Abstract: Aspects are provided for positive displacement pumps and methods and systems for controlling such pumps for dispensing at a flow rate based on a downstream flow sensor. A pump controller determines a targeted motor speed for a flow rate set point based on a flow rate function. The pump controller determines a predicted movement time for a motor of the pump to change from a current motor speed to the targeted motor speed, a predicted wait time to reach a flow rate corresponding to the targeted motor speed, and a measurement time after the wait time. The pump controller controls the positive displacement pump according to consecutive control cycles, each control cycle includes a pump movement sub-cycle, a wait sub-cycle, and a measurement sub-cycle. The pump controller determines a measured flow rate during the measurement sub-cycle. A subsequent control cycle is based on the measured flow rate.

Abstract: Aspects are provided for positive displacement pumps and methods and systems for controlling such positive displacement pumps for accurate volume dispensing. The pump may run a calibration procedure to determine a mapping between a pump speed and a flow rate for a current configuration of the positive displacement pump, a tubing size, and a fluid characteristic. A pump controller may determine a pump motion profile based on the mapping. The pump motion profile includes an acceleration phase, a constant speed phase, and a deceleration phase such that a total volume pumped according to the pump motion profile and the mapping is equal to a target volume. The pump controller may determine an adjustment to the pump motion profile based on a constant flow rate measured during operation. The pump controller may decelerate the positive displacement pump according to the adjusted pump motion profile until the target volume is dispensed.

Abstract: Aspects are provided for positive displacement pumps and methods and systems for controlling such positive displacement pumps for accurate volume dispensing. The pump may run a calibration procedure to determine a mapping between a pump speed and a flow rate for a current configuration of the positive displacement pump, a tubing size, and a fluid characteristic. A pump controller may determine a pump motion profile based on the mapping. The pump motion profile includes an acceleration phase, a constant speed phase, and a deceleration phase such that a total volume pumped according to the pump motion profile and the mapping is equal to a target volume. The pump controller may determine an adjustment to the pump motion profile based on a constant flow rate measured during operation. The pump controller may decelerate the positive displacement pump according to the adjusted pump motion profile until the target volume is dispensed.

Abstract: Aspects are provided for positive displacement pumps and methods and systems for controlling such pumps for dispensing at a flow rate based on a downstream flow sensor. A pump controller determines a targeted motor speed for a flow rate set point based on a flow rate function. The pump controller determines a predicted movement time for a motor of the pump to change from a current motor speed to the targeted motor speed, a predicted wait time to reach a flow rate corresponding to the targeted motor speed, and a measurement time after the wait time. The pump controller controls the positive displacement pump according to consecutive control cycles, each control cycle includes a pump movement sub-cycle, a wait sub-cycle, and a measurement sub-cycle. The pump controller determines a measured flow rate during the measurement sub-cycle. A subsequent control cycle is based on the measured flow rate.

Abstract: A telecommunication device for the hearing impaired having the capability of sending text communications via a telephone-style keypad and receiving text communications for display on an LCD display in addition to providing standard telephone voice communications. The telecommunications device automates voice carryover (VCO) calls and for provides automatic answering and recording capability for text messages on the same telephone line as a voice answering machine and or a facsimile machine. The telecommunications device further includes means for selectively adjusting the amplification of received voice messages and sent voice messages to provide maximum amplification of said received voice messages without producing feedback oscillation or to provide maximum amplification of sent voice messages without producing feedback oscillation.