A biopotential acquisition analog front-end (AFE) integrated circuit (IC) is presented. The biopotential AFE includes a capacitively coupled chopper instrumentation amplifier (CCIA) to achieve low input referred noise (IRN) and to block unwanted DC potential signals. A DC servo loop (DSL) is designed to minimize the offset voltage in the chopper amplifier and low frequency respiration artifacts...

A spectrometer based on the principle of photoacoustic spectroscopy has been developed recently at our laboratory for the detection of hazardous gases such as O3, C2H4, SO2, NO2 and SF6. In most of our earlier works, we employed a mechanical chopper to modulate the laser beam and this chopper modulation has the crucial disadvantage of instability in the chopper frequency. Even a minor shift of ...

Human listeners hear an asymmetry in the perception of damped and ramped sinusoids; the partial loudness of the envelope component is greater than the partial loudness of the carrier component for damped sinusoids. Here we show that an asymmetry also occurs in the physiological responses of most units in the ventral cochlear nucleus to these same sounds. The activity elicited by damped sinusoid...

At low frequencies, offset, 1/f noise and drift are the dominant error sources of operational amplifiers. This is especially true in CMOS technology. This chapter reviews precision techniques that can be used to achieve low 1/f noise and low offset in operational amplifiers. There are three types of CMOS offset cancellation techniques: trimming, chopping, and auto-zeroing. Trimming is usually p...

OBJECTIVE This study investigated whether affording objects with different levels of functional support would have an impact on reaching performance in patients after cerebrovascular accident (CVA) and in adults who were neurologically intact. Reaching performance was quantitatively analyzed, using several kinematic variables. METHOD Two groups, 14 participants after CVA and 24 age-matched ad...

The paper describes an improvement of the chopper method for elimination of parasitic voltages in a low resistance comparison and measurement procedure. The basic circuit diagram along with a short description of the working principle are presented and the appropriate low resistance comparator prototype was designed and realized. Preliminary examinations confirm the possibility of measuring ext...

The Front End Test Stand (FETS) under construction at RAL is a demonstrator for front end systems of a future high power proton linac. Possible applications include a linac upgrade for the ISIS spallation neutron source, new future neutron sources, accelerator driven sub-critical systems, high energy physics proton drivers etc. Designed to deliver a 60mA H-minus beam at 3MeV with a 10% duty fac...