Respirometer having thermosensitive elements on both sides of a hot wire
First Claim
Patent Images
1. A respirometer for use in measuring the rate of an air flow of respiration, comprising:
- means for defining a one-dimensional path of air flow of respiration;
a hot wire in said respiration air flow path;
means coupled to said hot wire for maintaining said hot wire substantially at a predetermined temperature;
a pair of temperature sensitive elements in said respiration air flow path on respective opposite sides of said hot wire relative to the air flow of respiration in said air flow path, said temperature sensitive elements having an electrical characteristic which varies as a function of temperature;
first means electrically connected to said hot wire for producing an electrical output signal representative of the rate of said air flow but without discriminating between the senses of the direction of said air flow; and
second means electrically connected to said first means and to said temperature sensitive elements, said second means including;
third means electrically connected to said temperature sensitive elements for producing a control signal that assumes a first value during expiration and a second value during inspiration; and
fourth means electrically connected to said first and third means and including;
switching means responsive to said control signal;
first electrical operating means coupled to said switching means and having a first electrical characteristic for operating on said electrical output signal of said first means during inspiration for providing an inspiration output signal;
second electrical operating means coupled to said switching means and having a second electrical characteristic for operating on said electrical output signal of said first means during expiration for providing an expiration output signal, and combining means coupled to said first and second electrical operating means for combining the inspiration and expiration output signals thereof and producing a respiration rate signal representative of the rate of said air flow with discrimination between the senses of the direction of said air flow.
0 Assignments
0 Petitions
Accused Products
Abstract
A respirometer for measuring the rate of an air flow of respiration includes a hot wire in a path of the air flow. For measuring the rate of the air flow with a discrimination made between the senses of the air flow, a pair of temperature sensitive elements are placed in the path of the air flow on respective opposite sides of the hot wire relative to the air flow.
-
Citations
10 Claims
-
1. A respirometer for use in measuring the rate of an air flow of respiration, comprising:
-
means for defining a one-dimensional path of air flow of respiration; a hot wire in said respiration air flow path; means coupled to said hot wire for maintaining said hot wire substantially at a predetermined temperature; a pair of temperature sensitive elements in said respiration air flow path on respective opposite sides of said hot wire relative to the air flow of respiration in said air flow path, said temperature sensitive elements having an electrical characteristic which varies as a function of temperature; first means electrically connected to said hot wire for producing an electrical output signal representative of the rate of said air flow but without discriminating between the senses of the direction of said air flow; and second means electrically connected to said first means and to said temperature sensitive elements, said second means including; third means electrically connected to said temperature sensitive elements for producing a control signal that assumes a first value during expiration and a second value during inspiration; and fourth means electrically connected to said first and third means and including;
switching means responsive to said control signal;
first electrical operating means coupled to said switching means and having a first electrical characteristic for operating on said electrical output signal of said first means during inspiration for providing an inspiration output signal;
second electrical operating means coupled to said switching means and having a second electrical characteristic for operating on said electrical output signal of said first means during expiration for providing an expiration output signal, and combining means coupled to said first and second electrical operating means for combining the inspiration and expiration output signals thereof and producing a respiration rate signal representative of the rate of said air flow with discrimination between the senses of the direction of said air flow. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
-
-
10. A respirometer for use in measuring the rate of an air flow of respiration, comprising:
-
means for defining a one-dimensional path of air flow of respiration; a hot wire in said respiration air flow path; means coupled to said hot wire for maintaining said hot wire substantially at a predetermined temperature; a pair of temperature sensitive elements in said respiration air flow path on respective opposite sides of said hot wire relative to the air flow of respiration in said air flow path, said temperature sensitive elements having an electrical characteristic which varies as a function of temperature; first means electrically connected to said hot wire for producing an electrical output signal representative of the rate of said air flow but without discriminating between the senses of the direction of said air flow; and second means electrically connected to said first means and to said temperature sensitive elements, and responsive to said electrical output signal of said first means and to said electrical characteristics of said temperature sensitive elements for producing a respiration rate signal representative of the rate of said air flow with discrimination between the senses of the direction of said air flow, said second means including; third means electrically connected to said temperature sensitive elements for producing a control signal that assumes a first value during expiration and a second value during inspiration; and fourth means electrically connected to said first and third means, said fourth means comprising a first amplifier means for producing a first output signal with an amplification substantially equal to minus unity, a second amplifier means for producing a second output signal with an amplification substantially equal to plus unity, a combining circuit coupled to said first and second amplifier means and reponsive to said first and second output signals from said first and second amplifier means for producing a combined output signal, and relay means electrically connected to said first and third means and operative responsive to said control signal from said third means for supplying said electrical output signal from said first means to said first amplifier means when said control signal assumes one of said first and second values, and for supplying said electrical output signal from said first means to said second amplifier means when said control signal assumes the other of said first and second values, said combined signal thereby becoming said respiration rate signal.
-
Specification