A syringe is modified to permit gradual administration of its contents with reduced problems due to seizing or stiction of its piston by dividing its piston axially into two parts, a front detached part and rear part which is the only part having provision for attachment to a syringe actuator. The rear...http://www.google.co.uk/patents/US6123685?utm_source=gb-gplus-sharePatent US6123685 - Syringe for infusion
