Methods and apparatus, such as a controller of a respiratory therapy device, generate a signal representing an estimate of flow rate of gas flow from the device. The respiratory therapy device may include a motor-operated blower. The method may include receiving in the controller, signals generated by a set of sensors, including measures of pressure and frequency (e.g., speed) of the motor. The controller may be configured to compute an entrained air density function and generate the estimate signal based on a function of the measures of pressure and frequency, and the entrained air density function. The entrained air density function may apply signals from additional sensors, such as atmospheric pressure, gas temperature, and ambient relative humidity, to compute atmospheric density. Control operations of the therapy device may then be based on the estimated signal, which may be applied to assess accuracy of a signal from a flow sensor.

A system adapted to regulate pressure of a flow of breathable gas generated by a motorized blower fan. The system may include a flow estimation analyzer adapted to receive a speed signal representative of a speed of the fan and estimate a parameter representative of the flow of breathable gas (e.g., a flow rate of the breathable gas). The parameter may be determined by inputting the speed signal into a function (e.g., an equation, matrix, or lookup table), which may be selected from a plurality of predetermined functions. The predetermined function may be selected based upon a specific characteristic of the speed signal as identified at the time of estimation of the parameter representative of flow.

A control device (100) for controlling the rotational speed (n.sub.VAD(t)) of a non-pulsatile ventricular assist device, VAD, (50) uses an event-based within-a-beat control strategy, wherein the control device is configured to alter the rotational speed of the VAD within the cardiac cycle of the assisted heart and to synchronize the alteration of the rotational speed with the heartbeat by at least one sequence of trigger signals (σ(t)) that is related to at least one predetermined characteristic event in the cardiac cycle. Further, a VAD (50) for assistance of a heart comprises the control device (100) for controlling the VAD, wherein the VAD is preferably a non-pulsatile rotational, for example catheter-based, blood pump.

A controller implantable within the body of a patient as part of a left ventricular assist device (LVAD) system and a method therefore are provided. According to one aspect, the controller includes processing circuitry configured to receive inputs from at least one of: at least one internal component of the LVAD system, at least one external component of the LVAD system, and at least one clinician's device, and determine a charging rate for charging a battery of the LVAD system internal to the patient based on at least one of the received inputs.

A patient interface for sealed delivery of a flow of air to ameliorate sleep disordered breathing may include: a seal-forming structure to form a pneumatic seal with the entrance to the patient's airways; a positioning and stabilising structure to maintain the seal-forming structure in sealing contact with an area surrounding the entrance to the patient's airways; a plenum chamber pressurised at a pressure above ambient pressure in use; a connection port for the delivery of the flow of breathable gas into the patient interface; and a device positioned within a breathing chamber defined, at least in part, by the seal-forming structure and the plenum chamber, wherein the device divides the breathing chamber into a posterior chamber and an anterior chamber, and wherein the device comprises a plurality of apertures such that turbulence of the air in the posterior chamber is less than turbulence in the air in the anterior chamber.

Electromechanical actuation systems and related operating methods are provided. A method of controlling an electromechanical actuator in response to an input command signal at an input terminal involves determining a commanded actuation state value based on a characteristic of the input command signal, generating driver command signals based on the commanded actuation state value and an actuator type associated with the electromechanical actuator, and operating driver circuitry in accordance with the driver command signals to provide output signals at output terminals coupled to the electromechanical actuator.

A method of compressing tissue during a surgical procedure is disclosed. The method comprises obtaining a surgical instrument comprising an end effector, wherein the end effector comprises a first jaw and a second jaw, establishing a communication pathway between the surgical instrument and a surgical hub, and inserting the surgical instrument into a surgical site. The method further comprises compressing tissue between the first jaw and the second jaw, determining a location of the compressed tissue with respect to at least one of the first jaw and the second jaw, communicating the determined location of the compressed tissue to the surgical hub, and displaying the determined location of the compressed tissue on a visual feedback device.

Electromechanical actuation systems and related operating methods are provided. A method of controlling an electromechanical actuator in response to an input command signal at an input terminal involves determining a commanded actuation state value based on a characteristic of the input command signal, generating driver command signals based on the commanded actuation state value and an actuator type associated with the electromechanical actuator, and operating driver circuitry in accordance with the driver command signals to provide output signals at output terminals coupled to the electromechanical actuator.

The systems and methods described herein determine metrics of cardiac or vascular performance, such as cardiac output, and can use the metrics to determine appropriate levels of mechanical circulatory support to be provided to the patient. The systems and methods described determine cardiac performance by determining aortic pressure measurements (or other physiologic measurements) within a single heartbeat or across multiple heartbeats and using such measurements in conjunction with flow estimations or flow measurements made during the single heartbeat or multiple heartbeats to determine the cardiac performance, including determining the cardiac output. By utilizing a mechanical circulatory support system placed within the vasculature, the need to place a separate measurement device within a patient is reduced or eliminated. The system and methods described herein may characterize cardiac performance without altering the operation of the heart pump (e.g., without increasing or decreasing pump speed).

The present disclosure provides a new and innovative method and system for flow rate compensation in devices, such as medical devices and other electronic devices. In various embodiments, a computer-implemented method includes dispensing, by a pump controlled by a controller, a fluid from a fluid supply in a pulse mode over a period by determining a pulse volume for a pulse, determining a pulse cycle time, and for the period: controlling the position of the pump to perform a delay and perform a pulse to dispense an amount of the fluid, the pulse performed for the pulse cycle time, calculating an overshoot or undershoot of the amount of the fluid dispensed relative to the pulse volume, adjusting the pulse cycle time based on the calculated overshoot or undershoot, and repeating the dispensing until the period has elapsed.