Portable infusion pumps

The mechanical pump approach employs miniature mechanical devices, such as implantable and portable infusion pumps and percutaneous infusion catheters, to deliver drugs into appro priate blood vessels or to a discrete site in the body. When compared with the... 

Drug is administered chronically on an ambulatory basis with a portable infusion pump through a permanent central venous cathether peripheral IV infusions may be used temporarily until central venous access obtained... 

In drug delivery, infusion pumps have achieved remarkable success in recent years. As of 1983, there were 18 different models of external pumps available (6). These battery-powered portable pumps are used to infuse insulin into diabetic patients. Although capable of variable delivery rates, they have a reservoir volume of less than 6 ml, which is unsuitable for fluid replenishment. Further, the cost of these small pumps is very high which limits the affordability to a few selected individuals. 

Stiles, M.L. Allen, L.V., Jr. Prince, S.J. Stability of various antibiotics kept in an insulated pouch during administration via portable infusion pump. Am.J.Health-Syst.Pharm., 1995, 52, 70-74... 

Nyhammar EK, Johansson SG, Seiving BE (1996) Stability of doxorubicin and vincristine sulfate in two portable infusion-pump reservoirs. Am J Health Syst Pharm 53(10) 1171-1173... 

There are various ways to classify today s infusion devices based upon their functionality, driving mechanism, size, or ability to be disconnected periodically from the infusion apparatus. In order to simplify the classification, we have chosen to differentiate only between stationary and portable devices. Stationary devices are used for patients who remain in bed during the treatment, either at home or in a hospital environment. In general, these devices are large, programmable systems that remain near the bedside and require close supervision by medical personnel. Portable infusion pumps, on the other hand, are used by patients who can freely move during then-therapy. They include implantable and externally worn pumps, which range from somewhat bulky forms to small and concealable devices as shown in Fig.l. 

Tamborlane, W. V., Sherwin, R. S., Genel, M., and Felig, P., 1979, Reduction to normal of plasma glucose in juvenile diabetes by subcutaneous administration of insulin with a portable infusion pump, N. Engl. J. Med. 300 573-578. 

The availability of safe, disposable and robust infusion pumps for intravenous fluid and drug delivery could provide a significant improvement in both private and public healthcare. An infusion pump should infuse medical fluids, bloods and nutrients into a patient without failure. Thus, there has been a demand for accurately controllable pump systems, from small capacity units such as insulin infusion to large volume feeding suppliers. Small volume infusion pumps, especially, are designed to be portable for use not only in a hospital but also for special purpose likes charity and battlefield use [23]. 

The former small unit infusion pumps are pressured by human blood pressure using a blood pressure cuff. However, this mechanism leads to serious problems, such as sudden change of the flow rate because the infusion flow rate is only dependent on the patient s blood pressure. Thus, recently, small volume pumps have been usually operated by an automatically controlled motor or a small embedded system. In addition, for the portable infusion pump, other possible pump power sources have been developed, such as osmotic pressure and spring-powered systems. However, with osmotic power needs it is necessary to change a salt solution bag after finishing infusion and with spring power it is necessary to overcome the limitation of the flow rate for use in various conditions. 

Alprostadil is PGEi available for exogenous administration. Alprostadil is widely used in neonates with cyanotic congenital heart disease to maintain the patency of the ductus arteriosus. Reported adverse effects include fever, apnea, flushing, bradycardia, and hyperostosis. Continuous chronic infusion of alprostadil via a portable pump and neuromuscular electrical stimulation help to improve the quality of life in patients with severe chronic heart failure waiting for a donor heart, as both treatments can be performed at home. 

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