Miniature disposable infusion IPMC micropumps

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. 

Furthermore, in order to be a certified infusion operation, it is required that the pump can operate if the power cuts out or is even unplugged and can detect the change of flow rate or pressure even if the flow is blocked or kinked, taken backward and finished when an infusion bag or pump is empty. An IPMC has characteristics both as an actuator and sensor. In addition, it is easy to control the frequency (flow interval) and flow rate by changing of the electric signals with low voltage. We propose a new miniaturized disposal IPMC infusion pump with embedded computer controlling, which can control a micro flow with a low power source, batteries. 

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Figure 9.3 An illustration of the IPMC infusion micropump (Reproduced with permission from Vohnout, S., Kim, S.-M., Park, l.-S. and Banister, M., IPMC-assisted miniature disposable infusion pumps with embedded computer control. Proceedings of the SPIE conference 2007. Copyright (2007) SPIE).

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