BioMimetic Systems (United States)

For amputees with powered transfemoral prosthetics, navigating obstacles or complex terrain remains challenging. This study addresses this issue by using an inertial sensor on the sound ankle to guide obstacle-crossing movements. A genetic algorithm computes the optimal neural network structure to predict the required angles of the thigh and knee joints. A gait progression prediction algorithm determines the actuation angle index for the prosthetic knee motor, ultimately defining the necessary thigh and knee angles and gait progression. Results show that when the standard deviation of Gaussian noise added to the thigh angle data is less than 1, the method can effectively eliminate noise interference, achieving 100% accuracy in gait phase estimation under 150 Hz, with thigh angle prediction error being 8.71% and knee angle prediction error being 6.78%. These findings demonstrate the method’s ability to accurately predict gait progression and joint angles, offering significant practical value for obstacle negotiation in powered transfemoral prosthetics.

Vessel forming assays are a valuable technology to evaluate the vasculogenic and angiogenic potential of different cell types, matrix proteins, and soluble factors. Recent advances in high-content microscopy allow for vascular morphogenesis assays to be captured in real-time and in high-throughput formats. Unfortunately, existing microvascular network (MVN) quantification algorithms are either inaccurate, not user-friendly, or manually analyse one image at a time, unfavourable to high-throughput screening. This manuscript introduces the Batch-Resourcing Angiogenesis Tool (BRAT), an open-source computer software which efficiently segments, skeletonizes, and analyses large batches of vascular network images with high accuracy. Benchmarked across diverse clinical and cultured MVN images, BRAT is the most sensitive vascular network image analysis tool (94.5%), exhibiting leading accuracy (93.3%). BRAT's multi-threaded processing automatically analyses 886 microscopy images at a speed of 0.17 s/image on a performance computer (2:29 min) or 2.31 s/image on a laptop (34:04). This is 10-to-100 fold more time-efficient than existing software, which require 12-16 s of direct user input per image. BRAT successfully compares diverse microvascular cell types cultured in 2D and 3D biomaterials. BRAT represents a powerful approach for the accurate and high-throughput screening of vessel forming assays for disease models, regenerative medicines, and therapeutic testing. BRAT is avaliable to download at:https://github.com/BMSE-UQ/BRAT-Vascular-Image-Tool.

This study aimed to assess the relative translucency parameter (RTP) of human enamel and dentin and set target RTP values for dental material development. Additionally, it seeks to validate the spectral RTP concept as supplementary quantitative information. Slides of extracted human teeth, 1 and 2 mm thick enamel or dentin slides, were evaluated. RTP was calculated using CIEDE2000 (RTP00) and CIELAB (RTPab) color difference formulas. Spectral RTP (SPECTRAL RTP) curves were also generated from differences between spectral reflectance values obtained against white and black backgrounds. Statistical analyses included multifactorial ANOVAs for each RTP and spectral RTP, and Pearson correlations between RTP and spectral RTP. Significant correlations were observed between the RTP and spectral RTP values (p < 0.001) at all studied wavelengths. RTP00 and RTPab values were significantly different (p < 0.001). Enamel showed more translucency than dentin (p < 0.001), and 1 mm slices were more translucent than 2 mm slices (p < 0.001). Spectral RTP values were influenced by the type of tissue (enamel, dentin), thickness (1 mm, 2 mm), and color difference formula (CIELAB2000, CIELAB). RTP curve values were influenced by tissue type, thickness, and wavelength. Spectral RTP and RTP curve values were correlated.

In this work, we introduce a control framework that combines model-based footstep planning with Reinforcement Learning (RL), leveraging desired footstep patterns derived from the Linear Inverted Pendulum (LIP) dynamics. Utilizing the LIP model, our method forward predicts robot states and determines the desired foot placement given the velocity commands. We then train an RL policy to track the foot placements without following the full reference motions derived from the LIP model. This partial guidance from the physics model allows the RL policy to integrate the predictive capabilities of the physics-informed dynamics and the adaptability characteristics of the RL controller without overfitting the policy to the template model. Our approach is validated on the MIT Humanoid, demonstrating that our policy can achieve stable yet dynamic locomotion for walking and turning. We further validate the adaptability and generalizability of our policy by extending the locomotion task to unseen, uneven terrain. During the hardware deployment, we have achieved forward walking speeds of up to 1.5 m/s on a treadmill and have successfully performed dynamic locomotion maneuvers such as 90-degree and 180-degree turns.

Dental radiographs are essential for diagnosis and treatment planning, but are sometimes difficult to acquire for patients with developmental disabilities (PDD). Optical Coherence Tomography (OCT) is a non-ionizing imaging modality that has the potential application as an alternative to dental radiographs for PDD. This study aimed to determine the feasibility of intraoral OCT imaging for PDD. Ten participants were recruited in the Dental Education in the Care of Persons with Disabilities (DECOD) Clinic to explore the utility of dental OCT. The prototype system (Yoshida Dental) creates in-depth and three-dimensional images of teeth. The participants indicated their degree of pain during imaging on the Wong-Baker FACES Pain Rating Scale, and the degree of discomfort after imaging on a visual analog scale. OCT can be used for patients with developmental disabilities with minimal levels of pain and discomfort, without ionizing radiation.

Properties and composition of leukocyte- and platelet-rich fibrin (L-PRF) clots may be largely affected by centrifugation protocols (function of relative centrifugal force [RCF]), which may impact biological potential repair in bone regeneration. The present in vivo study sought to assess the effect of the RCF on the composition of L-PRF clots, as well as to compare the repair potential of L-PRF clots obtained with different RCF protocols in submandibular boney defects using PLGA scaffolds for bone regeneration. Complete blood count and volumetric evaluations were performed on L-PRF clots obtained through centrifugation for 12 min at 200, 400, and 600 RCF-clot centrifugation speeds. These evaluations were completed from blood collected immediately prior to any surgical procedures. The in vivo portion comprised of three submandibular unilateral, full thickness, osteotomies (~0.40cm3 ) which were created in the submandibular region of six sheep, using rotary instrumentation under continuous irrigation. Subsequently, poly(lactic-co-glycolic acid) (PLGA) scaffolds were enveloped in a L-PRF membrane from one of the three spinning speeds (n=6/RCF) and inserted into the defect (sites were interpolated to avoid site bias). Six-weeks after surgery, the mandibles were harvested en bloc and prepared for volumetric and histomorphometric evaluations. Membranes harvested from 600 RCF produced significantly larger L-PRF clots (6.97g ± 0.95) in comparison to the lower 200 RCF (5.7g ± 0.95), with no significant differences between 600 and 400, and from 400 and 200 RCF. The three tested RCFs did not alter the platelet count of the L-PRF clot. For the in vivo component, quantitative bone regeneration analyses demonstrated significantly higher values obtained with L-PRF membranes extracted post 600 RCF (27.01 ± 8%) versus 200 RCF (17.54 ± 8%), with no significant differences regarding 400 RCF (~23 ± 8%). At the qualitative histological analyses, L-PRF membranes obtained at 600 and 400 RCFs yielded improved healing throughout the defect, where the L-PRF sourced from the lowest speed, 200 RCF, presented healing primarily at the margins along with the presence of connective tissue at the central aspect of the surgical defect. Higher 600 RCF yielded larger L-PRF clots/membranes, resulting in enhanced bone repair potential in association with PLGA scaffolds for the treatment of critical size bone defects.

BackgroundOsseodensification (OD) has shown to improve implant stability; however, the influences of implant design, dimensions, and surgical site characteristics are unknown.PurposeTo compare the insertion torque (IT) and temporal implant stability quotients (ISQ) of implants placed via OD or subtractive drilling (SD).Materials and MethodsThis multicenter controlled clinical trial enrolled 56 patients, whom were in need of at least 2 implants (n = 150 implants). Patients were treated with narrow, regular, or wide implants and short, regular, or long implants in the anterior or posterior region of the maxilla or in the posterior region of the mandible. Osteotomies were performed following manufacturers recommendation. IT was recorded with a torque indicator. ISQ was recorded with resonance frequency analysis immediately after surgery, 3 and 6 weeks.ResultsData complied as a function of osteotomy indicated significantly higher IT for OD relative to SD. OD outperformed conventional SD for all pairwise comparisons of arches (maxilla and mandible) and areas operated (anterior and posterior), diameters and lengths of the implants, except for short implants. Overall, ISQ data also demonstrated significantly higher values for OD compared to SD regardless of the healing period. Relative to immediate readings, ISQ values significantly decreased at 3 weeks, returning to immediate levels at 6 weeks; however, ISQ values strictly remained above 68 throughout healing time for OD. Data as a function of arch operated and osteotomy, area operated and osteotomy, implant dimensions and osteotomy, also exhibited higher ISQ values for OD relative to SD on pairwise comparisons, except for short implants.ConclusionsOD demonstrated higher IT and temporal ISQ values relative to SD, irrespective of arch and area operated as well as implant design and dimension, with an exception for short implants. Future studies should focus on biomechanical parameters and bone level change evaluation after loading.

To demonstrate a minimally invasive approach of a full-mouth rehabilitation of a severe case of erosion treated with v-shaped veneers, tabletops, overlays, veneerlays, laminate veneers, and a full contour veneer. The present case report successfully rehabilitated a full-mouth case of severely eroded teeth with minimal healthy structure removal, maintaining viability of all teeth that were vital before the treatment started, and promoting long-lasting esthetic and functional results after 3 years of use. A deep knowledge of etiology, etiopathogenesis, and classifications of dental erosion will guide the clinician in the right direction for solving this issue correctly, according to modern prosthetic and conservative principles. Dental erosion represents today a relatively widespread phenomenon among the global population and a significant challenge in each of its clinical stages for the clinicians who must treat it. In advanced stages, a careful evaluation phase of the case, a great patient motivation and a wise use of materials and clinical protocols are the success key of the case. Moreover, an advanced knowledge of adhesive dentistry is strictly required to successfully manage a severe erosion case with a modern and minimally invasive approach.

In article number 2001736, Luiz E. Bertassoni and co-workers present the use of lithography-based 3D printing to fabricate a novel modular microcage scaffold system. These hollow microcages can be stacked in thousands of geometric configurations with the ability to scale in size and shape to fit complex tissue defects. Different growth factors and cells can be placed inside each block, enabling cell-instructive and accelerated repair of musculoskeletal tissue injuries.