Neuroprostheses typically operate under supervised learning, in which a machine-learning algorithm is trained to correlate neural or myoelectric activity with an individual's motor intent. Due to the stochastic nature of neuromyoelectric signals, algorithm performance decays over time. This decay is accelerated when attempting to regress proportional control of multiple joints in parallel, compared with the more typical classification-based pattern recognition control.
View Article and Find Full Text PDFPurpose: This study aimed to establish a combined histological assessment system of neo-cartilage outcomes and to evaluate variations in an established rat defect model treated with human juvenile cartilage-derived chondrocyte (JCC) sheets fabricated from various donors.
Methods: JCCs were isolated from the polydactylous digits of eight patients. Passage 2 (P2) JCC sheets from all donors were transplanted into nude rat chondral defects for 4 weeks (27 nude rats in total).
Biomimetics (Basel)
January 2024
For people who have experienced a spinal cord injury or an amputation, the recovery of sensation and motor control could be incomplete despite noteworthy advances with invasive neural interfaces. Our objective is to explore the feasibility of a novel biohybrid robotic hand model to investigate aspects of tactile sensation and sensorimotor integration with a pre-clinical research platform. Our new biohybrid model couples an artificial hand with biological neural networks (BNN) cultured in a multichannel microelectrode array (MEA).
View Article and Find Full Text PDFPurpose: The purpose of this study was to determine the long-term results of the Green transfer (flexor carpi ulnaris to extensor carpi radialis brevis) for patient-reported outcomes, wrist position, and range of motion.
Methods: We re-examined 13 patients from a previous prospective study involving surgery for hemiplegia that included a Green transfer. The average follow-up was 8 years with the range from 5 to 11 years.
Background: Rates of mutilating hand injuries are increasing from accidents caused by all-terrain vehicles (ATVs) and the recently popularized side-by-side utility terrain vehicles (UTVs). Increasing surgeon familiarity with upper extremity (UE) injury patterns, severity, and outcomes following ATV and UTV accidents may improve patient care and advocacy.
Methods: Retrospective comparisons of UE injury patterns, severity, hospital and intensive care unit (ICU) admission lengths, and number of operations were made between ATVs and UTVs.
Loss of tactile sensations is a major roadblock preventing upper limb-absent people from multitasking or using the full dexterity of their prosthetic hands. With current myoelectric prosthetic hands, limb-absent people can only control one grasp function at a time even though modern artificial hands are mechanically capable of individual control of all five digits. In this paper, we investigated whether people could precisely control the grip forces applied to two different objects grasped simultaneously with a dexterous artificial hand.
View Article and Find Full Text PDFKnee cartilage does not regenerate spontaneously after injury, and a gold standard regenerative treatment algorithm has not been established. This study demonstrates preclinical safety and efficacy of scaffold-free, human juvenile cartilage-derived-chondrocyte (JCC) sheets produced from routine surgical discards using thermo-responsive cultureware. JCCs exhibit stable and high growth potential in vitro over passage 10, supporting possibilities for scale-up to mass production for commercialization.
View Article and Find Full Text PDFPurpose: Carpal tunnel release (CTR) surgical costs are minimized when performed in the procedure room (PR) setting, compared with the operating room. However, it remains unclear whether outcomes differ between surgical settings. Our purpose was to compare outcomes at 1 year or greater follow-up after open CTR between patients treated in PR versus operating room settings using the Boston Carpal Tunnel Questionnaire (BCTQ).
View Article and Find Full Text PDFPurpose: Performing hand surgeries in the procedure room (PR) setting instead of the operating room effectively reduces surgical costs. Understanding the safety or complication rates associated with the PR is important in determining the value of its use. Our purpose was to describe the incidence of medical and surgical complications among patients undergoing minor hand surgeries in the PR.
View Article and Find Full Text PDFBackground: Electrical stimulation of residual afferent nerve fibers can evoke sensations from a missing limb after amputation, and bionic arms endowed with artificial sensory feedback have been shown to confer functional and psychological benefits. Here we explore the extent to which artificial sensations can be discriminated based on location, quality, and intensity.
Methods: We implanted Utah Slanted Electrode Arrays (USEAs) in the arm nerves of three transradial amputees and delivered electrical stimulation via different electrodes and frequencies to produce sensations on the missing hand with various locations, qualities, and intensities.
Purpose: Surgical release of pediatric trigger thumbs has been recommended as definitive treatment, although controversy exists over the natural history of pediatric trigger thumb. This study sought to evaluate the incidence of spontaneous resolution of pediatric trigger thumb and the factors that may influence resolution.
Methods: Pediatric patients were prospectively enrolled by a single surgeon from August 2009 to July 2015.
Objective: We explore the long-term performance and stability of seven percutaneous Utah Slanted Electrode Arrays (USEAs) and intramuscular recording leads (iEMGs) implanted chronically in the residual arm nerves and muscles of three human participants as a means to permanently restore sensorimotor function after transradial amputations.
Approach: We quantify the number of functional recording and functional stimulating electrodes over time. We also calculate the signal-to-noise ratio (SNR) of USEA and iEMG recordings and quantify the stimulation current necessary to evoke detectable sensory percepts.
Purpose: The relationship between biopsychosocial factors and patient-reported function is less clear in pediatric than in adult hand surgery patients. Our primary hypothesis was that pain interference (PI) and peer relationships (PR) would demonstrate association with upper extremity function. Secondarily, we hypothesized that the magnitude of this effect would increase with age.
View Article and Find Full Text PDFThe purpose of this study was to compare the long-term revision rate of in situ ulnar nerve decompression with anterior subcutaneous transposition surgery for idiopathic cubital tunnel syndrome. This retrospective, multicenter, cohort study compared patients who underwent ulnar nerve surgery with a minimum 5 years of follow-up. The primary outcome studied was the need for revision cubital tunnel surgery.
View Article and Find Full Text PDFWe investigated whether incision type affects scar quality or outcome following trigger finger release. Our primary and secondary hypotheses were that transverse and longitudinal incision types yield similar scar quality and functional improvement. Digits undergoing trigger finger release at the participating hospitals were randomized to receive transverse or longitudinal incisions.
View Article and Find Full Text PDFJ Hand Surg Eur Vol
October 2019
Syndactyly release may be done by skin graft or graftless techniques. We prospectively examined bilateral syndactyly releases in the same patient at one operation. The grafted side was randomized and the contralateral side was done graftless.
View Article and Find Full Text PDFAlthough recent advances in neuroprostheses offer opportunities for improved and intuitive control of advanced motorized and sensorized robotic arms, practical complications associated with such hardware can impede the research necessary for clinical translation. These hurdles potentially can be reduced with virtual reality environments (VREs) with embedded physics engines using virtual models of physical robotic hands. These software suites offer several advantages over physical prototypes, including high repeatability, reduced human error, elimination of many secondary sensory cues, and others.
View Article and Find Full Text PDFWorking towards improved neuromyoelectric control of dexterous prosthetic hands, we explored how differences in training paradigms affect the subsequent online performance of two different motor-decode algorithms. Participants included two intact subjects and one participant who had undergone a recent transradial amputation after complex regional pain syndrome (CRPS) and multi-year disuse of the affected hand. During algorithm training sessions, participants actively mimicked hand movements appearing on a computer monitor.
View Article and Find Full Text PDFWe quantified prosthesis embodiment and phantom pain reduction associated with motor control and sensory feedback from a prosthetic hand in one human with a long-term transradial amputation. Microelectrode arrays were implanted in the residual median and ulnar arm nerves and intramuscular electromyography recording leads were implanted in residual limb muscles to enable sensory feedback and motor control. Objective measures (proprioceptive drift) and subjective measures (survey answers) were used to assess prosthesis embodiment.
View Article and Find Full Text PDFObjectives: Kilohertz high-frequency alternating current (KHFAC) electrical nerve stimulation produces a reversible nerve block in peripheral nerves in human patients with chronic pain pathologies. Although this stimulation methodology has been verified with nonselective extrafascicular electrodes, the effectiveness of producing a selective nerve block with more-selective intrafascicular electrodes has not been well documented. The objective of this study was to examine whether intrafascicular electrodes can block painful stimuli while preserving conduction of other neural activity within the implanted nerve.
View Article and Find Full Text PDFSomatic PIK3CA mutations may relate to pathogenesis of isolated macrodactyly. We set up to test the association between PIK3CA mutations with isolated macrodactyly in order to establish a more accurate and molecular mechanism-based diagnosis and classification. DNA extracted from affected tissues in 12 individuals with isolated macrodactyly was tested for PIK3CA mutation using targeted Sanger DNA sequencing.
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