Cataract surgery and artificial iris implantation in patient with oculocutaneous albinism: a case report.

We present a case report detailing the successful phacoemulsification surgery with artificial iris implantation for two individuals with oculocutaneous albinism. These women suffered from cataracts, resulting in reduced visual acuity and heightened photophobia due to iris pigmentary epithelium deficiency. The patients underwent phacoemulsification along with prosthetic artificial iris implantation into the posterior chamber. This intervention resulted in improved visual acuity, reduced photophobia and glare, and an overall enhanced quality of life. Our report highlights two cases of successful phacoemulsification and artificial iris implantation in patients with oculocutaneous albinism and cataracts, leading to improved visual acuity, reduced photophobia, and enhanced quality of life. Notably, there are no prior records in South American literature of cataract surgery combined with artificial iris implantation for oculocutaneous albinism patients up to the time of this publication.

Researchers propose ice 3D printing as a method to create internal channels in artificial organs.

By freezing water droplets into smooth, even columns, researchers from Carnegie Mellon University created complex internal channels that may eventually render viable complex artificial tissue.

Dealing With Pericylindrical Melts in Keratoprosthesis: Tenon Patch Graft to the Rescue.

PURPOSE: The aim of this study was to describe the outcomes of autologous Tenon patch graft in the management of Auro keratoprosthesis-related pericylindrical corneal melt. METHODS: We report 3 cases of sterile pericylindrical corneal melt in patients with Auro keratoprosthesis implantation after a mean duration of 5 years (1.5-8 years). Case 1 was a patient with severe graft-versus-host disease. Cases 2 and 3 were cases of chemical injury.All these cases of sterile pericylindrical corneal melt (4-6 mm) underwent autologous Tenon patch graft. The technique included freshening of the edges around the melt, followed by measuring the size of the defect. A Tenon graft harvested from the patient's own eye was used to seal the defect and act as a scaffold. The Tenon patch graft was spread over the melt and held in place by the application of fibrin glue and/or interrupted 10-0 nylon sutures. A bandage contact lens was then placed on the eye. RESULTS: Tenon patch graft was well taken in all patients. The mean duration of epithelial healing was 1 month. Globe integrity was well maintained with no postoperative complications at a mean follow-up duration of 12 months (6-18 months). CONCLUSIONS: Corneal melt is one of the most dreaded complications of KPro because its occurrence could threaten visual prognosis and globe integrity. Autologous Tenon patch is a simple yet innovative and effective option to steer such eyes away from potentially dreadful complications.

Air-Working Electrochromic Artificial Muscles.

Artificial muscles are indispensable components for next-generation robotics to mimic the sophisticated movements of living systems and provide higher output energies when compared with real muscles. However, artificial muscles actuated by electrochemical ion injection have problems with single actuation properties and difficulties in stable operation in air. Here, air-working electrochromic artificial muscles (EAMs) with both color-changing and actuation functions are reported, which are constructed based on vanadium pentoxide nanowires and carbon tube yarn. Each EAM can generate a contractile stroke of ≈12% during stable operation in the air with multiple color changes (yellow-green-gray) under ±4 V actuation voltages. The reflectance contrast is as high as 51%, demonstrating the excellent versatility of the EAMs. In addition, a torroidal EAM arrangement with fast response and high resilience is constructed. The EAM's contractile stroke can be displayed through visual color changes, which provides new ideas for future artificial muscle applications in soft robots and artificial limbs.

Robust voltage-controlled transcutaneous energy transfer system for artificial anal sphincter.

BACKGROUND: The artificial anal sphincter (AAS) system has gained significant attention as a solution for treating fecal incontinence (FI). It relies on transcutaneous energy transfer (TET) as its primary energy source. However, changes in posture or biological tissue can cause misalignment of the coil, resulting in unstable power reception. Inadequate power affects charging efficiency, while excessive power leads to excessive heating at the receiver side. Consequently, achieving safe and constant voltage charging for the AAS becomes a complex challenge. METHODS: To maintain a consistent charging voltage and overcome the issue of variations in load and coil coupling strength, this article proposes a wireless charging control system that utilizes an LCC-S-type resonant network and phase shift to adjust the transmitting voltage based on feedback charging voltage in real time. In particular, the PI controller and neural network are introduced to change the phase-shift angle swiftly. The dynamic performance is then evaluated under different misalignments and presented with comparative results. RESULTS: The results indicate that the multilayer perceptron control system outperforms the PI. Under the complex misalignment disturbance, the average error of receiver side load voltage is only 0.007 V, with an average settling time of 960 ms. Additionally, the average temperature at the receiver side is 40.4°C. CONCLUSION: The experiments demonstrate that the proposed system effectively addresses the misalignment issue in TET during the charging, ensuring constant voltage charging at the receiver side and thermal safety.

Development and evaluation of artificial organ models for ERCP training in patients with surgically altered anatomies.

Endoscopy training models (ETM) using artificial organs are practical, hygienic and comfortable for trainees. However, few models exist for training endoscopic retrograde cholangiopancreatography (ERCP) in patients with surgically altered anatomy. This training is necessary as the number of bariatric surgeries performed worldwide increases. ETM with human-like anatomy were developed to represent the postoperative anatomy after Billroth II (BII) reconstruction for a standard duodenoscope and the situs of a long-limbed Roux-en-Y (RY) for device-assisted enteroscopy (DAE). In three independent workshops, the models were evaluated by international ERCP experts. In RY model, a simulation for small bowel behavior in endoscopy was created. Thirty-three experts rated the ETM in ERCP expert courses. The BII model was evaluated as suitable for training (school grades 1.36), with a haptic and visual impression rating of 1.73. The RY model was rated 1.50 for training suitability and 2.06 for overall impression. Animal tissue-free ETMs for ERCP in surgically altered anatomy were successfully created. Evaluation by experienced endoscopists indicated that the models are suitable for hands-on ERCP training, including device-assisted endoscopy. It is expected that patient care will improve with appropriate training in advanced procedures.

[Long-term visual outcomes of Boston type I keratoprosthesis in Canada]. / Résultats à long terme de la kératoprothèse de Boston de type I au Canada.

BACKGROUND/PURPOSE: To evaluate long-term visual outcomes of Boston type I keratoprosthesis (KPro) surgery and identify risk factors for visual failure. METHODS: Single surgeon retrospective cohort study including 85 eyes of 74 patients who underwent KPro implantation to treat severe ocular surface disease, including limbal stem cell deficiency, postinfectious keratitis, aniridia and chemical burns. Procedures were performed at the Centre hospitalier de l'Université de Montréal from October 2008 to May 2012. All patients with at least 5 years of follow-up were included in the analysis, including eyes with repeated KPro. Main outcome measures were visual acuity (VA), visual failure, defined as a sustained VA worse than the preoperative VA, postoperative complications, and device retention. RESULTS: Mean follow-up was 7.2±1.3 years (±SD). Mean VA was 2.1±0.7 (logarithm of minimal angle resolution) preoperatively and 1.9±1.2 at last follow-up. In total, 2.4% of patients had VA better than 20/200 preoperatively vs. 36.5% at last follow-up. Maintenance of improved postoperative VA was seen in 61.8% of eyes at 7 years. Preoperative factors associated with visual failure were known history of glaucoma (HR=2.7 [1.2 to 5.9], P=0.02) and Stevens-Johnson syndrome (HR=7.3 [2.5 to 21.4], P<0.01). Cumulative 8-year complication rates were 38.8% retroprosthetic membrane formation, 25.9% hypotony, 23.5% new onset glaucoma, 17.6% retinal detachment, 8.2% device extrusion and 5.9% endophthalmitis. The majority (91.8%) of eyes retained the device 8 years after implantation. CONCLUSION: Nearly two-thirds of patients exhibited improved VA 7 years after KPro implantation. Preoperative risk factors for visual failure were known glaucoma and Stevens-Johnson syndrome.

The new frontier in ECLS: Artificial placenta and artificial womb for premature infants.

Outcomes for extremely low gestational age newborns (ELGANs), defined as <28 weeks estimated gestational age (EGA), remain disproportionately poor. A radical paradigm shift in the treatment of prematurity is to recreate the fetal environment with extracorporeal support and provide an environment for organ maturation using an extracorporeal VV-ECLS artificial placenta (AP) or an AV-ECLS artificial womb (AW). In this article, we will review clinical indications, current approaches in development, ongoing challenges, remaining milestones and ethical considerations prior to clinical translation.

INNOVATIONS IN ARTIFICIAL ORGANS AND TISSUE ENGINEERING: FROM 3D PRINTING TO STEM CELL THERAPY.

"Every year, many individuals with tissue or organ problems require urgent care due to medical emergencies, burns, congenital anomalies, and other causes". Regenerative medicine was created because there aren't enough donors, issues with graft rejection, and insufficient organs or tissues for patients to replace, repair, and regenerate. However, significant tissue defects are difficult to fill with injections alone, making stem cell therapy a crucial component of the area of regenerative medicine. To achieve the intended outcome, the researchers combine stem cells with three-dimensional (3D) printed organs tissue engineering scaffolding. These scaffolds can resemble bone, cartilage, or "extracellular matrix (ECM)" in that they provide structural support and promote adhesion, proliferation, and differentiation, finally resulting in the production of functional tissues or organs. In this study on stem cell regenerative medicine, the therapeutic focused mostly on scaffolding for 3D printed organ tissue engineering. The following applications are demonstrated and compared using various 3D printing processes and starting materials. Then, we go over the benefits of 3D printing over conventional methods, touch on certain issues and restrictions, and make some assumptions about potential applications in the future.

Simulation of artificial anal sphincter motion and interaction with intestinal environment using SOFA.

BACKGROUND: Artificial anal sphincter is an implantable medical device for treating fecal incontinence. Reasonable simulation facilitates the advancement of research and reduces experiments on biological tissue. However, the device's clamping motion and sensor interaction with the intestine in the simulation still require further exploration. This article presents a simulation of the artificial anal sphincter's clamping and sensing and its interaction with the intestinal environment using the Simulation Open Framework Architecture (SOFA). METHODS: Firstly, the proposed simulation algorithm and its principles in SOFA are analyzed. Secondly, the clamping motion and sensor system of the artificial anal sphincter are simulated. Thirdly, a finite element model of intestine is established based on the properties of intestinal soft tissue. Finally, the in vitro experiments are performed. RESULTS: The simulation results indicate that the sensor system of the artificial anal sphincter has good sensing performance during the clamping motion and fecal accumulation process. Experiments have shown that optimal sensory capabilities can be achieved as the posture of the artificial anal sphincter with a roll angle between 20° and 40°. The comparison demonstrates a mean absolute error of 10%-20% between simulation and in vitro experimental results for sensor forces, which verifies the effectiveness of the simulation. CONCLUSION: The proposed novel simulation achieves a more comprehensive interaction between the artificial anal sphincter motion and intestinal environment. This study may provide more effective simulation data for guidance in improving the performance of sensor perception of artificial anal sphincter for further research.

The economics of artificial organs.

Spurred by devoted research and institutional financing, organ replacement therapies have progressed monumentally over the last century. Concomitantly, there has been an escalation in healthcare costs. In an aging society where organ replacement therapy utilization is expected to continue to rise, will society need to rethink the economics of end-stage organ dysfunction management?

Bio-SHARPE: Bioinspired Soft and High Aspect Ratio Pumping Element for Robotic and Medical Applications.

The advent of soft robots has solved many issues posed by their rigid counterparts, including safer interactions with humans and the capability to work in narrow and complex environments. While much work has been devoted to developing soft actuators and bioinspired mechatronic systems, comparatively little has been done to improve the methods of actuation. Hydraulically soft actuators (HSAs) are emerging candidates to control soft robots due to their fast responses, low noise, and low hysteresis compared to compressible pneumatic ones. Despite advances, current hydraulic sources for large HSAs are still bulky and require high power availability to drive the pumping plant. To overcome these challenges, this work presents a new bioinspired soft and high aspect ratio pumping element (Bio-SHARPE) for use in soft robotic and medical applications. This new soft pumping element can amplify its input volume to at least 8.6 times with a peak pressure of at least 40 kPa. The element can be integrated into existing hydraulic pumping systems like a hydraulic gearbox. Naturally, an amplification of fluid volume can only come at the sacrifice of pumping pressure, which was observed as a 19.1:1 reduction from input to output pressure. The new concept enables a large soft robotic body to be actuated by smaller fluid reservoirs and pumping plant, potentially reducing their power and weight, and thus facilitating drive source miniaturization. The high amplification ratio also makes soft robotic systems more applicable for human-centric applications such as rehabilitation aids, bioinspired untethered soft robots, medical devices, and soft artificial organs. Details of the fabrication and experimental characterization of the Bio-SHARPE and its associated components are given. A soft robotic squid and an artificial heart ventricle are introduced and experimentally validated.

Current development and clinical applications of artificial anal sphincter.

INTRODUCTION: Fecal incontinence is a common chronic disease, which not only brings inconvenience to the lives of patients, but also causes great psychological harm to patients. Artificial anal sphincter is an innovative method that may treat fecal incontinence, and now has been clinically applied. AREAS COVERED: This article will review recent developments in mechanisms and clinical applications of artificial anal sphincter. The current results of clinical trials show that the implantation of artificial sphincter will cause morphological changes of surrounding tissues, and related biomechanical imbalance will lead to the loss of effectiveness of the device and various complications. In terms of safety, postoperative patients suffer from various complications such as infection, corrosion, tissue ischemia, mechanical failure, and difficulty in emptying. In terms of effectiveness, there is currently no long-term research data to prove that the implanted device can maintain a long-term functional state. EXPERT OPINION: The key issue for the safety and effectiveness of implantable devices is the biomechanical compatibility of implantable devices was proposed. Based on the superelasticity of shape memory alloy, this article proposes a new type of constant force artificial sphincter device, which provides a new direction for solving the clinical application of artificial anal sphincter.

[A multicenter clinical trial of collar-button type keratoprosthesis implantation for the treatment of corneal blindness in high-risk transplantation].

Objective: To evaluate the efficiency and safety of collar-button type keratoprosthesis (c-bKPro) implantation for corneal blindness in high-risk transplantation in China. Methods: It was a case series study. High-risk corneal blind patients who planned to undergo c-bKPro implantation were prospectively and continuously enrolled in the Eye Hospital of Shandong First Medical University, Ophthalmology Division of Chinese PLA General Hospital, Zhongshan Ophthalmic Center, Department of Ophthalmology in Eye & ENT Hospital of Fudan University, and Eye Hospital of Wenzhou Medical University from July 2019 to January 2020. The cure for blindness and surgical success were assessed based on visual acuity (VA)≥0.05. The complications and keratoprosthesis retention rate were recorded to determine the safety of the surgery. Results: Thirty-seven subjects (eyes) were included, of which 32 were male and 5 were female, aged 27 to 72 years old. The indications of c-bKPro implantation were corneal graft failure (21 eyes, 56.8%), chemical injury (8 eyes, 21.6%), thermal burn (5 eyes, 13.5%), unexplained corneal opacity (2 eyes, 5.4%), and corneal perforation (1 eye, 2.7%). Two patients withdrew from the clinical trial at 3 months postoperatively. Thirty-five patients were followed up for 6 months, and 31 were followed up for 12 months. The VA was ≥0.05 in 83.8% of eyes at 6 months and in 81.8% of eyes at 12 months. Among the 11 eyes diagnosed with concurrent glaucoma, 6 eyes achieved a VA of ≥0.05. At 12 months, the c-bKPro retention rate was 100%. The surgical complications included retroprosthetic membrane formation (5 eyes, 16.1%), persistent corneal epithelial defects (5 eyes, 16.1%), macular edema (4 eyes, 12.9%), new-onset glaucoma (4 eyes, 12.5%; including one eye withdrawn from the study at 3 months), sterile corneal melting (2 eyes, 6.5%), sterile vitritis (1 eye, 3.2%), and infectious keratitis (1 eye, 3.2%). Conclusions: C-bKPro implantation is an effective and safe option for treating corneal blindness in high-risk transplantation in China. Improved visual outcomes could be achieved in most cases, with a relatively low incidence of postoperative complications.