By James Cavuoto, editor
August 26, 2026 | Implantable neuromodulation is entering a period in which technical performance alone will no longer be enough to determine commercial success. In a new American Journal of Psychiatry article (DOI: 10.1176/appi.ajp.20251187), Gabriel Lázaro-Muñoz and Amanda Merner of Mass General Brigham and Harvard Medical School argue that companies, clinicians, funders, regulators, and health systems need a measurable standard for what they call “human fidelity”—the degree to which an implantable brain device aligns with the needs and expectations of the people and institutions that must use, support, pay for, and live with it.
The concept is timely. Deep brain stimulation, responsive neurostimulation, vagus nerve stimulation, and emerging brain-computer interfaces are increasingly being positioned for severe, treatment-resistant psychiatric and neurological disorders, as well as loss-of-function conditions such as paralysis or blindness. Yet many promising devices struggle after leaving the lab because they do not fit clinical workflows, reimbursement realities, patient preferences, family expectations, or public trust requirements. The authors’ central point is that stakeholder alignment should be treated as an engineering and implementation property—not as a marketing message or late-stage usability exercise.
The authors identified five domains where the gap between devices and stakeholders is most pressing: access and uptake, invasiveness, identity and agency, patient-centered outcomes, and long-term device maintenance. For each domain, they offered concrete recommendations for developers and trial teams.
The proposed framework draws on published literature and nearly a decade of empirical neuroethics research, including more than 300 interviews with patients, caregivers, researchers, clinicians, funders, device manufacturers, and insurers, as well as policy analysis, observation within device trials, and public-perception studies. That breadth is important for the neurotechnology industry because adoption barriers are rarely confined to a single stakeholder group. A device may satisfy surgeons and investors but fail patients—or vice versa; it may demonstrate safety and efficacy but remain too burdensome for clinics; or it may impress regulators while leaving payers unconvinced that the care pathway is sustainable.
Patients’ Experiences
An example from the early days of the neurotechnology industry was the Freehand device for restoring function to quadriplegics from NeuroControl Corp. End users who received the product were very happy with the system and the company did a good job of recruiting surgeons to implant the device. But if failed to win widespread support from physiatrists (PM&R doctors), the clinicians who “owned” the SCI patients.
In a press release, Lázaro-Muñoz and Merner framed the unmet need in practical terms: despite major U.S. investment in implantable brain-device development, there is still no shared, measurable way to determine whether these systems meet the needs and expectations of stakeholders. “All too often, good technology that works in the lab fails to reach or be a good fit for ‘stakeholders,’ such as patients, clinicians, and healthcare systems,” they said. Their answer is to make human fidelity measurable so it can be benchmarked, compared across devices, and improved over time.
For device developers, the implication is significant. A human-fidelity lens could reshape product requirements, trial design, evidence generation, service models, and go-to-market strategy. It asks companies to demonstrate not only that stimulation works, but that the full intervention—implant, programming, monitoring, maintenance, consent, messaging, training, and long-term support—can be integrated into real lives and real health systems. In psychiatry, where stigma, autonomy, identity, and trust are especially sensitive, that integration may be decisive.
The article also raised the key issue of ensuring patient access to a workable device after the completion of a clinical trial, or after a commercial device vendor goes out of business. “While posttrial access and maintenance of drugs and devices is not a novel issue, we believe that there is a heightened responsibility to help ensure posttrial access when the devices help manage a severe and treatment-resistant condition,” the authors write.
One example of this breakdown was the PROSPECT trial of cortical stimulation for treatment-resistant depression. When the trial sponsor, Northstar Neuroscience, closed its doors in 2009, several participants had to be explanted even though they were getting good results from the device. This editor offered potential ways of addressing the problem six years ago. Lázaro-Muñoz and Merner suggested other approaches. “Insurance pools could require device developers to pay into the pool for every participant who joins a neural device trial for treatment-resistant indications. If the patient benefits from the device, the patient would then be eligible to petition this fund for assistance in covering the cost of maintenance.” They also suggest that CMS could ensure coverage of the maintenance of investigational neural devices with FDA investigational device exemptions if the patient participated in an NIH or other federally funded trial and the device provides symptom relief for a severe and otherwise treatment-resistant condition. Although it does not have premarket approval, the investigational device should be considered “medically necessary” for that patient-participant, and maintenance of the beneficial device should be covered by insurance, the authors contend.
The article also points to a broader maturation of the neurotechnology market. Early-stage enthusiasm often centers on miniaturization, signal processing, closed-loop control, or novel targets. Human fidelity shifts attention to whether those advances can survive the messy implementation environment of psychiatric care. It invites a future in which a neuromodulation platform is evaluated much like any other complex health technology: by safety, efficacy, usability, equity, acceptability, affordability, workflow compatibility, and long-term governance.
That may sound less glamorous than a breakthrough implant, but it is likely to be more consequential for market formation. If human fidelity becomes a formal development metric, it could help investors identify lower-risk platforms, give regulators and payers more practical evidence, and help health systems avoid technologies that cannot be operationalized. Most importantly, it could improve the odds that people with severe psychiatric and neurological conditions receive devices that are not only sophisticated, but also appropriate, durable, and trusted.
