re polishing ( a lot of work for little gain).

Second stage, grinding the tube The side of the tubular portion could then be ground away in the fashion shown in the diagram at right.

A second piece of tubing could have it's end ground to match the curved wall as in this diagram at right.

  third stage, grinding the stub

finished glassware portion Then the second tube could be welded on to form a right angled stub for hydraulic drive.

I have ideas about designs for heating coils powered by a special transformer which would produce melted regions of the correct shape to enable such welding to be carried out, with a little assistance from a Bunsen burner flame.

The glass rod envisaged would only be 2 mm diameter. The light from a 5 mm LED could be fed into it using a turned aluminium, grazing incidence reflector shown below (small squares = 0.5 mm) the interior surface being highly polished. Since writing the previous paragraph, high brightness LEDs of 3 mm diameter have become available, which makes this an easier process and shortens the overall length of the assembly.

Female Reflector shape

The majority of the light would be transmitted axially by this method, although a certain amount of spillage will occur at the welded unions.

I have also thought that... by using a 4 mm (or 5 mm) glass tube drawn down in a tapered fashion to a 1.5 mm or 2 mm parallel section and then having a tip formed on the end of this portion, saline could be delivered via a right angle stub "tee piece" placed so that several doses of semen could be accommodated in the straight portion of the tube.

Two stage drawn tube

The blob on the side of the straight tube would cause much less disruption to the passage of light and less spillage (of light) would occur. I have an idea about modifying a 5 mm led to produce an annular beam that would match a 5 mm OD tube. The large diameter portion of this tube would be blocked by a highly polished aluminium "grazing incidence" reflecting, secant or asymptotic shaped cone, that would feed the light into the annular wall.

grazing incedence reflecting cone

The exterior surface of the large diameter portion of the multi diameter tube would be enclosed by an internally polished mirror finished aluminium tube to further collimate the light and avoid a distracting light at the edge of your field of view.

These are early ideas... the LED could be pared down until the chip itself, surrounded by a minimum of package plastic could be glued direct onto the end of a 1.5 mm or 2 mm diameter tip that had a side stub for saline entry.

I am also hopeful that the amount of light within the tip will enable actual viewing, or a sort of shadow graph, of valvefold bypassing.

Printed from Dave Cushman's website Live CD version

 Written... Spring 2001 Revised... 10, 31 October 2001, Revised... 21 January 2003, Upgraded... 19 April 2006, Further Upgraded... 26 December 2007,
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