An infusion apparatus includes a housing and a chamber configured to be connected to the housing. The apparatus further includes a weight sensor coupled to a load connector connected to the housing and an optical sensor disposed in the housing. The weight sensor is configured to generate a first signal based on a measured weight of the fluid container attached to the housing in a weight-bearing configuration. The optical sensor is configured to generate a second signal based on detecting drops of the fluid traversing the chamber. The apparatus also includes a flow control mechanism to control a flow rate of the fluid into an outlet channel. The apparatus includes one or more processing devices configured to perform operations including transmitting a control signal to the flow control mechanism to adjust the flow rate.