Syringe drive assembly
US4833384A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 20, 1987 |
| Grant date | May 23, 1989 |
| Priority date | — |
| Expiry date | Jul 20, 2007 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S128/01
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
An assembly is described for accurately and precisely controlling the position of a plunger in a syringe to deliver precise fluid volumes. The assembly includes a motor coupled to a lead screw that drives a bearing block along a linear guide rod to move the plunger of the syringe in a linear fashion. The position of the plunger is accurately controlled by attaching a digital encoder to the rotating motor shaft. The encoder and associated electronics output to a controlling processor that generates a series of regular pulses, typically 300 to 500 responsive to each motor revolution. Utilizing appropriate gear ratios of the motor and the lead screw, the number of pulses per full syringe stroke in typical applications can be on the order of one hundred thousand. The final position and the motion of the plunger (velocity and acceleration) can be controlled to within a few encoder pulses, thus precisely controlling the rate of delivery of the fluid and the volume of the fluid actually delivered by the syringe. A closed positive feedback system is utilized to detect positional errors and obtain improved precision and accuracy.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.