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Developing and Evaluating a Flexible Wireless Microcoil Array Based Integrated Interface for Epidural Cortical Stimulation

“…We employed an analog passive circuit scheme to build the system, which minimized the size of the IPG prototype circuit and did not need a power supply. Unlike the previously published iteration [30], which used a NE555 chip whose pulse output width and frequency could not be adjusted, our single-channel IPG has a two-stage signal generator circuit to regulate the width and frequency of the pulse voltage output. The first stage uses an ICL8038, which regulates the frequency of the output signal.…”

“…As seen in Figure 4a, the external part includes a signal generator, carrier oscillator, amplitude modulation (AM) circuit, and power amplifier circuit supplied by regulated direct-current (DC) power supplies. We developed the implant interface with the external part modified from a previously described setup [30]. The implanted part includes a microcoil, passive demodulated circuit, and surface electrodes (Figure 5a).…”

“…The passive demodulated circuit included a double-diode peak envelope detector and low-pass filter for demodulating the low frequency stimulus signal. We designed a two-stage signal generator circuit in the transmitter module to replace the NE555 circuit used in the previous version [30]. As shown in Figure 4b, the first stage used an ICL8038 waveform generation, which was responsible for adjusting target frequency, and a NE555, which was responsible for target pulse width.…”

“…However, the multiple wire connections between the electrode and stimulator circuit were vulnerable and easy to twist, which could possibly disrupt the IPG [29], thus this system was not feasible for ECS. Recently, Mou and Hou et al explored a multichannel signal transmission system using a microcoil array [30]. Due to poor output controllability of the signal generator inside the transmitter, this system could not be used for electrical stimulation.…”

Upregulated plasma and urinary levels of nucleosides as biological markers in the diagnosis of primary gallbladder cancer

“…and positron emission tomography are the most frequently used techniques for the diagnosis of gallbladder abnormalities [9][10][11]. Unfortunately, the positive predictive value of these strategies in the early detection of gallbladder carcinoma has been consistently <10% [12], including the utilization of the complex longitudinal algorithms for CA199 [13], sequential testing [14,15], and the addition of newer markers such as XPC [16].…”