Medico-surgical instruments
US4414983A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Aug 19, 1981 |
| Grant date | Nov 15, 1983 |
| Priority date | — |
| Expiry date | Aug 19, 2001 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61B17/3401
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
An instrument for detecting penetration of the epidural space comprises a barrel within which a plunger is urged forwardly by a resilient strap. The barrel has a nose on which a Tuohy needle is mounted. The inner surface of the barrel has a groove that extends along the barrel, being spaced from the nose. In operation the assembly is pushed forwardly until the tip of the needle contacts the spinal ligaments. The plunger is then pulled rearwardly past the end of the groove so that air enters the barrel and becomes trapped when the plunger is released and urged forwards by the strap. Penetration of the epidural space by the tip of the needle allows the trapped air to escape through the needle thereby providing an indication of penetration of the epidural space by causing the plunger to be moved forwards.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.