135 results about "Blood gas test" patented technology

A method and apparatus for the transcutaneous monitoring of blood gases generally comprises a blood gas data acquisition device, a vacuum source and a blood gas transducer unit. The blood gas transducer unit is adapted for application to a patient's skin and administration of a local vacuum at the area of patient application. It further comprises an electrochemical blood gas transducer, well known to those of ordinary skill in the art, which is disposed entirely within the local vacuum at the area of patient application. The vacuum source is placed in fluid communication with the blood gas transducer unit, through a hydrophobic membrane filter for safety purposes, in order to induce a condition of hyperperfusion in the locality of the electrochemical blood gas transducer. Under the control of a microcontroller, or equivalent means, the blood gas acquisition device is then utilized to capture a measure of skin surface oxygen or carbon dioxide pressure. The microcontroller can then utilize this measure to arrive at an estimate of arterial partial pressure of oxygen or carbon dioxide, accordingly. Because vacuum induced perfusion produces the requisite condition of hyperperfusion without local heating and, therefore, without acceleration of the local metabolic function, the present invention results in more accurate than previously available estimates of partial pressure blood gas pressures and does so while eliminating a significant risk for injury to the patient.

The present invention is directed towards apparatuses and methods for the automated measurement of blood analytes and blood parameters for bedside monitoring of patient blood chemistry. Particularly, the current invention discloses a programmable system that can automatically draw blood samples at a suitable programmable time frequency (or at predetermined timing), can automatically analyze the drawn blood samples and immediately measure and display blood parameters such as glucose levels, hematocrit levels, hemoglobin blood oxygen saturation, blood gases, lactate or any other blood parameter.

The present invention is directed towards apparatuses and methods for the automated measurement of blood analytes and blood parameters for bedside monitoring of patient blood chemistry. Particularly, the current invention discloses a programmable system that can automatically draw blood samples at a suitable programmable time frequency (or at predetermined timing), can automatically analyze the drawn blood samples and immediately measure and display blood parameters such as glucose levels, hematocrit levels, hemoglobin blood oxygen saturation, blood gases, lactate or any other blood parameter.

A stimulation device is provided that stimulates breathing to manipulate blood gas concentrations such as SaO₂ or PCO₂ and thereby treat underlying causes of breathing disorders and heart failure progression. A programmable device is provided for setting diaphragm stimulation waveforms that adjust minute ventilation about a predetermined baseline value. Normal breathing of the subject is observed to establish a baseline reference minute ventilation, and the device is programmed to produce stimulation waveforms that may provide either a decrease or an increase in the patients minute ventilation. The minute ventilation of the subject may be decreased or increased from the baseline level by decreasing or increasing a parameter that changes minute ventilators.

A compact device (20) for non-invasively monitoring concentration levels of blood constituents, including glucose, cholesterol, alcohol, blood gases and various ions. The device includes a finger receptor (140) having a channel for receiving a finger of a user. The channel has a light entrance and a light exit so that light can be passed from a light source (91) through a finger located in the channel in a direction generally normal to the finger. Certain heat generating components, including a stable power supply for the device, are external to the device housing so as to reduce heat generation and thereby increase stability of the device. The device includes a communications interface for interacting with a computer. The device can be used for clinical use or for home use and the memory of the computer can be used to assist with record keeping and with dosage calculations.

Methods and systems for diagnosing disorders, including, for example, disordered breathing, involve sensing one or more of a blood chemistry parameter and/or an expired gas parameter, such as expired respiratory gas concentration, blood gas concentration, and blood pH. Diagnosis of the disorder may be performed by a medical device, such as a respiratory therapy device or a cardiac therapy device, based on implantably detected blood gas/pH concentration/level or externally detected expired respiratory gas concentration. Cardiac and respiratory therapies for addressing the disorder may be adjusted based on the detected parameters.

The present invention provides a method for determining at least one evaluation parameter of a blood sample, comprising the following steps: providing (S4) at least one blood gas parameter; providing (S5) at least one hemostasis parameter; and determining (S6 . . . 310″) the at least one evaluation parameter as a function of the blood gas parameter and/or the hemostasis parameter.

A method for non-invasively determining pulmonary characteristics by measuring breath gas and blood gas and a display apparatus for the same, and for estimating major physiological characteristics, such as respiratory characteristics of lungs-pulmonary circulation system, cardiac functional characteristics, structural characteristics of lungs, etc. by applying primary measurement parameters obtained from ventilation gas and blood during breathing; and a display apparatus useful for the same.

A disposable, integrated extracorporeal blood circuit employed during cardiopulmonary bypass surgery performs gas exchange, heat transfer, and microemboli filtering functions in a way as to conserve volume, to reduce setup and change out times, to eliminate a venous blood reservoir, and to substantially reduce blood-air interface. Blood from the patient or prime solution is routed through an air removal device that is equipped with air sensors for detection of air. An active air removal controller removes detected air from blood in the air removal device. A disposable circuit support module is used to mount the components of the disposable, integrated extracorporeal blood circuit in close proximity and in a desirable spatial relationship to optimize priming and use of the disposable, integrated extracorporeal blood circuit. A reusable circuit holder supports the disposable circuit support module in relation to a prime solution source, the active air removal controller and other components.

Positioning of the distal end of a catheter at a desired location, for example, in the desired atrium of a patient's heart, can be determined or verified through measurement of blood gas values proximate to the distal end. In one embodiment, an oximeter is used to monitor oxygen saturation, for example, to distinguish between de-oxygenated venous blood and well-oxygenated arterial blood. Optical signals may be transmitted to the distal end of the catheter and received therefrom via optical fibers. Specifically, a catheter (300) has a number of optical fiber ends (308, 310 and 312) disposed at a distal end (304) thereof. A first fiber end (310) transmits the red and infrared optical signals. Fiber ends (308 and 312) are used for detecting reflected optical signals. The optical signals are then processed by a detector and an oximeter instrument to provide oxygen saturation readings that can indicate the position of the distal end of the catheter within the patient's heart or successful penetration of the interatrial septum.

A disposable, integrated extracorporeal blood circuit employed during cardiopulmonary bypass surgery performs gas exchange, heat transfer, and microemboli filtering functions in a way as to conserve volume, to reduce setup and change out times, to eliminate a venous blood reservoir, and to substantially reduce blood-air interface. Blood from the patient or prime solution is routed through an air removal device that is equipped with air sensors for detection of air. An active air removal controller removes detected air from blood in the air removal device. A disposable circuit support module is used to mount the components of the disposable, integrated extracorporeal blood circuit in close proximity and in a desirable spatial relationship to optimize priming and use of the disposable, integrated extracorporeal blood circuit. A reusable circuit holder supports the disposable circuit support module in relation to a prime solution source, the active air removal controller and other components.

Systems and methods provide for determining blood gas saturation based on one or more measured respiration parameters. A parameter of respiration is measured implantably over a duration of time. The measured respiratory parameter is associated with a blood gas saturation level. Blood gas saturation is determined based on the measured respiration parameter. At least one of associating the measured respiratory parameter and determining blood gas saturation is preferably preformed implantably.

Methods for noninvasively evaluating indicators of cardio-pulmonary performance of a subject, such as cardiac output, pulmonary capillary blood flow, and blood carbon dioxide content, include obtaining data of an expiratory carbon dioxide signal and comparing data generated by an algorithmic lung model to the data of the expiratory carbon dioxide signal of a subject. The variables that are input into the algorithmic lung model are adjusted until the data generated thereby reflects that of the measured expiratory carbon dioxide signal with a desired degree of accuracy. Once the algorithmic lung model replicates the data of the measured expiratory carbon dioxide signal with the desired degree of accuracy, one or more of the input values may be used to determine one or more of the cardiac output, pulmonary capillary blood flow, or a blood gas content of the subject from which the expiratory carbon dioxide signal was obtained.

A medical device having a frontal attachment and a connector housing having at least a body part of an associated medical apparatus, the frontal attachment slidably engaging the connector housing and having a forwardly projecting, rearwardly biased needle and a needle retraction assembly, and the connector housing having a needle retraction cavity laterally offset from the needle in a first position, the needle retraction cavity being selectively movable relative to the frontal attachment following use to reposition the needle retraction cavity into alignment with the needle to permit retraction. The subject device is desirably specially modified for use in blood gas sampling by the addition of a filter plug.

Physiologic sensors and methods of application are described. These sensors function by detecting recently discovered variations in the spectral optical density at two or more wavelengths of light diffused through the skin. These variations in spectral optical density have been found to consistently and uniquely relate to changes in the availability of oxygen in the skin tissue, relative to the skin tissue's current need for oxygen, which we have termed Physiology Index (PI). Current use of blood gas analysis and pulse oximetry provides physiologic insight only to blood oxygen content and cannot detect the status of energy conversion metabolism at the tissue level. By contrast, the PI signal uniquely portrays when the skin tissue is receiving ‘less than enough oxygen,’‘just the right amount of oxygen,’ or ‘more than enough oxygen’ to enable aerobic energy conversion metabolism. The PI sensor detects one pattern of photonic response to insufficient skin tissue oxygen, or tissue hypoxia, (producing negative PI values) and a directly opposite photonic response to excess tissue oxygen, or tissue hyperoxia, (producing positive PI values), with a neutral zone in between (centered at PI zero). Additionally, unique patterns of PI signal response have been observed relative to the level of physical exertion, typically with a secondary positive-going response trend in the PI values that appears to correspond with increasing fatigue. The PI sensor illuminates the skin with alternating pulses of selected wavelengths of red and infrared LED light, then detects the respective amount of light that has diffused through the skin to an aperture located a lateral distance from the light source aperture. Additional structural features include means of internally excluding light from directly traveling from the light emitters to the photodetector within the sensor. This physiology sensor and methods of use offer continuous, previously unavailable information relating to tissue-level energy conversion metabolism. Several alternative embodiments are described, including those that would be useful in medical care, athletics, and personal health maintenance applications.

Catheter systems with blood measurement device and methods are disclosed. An exemplary catheter system for use in positioning a distal end of a catheter body at a desired location in a patient's body may include a needle provided at the distal end of the catheter body to withdraw blood from the patient's body. The needle is fluidically connected to a proximal end of the catheter body. The catheter system may also include a measurement device provided at the proximal end of the catheter body. The measurement device is configured to receive blood withdrawn by the needle for measuring a blood gas value of the blood for use in positioning the distal end of the catheter body at the desired location in the patient's body.

A breathing circuit for use in conjunction with a ventilator serving a mechanically-ventilated patient includes an expiratory gas airflow pathway; an inspiratory gas airflow pathway; and a gas mixing mechanism operable to mix inspiratory gas and expiratory gas in an amount sufficient to equilibrate the patient's PETCO₂ and arterial PCO₂ such that the patient's PETCO₂ is a clinically reliable approximation of the patient's PaCO₂.

A method and apparatus for measuring blood gas concentrations and partial pressures, in real time, using a pneumatic detector to indicate partial pressure variations in the blood gas.

A gas therapy system involves sensing the blood gas concentration of the patient and adapting a gas therapy based on the sensed gas concentration. Disordered breathing may be detected bases on blood gas concentration, and gas or cardiac electrical therapy may be adapted to treat the detected disordered breathing. One or more of sensing the blood gas concentration, detecting disordered breathing, or adapting the therapy may be performed at least in part implantably. The gas therapy is delivered to the patient through an external respiratory device, such as a positive airway pressure device.