 The investigators aim to develop a novel and wireless method for monitoring medication adherence among heart failure patients with left ventricular assist devices LVADs. Proteus DigitalTM has developed an ingestible and bio-absorbable micro-sensor as a strategy to monitor medication compliance. The edible sensor has at its core a silicon-based integrated circuit measuring 1.0 mm x 0.45 mm and is imbedded on a pill. Once ingested, this circuit is activated by gastric acid resulting in an electrochemical redox reaction and an electrical charge that is transmitted to a patch worn over the abdomen and wirelessly to a portable device such as a smart phone. This strategy of medication adherence differs from conventional adherence monitoring including pill counting and patient-recall by precisely tracking medication ingestion. 