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

• US 7,066,892 B2
• Filed: 07/18/2005
• Issued: 06/27/2006
• Est. Priority Date: 09/27/2001
• Status: Expired due to Fees

• Current Assignee: Charlotte-Mecklenburg Hosptial
• Original Assignee: Charlotte-Mecklenburg Hosptial
• Inventors: Kline, Jeffrey A.
• Primary Examiner(s): Nasser, Robert L.
• Application Number:
  US11/160,960
• Publication Number:
  US 20050241638A1
• Time in Patent Office: 344 Days
• Field of Search: None
• US Class Current: 600/532
• 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, in particular, for measuring the efficiency of alveolar ventilation of a patient. 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. The patient is provided a mouthpiece for breathing into and out of the device, which subsequently measures the oxygen and carbon dioxide partial pressures of inhaled and exhaled air. From these measurements, the efficiency of alveolar ventilation during each tidal volume breath may be calculated.

Claims

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

providing a mouthpiece to a patient;

allowing said patient to inhale and exhale through said mouthpiece;

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

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

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

2. The method of claim 1, further comprising the step of displaying a plot of the expired oxygen and carbon dioxide partial pressures prior to said step of estimating the efficiency of alveolar ventilation.

3. The method of claim 2, wherein the oxygen and carbon dioxide partial pressures of inhaled and exhaled air are measured by an oxygen monitor in fluid communication with said breathing tube.

4. The method of claim 2, wherein the carbon dioxide partial pressures of said inhaled and exhaled air are measured by a capnometer in fluid communication with said breathing tube.

5. The method of claim 1, further comprising the step of adjusting the pressure and volume parameters of a mechanical ventilator based on said estimation of the efficiency of alveolar ventilation.

6. The method of claim 1, wherein the step of estimating the efficiency of alveolar ventilation comprises the steps of:

determining the amount of carbon dioxide released from the patient,

determining the percentage of oxygen extracted by the patient; and

calculating the efficiency of alveolar ventilation from said amount of carbon dioxide released from the patient and said percentage of oxygen extracted by the patient.

7. The method of claim 6, further comprising the step of determining the barometric pressure.