DEVICE FOR MEASURING THE FLOW OF BLOOD

• US 3,670,715 A
• Filed: 02/11/1970
• Issued: 06/20/1972
• Est. Priority Date: 02/12/1969
• Status: Expired due to Term

• Current Assignee: Honeywell BV (Honeywell International Inc.)
• Original Assignee: Jean Robert Perilhou, Michel Joseph Auphan
• Inventors: Perilhou, Jean Robert, Auphan, Michel Joseph
• Primary Examiner(s): Borchelt, Archie R.
• Application Number:
  US05/010,519
• Time in Patent Office: 860 Days
• Field of Search: 250/43.5FC,71.5R,71.5S,16T 128/2.5R,2.5F,2.5V,2.1R
• US Class Current: 600/436
• CPC Class Codes: A61B 5/0275 using tracers, e.g. dye dilution
• CPC Class Codes: G01F 1/7042 using radioactive tracers
• CPC Class Codes: G01F 1/708 Measuring the time taken to traverse a fixed distance
• CPC Class Codes: G01N 2223/0745 neutron-gamma activation analysis
• CPC Class Codes: G01N 23/222 using neutron activation analysis [NAA]

Abstract

a. The device according to the invention permits of measuring the flow of liquids which contain oxygen, especially blood flow. B. It comprises a pulsed neutron source which partly irradiates the liquid; the oxygen O16 of the liquid is converted into N16 which emits radiation. A detector measures the radioactivity of the liquid as a function of flow. C. The device can be used especially in medical diagnosis for measuring blood flow, for example cardiac output, arterial flow or the supply of blood to an organ.

Claims

1. A method for measuring the cardiac output of a heart in an animal body, comprising the steps of irradiating a substantially cylindrical portion of said body including the heart with a dose of neutrons at the instant ventricles of the heart are filled with blood, measuring gamma radiation level emitted by the irradiated portion of the body immediately after the irradiation in a shadow region with respect to the dose of neutrons, measuring gamma radiation level emitted by the irradiated portion of the body at the end of a contraction of the ventricles in said shadow region and determining the difference in the levels of the gamma radiation measurements.

2. A method for measuring the cardiac output of a heart in an animal body comprising the steps of irradiating a substantially cylindrical portion of said body including the heart with a dose of neutrons at the instant ventricles of the heart are filled with blood, and measuring the gamma radiation level emitted by a part of the body outside said irradiated portion at the end of a contraction of the ventricles in a shadow region with respect to the dose of neutrons.

3. A device for measuring the cardiac output in an animal body comprising a pulsed neutron source contained within a neutron absorbing envelope having an opening adapted to emit a substantially cylindrical beam of neutrons, a radiation detector to measure gamma radiation, screening means to prevent neutrons from said neutron source and gamma radiation from the region that has been irradiated by said beam of neutrons from reaching the radiation detector along a direct path, and absorbing means adapted to compensate for gamma radiation reduction in accordance with distance between the radiation detector and a point of gamma radiation emission.

4. A device as claimed in claim 3, wherein the radiation detector is opposite the neutrons emitting opening and the screening means is located between said radiation detector and said opening.

5. A device as claimed in claim 3, wherein the radiation detector is located next to a lateral wall of said envelope and the screening means forms a part of said lateral wall.