An ingestible bioimpedance sensing device for wireless monitoring of epithelial barriers.

Existing gastrointestinal (GI) diagnostic tools are unable to non-invasively monitor mucosal tight junction integrity in vivo beyond the esophagus. In the GI tract, local inflammatory processes induce alterations in tight junction proteins, enhancing paracellular ion permeability. Although transepithelial electrical resistance (TEER) may be used in the laboratory to assess mucosal barrier integrity, there are no existing methodologies for characterizing tight junction dilation in vivo.

Miniaturized Capsule System Toward Real-Time Electrochemical Detection of H S in the Gastrointestinal Tract.

Hydrogen sulfide (H S) is a gaseous inflammatory mediator and important signaling molecule for maintaining gastrointestinal (GI) homeostasis. Excess intraluminal H S in the GI tract has been implicated in inflammatory bowel disease and neurodegenerative disorders; however, the role of H S in disease pathogenesis and progression is unclear. Herein, an electrochemical gas-sensing ingestible capsule is developed to enable real-time, wireless amperometric measurement of H S in GI conditions.

Sensorized Endovascular Technologies: Additional Data to Enhance Decision-Making.

Background: Current endovascular procedures rely mostly on anatomic information, guided by fluoroscopy, to perform interventions (i.e. angioplasty, stent placement, coils).

Recreating the Trabecular Outflow Tissue on Implantable, Micropatterned, Ultrathin, Porous Polycaprolactone Scaffolds.

Glaucoma, where increased intraocular pressure (IOP) leads to damage to the optic nerve and loss of sight, is amongst the foremost causes of irreversible blindness worldwide. In primary open angle glaucoma, the increased IOP is a result of the malfunctioning human trabecular meshwork (HTM) cells' inability to properly regulate the outflow of aqueous humor from the eye. A potential future treatment for glaucoma is to replace damaged HTM cells with a tissue-engineered substitute, thus restoring proper fluid outflow.

Freestanding region-responsive bilayer for functional packaging of ingestible devices.

Ingestible capsules have the potential to become an attractive alternative to traditional means of treating and detecting gastrointestinal (GI) disease. As device complexity increases, so too does the demand for more effective capsule packaging technologies to elegantly target specific GI locations. While pH-responsive coatings have been traditionally used for the passive targeting of specific GI regions, their application is limited due to the geometric restrictions imposed by standard coating methods.

Submarine medicine: An overview of the unique challenges, medical concerns, and gaps.

Submariners face many challenges. For example, they "live where they work" and can be called to duty anytime. They have limited access to open space, natural settings, fresh air, fresh food, sunlight, privacy, exercise, and outside communication.

Integrated System for Bacterial Detection and Biofilm Treatment on Indwelling Urinary Catheters.

Goal: This work introduces an integrated system incorporated seamlessly with a commercial Foley urinary catheter for bacterial growth sensing and biofilm treatment.

Methods: The system is comprised of flexible, interdigitated electrodes incorporated with a urinary catheter via a 3D-printed insert for impedance sensing and bioelectric effect-based treatment. Each of the functions were wirelessly controlled using a custom application that provides a user-friendly interface for communicating with a custom PCB via Bluetooth to facilitate implementation in practice.

Capacitive sensing of triglyceride film reactions: a proof-of-concept demonstration for sensing in simulated duodenal contents with gastrointestinal targeting capsule system.

Ingestible capsule systems continue to evolve to overcome drawbacks associated with traditional gastrointestinal (GI) diagnostic and therapeutic processes, such as limitations on which sections of the GI tract can be accessed or the inability to measure local biomarker concentrations. We report an integrated capsule sensing system, utilizing a hybrid packaging scheme coupled with triglyceride film-coated capacitive sensors, for measuring biochemical species present in the duodenum, such as pancreatic lipase and bile acids. The system uses microfabricated capacitive sensors interfaced with a Bluetooth low-energy (BLE)-microcontroller, allowing wireless connectivity to a mobile app.

Ingestible Sensors and Sensing Systems for Minimally Invasive Diagnosis and Monitoring: The Next Frontier in Minimally Invasive Screening.

Ingestible electronic systems that are capable of embedded sensing, particularly within the gastrointestinal (GI) tract and its accessory organs, have the potential to screen for diseases that are difficult if not impossible to detect at an early stage using other means. Furthermore, these devices have the potential to (1) reduce labor and facility costs for a variety of procedures, (2) promote research for discovering new biomarker targets for associated pathologies, (3) promote the development of autonomous or semiautonomous diagnostic aids for consumers, and (4) provide a foundation for epithelially targeted therapeutic interventions. These technological advances have the potential to make disease surveillance and treatment far more effective for a variety of conditions, allowing patients to lead longer and more productive lives.

In-Plane Vibration of Hammerhead Resonators for Chemical Sensing Applications.

Thermally excited and piezoresistively detected in-plane cantilever resonators have been previously demonstrated for gas- and liquid-phase chemical and biosensing applications. In this work, the hammerhead resonator geometry, consisting of a cantilever beam supporting a wider semicircular "head", vibrating in an in-plane vibration mode, is shown to be particularly effective for gas-phase sensing with estimated limits of detection in the sub-ppm range for volatile organic compounds. This paper discusses the hammerhead resonator design and the particular advantages of the hammerhead geometry, while also presenting mechanical characterization, optical characterization, and chemical sensing results.

Flexible Platform for In Situ Impedimetric Detection and Bioelectric Effect Treatment of Escherichia Coli Biofilms.

Goal: This paper reports a platform for real-time monitoring and treatment of biofilm formation on three-dimensional biomedical device surfaces.

Methods: We utilize a flexible platform consisting of gold interdigitated electrodes patterned on a polyimide substrate. The device was integrated onto the interior of a urinary catheter and characterization was performed in a custom-developed flow system.

Reducing the effect of parasitic capacitance on implantable passive resonant sensors.

Passive, LC resonators have the potential to serve as small, robust, low cost, implantable sensors to wirelessly monitor implants following orthopedic surgery. One significant barrier to using LC sensors is the influence on the sensor's resonance of the surrounding conductive high permittivity media in vivo. The surrounding media can detune the resonant frequency of the LC sensor resulting in a bias.

A simple sensing mechanism for wireless, passive pressure sensors.

We have developed a simple wireless pressure sensor that consists of only three electrically isolated components. Two conductive spirals are separated by a closed cell foam that deforms when exposed to changing pressures. This deformation changes the capacitance and thus the resonant frequency of the sensors.

A sacrificial process for fabrication of biodegradable polymer membranes with submicron thickness.

A new sacrificial molding process using a single mask has been developed to fabricate ultrathin 2-dimensional membranes from several biocompatible polymeric materials. The fabrication process is similar to a sacrificial microelectromechanical systems (MEMS) process flow, where a mold is created from a material that can be coated with a biodegradable polymer and subsequently etched away, leaving behind a very thin polymer membrane. In this work, two different sacrificial mold materials, silicon dioxide (SiO2 ) and Liftoff Resist (LOR) were used.

Mass-sensitive detection of gas-phase volatile organics using disk microresonators.

The detection of volatile organic compounds (VOCs) in the gas phase by mass-sensitive disk microresonators is reported. The disk resonators were fabricated using a CMOS-compatible silicon micromachining process and subsequently placed in an amplifying feedback loop to sustain oscillation. Sensing of benzene, toluene, and xylene was conducted after applying controlled coatings of an analyte-absorbing polymer.