Systems, apparatus, and methods are disclosed for conveying signals between a patient and monitoring and treatment devices. An EP system provides large-signal input protection and RF ablation signal noise suppression while preserving the integrity of relevant components of small signals. The EP system has a low-noise amplifier topology with minimal hardware filtering. An input protection circuit shunts to ground signals with amplitude above an ablation voltage. An RF filter circuit linearly attenuates the signals between 300 kHz and 600 kHz. A low-frequency feedback circuit drives a common mode node of the RF filter circuit for additional attenuation. A signal amplification circuit amplifies the signals between 0.01 Hz and 1000 Hz. A fast recovery circuit feeds back a low-frequency voltage signal to the signal amplification circuit to gradually reduce offset voltage of the signals. A high-resolution A/D converter converts the signals from the signal amplification circuit to clean digital signals.

A trans-impedance amplifier (TIA) includes a first circuit, a second circuit, and a third circuit. Both the first circuit and the second circuit are coupled to a current source, an operational amplifier, and the third circuit. The first circuit is configured to receive a first current, provide a third voltage to the third circuit, perform shape filtering on the first current, and convert the shape filtered first current to a first voltage for output. The second circuit is configured to receive a second current, provide a fourth voltage to the third circuit, perform shape filtering on the second current, and convert the shape filtered second current to a second voltage for output. The third circuit is configured to cooperate with the first circuit and the second circuit in performing shape filtering. The operational amplifier is configured to provide a small-signal virtual ground point to the first circuit.

Apparatus and methods remove a voltage offset from an electrical signal, specifically a biomedical signal. A signal is received at a first operational amplifier and is amplified by a gain. An amplitude of the signal is monitored, by a first pair of diode stages coupled to an output of the first operational amplifier, for the voltage offset. The amplitude of the signal is then attenuated by the first pair of diode stages and a plurality of timing banks. The attenuating includes limiting charging, by the first pair of diode stages, of the plurality of timing banks and setting a time constant based on the charging. The attenuating removes the voltage offset persisting at a threshold for a duration of at least the time constant. Saturation of the signal is limited to a saturation recovery time while the saturated signal is gradually pulled into monitoring range over the saturation recovery time.

A bias circuit includes a differential amplifier including at least two field effect transistors each having a gate, a source and a drain, a gain of the differential amplifier being based at least in part on a gate bias voltage, and a temperature compensation element selectively coupled to the gate of each of the two field effect transistors, the temperature compensation element configured to provide a compensated gate bias voltage across a temperature range.

In an amplifier that uses a transistor, a minimum operation voltage is lowered. An amplifier includes a P-type transistor and an N-type transistor connected in series, and an operational amplifier. An output terminal of the operational amplifier is connected to gates of both the P-type transistor and the N-type transistor. One of an inverting input terminal and a non-inverting input terminal of the operational amplifier is connected to drains of both the P-type transistor and the N-type transistor. Further, a predetermined reference voltage is applied to another of the inverting input terminal and the non-inverting input terminal.

Aspects disclosed herein eliminate audible disturbances that may occur when an audio amplifier is activated and deactivated. A feedback circuit is used to maintain a closed loop when transistors of a power output stage are activate or deactivated, thereby enabling the charge to build or dissipate without causing an audible disturbance. Further, in certain implementations, the power output stage may remain in an enable state for a period of time after deactivation of the audio amplifier regardless of whether an audio input signal is received enabling dissipation of charge without causing an audible disturbance.

Systems, apparatus, and methods are disclosed for processing biomedical signals. An electrophysiology (EP) system includes a differential circuit to process the biomedical signals; a differential amplifier circuit to amplify an output of the differential circuit; an analog-to-digital converter to digitize an output of the differential amplifier circuit; a communication module to interface between the analog-to-digital converter and a digital processing stage having a plurality of signal modules; and at least one processor to execute the plurality of signal modules, applying digital signal processing to the output from the analog-to-digital converter, to extract features of interest of the biomedical signals.

The present disclosure relates to a power amplifier (PA) system provided in a semiconductor device and having feed forward gain control. The PA system comprises a transmit path and control circuitry. The transmit path is configured to amplify an input radio frequency (RF) signal and comprises a first tank circuit and a PA stage. The control circuitry is configured to detect a power level associated with the input RF signal and control a first bias signal provided to the PA stage based on a first function of the power level and control a quality factor (Q) of the first tank circuit based on a second function of the power level.

Systems, methods, and computer program product embodiments are disclosed for performing electrophysiology (EP) signal processing. An embodiment includes an electrocardiogram (ECG) circuit board configured to process an ECG signal. The embodiment further includes a plurality of intracardiac (IC) circuit boards, each configured to process a corresponding IC signal. The embodiment further includes a communications interface communicatively coupled to a remote device, and a processor, coupled to the ECG circuit board, the plurality of IC circuit boards, and the communications interface. The processor is configured to receive, via the communications interface, feedback from the remote device. The processor is further configured to control, via the communication interface, the remote device based on the ECG signal, the IC signals, or the feedback from the remote device.

Systems, methods, and computer program product embodiments are disclosed for performing electrophysiology (EP) signal processing. An embodiment includes an electrocardiogram (ECG) circuit board configured to process an ECG signal. The embodiment further includes a plurality of intracardiac (IC) circuit boards, each configured to process a corresponding IC signal. The ECG circuit board and the plurality of IC circuit boards share substantially a same circuit configuration and components. The ECG circuit board further processes the ECG signal using substantially a same path as each IC circuit board uses to process its corresponding IC signal.