Aims, development, and early results of an interdisciplinary primary care initiative to address patient vulnerabilities.

Addressing substance use disorders and social determinants of poor health at a population level is a major national healthcare priority. One promising model to improve healthcare outcomes for patients with these conditions is the Vulnerable Veteran Innovative Patient-Aligned Care Team (PACT) Initiative, or VIP - an interdisciplinary, team-based primary care delivery model designed to address the needs of vulnerable patients in the Veterans Health Administration. VIP establishes a single, integrated primary care environment for the management of substance use disorders, mental illness, social determinants of poor health, and complexities in care resulting from the co-occurrence of these conditions. We describe the origination, goals, and evolution of VIP to provide an example of how clinics and health systems can address vulnerable patient populations within a primary care clinic framework. While ongoing evaluation will be essential to understand its impact on patient outcomes and its sustainability and scalability in the future, VIP holds promise as a novel model to improve care for patients with addiction and other vulnerabilities.

A closed-loop hand prosthesis with simultaneous intraneural tactile and position feedback.

Current myoelectric prostheses allow transradial amputees to regain voluntary motor control of their artificial limb by exploiting residual muscle function in the forearm. However, the overreliance on visual cues resulting from a lack of sensory feedback is a common complaint. Recently, several groups have provided tactile feedback in upper limb amputees using implanted electrodes, surface nerve stimulation, or sensory substitution. These approaches have led to improved function and prosthesis embodiment. Nevertheless, the provided information remains limited to a subset of the rich sensory cues available to healthy individuals. More specifically, proprioception, the sense of limb position and movement, is predominantly absent from current systems. Here, we show that sensory substitution based on intraneural stimulation can deliver position feedback in real time and in conjunction with somatotopic tactile feedback. This approach allowed two transradial amputees to regain high and close-to-natural remapped proprioceptive acuity, with a median joint angle reproduction precision of 9.1° and a median threshold to detection of passive movements of 9.5°, which was comparable with results obtained in healthy participants. The simultaneous delivery of position information and somatotopic tactile feedback allowed both amputees to discriminate the size and compliance of four objects with high levels of performance (75.5%). These results demonstrate that tactile information delivered via somatotopic neural stimulation and position information delivered via sensory substitution can be exploited simultaneously and efficiently by transradial amputees. This study paves a way to more sophisticated bidirectional bionic limbs conveying richer, multimodal sensations.