Abbott Laboratories Corporation

Entrack, Inc.

Icu Medical Inc.

Abbott Critical Care Systems

Timothy J Hughes

Mir A Imran

Ted W Layman

Harm TenHoff

Sharon L Lake

Olivier K Colliou

David A Gallup

John M Sperinde

Lina Derderian

Anthony J Pantages

James Howell Cobb

Jeffrey A Sarge

George H Fellingham

Alison Diana Burcar

Oliver K Colliou

Scott T Tsuchitani

Tom McCall

William A Ambrisco

David N Swingler

Lance B Koll

David Snider

Harm Tenhoff

A patient monitor configured to receive patient-information electrical signals from an invasive patient sensor and a minimally invasive patient sensor, the patient monitor including a base unit and a detachable user interface unit for displaying hemodynamic parameters determined by the base unit. The base unit and user interface unit can be docked together, tethered together through a cabled connection, or physically separated from one another using wireless communication to transmit and receive information. The base unit and the user interface unit may pair before the user interface unit displays data to link the base unit with the user interface unit. The patient monitor can be configured to switch between invasive and minimally invasive monitoring of hemodynamic parameters of a patient, using invasive measurements to calibrate minimally invasive measurements.

Hemodynamic monitoring system with detachable display unit

A gatekeeper electronic signal can be generated by a patient sensor and/or in an intermediate device, such as an electrical cable, that is separate from a patient's physiological information electronic signal. The gatekeeper signal can be generated to indicate to a computer monitor that the sensor and/or cable is of the type that is compatible with, and/or usable with, such computer monitor, and/or that the sensor and/or cable is properly attached to the computer monitor. The gatekeeper signal can be created by an ambient temperature sensor on, or in electrical communication with, the patient monitor, and/or the gatekeeper signal can be created by a gatekeeper electronic signal generator to simulate an ambient temperature value. The gatekeeper signal can be separate from an electronic signal or plurality of signals that include patient physiological information, and the gatekeeper signal may not include any patient physiological information.

Patient monitoring system with gatekeeper signal

A device and method for mapping, diagnosing and treating the intestinal tract is provided using a capsule passing through the intestinal tract. Further, a capsule tracking system is provided for tracking a capsule's location along the length of an intestinal tract as various treatment and/or sensing modalities are employed. In one variation, an acoustic signal is used to determine the location of the capsule. A map of sensed information may be derived from the pass of a capsule. Capsules may be subsequently passed through to treat the intestinal tract at a determined location along its length. One variation uses an electrical stimulation capsule to treat and/or diagnose a condition in the intestinal tract.

System for marking a location for treatment within the gastrointestinal tract

Capsule and method for treating or diagnosing the intestinal tract

A multi-lumen, multi-purpose cardiac catheter which incorporates optical filaments and an optical coupler for use with external apparatus for determining the oxygen concentration in the blood of a patient under critical care conditions, as well as incorporating therein a thermal element useable with a second external apparatus for measurement of continuous cardiac output. A thermal plug provides an interface between a temperature control apparatus and the thermal element to simply and accurately monitor and control the temperature of the thermal element. A temperature monitoring circuit in the thermal plug facilitates temperature measurement at the thermal element. The catheter also includes a thermistor and at least one injectate port for enabling the user to also conduct thermal dilution readings and obtain intermittent measurements of cardiac output. The combination of a thermal dilution catheter with a SV0.sub.2 catheter and a continuous cardiac output catheter gives the multi-purpose catheter above described substantial versatility as well as providing the user with a versatile cardiac catheter device which enables him to conduct multiple evaluations of disparate blood-related parameters which require the use of separate apparatus. Simply by switching from one external apparatus to the other, the user can obtain readings for different blood-related parameters useful in the treatment of the cardiac patient.

Multi-purpose multi-parameter cardiac catheter

A method and apparatus for correcting thermal drift in cardiac output measurements based upon a temperature signal indicative of the change in temperature of blood leaving the heart is disclosed. In a first preferred embodiment of a cardiac output monitoring system (10), the catheter (14) is provided with an electrical resistance heater (22). An electrical current having a sinusoidal waveform with a period of from 30 to 60 seconds is applied to the heater, causing power to be dissipated into the blood within a patient's heart (12). A temperature sensor (24) disposed near a distal end of the catheter produces a signal indicative of the temperature of blood leaving the heart. The temperature signal and the signal corresponding to the electrical power dissipated in the heater (an input signal) are filtered at a frequency .omega.n corresponding to the frequency of the applied electrical current, i.e., the frequency of the input signal. An output signal indicative of the temperature of the blood leaving the heart corrected for the effects of thermal drift is then calculated. The blood temperature output signal is first split into two equal overlapping time periods. The two signals are then filtered separately to produce two partially independent output signals in the frequency domain. These two frequency domain output signals are then combined into a single corrected frequency domain output signal with the effects of thermal drift removed. The amplitude of the input power, the amplitude of the temperature signal corrected for thermal drift, and their phase difference are then used in calculating cardiac output.

Method for correcting thermal drift in cardiac output determination

A multi-lumen, multi-purpose cardiac catheter which incorporates optical filaments and an optical coupler for use with external apparatus for determining the oxygen concentration in the blood of a patient under critical care conditions, as well as incorporating therein a thermal element useable with a second external apparatus for measurement of continuous cardiac output. The thermal element is disposed at a necked down portion of the catheter at the distal end thereof, with at least one of the lumens of the catheter substantially compressed at the necked down portion thereof. The catheter also includes a thermistor and at least one injectate port for enabling the user to also conduct thermal dilution readings and obtain intermittent measurements of cardiac output. The combination of a thermal dilution catheter with a SVO.sub.2 catheter and a continuous cardiac output catheter gives the multi-purpose catheter above described substantial versatility as well as providing the user with a versatile cardiac catheter device which enables him to conduct multiple evaluations of disparate blood-related parameters which require the use of separate apparatus. Simply by switching from one external apparatus to the other, the user can obtain readings for different blood-related parameters useful in the treatment of the cardiac patient.

A method of using a heated catheter for monitoring cardiac output. Displaced from a distal end of a heated catheter (30) is a resistive heater (39) that heats blood flowing within a heart muscle (10). The resistive heater is mounted on the catheter so that when the catheter is inserted into the heart, the resistive heater is disposed in the right ventricle. A temperature sensor (34) is disposed downstream of the resistive heater, in or proximate the pulmonary artery during use. The temperature of the resistive heater is monitored using the temperature sensor to prevent the temperature from exceeding a predetermined level. A differential amplifier (40, 70) provides an electrical current to the resistive heater that varies as a function of the difference between the temperature of the resistive heater, measured by a temperature sensor (35), and a predetermined temperature. In another embodiment of the invention, a resistive heater (90) has a resistance that varies with temperature. The resistive heater comprises one arm of a bridge circuit (85). A differential amplifier (110) provides an electrical current to the bridge circuit in response to the voltage developed across the bridge circuit. In yet another embodiment, a constant power dissipation is maintained in a resistive heater (60), so long as its temperature does not exceed a predetermined maximum. Should that occur, a power control block (80) incrementally reduces the power dissipated in the resistive heater, thereby insuring that the temperature of the resistive heater does not damage blood cells, yet is sufficient to provide a good signal-to-noise ratio in respect to a signal indicative of the temperature rise in blood flowing from the heart.

Method for monitoring cardiac output and protecting blood and tissue

A multi-lumen, multi-purpose cardiac catheter which incorporates optical filaments and an optical coupler for use with external apparatus for determining the oxygen concentration in the blood of a patient under critical care conditions, as well as incorporating therein a heater coil useable with a second external apparatus for measurement of continuous cardiac output. The catheter also includes a thermistor and at least one injectate port for enabling the user to also conduct thermal dilution readings and obtain intermittent measurements of cardiac output. The combination of a thermal dilution catheter with a SVO.sub.2 catheter and a continuous cardiac output catheter gives the multi-purpose catheter above described substantial versatility as well as providing the user with a versatile cardiac catheter device which enables him to conduct multiple evaluations of disparate blood-related parameters which require the use of separate apparatus. Simply by switching from one external apparatus to the other, the user can obtain readings for different blood-related parameters useful in the treatment of the cardiac patient.

A method and apparatus for correcting thermal drift in cardiac output measurements based upon a temperature signal indicative of the change in temperature of blood leaving the heart is disclosed. In a first preferred embodiment of a cardiac output monitoring system(10), the catheter(14) is provided with an electrical resistance heater (22). An electrical current having a sinusoidal waveform with a period of from 30 to 60 seconds is applied to the heater, causing power to be dissipated into the blood within a patient's heart (12). A temperature sensor (24) disposed near a distal end of the catheter produces a signal indicative of the temperature of blood leaving the heart. The temperature signal and the signal corresponding to the electrical power dissipated in the heater (an input signal) are filtered at a frequency .omega. corresponding to the frequency of the applied electrical current, i.e., the frequency of the input signal. An output signal indicative of the temperature of the blood leaving the heart, corrected for the effects of thermal drift, is then determined. The corrected cardiac output signal is determined by first determining a drift slope of the blood temperature signal due to thermal drift. The drift slope is then used to produce a signal corrected for thermal drift. Cardiac output is determined as a function of the amplitude of the input power, the amplitude of the signal corrected for thermal drift, and their phase difference.

Correcting thermal drift in cardiac output determination

A method and apparatus for continuously monitoring cardiac output based upon the phase shift between an input signal and a temperature signal indicative of the change in temperature of blood leaving the heart. In a first preferred embodiment of a cardiac output monitoring system (10), a catheter (14) is provided with an electrical resistance heater (22). An electrical current having a sinusoidal wave form with a period of from 30 to 60 seconds is applied to the heater, causing power to be dissipated into the blood within a patient's heart (12). A temperature sensor (24) disposed near a distal end of the catheter produces a signal indicative of the temperature of blood leaving the heart. The temperature signal and the signal corresponding to the electrical power dissipated in the heater (an input signal) are filtered at a frequency .omega. corresponding to the frequency of the applied electrical current, i.e., the frequency of the input signal. The amplitude of the input power, the amplitude of the temperature signal, and their phase difference are used in calculating cardiac output. In another embodiment, a temperature conditioned saline solution (84 ) is circulated through a catheter (14') in a closed loop, so that it flows through a heat exchanger (60) disposed within the heart. The fluid is circulated through the catheter on a periodic basis, providing a periodic input signal. The temperature signal produced by the temperature sensor on the catheter distal end and power dissipated to or absorbed from the blood by the heat exchanger comprise the two signals from which the cardiac output is determined as described above. The determination of cardiac output is also corrected for the time constant of the catheter/heater (or heat exchanger) and of the temperature sensor.

Method for continuously monitoring cardiac output

A heated catheter for monitoring cardiac output. Displaced from a distal end of a heated catheter (30) is a resistive heater (32) that heats blood flowing within a heart muscle (10). The resistive heater is mounted on the catheter so that when the catheter is inserted into the heart, the resistive heater is disposed in the right ventricle. A temperature sensor (34) is disposed downstream of the resistive heater, in or proximate the pulmonary artery during use. A differential amplifier (40, 70) provides an electrical current to the resistive heater that varies as a function of the difference between the temperature of the resistive heater, measured by a temperature sensor (35), and a predetermined temperature. In another embodiment of the invention, a resistive heater (90) has a resistance that varies with temperature. The resistive heater comprises one arm of a bridge circuit (85). A differential amplifier (110) provides an electrical current to the bridge circuit in response to the voltage developed across the bridge circuit. In yet another embodiment, a constant power dissipation is maintained in a resistive heater (60 ), so long as its temperature does not exceed a predetermined maximum. Should that occur, a power control block (80) incrementally reduces the power dissipated in the resistive heater, thereby insuring that the temperature of the resistive heater does not damage blood cells, yet is sufficient to provide a good signal-to-noise ratio in respect to a signal indicative of the temperature rise in blood flowing from the heart.

Growing community of inventors

Palo Alto, CA, United States of America

Timothy J Hughes