Neuroendoscopy-compatible neurostimulation catheter for minimally-invasive and multifunctional hypothalamic deep brain stimulation

Biomedical Microdevices · 2026-03-01

As hypothalamic deep brain stimulation (DBS) has been clinically proven effective for treating various neurological conditions, there is a growing need for strategies that minimize invasiveness while maximizing therapeutic efficacy. We propose a highly translational multifunctional neurostimulation catheter compatible with endoscopic access to the third ventricule for targeted ventromedial hypothalamic deep brain stimulation. This approach offers several key advantages: (1) a multifunctional catheter for both electrical and pharmaceutical intervention, (2) a minimally-invasive implantation procedure, and (3) enhanced electrode contacts with the third ventricle wall to access the underlying hypothalamic nuclei. The system comprises a flexible catheter with integrated thin-film microelectrodes, a customized cylindrical connector, extension wires, and a customized neurostimulator. The design features its high compatibility with clinically available neurosurgical tools, including guide wires and burr hole valves. We evaluated electrochemical performance under various bending conditions and assessed the safety and long-term device reliability. In addition, we demonstrated successful implantation into a Polydimethylsiloxane (PDMS) mold shaped to sit in the third ventricle, simulated the electric potential distribution using finite element analysis, and validated a clinically compatible drug delivery procedure. This novel implantation strategy holds promise for reducing procedural risks associated with hypothalamic deep brain stimulation.

In-Vitro Evaluations of Shape Memory Polymer Scaffolds With Tunable Architecture for the Endovascular Embolization of Unruptured Intracranial Aneurysms

Journal of Biomechanical Engineering · 2026-02-06

Translationally relevant metrics for shape memory polymer (SMP) scaffolds intended for the endovascular treatment of intracranial aneurysms were evaluated in various in vitro experiments. Multiple SMP formulations were first evaluated for glass transition properties, with saturated scaffolds demonstrating Tg midpoints of 39 °C, 35 °C, and 32 °C, respectively. Then, the scaffold's porosity (85-95%) and infill pattern (rectilinear, honeycomb, gyroid) were varied, and these designs were systematically compared by compressibility, shape recovery (SR), and pulsatile compaction resistance. The compressibility of ideal and wide-necked aneurysm geometries, each in 6 mm and 8 mm diameter sizes, indicated an upper limit of ∼9 mm in treatable aneurysm diameter for a 5 French catheter. Under physiologically relevant pulsatile loading, all scaffold designs resisted notable compaction, with maximum deformation values not exceeding 55 μm. The shape recovery forces were primarily governed by the porosity level, with low- and medium-porosity scaffolds showing complete and reliable shape recovery, and high-porosity scaffolds exhibiting reduced completeness of shape recovery. Shape recovery rates varied both within and across infill pattern and porosity groups. Together, these findings provide quantitative benchmarks for the translational viability of our SMP scaffold in different key stages of device deployment and establish design guidelines for further optimization of patient-specific endovascular devices.

Smart Garment for Continuous Respiration Monitoring in Canines

ACS Sensors · 2026-03-03

There is a growing need for at-home respiration monitoring in canines, who are prone to respiratory issues due to breed-specific anatomy and active lifestyles. Continuous monitoring of respiration provides critical insight into stress and illness; however, current solutionsranging from clinical instruments to wearable devicesare either accurate but invasive and episodic or limited in fit and comfort. Here, we introduce a smart garment that integrates a spongy-like strain sensor and compact data acquisition module into commercially available canine apparel, enabling continuous, non-invasive monitoring of respiration, body temperature, and physical activity. Validation with two breeds, Labrador and Boxer, confirmed its ability to capture breed- and activity-specific respiration patterns, including differences in breathing rate, amplitude, and panting behavior. Using convolutional neural network (CNN)-assisted machine learning (ML), the system classified respiratory patterns across breeds and activity levels with over 94.3% accuracy. Beyond canines, this platform may hold potential for future adaptation to other companion animals, such as cats, suggesting a broader scope for home-based veterinary monitoring.

Mechanically Stable Fractal Microelectrode with Nanostructured Pt/PEDOT:PSS for a Reliable Neural Stimulation

ACS Applied Materials & Interfaces · 2025-08-05 · 1 citations

Neural stimulation provides significant therapeutic benefits for patients with neurological disorders. PEDOT:PSS has gained attention as a neural electrode material, but its poor mechanical stability due to continuous cyclic charge injection, which is especially severe on ultrathin substrates, remains a big challenge for its clinical utility. To address this problem, we developed a mechanically and electrochemically stable PEDOT:PSS-based microelectrode for neural stimulation by utilizing enhanced adhesion on the vertical interface between the three-dimensional (3D) nanostructured substrate. Our microelectrode design incorporates a fractal geometry that increases the perimeter-to-area ratio, coupled with nanostructured platinum to enhance the surface area. The simple PEDOT:PSS-coated microelectrode exhibited outstanding mechanical stability, evidenced by various metrologies, such as scanning electron microscopy (SEM), energy-dispersive X-ray (EDX), and atomic force microscopy (AFM), which can facilitate wide industrial adoption. We further verified using numerical analysis that the fractal electrode with a nanostructured Pt/PEDOT:PSS coating outperforms the traditional PEDOT:PSS-coated circular electrode. This innovative combination of geometrical design and surface treatment introduces a novel approach to developing robust microelectrodes for reliable neural stimulation.

Enhanced Thermal Conductivity in Tough and Environmentally Resilient Hydrogels

Advanced Materials Interfaces · 2025-12-07

ABSTRACT Hydrogels, known for their biocompatibility and responsiveness to external stimuli, are promising candidates for wearable sensors and electronics. However, conventional hydrogels exhibit low thermal conductivity (0.2–0.6 W/m·K), which limits efficient heat dissipation and leads to performance degradation during continuous operation, such as in long‐term wearable health monitors. Moreover, their weak mechanical and environmental stability further constrains their broader applications. In this study, we introduce a multiscale structural engineering approach that leverages the dynamics of pores, crystallization, and hydrogen bonding. Inspired by the design motifs of natural materials such as spider silk, we enhance the thermal conductivity of hydrogels to 1.5 W/m·K. This multiscale structural strategy also improves their mechanical strength and environmental resilience. Our findings provide a blueprint for understanding the process–structure–property relationships and offer a design framework for expanding the practical applications of hydrogels.

Wearable smart textile band for continuous equine health monitoring

Biosensors and Bioelectronics · 2025-10-10

Towards the Intravascular Delivery of 3D-printed Leached SMP for Endovascular Treatment of Intracranial Aneurysm

Annals of Biomedical Engineering · 2025-08-03 · 1 citations

PURPOSE: Intracranial aneurysms (ICAs) pose a serious clinical risk due to their potential for rupture, leading to subarachnoid hemorrhage, high morbidity, and mortality. This study aims to develop a proof-of-concept device for the targeted delivery of shape memory polymers (SMPs)-based embolic devices to improve aneurysm occlusion and reduce recurrence. METHODS: A novel system was designed combining a radial compression fixture and an electronic device for Joule heating and electrolytic detachment (ED). Three SMP geometries (5, 6.5 mm spherical, and patient-specific) were evaluated for the shape recovery and thermal responses. In-vitro testing was performed using 6.5 mm and patient-specific geometries in PDMS aneurysm phantoms under physiological relevant conditions utilizing ovine blood. RESULTS: Controlled activation of the SMPs at currents of 400 mA achieved reproducible shape recovery ratios (SRRs) up to 75.71%, with detachment occurring at < 100 mA. Surface temperatures remained below 45 °C. In-vitro deployment resulted in aneurysm sac occlusion of 90.32% (patient-specific) and 94.12% (idealized), without evidence of thermal damage or gas accumulation. Flow visualization confirmed reduced bubble entry into the aneurysm sac post-deployment. CONCLUSION: This study demonstrates the feasibility of a targeted delivery system for patient-specific ICA treatment using SMPs. While further refinement and in-vivo validation are required, these findings highlight the potential of SMPs as durable embolization devices capable of conforming to complex aneurysm geometries and providing more effective occlusion compared to current methods.

Lessons Learned and Challenges Ahead in the Translation of Implantable Microscale Sensors and Actuators

Annual Review of Biomedical Engineering · 2025-02-06 · 10 citations

Microscale sensors and actuators have been widely explored by the scientific community to augment the functionality of conventional medical implants. However, despite the many innovative concepts proposed, a negligible fraction has successfully made the leap from concept to clinical translation. This shortfall is primarily due to the considerable disparity between academic research prototypes and market-ready products. As such, it is critically important to examine the lessons learned in successful commercialization efforts to inform early-stage translational research efforts. Here, we review the regulatory prerequisites for market approval and provide a comprehensive analysis of commercially available microimplants from a device design perspective. Our objective is to illuminate both the technological advances underlying successfully commercialized devices and the key takeaways from the commercialization process, thereby facilitating a smoother pathway from academic research to clinical impact.

Hydrogel Adhesive Integrated‐Microstructured Electrodes for Cuff‐Free, Less‐Invasive, and Stable Interface for Vagus Nerve Stimulation

Advanced Healthcare Materials · 2025-04-02 · 6 citations

Vagus nerve stimulation (VNS) is a recognized treatment for neurological disorders, yet the surgical procedure carries significant risks. During the process of isolating or cuffing the vagus nerve, there is a danger of damaging the nerve itself or the adjacent carotid artery or jugular vein. To minimize this risk, here we introduce a novel hydrogel adhesive-integrated and stretchable microdevice that provides a less invasive, cuff-free option for interfacing with the vagus nerve. The device features a novel hydrogel adhesive formulation that enables crosslinking on biological tissue. The inclusion of kirigami structures within the thin-film microdevice creates space for uniform hydrogel-to-epineurium contact while accommodating the stiffness changes of the hydrogel upon hydration. Using a rodent model, we demonstrate a robust device adhesion on a partially exposed vagus nerve in physiological fluid even without the vagus nerve isolation and cuffing process. Our device elicted stable and clear evoked compound action potential (~1500 µV peak-to-peak) in C-fibers with a current amplitude of 0.4 mA. We believe this innovative platform provides a novel, less-risky approach to interface with fragile nerve and vascular structures during VNS implantation.

Microfluidic technologies for wearable and implantable biomedical devices

Lab on a Chip · 2025-01-01 · 16 citations

therapeutic systems are explored, alongside current challenges in long-term stability, power management, and clinical translation. Finally, we discuss future directions involving bioresorbable materials, AI-assisted diagnostics, and wireless integration that may drive the next generation of personalized microfluidic healthcare systems.