Non-invasive device and method for the diagnosis of pulmonary vascular occlusions

• US 20030167017A1
• Filed: 03/26/2003
• Published: 09/04/2003
• Est. Priority Date: 09/27/2001
• Status: Active Grant

• Current Assignee: Jeffrey A. Kline
• Original Assignee: Jeffrey A. Kline
• Inventors: Kline, Jeffrey A.
• Granted Patent: US 7,083,574 B2
• Time in Patent Office: Days
• US Class Current: 600/529
• CPC Class Codes: A61B 5/08 Detecting, measuring or recording devices for evaluating the respiratory organs A61B5/0205 takes precedence
• CPC Class Codes: A61B 5/082 Evaluation by breath analysis, e.g. determination of the chemical composition of exhaled breath A61B5/083, A61B5/091 take precedence
• CPC Class Codes: A61B 5/083 Measuring rate of metabolism by using breath test, e.g. measuring rate of oxygen consumption
• CPC Class Codes: A61B 5/0833 Measuring rate of oxygen consumption
• CPC Class Codes: A61B 5/0836 Measuring rate of CO2 production
• CPC Class Codes: A61B 5/087 Measuring breath flow
• CPC Class Codes: A61B 5/091 Measuring volume of inspired or expired gases, e.g. to determine lung capacity
• CPC Class Codes: A61B 5/417 the bone marrow
• CPC Class Codes: H02M 5/4585 having a rectifier with controlled elements

Abstract

The invention involves a device and method for ascertaining the functioning of the respiratory system and determining whether a pulmonary embolism is present. The device comprises an apparatus containing sensors for measuring the oxygen and carbon dioxide concentrations as well as the volume of air inhaled and exhaled by a patient. From this data, a processor computes the ratio of carbon dioxide to oxygen for the volume of expired air and displays the results on a screen. By comparing the results to predetermined normal values, an accurate determination can be made regarding the presence of a pulmonary embolism.

Claims

1. A method for measuring the response to resuscitation, comprising the steps of:

allowing said patient to inhale through a mouthpiece;

measuring the oxygen and carbon dioxide partial pressures of the inhaled air.

allowing said patient to exhale air through said mouthpiece;

measuring the oxygen and carbon dioxide partial pressures of the exhaled air;

calculating the amount of oxygen delivered to the patient; and

determining whether resuscitation is complete.

2. The method of claim 1, wherein the step of determining whether resuscitation is complete comprises comparing the amount of oxygen delivered to predetermined data from normal populations.

3. A method for measuring a patient'"'"'s response to resuscitation, comprising the steps of:

providing a device capable of measuring oxygen and carbon dioxide partial pressures;

supplying a relatively low concentration of inspired oxygen of about 21 to 30 percent;

providing a relatively high concentration of inspired oxygen of about 45 to 50 percent;

calculating the amount of oxygen delivered to the patient for both the lower concentration of inspired oxygen and the higher concentration of inspired oxygen; and

comparing the difference in oxygen delivered between the lower concentration and the higher concentration with expected values.

4. A method of measuring the efficiency of alveolar ventilation, comprising the steps of:

providing a mouthpiece to a patient;

allowing said patient to inhale through said mouthpiece;

measuring the oxygen and carbon dioxide partial pressures of the inhaled air;

calculating the amount of oxygen delivered;

calculating the amount of carbon dioxide released;

determining the efficiency of alveolar ventilation during each tidal volume breath.

5. A method of measuring the cardiac output of a patient, comprising the steps of:

providing a mouthpiece to a patient;

allowing said patient to inhale and exhale through said mouthpiece;

continuously measuring oxygen partial pressures of the inhaled and exhaled air;

continuously measuring the arterial oxygen saturation through pulse oximetry;

measuring the pH and hemoglobin concentration of a venous blood sample; and

calculating the cardiac output.

6. The method of claim 5, wherein the step of calculating the cardiac output further comprises the steps of:

calculating the average total oxygen consumed over a predetermined time period;

calculating the arterial oxygen content as the product of measured arterial oxygen saturation and hemoglobin concentration;

determining the lowest mean oxygen tension during expiration over the predetermined time period;

estimating the venous oxygen saturation from the mean lowest oxygen tension according to published oxygen binding curves for the measured pH;

calculating the venous oxygen content as the product of venous oxygen saturation and the measured hemoglobin concentration; and

dividing the average total oxygen consumed by the difference between the arterial oxygen content and venous oxygen content.