Syringe dead space: difference between revisions
Diff·revision 16 → 17·21:58, 17 Jan 2026
Difference between revision 16 and revision 17 of Syringe dead space. 7 lines changed; the page grew by 1,613 bytes.
| Revision 16 — 20:01, 3 Jan 2026 SeeAlsoSelma (talk) convert the conversion list to a table so the three syringe scales align 16,549 bytes +662 | Revision 17 — 21:58, 17 Jan 2026 ColdChainCleo (talk) add the sharps-disposal cross-link 18,162 bytes +1,613 | ||
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| 126 | * '''Extended plunger tip.''' The plunger tip carries a projection that enters the hub. Values are intermediate and depend on the fit achieved. | 126 | * '''Extended plunger tip.''' The plunger tip carries a projection that enters the hub. Values are intermediate and depend on the fit achieved. |
| 127 | 127 | ||
| + | 128 | == Measurement and standards == | |
| + | 129 | Dead space is not itself a specified parameter in the principal device standards. ISO 7886-1 specifies the graduated capacity, the tolerance on delivered volume, dimensional requirements, freedom from leakage and the force required to operate the plunger; ISO 8537 does the equivalent for insulin syringes; ISO 7864 covers needles and ISO 9626 the stainless-steel tubing from which they are made. None sets a maximum retained volume, and none requires it to be declared.{{r|iso7886,iso8537,iso7864,iso9626}} | |
| + | 130 | ||
| + | 131 | The practical consequence is that dead space must be measured or inferred rather than looked up. Published measurement follows a gravimetric protocol: the device is assembled, filled with water of known temperature, fully discharged against no back-pressure, and weighed before and after; the retained mass converted to volume gives the dead space. Reported precision is adequate to distinguish the device classes in the table above but not to distinguish nominally identical products from different manufacturers, where differences of 10–20 µL have been reported.{{r|zule2009}} | |
| + | 132 | ||
| + | 133 | Because the parameter is undeclared, comparison between published studies requires care. Studies differ in whether the needle is included, whether the measurement is made with the plunger merely bottomed or forced, and whether back-pressure representative of tissue is applied. Values quoted without those details are not strictly comparable, and a difference between two published figures for the same device class is at least as likely to reflect protocol as product.{{r|bobashev2010}} | |
| + | 134 | ||
| 128 | == References == | 135 | == References == |
| 129 | {{reflist}} | 136 | {{reflist}} |