How long have they been making hollow needles?

In another terrific Staff Report, Una addresses the question How do they get the hole through a hypodermic needle?.

She notes: “Processes to make small tubes and hollow needles are quite old.”

Q1: How old?
Q2: I want pictures and diagrams.

A1: See’s article on Syringes. The first syringe capable of piercing skin was introduced in 1853. Earlier, hollow tubes used for (gulp) enemas had been developed: here’s one from about 1770.

A .pdf of syringe history from 1853 onwards (851K) is [here]( Syringe_and_Needle_History.pdf). It’s a promo piece by Becton Dickerson and a little detailed. It doesn’t discuss manufacturing too much. Apparently, many of the early syringes were made of glass, though the 1853 model was steel.

Cool stuff.

Far be it from me to criticize your preferences, but it would be decidedly unhealthy to gulp an enema. But hey, your choice.

Thank you for finding links to the additional information on the history. I had some items noted from research in the modern process, but not enough that I thought I could legitimately write about it.

Try here.

Not to pry into Una’s personal business, but 30,000 injections sounds like a lot. That would be around thirty years worth of injections, three times a day, wouldn’t it?

A lot of diabetics do finger pokes 4 or more times a day just to monitor the blood sugar. Then consider dosing with short acting insulin 4 times a day or more, and nowadays, an injection of the long-acting lantus insulin (injected separately from the short acting stuff) once and sometimes twice a day.

So you have some diabetic individuals poking themselves with needles 10 or more times a day, and giving separate injections up to 6 or even more times a day.

Wouldn’t one end up with an awful lot of holes in one’s skin that way? It seems when I give blood that the wound left by the needle takes a week or so to heal completely, and I’m not sure I could find 42 separate places to jab a needle. Granted, blood-donation needles are pretty big, and an insulin needle wound might heal more quickly, but it still seems like it would be easier to have some sort of permanently-installed shunt to which one could attach the syringes of medicine, leaving a single hole continually open. Or would that prompt an autoimmune response?

Evidently not for diabetics, but I do know someone who has to put stuff in or take stuff out of her body often enough that she has a sort of implant. It’s off to the side of her abdomen, completely subdermal, and I think (from feeling it) that it’s basically a ball inside a metal sleeve. How exactly it works I have no idea.

She named it Harvey. Honestly. I’m too boring to make sh!t like this up.

Basically, I figured for most of my 24 years as a diabetic I’ve been on a 3-4 shot a day regimen, taking at first NPH and regular; then NPH, regular, and Humalog; then Lantus and Humalog. Right now I take 1 of Lantus and 2 of Humalog, so I’m down to 3/day.

I do get a lot of holes in my skin, and my legs are somewhat scarred. The worst thing, however, are these things which I believe are called “lipoliths”, which are grape to olive-sized, hard, painful lumps under my skin, reputedly from some reaction of fat cells with the insulin.

Two of my fingers are scarred badly by the blood tests (5-6 per day), but since I’ve been very careful with that, that’s much better than many people I know.

Absolutely, that’s a lot of holes. But that’s how it goes. My goddaughter has a child themed chart of the human body with roughly 50 injection sites. She colors in a little square to signify which site she used last. If you scroll down a little on this page and click on the names of the body parts next to the little girl, dots will show up showing injection sites.

There is indeed an insulin pump for some diabetics. It’s not suitable for everyone, and it’s still in pretty early stages of use. It’s also pretty expensive, and carries a slightly elevated chance of infection at the entry point. I believe it’s still mostly used for young children who can’t reasonably be expected to do multiple shots each day, but there is a section on that website for adult users of the insulin pump.

Far be it from me to teach an old diabetic new tricks, but for those in our audience, lumps under the skin can also be caused by injecting the insulin too shallowly. The insulin needs to go into the fat layer underneath the skin. If it’s not deep enough, a bump will result. Too deep, and you hit muscle and it hurts a lot. Thin diabetics tend to get more of these bumps, because it’s harder to be sure you hit fat every time.

I don’t think we’re talking about the same things here. You do get a temporary lump if the shot is too shallow, but these are hard, permanent lumps that feel like a solid mass beneath the skin, but deep. They are supposed to go away if you leave a site alone for a while - so I left an entire leg free from injections for a year or more, and it turned out not to work for me. They said the only thing they can do is surgery to cut them out (apparently, they’re too solid to lipo out) and since all elective surgery is out for me due to my health, no doctor will attempt it.

Textbooks say that they’re caused by giving too many injections in the same site, and that’s possibly what happened to me. I am so thin that there are limited places that I can even stick needles.

It’s of mild interest to note that “anneal” can mean both softening and hardening. The steel is annealed in order to extrude it, then annealed in order to harden it.

It includes both softening and hardening :slight_smile:

At the risk of being argumentative, while the dictionary may give alternate definitions for anneal, such as “firing in a kiln” and heating for hardening - in all my time in engineering, when I worked in a metal shop in school, when I worked in a manufacturing plant which hosted many huge annealing ovens, and in power plant work, I’ve never heard mention of it used with respect to hardening metal. I’m sure it may be technically correct to use it to speak of heating for hardening, but IMHO - and it is H - it would be a usage which would be out of the ordinary.

You’re probably right. Here’s a question for you: as any electrician knows, if you overwork a copper wire, it will “work-harden” and become brittle, stiff and difficult to work with. One can actually break a thin copper wire by bending it back and forth until it gets hot and brittle. What would this be called, if not annealing?

So far as I know, the opposite of annealing is tempering. Hardening a wire by bending it repeatedly is stress tempering.

Hmm…I don’t know enough about it to say that you’re annealing anything. I mean, thinking about the situation, what’s causing the wire to break - exceeding the elastic limit repeatedly and finally propagating a crack through the metal, or is the heat doing it? Many metals become brittle if heated and then quenched (tempering) so the crystal structure of the metal is in a state that is harder but more brittle. And when a metal undergoes stress, it can in some situations become tempered in that manner. But what’s really happening with the wire is the question - is one really heating it enough and cooling it enough that it is undergoing a “quenching” process, thus one is microtempering portions of the metal - or is one just overstraining it, producing heat as a result?

I don’t know the answer to that.

Could be, although I can’t find any reference on the web. Are you sure you didn’t just make this up? :dubious:

I presume that you can find references to tempering, so I imagine that you’re referring to the term “stress tempering”. In which case, no, I’m not sure I didn’t just make it up. I know there’s a term for that process, and I’m pretty sure that it includes the word “tempering”, but I could be misremembering the “stress” part.

As for the mechanism, the simple test would be to repeatedly bend a wire while holding it under water, to keep the temperature constant. Or, if one wanted to be more thorough about it, compare the number of bends needed underwater with the number needed in air. When I get home, I’ll try this.

I’m not sure about this either. Here’s what I find in my 25th edition of Machinery’s Handbook - the bible of manufacturing and mechanical engineering as far as I’m concerned.

First, a brief statement found under the definition of annealing:
“When [annealing] is applied only for the relief of stress, the process is properly called stress relieving.”

The section then expounds on at least a dozen different methods and processes for annealing and explains why you’d wanna use any particular method.

Next up, a definition of stress relieving:
"A process to reduce internal residual stresses in a metal object by heating the object to a suitable temperature and holding it for a proper time at that temperature. This treatment may be applied to relieve stresses induced by casting, quenching, normalizing, machining, cold-working or welding.

Finally, while I don’t find an entry for “stress tempering,” in the section describing the methods of tempering, I note a process called “Snap Tempering.” Snap tempering is described thusly:
"A precautionary interim stress-relieving treatment applied to high hardenability steels immediately after quenching to prevent cracking because of delay in tempering them at the prescribed temperature.