Materials and Orthopedic Applications for Bioresorbable Inductively Coupled Resonance Sensors.

Bioresorbable passive resonance sensors based on inductor-capacitor (LC) circuits provide an auspicious sensing technology for temporary battery-free implant applications due to their simplicity, wireless readout, and the ability to be eventually metabolized by the body. In this study, the fabrication and performance of various LC circuit-based sensors are investigated to provide a comprehensive view on different material options and fabrication methods. The study is divided into sections that address different sensor constituents, including bioresorbable polymer and bioactive glass substrates, dissolvable metallic conductors, and atomic layer deposited (ALD) water barrier films on polymeric substrates.

Bioresorbable Conductive Wire with Minimal Metal Content.

The emergence of transient electronics has created the need for bioresorbable conductive wires for signal and energy transfer. We present a fully bioresorbable wire design where the conductivity is provided by only a few micrometers thick electron-beam evaporated magnesium layer on the surface of a polymer fiber. The structure is electrically insulated with an extrusion coated polymer sheath, which simultaneously serves as a water barrier for the dissolvable magnesium conductor.

Nanocellulose and chitosan based films as low cost, green piezoelectric materials.

Nanocellulose and chitosan have recently started to get attention as environmentally friendly piezoelectric materials for sensor and energy harvesting applications. Conversely, current commercially available flexible piezoelectric films made of for example polyvinylidene difluoride (PVDF) are relatively expensive and made from non-renewable materials. We measured the piezoelectric responses (2-8 pC/N) for solvent casted films based on nanocellulose, microcrystalline chitosan and their blends.

Testing and comparing of film-type sensor materials in measurement of plantar pressure distribution.

Simple in-shoe sensors based on film-type sensor materials were developed in this study. Three sensor materials were tested: polyvinylidenefluoride (PVDF), cellulose nanofibrils (CNF) and ElectroMechanical Film (EMFi). Plantar pressure distributions of a subject were measured with the developed in-shoe sensors; each consisting of three sensor channels (lateral and medial metatarsal heads and heel).

Novel wireless electroencephalography system with a minimal preparation time for use in emergencies and prehospital care.

Background: Although clinical applications such as emergency medicine and prehospital care could benefit from a fast-mounting electroencephalography (EEG) recording system, the lack of specifically designed equipment restricts the use of EEG in these environments.

Methods: This paper describes the design and testing of a six-channel emergency EEG (emEEG) system with a rapid preparation time intended for use in emergency medicine and prehospital care. The novel system comprises a quick-application cap, a device for recording and transmitting the EEG wirelessly to a computer, and custom software for displaying and streaming the data in real-time to a hospital.

Embedded capacitive sensor system for hip surgery rehabilitation: online measurements and long-term stability.

We are developing an embedded system that measures the force between foot and insole with a low-cost laminated capacitive sensor matrix. The system is intended to guide a hip surgery patient to train the operated leg with a suitable force. In this paper, we present an embedded measurement system, which is able to estimate the total plantar force in real-time and to give instant feedback to a user.