Plethysmograph
Inventors
Altmejd, Simon • Robichaud, Annette • Urovitch, Ilan Benjamin • Guevara Garzon, Camilo
Assignees
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Publication Number
US-11759120-B2
Publication Date
2023-09-19
Expiration Date
Abstract
The present disclosure concerns a plethysmograph. The plethysmograph comprises a housing defining a test cavity configured to enclose a test subject. The plethysmograph further comprises an optical filter providing a spectrally restricted optical access to the test cavity from an exterior of the housing, the optical filter being configured to at least partially transmit light in a transmission band ranging from about 560 nm to about 750 nm; and to at least partially block light in a blocking band ranging from about 380 nm to about 560 nm.
Core Innovation
The invention provides an improved plethysmograph for small animals that includes a housing forming a test chamber and a reference chamber distinct from the test chamber. Each chamber defines a cavity, and each cavity is configured to enclose a test subject or to define a reference cavity. The plethysmograph includes a test pneumotach and a reference pneumotach, where the test pneumotach has a test airflow opening formed in a test pneumotach body and the reference pneumotach has a reference airflow opening formed in a reference pneumotach body.
The device uses a comparison of pressure variations of air circulating in the test airflow opening and the reference airflow opening, such that the comparison is representative of a respiratory function of the test subject. The housing and pneumotach bodies are arranged so that one of the test pneumotach body and the reference pneumotach body at least partially extends in the other one. Additional structural refinements specify that the test airflow opening and the reference airflow opening can have geometrical centers that correspond, and that one opening can at least partially surround the other.
A further core refinement is spectrally restricted optical access for reducing subject stress while improving breathing reproducibility. The housing includes an optical filter that transmits an about 560–750 nm band while blocking an about 380–560 nm band, with described complementary ranges for different colors. The plethysmograph further includes test and reference pneumotach resistive screens that are at least partially covering the respective airflow openings, with the resistive screens formed by a resistive plate, and described construction includes non-conductive substrate layers and printed circuit board construction.
Claims Coverage
The provided independent claims cover three main inventive feature sets: a plethysmograph with separate test and reference chambers and pneumotachs using pressure-variation comparison representative of respiratory function, resistive screens covering both airflow openings formed by a resistive plate, and an arrangement in which one airflow opening at least partially surrounds the other. Across the claims, the test/reference pneumotach-body relationship and the airflow-opening geometry are central.
Test and reference chambers with pneumotachs and representative respiratory pressure comparison
A housing forming a test chamber defining a test cavity configured to enclose a test subject, and a reference chamber distinct from the test chamber and defining a reference cavity; the test chamber comprising a test pneumotach having a test pneumotach body in which a test airflow opening is formed; the reference chamber comprising a reference pneumotach having a reference pneumotach body in which a reference airflow opening is formed; when in use, a comparison of pressure variations of air circulating in the test airflow opening and the reference airflow opening is representative of a respiratory function of the test subject; and one of the test pneumotach body and the reference pneumotach body at least partially extends in the other one.
Resistive screens covering both airflow openings formed by a resistive plate
The test pneumotach further comprises a test resistive screen at least partially covering the test airflow opening; the reference pneumotach further comprises a reference resistive screen at least partially covering the reference airflow opening; and the plethysmograph further comprises a resistive plate forming the test resistive screen and the reference resistive screen.
One airflow opening at least partially surrounds the other
One of the test airflow opening and the reference airflow opening at least partially surrounds the other one of the test airflow opening and the reference airflow opening.
The claims collectively define a plethysmograph that compares pressure variations between separate test and reference airflow openings to represent respiratory function, and further specify either an extending pneumotach-body relationship, resistive screens formed by a resistive plate, or a surrounding relationship between the airflow openings.
Stated Advantages
Reduced stress.
Improved breathing reproducibility.
Improved noise cancellation.
Reduced breathing variability.
Reduced acclimation time.
Documented Applications
Whole-body plethysmograph (WBP) use with a test subject for representing respiratory function via comparison of pressure variations between test and reference airflow openings.
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