Closed-loop neuromodulation represents an emerging area in clinical medicine. Neural devices capable of measuring brain function and using measurements to iteratively guide output, such as deep brain stimulation, will be a significant advance in neuromodulatory technology. The introduction of closed-loop devices, particularly 'smart" machines, will require changes in clinical ethical practice. A model of the clinical relationship could be a useful tool for addressing ethical challenges arising in this new area. Traditional models of the clinical relationship, like Emanuel and Emanuel's "four models," are suited to current unidirectional forms of neuromodulation. An adequate model of the patient-machine-clinician relationship may need to move beyond traditional models. Thus, I explore three new models: the design model, the customer service model, and the quality monitoring model. The exploration of these models of the patient-machine-clinician relationship will benefit from keeping an Aristotelian ideal of friendship in mind.