TWEEZERS (fr. pincette tweezers) — the tool consisting from two the springing a branch for capture and short keeping of fabrics at surgeries and other manipulations. Items were known in Ancient Egypt (see. Meditsina ). In a collection of surgical instruments in Leipzig in-those stories of medicine are available samples of the Item V—IV of centuries BC
P. consists of two plates welded or riveted on one end from which working branches (branches) of tweezers disperse under some corner. The ends a branch (sponge) are a working part; fabric or a subject is taken and kept by them. P.'s branches are connected rigidly therefore sponges meet without distortion. Important advantage of P. in front of other medical tools (e.g., clips) is that force of impact of P. on fabric is controlled by finger-tips and can be dosed.
P.'s branches are made of U7A carbon steel (0,7% of carbon) with chrome plating or of stainless chrome steel and shall spring well without residual deformation. Nek-ry eye P. produce from the titanium alloy having nonmagnetic properties. Items disposable make of plasts.
P.'s back for prevention of sliding of fingers has a mat surface or cutting of a semicircular profile, other surface of P. shall be well polished.
In a form of a working part (sponges) of P. divide on surgical, anatomic and special.
Surgical P. on the end of a working part have teeth (one or several), to-rye at manipulations partially get into fabrics, including and dense, and strongly hold them. Width of sponges of all-surgical P. usually 1,5 — 2,5 mm. Neurosurgical P. have more tiny working part, width of sponges and height of cloves considerably, is, less, approximately twice, than at all-surgical P. (see. Neurosurgical tools ). In P.'s ophthalmology surgical are the main fixing tool (see. Ophthalmologic tools ). For the purpose of more reliable keeping of eye P. fingers the design of a back of microsurgical P. is improved and has an opening and spherical deepening or a longitudinal groove. Nek-ry eye P. are supplied with the fixing pin, and sometimes and persistent pins on opposite sponges that ensures their more reliable functioning and practically excludes a distortion and discrepancy of working sponges; eye P.' part have the lock latch and are intended for such operations when an oculomotor muscle it is necessary to hold rather long time. At operations on a brush apply P. which is modification of a pronged-tenaculum forceps of D. O. Ott, having two groups of teeth on a working part to keeping of dense cicatricial fabric.
Anatomic P. on a working part have cross or other character cutting (small cloves) 15 mm long that allows to hold strongly fabric, injuring it less. Items with similar cutting more than 15 mm long, with a longitudinal ledge on one sponge and a groove on another received the name P. with atraumatic cutting.
Vascular tweezers have shorter cutting and a longitudinal flute on one of a branch that improves conditions of keeping of vessels. Apply P. with narrow sponges to a razbortovka of vascular walls and short (1,5 — 2,2 mm) cutting.
Special P. differ in a special configuration of a working part.
E.g., P. for removal of foreign bodys from a cornea, for an oncotomy of a brain, ear Items, II. for extraction of a cataract have a working part in the form of the pointed spoon, P. for operations on centuries — in the form of an oval window. Hinged P. in the form of small tweezers, but without ring-shaped are created by a branch for an ophthalmosurgery, chest surgery and microsurgeries.
P.'s rigidity characterized by the effort necessary for data a branch is metrological regulated.
Usually the effort shall not exceed 0,15 — 0,2 kg» with for ophthalmologic P. up to 72 mm long; 0,2 — 0,5 kgfs for other ophthalmic forceps and 0,4 — 0,8 kgfs for all-surgical P. 150 — 300 mm long.
In the USSR the St. 100 types of P. V to the table are issued nek-ry types of P., area of their main medical use, a habit view, a design of working sponges and some characteristic are given.
See also Clips surgical .
Table. Some types of the tweezers which are released in the USSR, area of their main medical use and &harakteristikanbsp; (according to 1981)
The name of tweezers and their appointment (in brackets number of the drawing, with &bukvoynbsp is specified; &anbsp; — working sponge). Total length (L); width of the worker &chastinbsp; (b). Outward and working sponges of some tweezers are given without observance of scale.
Bibliography: History of medicine, under the editorship of B. D. Petrov, M., 1964; Krendal P. E. and KA and that in To). T. Medical merchandizing, page 277, etc., M., 1974.
Yu. F. Kabatov.