Restoring the Sense of Touch Using a Sensorimotor Demultiplexing Neural Interface

Paralyzed muscles can be reanimated following spinal cord injury (SCI) using a brain-computer interface (BCI) to enhance motor function alone. Importantly, the sense of touch is a key component of motor function. Here, we demonstrate that a human participant with a clinically complete SCI can use a BCI to simultaneously reanimate both motor function and the sense of touch, leveraging residual touch signaling from his own hand. In the primary motor cortex (M1), residual subperceptual hand touch signals are simultaneously demultiplexed from ongoing efferent motor intention, enabling intracortically controlled closed-loop sensory feedback. Using the closed-loop demultiplexing BCI almost fully restored the ability to detect object touch and significantly improved several sensorimotor functions. Afferent grip-intensity levels are also decoded from M1, enabling grip reanimation regulated by touch signaling. These results demonstrate that subperceptual neural signals can be decoded from the cortex and transformed into conscious perception, significantly augmenting function

Engineering a Bamboo Bicycle

The primary objective of this Major Qualifying Project was to design and construct a bamboo bicycle that could be made available in developing nations and be assembled quickly with minimal training. In order to meet this objective, the project was decomposed into three main components: bicycle joint design, manufacturing fixture design, and safety and testing. The project team was divided into three corresponding groups, utilizing axiomatic design to break down each of the three components. The team successfully manufactured a prototype bamboo bicycle using the Joints Team's system of gussets, the Jig Team's manufacturing fixture, and the bamboo selected by the Safety and Testing Team

Factors Predicting Visual Acuity Outcome in Intermediate, Posterior, and Panuveitis: The Multicenter Uveitis Steroid Treatment (MUST) Trial

PurposeTo identify factors associated with best-corrected visual acuity (BCVA) presentation and 2-year outcome in 479 intermediate, posterior, and panuveitic eyes.DesignCohort study using randomized controlled trial data.MethodsMulticenter Uveitis Steroid Treatment (MUST) Trial masked BCVA measurements at baseline and at 2 years follow-up used gold-standard methods. Twenty-three clinical centers documented characteristics per protocol, which were evaluated as potential predictive factors for baseline BCVA and 2-year change in BCVA.ResultsBaseline factors significantly associated with reduced BCVA included age ≥50 vs <50 years; posterior vs intermediate uveitis; uveitis duration >10 vs <6 years; anterior chamber (AC) flare >grade 0; cataract; macular thickening; and exudative retinal detachment. Over 2 years, eyes better than 20/50 and 20/50 or worse at baseline improved, on average, by 1 letter (P = .52) and 10 letters (P < .001), respectively. Both treatment groups and all sites of uveitis improved similarly. Factors associated with improved BCVA included resolution of active AC cells, resolution of macular thickening, and cataract surgery in an initially cataractous eye. Factors associated with worsening BCVA included longer duration of uveitis (6-10 or >10 vs <6 years), incident AC flare, cataract at both baseline and follow-up, pseudophakia at baseline, persistence or incidence of vitreous haze, and incidence of macular thickening.ConclusionsIntermediate, posterior, and panuveitis have a similarly favorable prognosis with both systemic and fluocinolone acetonide implant treatment. Eyes with more prolonged/severe inflammatory damage and/or inflammatory findings initially or during follow-up have a worse visual acuity prognosis. The results indicate the value of implementing best practices in managing inflammation

Dissociations of the Fluocinolone Acetonide Implant: The Multicenter Uveitis Steroid Treatment (MUST) Trial and Follow-up Study

PurposeTo describe fluocinolone acetonide implant dissociations in the Multicenter Uveitis Steroid Treatment (MUST) Trial.DesignRandomized clinical trial with extended follow-up.MethodsReview of data collected on the first implant in the eye(s) of participants. Dissociation was defined as the drug pellet no longer being affixed to the strut and categorized as spontaneous or surgically related.ResultsA total of 250 eyes (146 patients) had at least 1 implant placed. Median follow-up time after implant placement was 6 years (range 0.5-9.2 years). Thirty-four dissociations were reported in 30 participants. There were 22 spontaneous events in 22 participants; 6-year cumulative risk of a spontaneous dissociation was 4.8% (95% confidence interval [CI]: 2.4%-9.1%). The earliest event occurred 4.8 years after placement. Nine of 22 eyes with data had a decline in visual acuity ≥5 letters temporally related to the dissociation. Thirty-nine implant removal surgeries were performed, 33 with replacement. Twelve dissociations were noted during implant removal surgeries in 10 participants (26%, 95% CI 15%-48%); 5 of these eyes had a decline in visual acuity ≥5 letters after surgery. The time from implant placement to removal surgery was longer for the surgeries at which dissociated implants were identified than for those without one (5.7 vs 3.7 years, P < .001). Overall, visual acuity declined 15 or more letters from pre-implant values in 22% of affected eyes; declines were frequently associated with complications of uveitis or its treatment.ConclusionThere is an increasing risk of dissociation of Retisert implants during follow-up; the risk is greater with removal/exchange surgeries, but the risk of both spontaneous and surgically related events increases with longevity of the implants. In 22% of affected eyes visual acuity declined by 15 letters. In the context of eyes with moderate to severe uveitis for years, this rate is not unexpected