Optical Sensors, Inc.

Vasamed, Inc.

Exostat Medical, Inc.

Institute of Critical Care Medicine

Victor E Kimball

Irvin T Pierskalla

Christopher H Porter

Kent R Winger

Brandon W Reynolds

Paulita M LaPlante

Laurie E Lynch

Steven Charles Furlong, Sr

Daniel J Bartnik

Paul Hindrichs

Max Harry Weil

Wanchun Tang

Jose Bisera

Richard L Summers

Rochell S Gifford

Brian E Honebrink

The invention provides a device for contacting a surface of a patient's body to determine a physiologic parameter in a measurement region of a tissue of the patient. The device typically comprises a sensor responsive to the physiologic parameter and a probe housing the sensor. The probe is constructed to allow the sensor to be secured at a sensing site adjacent to the measurement region, without disturbing the blood flow within the measurement region of the tissue. The device may also include a means for reducing interference in the sensing area. Preferably, the device further comprises an indicating means operably connected to the sensor for indicating an analyte quantity and/or concentration associated with the physiologic parameter.

Detection of a physiologic parameter with a probe

The invention provides a device for contacting a surface of a tissue within a patient's body to determine a physiologic parameter of the patient. The device typically comprises a sensor responsive to the physiologic parameter and a probe housing the sensor. The probe is constructed to allow the sensor to be secured at a sensing area adjacent to a surface of a patient's tissue, without need for an adhesive and without disturbing the blood flow within the measurement region of the tissue. The device may also include a means for reducing interference in the sensing area. Preferably, the device further comprises an indicating means operably connected to the sensor for indicating an analyte quantity and/or concentration associated with the physiologic parameter. The invention also provides a method for determining a physiologic parameter of a patient.

Noninvasive detection of a physiologic parameter within a body tissue of a patient

A cardiography system and method using automated recognition of hemodynamic parameters and waveform attributes is provided. The cardiography system and method includes at least one sensor, a knowledge base and a processing device. The at least one sensor provides a waveform signal and a hemodynamic parameter input. The knowledge base includes data corresponding to various disease states. The processing device receives the waveform signal and hemodynamic parameter input from the sensor, identifies waveform attributes on the waveform signal, measures the waveform attributes, accesses the knowledge base, cross-references the waveform attributes and the hemodynamic parameters with data in the knowledge base, and outputs a suggested likelihood of a particular disease state. The knowledge base optionally includes goal-directed therapies associated with particular disease states for providing suggested goal-directed therapies based on the cross-referencing of the waveform attributes and the hemodynamic parameters with the knowledge base.

Cardiography system and method using automated recognition of hemodynamic parameters and waveform attributes

A device for assessing capillary vitality comprises an inflatable cuff, a blood flow sensor and a pressure sensor in communication with the cuff, a pressure instrument in fluid communication with the cuff for inflation and deflation thereof, a microprocessor coupled to the pressure instrument for controlling airflow, at least one metabolic sensor for measuring a metabolic condition, and a computer program executable by the microprocessor. The pressure instrument includes a source of pressurized air and a conduit connecting the source of pressurized air to the cuff. The microprocessor is arranged to receive inputs from the blood flow, pressure and metabolic sensors. When executed by the microprocessor, the computer program causes the microprocessor to initiate an automatic inflation sequence resulting in a no flow condition, initiate an automatic deflation sequence, automatically qualify a perfusion measurement as an SPP value upon one or more conditions being met during the deflation sequence, and initiate the measurement of at least one metabolic factor.

System and method for assessing capillary vitality

A device is provided for assessing impairment of blood circulation in a patient, such as that in perfusion failure, by measurement of blood flow adjacent a mucosal surface accessible by a mouth or nose and connecting with the gastrointestinal tract or upper respiratory/digestive tract of a patient. The device includes a blood-flow sensor adapted to be positioned adjacent a mucosal surface with a patient's body and measuring blood flow in adjacent tissue and a PCO.sub.2 sensor adapted to be positioned adjacent the mucosal surface and measuring PCO.sub.2. In addition a pH sensor may be used in combination with the blood flow determination. A method of detecting perfusion failure is also disclosed. The method includes utilizing blood-flow measurements in conjunction with a surface perfusion pressure index and/or an optical plethysmography index to more accurately assess perfusion failure. These measurements may also be supplement by taking measurements of pH, sublingual PCO.sub.2, and Sa O.sub.2. The invention affords rapid measurement and detection of perfusion failure.

Device for assessing perfusion failure in a patient by measurement of blood flow

There is a need within the medical community for non-invasive instruments to measure critical physiologic parameters at the point of care. Such a technique may be applicable to a wide variety of commonly monitored physiologic parameters during critical care patient management. The invention is directed to a method of measuring the pH of a patient's tissue. The method includes measuring the optical signal from a specie whose fluorescence is pH sensitive, such as nicotinamide adenine dinucleotide (NADH) and also measuring the optical signal from a second biological marker, such as FAD, the fluorescence from the second marker being substantially insensitive to pH. The method includes determining the patient's pH by using the first and second optical signals.

Non-invasive measurement of pH

There is a need for a technique to compensate for, or eliminate, motion-induced artifacts in patient-attached critical care monitoring instruments. Consequently, the invention is directed to improving pulse-oximetry by incorporating additional signals to aid in the triggering of the pulse-oximeter or in analyzing the data received by the pulse oximeter. This includes detecting when the patient moves and analyzing the pulse-oximetry data in light of the detected movement.

Pulse oximeter with motion detection

There is a need for a non-invasive method of calibrating medical devices at the point of care, where the calibration is performed without the removal of blood or bodily fluids. The invention is directed to an approach for calibrating a first non-invasive sensor in which the tissue being measured is modulated in some way so as to after the value of the parameter being measured by the first optical sensor. A second sensor detects another parameter that also changes with the modulation. The second sensor is absolutely calibrated. Where there is a known relationship between the first and second parameters, a calibration may be derived for the first sensor. Such a technique is applicable to calibrating non-invasive sensors for monitoring a wide variety of physiologic parameters including, inter alia, glucose, blood gases, blood electrolytes and blood pH.

Calibration technique for non-invasive medical devices

There is a need for a technique to compensate for, or eliminate, motion-induced artifacts in patient-attached critical care monitoring instruments. Also, a need exists to extend the accurate operational range of patient-attached pulse oximeters in environments when the patient's blood oxygen saturation is well below the normal physiologic range, or where there is low blood flow. Accordingly, the invention is directed to improving pulse-oximetry by incorporating additional signals to aid in the triggering of the pulse-oximeter or in analyzing the data received by the pulse oximeter. These approaches include measuring a pulsatile characteristic of the patient at a position close to, or at the pulse-oximetry measurement site, or using pulsatile characteristics that result from contraction of the patient's heart.

Pulse oximeter

The invention relates to a cartridge for packaging an analyte-containing fluid calibrant. The cartridge is formed from a container having an opening sealed by a sealing member. A septum divides the container into a calibrant compartment and an outer compartment. A probe is provided comprising an analyte-detecting portion and a connecting portion that allows for operative connection to a device for quantitating or determining the concentration of the analyte. The probe may extend sealingly through the septum such that the analyte-detecting portion is located in the calibrant compartment and the connecting portion is located in the outer compartment. The construction of the cartridge provides ease and reduces the likelihood of error in calibrating the probe. The invention also relates to a method of manufacturing the cartridge and a method for calibrating a device for analyte concentration determination and quantitation using the inventive cartridge.

Cartridge for packaging a sensor in a fluid calibrant

Methods and devices are provided for assessing impairment of blood circulation in a patient, such as that in perfusion failure, by measurement of blood flow in the gastrointestinal tract or upper respiratory/digestive tract of the patient. The method comprises introducing a blood-flow sensor into the gastrointestinal tract or the upper respiratory/digestive tract of a patient, placing the sensor adjacent a mucosal surface therein, and measuring blood flow in adjacent tissue to determine blood flow in that tissue. The method may also involve measurement of PCO,and/or pH in combination with the blood flow determination. The invention affords rapid measurement and detection of perfusion failure.

Method and device for assessing perfusion failure in a patient by measurement of blood flow

A method is provided for calibrating sensors used to analyze characteristics of physiologic fluids such as blood. The method involves the use of a sensor assembly having an analyte-responsive sensor in communication with a passageway which is in divertable fluid communication with a physiologic line and a conduit by which a reference sample may be introduced into the passageway. The method involves exposing the sensor to the reference sample, thereby producing a sensor response. The method also allows performing quality control on the sensors. Also provided is an apparatus with which the claimed method may be practiced.

In situ calibration system for sensors located in a physiologic line

A cartridge assembly is provided for analyzing characteristics of a sample fluid. The cartridge assembly comprises an assembly body having a passageway, a cavity and, interposed between the passageway and the cavity, a manifold containing a port that serves as a feedthrough between the cavity and the passageway. The passageway forms a flow path through which the sample is drawn. The cartridge assembly also comprises a sensor responsive to a characteristic of the sample fluid. The sensor is housed in the assembly body cavity and is in communication with the passageway by way of the port in the manifold. Optionally, the cartridge assembly includes a temperature monitoring means and a heating means in thermal communication with the passageway. In addition, a method is provided in which the cartridge assembly is used for analyzing a characteristic of a sample. A bedside system for monitoring characteristics of a physiologic fluid comprising the cartridge assembly is provided as well.

Disposable cartridge assembly with optional integrated temperature

A device is provided for maintaining a volume of gas dissolved in a fluid at a predetermined partial pressure. The device includes a first sealable, gas-tight pouch containing the fluid and a second sealable, gas-tight pouch encasing the first pouch and providing a space between the first and second pouches. The space may be charged with an atmosphere containing a volume of the gas dissolved in the fluid that is greater than the volume of dissolved gas, at a partial pressure that is substantially the same as the partial pressure of the dissolved gas. A method is also provided for using the device to maintain a volume of a gas dissolved in a fluid at a predetermined partial pressure.

Growing community of inventors

Burnsville, MN, United States of America

Victor E Kimball