Airway geometry imaging

A method for imaging a confined volume comprising,

• connecting an open first end of a conduit having an interior free of sound-absorbing or acoustic energy-absorbing material to an opening in said confined volume,
• propagating acoustical energy inside said conduit through said open first end and into said confined volume through said opening to produce a first wave traveling towards said opening in said confined volume and the confined volume producing a second wave traveling away from said opening towards said second end in response to the first wave the second wave having a wave field in said conduit representative of said confined volume geometry,
• transducing acoustic wave field parameters of said wave field at at least two spaced locations along said conduit to provide first and second transduced signals representative of said wave field,
• and processing said first and second transduced signals in accordance with an algorithm that takes into account said first wave and said second wave to provide an output signal representative of a characteristic of said confined volume.

Apparatus for providing an output signal characteristic of a confined volume geometry comprising,

• a conduit for exchanging acoustical energy with said confined volume, said conduit having a predetermined length a sidewall and an open first end in communication with an opening in said confined volume,
• a launching transducer coupled to launch acoustical energy through the sidewall of said conduit and produce an incident wave towards said opening in said confined volume and the confined volume producing a reflected wave in response to the incident wave, the reflected wave having a wave field in said conduit representative of said confined volume geometry,
• a plurality of pressure-wave-sensing transducers mounted along the length of said conduit in spaced relationship for providing first and second transduced signals representative of said wave field, and
• a processor means for providing high-pass filtering in processing said first and second transduced signals and providing, from said processing, said output signal characteristic of said confined volume geometry.

Apparatus for providing an output signal characteristic of a confined volume geometry comprising,

• a conduit for exchanging acoustical energy with said confined volume, said conduit having:
• a sidewall;
• an open first end in communication with an opening in said confined volume;
• and an open second end,
• a launching transducer coupled to said conduit for launching acoustical energy through the sidewall of said conduit to produce an incident wave towards said opening in said confined volume and said confined volume producing a reflected wave in response to the incident wave, the reflected wave having a wave field in said conduit representative of said confined volume geometry,
• a plurality of pressure-wave-sensing transducers mounted in spaced relationship along a length of said conduit for providing first and second transducers signal representative of said wave field, and
• a processor means for processing said transduced signals to provide, from said processing, a signal representative of the response of the incident wave to the confined volume and for high-pass filtering the response to produce said output signal characteristic of said confined volume geometry.

Apparatus for providing an output signal characteristic of a confined volume geometry comprising,

• a conduit having an interior free of sound-absorbing or energy-absorbing material for exchanging acoustical energy with said confined volume,
• said conduit having:
• a predetermined length;
• a sidewall;
• an open first end adapted for communication with an opening in said confined volume;
• and, a second end separated from said first end by the conduit length,
• a launching transducer coupled to launch acoustical energy through the sidewall of said conduit producing a first wave traveling towards said opening in said confined volume and the confined volume producing a second wave traveling away from said opening toward said second end in response to the first wave, the second wave having a wave field in said conduit representative of the geometry of said confined volume,
• a plurality of pressure-wave-sensing transducers mounted along said length of the conduit in spaced relationship for providing first and second transduced signals representative of said wave field,
• and a processor means coupled to said plurality of pressure-wave-sensing transducers including means for processing said first and second transduced signals in accordance with an algorithm that takes into account said first wave and said second wave to provide said output signal characteristic of said confined volume geometry.

Apparatus for providing an output signal characteristic of a confined volume geometry comprising,

• a conduit for exchanging acoustical energy with said confined volume,
• said conduit having:
• a predetermined length;
• a sidewall;
• an open first end adapted for communication with an opening in said confined volume;
• and, a second end separated from said first end by the conduit length,
• a launching transducer coupled to launch acoustical energy through the sidewall of said conduit for launching acoustical energy into said conduit producing an incident wave towards said opening in said confined volume and said confined volume producing a reflected wave in response to the incident wave, the reflected wave having a wave field in said conduit representative of the geometry of said confined volume,
• a plurality of pressure-wave-sensing transducers mounted along said conduit length in spaced relationship for providing first and second transduced signals representative of said wave field, and
• a processor means coupled to said plurality of pressure-wave-sensing transducers for processing said first and second transduced signals to provide said output signal characteristic of said confined volume geometry,
• wherein said confined volume is characterized by cross-sectional area as a function of distance from said opening in said confined volume and said processor means provides as said output signal an area signal that is characteristic of cross-sectional area of said confined volume as a function of distance from said opening in said confined volume,
• wherein said conduit is less than or equal to 15 cm in length.

A method for imaging a confined volume comprising:

• connecting an open first end of a conduit to an opening in said confined volume;
• propagating acoustical energy into a sidewall of the conduit, through said open first end, and into said confined volume through said opening to establish a pressure field in said conduit representative of said confined volume;
• and
• transducing acoustic wave field parameters of said pressure field at a plurality of spaced locations along said conduit;
• and
• processing said transduced parameters to provide a response of the confined volume to the propagating acoustical energy and high-pass filtering the response to provide the output signal representative of said confined volume.

Apparatus for providing an output Signal characteristic of a confined volume geometry comprising,

• a conduit for exchanging acoustical energy with said confined volume,
• said conduit having a predetermined length and an open first end adapted for communication with an opening in said confined volume and a second end separated from said first end by the length of the conduit,
• a launching transducer coupled to said conduit for launching acoustical energy into said conduit producing an incident wave towards said opening in said confined volume and the confined volume producing a reflected wave in response to the incident wave, the reflected wave having a wave field in said conduit representative of said confined volume geometry,
• a Plurality of pressure-wave-sensing transducers mounted along said length of the conduit in spaced relationship for providing first and second transduced signals representative of said wave field, and
• a processor means coupled to said plurality of pressure-wave-sensing transducers for processing said first and second transduced signals produced in response to the incident wave, the reflected wave and any rereflected wave from the second end to provide a signal representative of an impulse response of the geometry and to provide said output signal characteristic of said confined volume geometry,
• wherein said confined volume is characterized by cross-sectional area as a function of distance from said opening in said confined volume and said processor means provides as said output signal an area signal that is characteristic of cross-sectional area of said confined volume as a function of distance from said opening in said confined volume.

A method for imaging a confined volume comprising:

• connecting an open first end of a conduit to an opening in said confined volume;
• propagating acoustical energy inside said conduit, through said open first end, and into said confined volume through said opening to establish a pressure field in said conduit representative of said confined volume;
• transducing acoustic wave field parameters of said pressure field at a plurality of spaced locations along said conduit to produce signals representative of both incident and reflected waves;
• and
• processing said transduced parameters produced in response to the incident wave, the reflected wave and any rereflected wave from a second end of the conduit to provide a signal representative of an impulse response of the confined volume and providing said output signal characteristic of said confined volume geometry and providing an output signal representative of said confined volume geometry,
• wherein said confined volume is characterized by cross-sectional area as a function of distance from said opening in said confined volume and said output signal is representative of cross-sectional area of said confined volume as a function of distance from said opening in said confined volume.