N euromodulation therapy, specifically Deep Brain Stimulation (DBS) of the ventral capsule/ventral striatum (VC/VS), is promising treatment for severe and intractable obsessive-compulsive disorder (OCD). To assess treatment response to DBS, reliable biomarkers are needed. We explored the hypothesis that facial action units and head dynamics in an interview context reveal severity of OCD, related depression, and DBS energy in participants undergoing DBS treatment. Participants were 5 patients (3 females, 2 males) with implanted DBS to VC/VS. They were recorded during brief open-ended interviews by a clinician at pre- and post-surgery baselines and then at 3-month intervals following activation of the DBS electrodes. Facial action units and head dynamics were assessed using AFAR (Automatic Facial Affect Recognition). OCD severity was assessed using clinical interview (YBOCS-II) and depression symptoms were assessed using participant self-report (BDI). After testing for multicollinearity and dropping highly-correlated features, a linear mixed-effects model using chi-square feature selection predicted 61% of the variation in YBOCS-II; 59% of the variation in BDI; and 37% of the variation in delivered energy by DBS to VC/VS. These findings suggest that automatically detected facial action units and head dynamics are potential biomarkers of OCD, depression se verity, and DBS energy.

Brain-computer interfaces (BCIs) offer avenues to treat neurological disorders, shed light on brain function, and interface the brain with the digital world. Their wider adoption rests, however, on achieving adequate real-time performance, meeting stringent power constraints, and adhering to FDA-mandated safety requirements for chronic implantation. BCIs have, to date, been designed as custom ASICs for specific diseases or for specific tasks in specific brain regions. General-purpose architectures that can be used to treat multiple diseases and enable various computational tasks are needed for wider BCI adoption, but the conventional wisdom is that such systems cannot meet necessary performance and power constraints. We present HALO (Hardware Architecture for LOw-power BCIs), a general-purpose architecture for implantable BCIs. HALO enables tasks such as treatment of disorders (e.g., epilepsy, movement disorders), and records/processes data for studies that advance our understanding of the brain. We use electrophysiological data from the motor cortex of a non-human primate to determine how to decompose HALO's computational capabilities into hardware building blocks. We simplify, prune, and share these building blocks to judiciously use available hardware resources while enabling many modes of brain-computer interaction. The result is a configurable heterogeneous array of hardware processing elements (PEs). The PEs are configured by a low-power RISC-V micro-controller into signal processing pipelines that meet the target performance and power constraints necessary to deploy HALO widely and safely.

Automated measurement of affective behavior in psychopathology has been limited primarily to screening and diagnosis. While useful, clinicians more often are concerned with whether patients are improving in response to treatment. Are symptoms abating, is affect becoming more positive, are unanticipated side effects emerging? When treatment includes neural implants, need for objective, repeatable biometrics tied to neurophysiology becomes especially pressing. We used automated face analysis to assess treatment response to deep brain stimulation (DBS) in two patients with intractable obsessive-compulsive disorder (OCD). One was assessed intraoperatively following implantation and activation of the DBS device. The other was assessed three months post-implantation. Both were assessed during DBS on and o conditions. Positive and negative valence were quantified using a CNN trained on normative data of 160 non-OCD participants. Thus, a secondary goal was domain transfer of the classifiers. In both contexts, DBS-on resulted in marked positive affect. In response to DBS-off, affect flattened in both contexts and alternated with increased negative affect in the outpatient setting. Mean AUC for domain transfer was 0.87. These findings suggest that parametric variation of DBS is strongly related to affective behavior and may introduce vulnerability for negative affect in the event that DBS is discontinued.

A 100-ch fully head-implantable wireless broadband neural recording system was developed. It features 100 parallel wideband (0.1Hz ~ 7.8 kHz) neural recording channels, a medical grade 200mAh Li-ion battery recharged inductively at 2 MHz, and data telemetry using both 3.2/3.8GHz FSK wireless and 850nm IR laser data link. All active electronics are hermetically sealed in a titanium enclosure with a sapphire window. Custom 100 individual hermetic feedthroughs enable connection to the microelectrode intracortical array. This wireless implant has been validated both on-bench and in freely moving pig and monkey models.

Acquiring neural signals at high spatial and temporal resolution directly from brain microcircuits and decoding their activity to interpret commands and/or prior planning activity, such as motion of an arm or a leg, is a prime goal of modern neurotechnology. Its practical aims include assistive devices for subjects whose normal neural information pathways are not functioning due to physical damage or disease. On the fundamental side, researchers are striving to decipher the code of multiple neural microcircuits which collectively make up nature's amazing computing machine, the brain. By implanting biocompatible neural sensor probes directly into the brain, in the form of microelectrode arrays, it is now possible to extract information from interacting populations of neural cells with spatial and temporal resolution at the single cell level. With parallel advances in application of statistical and mathematical techniques tools for deciphering the neural code, extracted populations or correlated neurons, significant understanding has been achieved of those brain commands that control, e.g., the motion of an arm in a primate (monkey or a human subject). These developments are accelerating the work on neural prosthetics where brain derived signals may be employed to bypass, e.g., an injured spinal cord. One key element in achieving the goals for practical and versatile neural prostheses is the development of fully implantable wireless microelectronic "brain-interfaces" within the body, a point of special emphasis of this paper.