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Using the rete list for collective curating online

Posted Feb 20 2010 12:00am

Recently I announced a quiz to get more information about a historical syringe that a couple of friends had bought for me. This quiz was far from easy since we had no information on the syringe whatsoever. Medical Museion’s guest researcher and former chief physician Sven Erik Hansen was the first to make a suggestion on our Danish blog — he thought it might had been be used to treat haemorrhoids.

Sven Erik’s was a qualified guess, but it seems like the area of expertise that we are dealing with here is rather odontology. Thomas put a query about the syringe on rete, the mailing list for curators, historians, students, collectors, dealers, etc, interested in the history of scientific instruments, and immediately received some very interesting answers. First out was Frank Manasek: 

This type of syringe was common in dentistry or in minor surgery where local anesthetics (such as lidocaine) would be used. Later syringes of this style were designed to use disposable ampoules of anesthetic, and disposable needles. (This one predates both.) The needle on this example is long, suggesting its use in mandibular blocks.

Following Franks lead Alistair Kwan elaborated:

I was just about to write almost the same thing. The last time I asked a dentist about the move away from these, he said that patients are more scared of them because they are big and shiny, and harder to
keep out of sight — convenience and cost of disposables did not play into his decision, though they are primary issues in debates between surgeons, surgical nurses and hospital administrators.

If you compare with today’s common disposables, the plunger design involves a different handhold that increases control through tight spaces and increases pressure on the contents. If you try them out, you can experience how the palm-grip hold is much less subject to little wobbles in the finger and thumb joints. (A high-stability grip for the disposables is to wrap them in all four fingers of a fist, which limits where you can work.)

You can also experience how the palm-grip hold and the lighter two-finger hold are suited to injecting targets at different heights and orientations. You cannot comfortably inject straight down with the
palm grip hold unless you are leaning right over the patient. But your forearm is positioned for easy aiming sideways or forwards or upwards, as into the nerves in the mandibular joint.

For times when you want a pistol or palm grip (e.g. in veterinary medicine), there are handles for disposable syringes. The handles derive from earlier syringes in which they were inbuilt. In recent years (decades?) they have simply had the syringe removed, leaving a hollow or brackets in which to insert a disposable. Similarly with ring grips, now marketed for use by non-medical people with frail hands who need to administer to themselves or family members, and for cake decorating.

Easy disassembly makes cleaning easier but it sometimes owes more to manufacturing processes than concern for scrubbing and autoclaving. A device like this is often cheaper to mass-produce from standard stock than by building all components from scratch. If it goes together easily, it often follows that it comes apart easily as well. Today’s one-way barbed fasteners and sonic welders have of course
cancelled that rule.

Now what began as an artefact without a history suddenly had spawned a fascinating insight into the world of dentistry. Peter Morris continued (still on the rete list):

These syringes are still in very common use by dentists in the UK. I don’t recognise the disposables mentioned by Alistair. Personally I always try to avoid the jab if I can which provokes friction between me and the dentist. I would say the needle is a little bit thicker than it appears in the photograph, but it may just be a matter of the scale of the photograph (and the psychological effect of it going into your mouth). A quick look on the web throws up JS Dental Manufacturing Inc of Ridgefield Connecticut. I cannot find out how long it has been in business but it seems well established.

And back to Alistair:

I should clarify a bit though: the common disposables are less stable than the big dental model when used in the mouth owing to how they  have to be held. What I originally wrote (in a low-energy moment at the end of work yesterday) was unclear, though I’m sure that your exhibit writers will have no trouble doing better. (I’m now at the start of the day so am more critical of what I write!)

And that critical attitude might be what made Alistair return with one last comment:

It might also be worth indicating that some anaesthesia techniques begin with aspirating by withdrawing the plunger to suck a little on the tissue that the needle has entered. This tests whether you are in the right place: the colour of the liquid obtained indicates the extent of blood supply. If you get blood, you know to withdraw the needle and start again. (I find needle-guiding techniques very clever. Other common rules are to locate external markers for guidance, and to hit bone or a sudden resistance change as an indicator for depth. Some markers for mandibular anaesthesia are in the ear which is why the dentist puts his finger there — as target to aim for — while inserting the needle.)

Aspiration is reflected in some plunger handles: they have a ring for the thumb.

It’s more difficult to aspirate with pistol-grip and palm-grip syringes because pulling and pushing require different holds. That may entail having an assistant steady the patient’s head.

Following Peter’s post, I had a quick look at some on-line catalogues and saw that both metal and disposable plastic syringes are sold by dental equipment suppliers.

So thanks to our fellow histrorians and curators on the rete list, we’ve been able to construct a much more detailed curatorial story about the syringe than I ever imagined when I first posted the original quiz.

And so we need a winner. The stern panel of judges (who will remain anonymous) has decided to a name Alistair Kwan the winner. So Alistair, whenever you come to Copenhagen, please visit us here at Medical Museion and claim your prize.

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