Infusion
system made with PC/ABS compound. The AutoDose infusion system produced
by Tandem Medical (San Diego; 858/673-3900) is reportedly the first automated,
portable system that can deliver premeasured intravenous drugs without electricity
or batteries. RTP Co. (Winona, MN; 800/433-4787) provided the material for the
pump housing and internal components: a 2505 PC/ABS compound containing 30%
glass fiber. The compound displays sufficient dimensional stability, resistance
to alcohol (for cleaning), and an aesthetically pleasing appearance. Another
motivating factor for Tandem's choosing RTP's compound was the material's ability
to be formed into large, complex shapes without distortion. The pump itself
features a large, flat, stainless-steel spring that operates similarly to those
found in mechanical watches: as the housing is opened, the spring retracts to
its original position. The stored force then dispenses up to four intravenous
solutions from the bag. If the system is dropped, RTP's compound offers protection
with unnotched Izod impact strength at 3.18 mm of 801 J/m. The compound's flexural
strength is 26,000 psi; its tensile strength is 18,000 psi.