Technical use of surgical instruments - some info - Page 1
Forum section: electronics / general

author: Neomys Sapiens
author_rank: Super Contributor
timestamp: October 07, 2019, 01:17:34 am
content: Let us look at two pictures first:They just seem to be the same type of tool, don't they?Well, they are not!The first one is the one best known, as they are used by the medical profession in greater numbers and so they are cheaper and are discarded more frequently. It is called a Hemostat (artery clamp) and what it is intended to do governs its action: it is intended to shut off a blood vessel without destroying it.Therefore, it has a rather benighn strenght of grip, even when locked in the second or third detent.It can be used for a multitude of purposes in electroncs, like holding a wire or component lead, holding insulated wire without damage, and it can be used as a heat sink to protect a component or to avoid wicking when no special tool is available.The second tool is a completely different beast despite its similar appearance.It is called a NEEDLE HOLDER. As one can easily deduce from the intended application, that is, surgical sewing in places hard to reach and at awkward orientation, it grips an object with a much greater force when compared to the Hemostat. Used on a insulated wire, one must be very careful not do destroy the insulation.Another example is a SMD component: while a typical Hemostat can be locked over a SOT-23 case, the Needle Holder might crush it. On the other side, the latter can be used where force is necessary, like manipulation of small but sturdy springs, extraction of broken pins from a connector etc., as it will reliably grip any object even when only minimal surface is engaged.The difference between the two is not the lenght of the beak, as the difference in force is not depending on the length of the acting lever, but the position of the detents in relation of the degree of closure. Typically, a hemostat engages its first detent visibly before the beak closes at the tip. Also, needle holders tend to be of slightly sturdier construction. Needle holders have mostly short beaks, but this can't be relied upon for identification, as there are hemostats with short beaks also.Both instruments are incredibly versatile hand tools in electronics and can serve a multitude of applications. That the difference is not so well known might be the reason behind the starkly different experiences of some users.Needle holders are also available in another design more akin to conventipnal pliers:In this case, the scissor-like grip is replaced by a pliers grip and the detent mechanism is transferred to the end. This design makes it easier to keep the two apart, as it does not appear on hemostats.So, whether re-utilizing surplus medical instruments or deliberately looking to those to extend your capability for manipulation, I hope to have been of help.Those are not the only useful tools which are available from the surgeon's supplies and I will share some other info on them.To be continued....

author: coppercone2
author_rank: Super Contributor
timestamp: October 07, 2019, 04:38:14 am
content: look up robrenz on eevblog, he modified his to hold wires ( I followed his lead)

author: tautech
author_rank: Super Contributor
timestamp: October 07, 2019, 07:43:59 pm
content: For delicate things Fly Tying hackle pliers can be useful too.This pic should be self explanatory as to their form factor and how they work:As they are made to firmly grip the tip of a feather their jaws are smooth but can be covered in heatshrink for better grip.

author: nukie
author_rank: Frequent Contributor
timestamp: October 11, 2019, 05:05:46 am
content: A very nicestainless Swann Morton Scalpel knife handlewith ano 10A blade.Win any X-ACTO hobby knife.

author: ivaylo
author_rank: Frequent Contributor
timestamp: October 11, 2019, 05:43:14 am
content: Quote from: nukie on October 11, 2019, 05:05:46 amI love the detachable scalpel blades system. Someone produced a titanium folding handle for them lately as well -https://drop.com/buy/titaner-titanium-dragonfly-scalpel-knife

author: KE5FX
author_rank: Super Contributor
timestamp: October 11, 2019, 07:36:30 am
content: Hemostats make good pick-up tools, especially the really long ones. They will reach into spots that no pliers can come near.Also a big fan of thesedisposable scalpels. Much sharper than X-Acto knives. They don't hold an edge very well, but they're cheap, so.

author: KL27x
author_rank: Super Contributor
timestamp: October 13, 2019, 11:27:53 pm
content: Hemostats were indispensible to me when doing thru hole stuff. It's been a long while since I used them, though.I have used the same set of scalpels for years, made with used jig saw blades. The steel is incredibly abrasion resistant and slow to sharpen, but it will hold an edge for a really long time.

author: Gyro
author_rank: Super Contributor
timestamp: October 14, 2019, 05:25:57 pm
content: A lot of the needle holders and dental cutters are available with Tungsten Carbide jaw inserts, making them suitable for fairly heavy duty with harder materials.