Hydrocephaly treatment device including a variable impedance filter
US4605395A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 13, 1984 |
| Grant date | Aug 12, 1986 |
| Priority date | — |
| Expiry date | Jan 13, 2004 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61M27/006
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
To treat hydrocephaly, an intracranial catheter is implanted in the head. It is connected to a tube fitted with a non-return valve and serves to divert the flow of cephalo-rachidian liquid to the peritoneum or to the right auricle of the heart. In accordance with the invention a hydraulic filter of non-linear variable impedance is connected in the tube in series with the valve. The filter maintains an average flow rate of the cephalo-rachidian liquid close to the physiological flow rate, but prevents sudden rushes of fluid flow, thereby permitting the intracranial pressure to vary in the short term in the normal manner over a characteristic period of about one second, while preventing said pressure from rising slowly in the long term, e.g. over a characteristic period of about one minute. This is done by a bead (160) which is housed in a cavity (161) extending between a proximal orifice (111) and a distal orifice (136). The distal orifice constitutes a leaky valve seat for the bead.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.