Preparation and Characterization of Novel Poly(thiourethane)-Poly(isocyanurate) Covalent Adaptable Networks: Effect of the Catalysts.

Poly(thiourethane)-based covalent adaptable networks are synthesized by reacting a trimer of hexamethylene diisocyanate (Desmodur N3300) containing isocyanurate groups in its structure with 1,6-hexanedithiol. The catalysts evaluated for this process include dibutyltin dilaurate (DBTDL), lanthanum triflate (La(OTf)), and a thermal precursor of 1,8-diazabicyclo[5.4.

Preparation and Characterization of a Series of Self-Healable Bio-Based Poly(thiourethane) Vitrimer-like Materials.

A series of poly(thiourethanes) (PTUs) from biobased monomers have been synthesized. Limonene and squalene were transformed into polyfunctional thiols by thiol-ene reaction with thioacetic acid and further saponification. They were then reacted in different proportions with hexamethylene diisocyanate (HDI) in the presence of a catalyst to prepare bio-based poly(thiourethane) vitrimer-like materials.

Behavioral Responses to Losses Disguised as Wins: A Field Study of Slot Machine Players.

We present the results of a field study examining the effect of losses disguised as wins (LDWs) on subsequent slot machine gambler betting behavior. An LDW occurs when the amount won is less than the amount bet. Using non-experimental, individual transaction gambling data, we examine post LDW betting behavior in a panel of 42,669 gamblers and 17 million slot machine plays.

A Two-Wired Ultra-High Input Impedance Active Electrode.

This paper presents a novel two-wired active electrode that achieves ultrahigh input impedance using power supply bootstrapping. The proposed circuit reduces the input capacitance of a buffer amplifier while enabling measurements using leads with only two wires, providing a low-complexity and low-cost solution for interference rejection and artifact reduction in dc-coupled dry-contact biopotential measurements. An implemented prototype shows that, even using standard operational amplifiers, an input capacitance as low as 71 fF can be obtained, maintaining a high impedance in a 0-1 kHz bandwidth, sufficient for ECG, EEG, and EMG measurements.

A simple encoding method for Sigma-Delta ADC based biopotential acquisition systems.

Sigma Delta analogue-to-digital converters allow acquiring the full dynamic range of biomedical signals at the electrodes, resulting in less complex hardware and increased measurement robustness. However, the increased data size per sample (typically 24 bits) demands the transmission of extremely large volumes of data across the isolation barrier, thus increasing power consumption on the patient side. This problem is accentuated when a large number of channels is used as in current 128-256 electrodes biopotential acquisition systems, that usually opt for an optic fibre link to the computer.

High gain driven right leg circuit for dry electrode systems.

This paper presents an improved driven right leg (DRL) circuit compensation together with a practical implementation. The proposed design allows to increase common mode voltage attenuation compared with the widely used dominant pole compensation while maintaining the same proven stability margin and design criteria, and requiring only a modification of its passive feedback network. A sample implementation of the proposed DRL was obtained estimating the values of interference model parameters for a dry electrode measurement system.

Analysis and Simple Circuit Design of Double Differential EMG Active Electrode.

In this paper we present an analysis of the voltage amplifier needed for double differential (DD) sEMG measurements and a novel, very simple circuit for implementing DD active electrodes. The three-input amplifier that standalone DD active electrodes require is inherently different from a differential amplifier, and general knowledge about its design is scarce in the literature. First, the figures of merit of the amplifier are defined through a decomposition of its input signal into three orthogonal modes.

A simple and reproducible capacitive electrode.

Capacitive Electrodes (CE) allow the acquisition of biopotentials through a dielectric layer, without the use of electrolytes, just by placing them on skin or clothing, but demands front-ends with ultra-high input impedances. This must be achieved while providing a path for bias currents, calling for ultra-high value resistors and special components and construction techniques. A simple CE that uses bootstrap techniques to avoid ultra-high value components and special materials is proposed.

A capacitive electrode with fast recovery feature.

Capacitive electrodes (CEs) allow for acquiring biopotentials without galvanic contact, avoiding skin preparation and the use of electrolytic gel. The signal quality provided by present CEs is similar to that of standard wet electrodes, but they are more sensitive to electrostatic charge interference and motion artifacts, mainly when biopotentials are picked up through clothing and coupling capacitances are reduced to tens of picofarads. When artifacts are large enough to saturate the preamplifier, several seconds (up to tens) are needed to recover a proper baseline level, and during this period biopotential signals are irremediably lost.