Infusion devices having multiple pumping segments connected in parallel to a fluid source and configured to operate together to pump a fluid from the fluid source are described herein. An infusion device includes a first deformable body coupled between the fluid source and an IV set and a second deformable body coupled between the fluid source and the IV set in parallel with the first deformable body. The first deformable body is configured to be hand-compressed and direct a portion of fluid from the first deformable body to an outlet of the IV set for administering the fluid to a patient at a first flow rate. The second deformable body is configured to be hand-compressed and direct another portion of fluid from the second deformable body to the outlet of the IV set for administering the fluid to the patient at a second flow rate.