Lightweight, Compact System for Generating Lactated Ringer's Solution

G. Srinivas, N. Metcalf, A. Robinson, B. Yamona, J. Fredrickson, N. Weinstein
TDA Research, Inc.,
United States

Keywords: Lactated Ringer's solution, sterile, portable, point-of-injury


Currently, deployed medics must transport, maintain, and be resupplied with liquid-based medications that are heavy, expensive to transport, perishable, and may require refrigeration. In a battlefield scenario IV resuscitation is critical, and treatment of mass casualties can rapidly deplete a deployed medical unit’s supply. This reduces patient recovery and survivability, impacting the unit’s ability to accomplish their mission. Furthermore, access to these fluids requires continuous logistical support; often the military relies on valuable airlift assets to transport prepackaged IV solutions (containing 97% water). This is vulnerable to disruption, as the distances required for transport can be vast and the USAF may not have Air Superiority. One solution that is important in IV resuscitation is Lactated Ringer’s (LR) solution. Using locally available water to reconstitute concentrated LR solutions would significantly enhance current capabilities, but a lightweight, portable technology that allows medics on the battlefield to generate LR solution does not yet exist. TDA Research, Inc. (TDA), in collaboration with Mountain Safety Research (MSR), a division of Cascade Designs (the maker of the MSR line of outdoor products and MSR Global Health Products used by the US military and NGOs worldwide) and Aquaporin (the developer and supplier of Aquaporin Inside® Forward Osmosis (FO) Membrane Technology) set out to develop, test and manufacture a compact, easy-to-use, portable, system for reconstituting concentrated LR solutions. We have achieved this using a combination of membrane filtration and FO. By using FO we can drive flow through the system without any pumps, so no electrical power is required to produce the solution. The device only uses a small, rechargeable battery to power components including automated valves and a screen for user feedback. During the Phase I SBIR project TDA designed, developed, and tested a device that met the DHA requirements listed in the SBIR solicitation. In Phase II we have further refined our device design and made operation even simpler. To produce LR from available freshwater and a concentrated LR solution, the unit uses a prefilter (to remove particulates and biologicals), carbon column (to remove dissolved organics), and an FO membrane that allows only water (not salts, dissolved contaminants, or biologicals) to cross from the feed water side to the concentrated LR. The FO module takes advantage of the osmotic pressure difference between a freshwater source and the concentrated LR salt solution, providing the energy required to drive flow without a pump. The hollow fiber FO module (manufactured by our development partner Aquaporin) is a unique biomimetic design that is functionalized with integrated aquaporin proteins, which provide very high selectivity to only allow water to cross the membrane. The current prototype design can produce sterile LR solution meeting the USP requirements for ion concentrations. We thank the USA Medical Research ACQ for funding this project through the SBIR program (Contract # W81XWH-19-C-0062, Technical Monitor Dr. George Cook) and the guidance from Austin Langdon (Assistant Product Manager, Warfighter Deployable Medical Systems, USAMMDA).