Baxter International Inc.

Sharp Kabushiki Kaisha Corporation

Honeywell G.m.b.h.

George A Bowman

Joseph B Matthews

Kurt Eyster

Edmund D D'Silva

Masafumi Kawahara

Grace M Esche

Eiichi Sakai

Leonard F Goloski, Sr

Nobuaki Goi

The present invention provides an apparatus for detecting excessive air in a liquid flow-through tube. The apparatus includes an ultrasonic transmitter for transmitting ultrasonic signals and an ultrasonic receiver for receiving ultrasonic signals. The ultrasonic transmitter and ultrasonic receiver are separated by the IV tube. The apparatus further provides circuit means for generating at least two transmitting signals to actuate the ultrasonic transmitter and circuit means for detecting received signals. Means are provided for determining whether the received signal is indicative of air or liquid in the IV tube. The apparatus further relies on logarithmic detection of air in fluids rather than linear detection which provides a larger safety factor in prediction of air embolus.

Air detector

Air detector for intravenous infusion system

The present invention provides an estimate of the amount of time left on the battery by monitoring not only the voltage available from the battery, but also the amount of current flowing from the battery. It has been found that periodic sampling of the battery voltage and current drain enables accurate battery monitoring. The sampling technique alternates between sampling battery voltage and sampling current drain. An electric circuit is provided which enables the cost-effective sampling to occur. A method is then applied to the sampling signals by a microprocessor which determines the amount of time left under battery power. In a preferred embodiment, a graphic representation is provided of the amount of battery time left.

Battery gauge for a battery operated infusion pump

The present invention provides an improved, low cost method and apparatus for monitoring the intravenous metering of fluids to a patient. The present invention provides a strain gauge which is preferably a balanced metal beam. Conditioning circuitry is provided which has as input the strain gauge output. The output of the conditioning circuit is inputted into occlusion sensing circuit. The output of occlusion sensing circuit is inputted into an air sensing circuit. The output of both the occlusion sensing circuit and the air sensing circuit are inputted into an analog to digital convertor which is monitored by a microprocessor for abnormal signals.

Intravenous metering monitoring device

A rotary encoder comprises a rotary plate having a plurality of primary slits defined in the rotary plate in a circular row coaxial with the axis of rotation of the rotary plate. The rotary plate also has at least one reference slit defined therein at a position radially of the circular row of the primary slits. A primary photoelectric detector including a source of light and a photo-sensor positioned one above the other with the circular row of the primary slits intervening therebetween is used to detect the passage of the primary slits therethrough while an auxiliary photoelectric detector including a source of light and a photo-sensor positioned one above the other with the path of travel of the reference slit intervening therebetween is used to detect the passage of the reference slit therethrough.

Peristaltic pump with rotary encoder

The present invention provides a drive signal for a peristaltic pump motor. A first circuit is provided which generates a first series of pulses at a given frequency. A second circuit is provided which generates a second series of pulses having a frequency higher than the frequency of the first series of pulses. A third circuit is provided which generates a third series of pulses having a frequency between the frequency of the first and second series of pulses. Finally, a circuit is provided which combines the three series of pulses into a drive signal. The drive signal length is determined by the frequency of the first series of pulses. The drive signal further is divided into two sections, an initial pulse stage determined by the frequency of the third series of pulses, and a modulated pulse stage being a series of pulses determined by the frequency of the second series of pulses.

Peristaltic pump motor drive

An air detector according to the present invention utilizes a unitary type sensor for detecting air bubbles or columns in an infusion solution flowing through a tube. Because of a unique design for a tube-receiving groove and a cooperating abutting member, the difficulty in loading a tube heretofore encountered with the use of unitary type sensor is obviated. Thus, the tube can be loaded in the air detector easily with good reliability.

Air detector for use in infusion pump

A stepping motor driving apparatus includes a stepping motor and a pulse output circuit for outputting drive pulses for driving the stepping motor. A pulse generator generates further pulses which not only have frequency higher than that of the drive pulses but are capable of a variable duty factor at the frequency of the further pulses. A gate circuit receives the drive pulses from the pulse output circuit and the further pulses from the pulse generator so as to output the further pulses of the pulse generator during excitation of the drive pulses such that the stepping motor is driven by the further pulses outputted from the gate circuit.

Steeping motor driving apparatus

An encoder wheel (60) is provided for monitoring a peristaltic pump (20). The encoder wheel (60) provides a plurality of equispaced sectors (62) and a reference sector (66) provided at the outer radius of the encoder wheel (60). A vane slit (68) is provide radially offset from the sectors (62,66). A pair of optical couplers (72,74) are provided to read the sectors (62,66) and the vane slit (68).

Peristaltic pump monitoring device

A modem for transmitting and receiving digital information includes an oscillator, a switch connected to both the oscillator and to a data input for switchably controlling the oscillator to impress data on a transmission channel, and a receiver also connected to the transmission channel for receiving data thereon to demodulate the data and supply it to a processor.

Data transceiving modem

A wireless superheterodyne receiver is provided having an antenna for receiving wireless transmissions, a preamplifier having an input connected to the antenna and an output, a crystal filter having an input connected to the output of the preamplifier and an output, a demodulator having an input connected to the output of the filter, the demodulator having a single mixer, an oscillator having a second crystal connected to the single mixer of the demodulator wherein the demodulator supplies at an output a demodulated signal based upon the wireless transmissions.

Wireless receiver having crystal filter at outputs of preamplifier

A modem for transmitting data over one frequency and receiving data over another frequency is disclosed having an oscillator for generating a first signal, a voltage controlled oscillator for generating a second signal, a mixer for mixing the first and second signals to provide a mixer output signal having the transmission frequency, an input data switch for modulating the mixer output signal in accordance with input data, a second mixer connected to the voltage controlled oscillator and to the received incoming signal and a receiver for demodulating the received signal data.

Growing community of inventors

Vernon Hills, IL, United States of America

George A Bowman