Standardized swallow challenge medium and method of use for esophageal function testing
A swallow challenge medium ( 10 ) is thixotropic for easy swallowing and to provide enough viscosity for effective challenge to peristalsis ( 20 ) and has high ionic density for effective impedance measurements by contact with electrodes ( 41–48 ) positioned in a person's esophagus (E) or oropharynx during swallow testing. The medium ( 10 ) also has a high surface tension so as not to adhere to or coat the electrodes ( 41–48 ) or probe ( 12 ) surfaces. These physical characteristics are stabilized and consistent enough to provide standard for esophageal and/or oropharyngeal function testing and diagnostics.
1. A method of testing peristalsis and bolus transit in a person's esophagus comprising:
positioning a probe comprising a plurality of electrodes in longitudinally spaced relation to each other in the person's esophagus;
having the person swallow a swallow challenge medium that has viscosity in a range of 1,000 to 100,000 centipoise (high shear), conductivity in the range of 3.8 to 7.6 mS/cm, and sufficient surface tension to cause the swallow challenge medium to clear sufficiently from surfaces of the electrodes and probe as the swallow challenge medium passes the electrodes and probe such that impedance measurements across the electrodes after the swallow challenge medium passes the electrodes is not less than 50% of impedance measurements across the electrodes before the challenge medium reaches the electrodes;
measuring impedance across the electrodes on a real time basis as the challenge medium moves though the esophagus, and
recording the impedance measurements as a function of time.
2. The method of claim 1 , wherein the surface tension is sufficient such that said drop in impedance is not more than 1%.
3. The method of claim 1 , wherein the swallow challenge medium is thixotropic.
4. The method of claim 1 , wherein the swallow challenge medium has conductivity in a range of 4.5 to 7.6 mS/cm.
5. The method of claim 1 , wherein the swallow challenge medium provides impedance in a range of 300 to 600 ohms.
6. The method of claim 1 , wherein the swallow challenge medium provides impedance in a range of 300 to 500 ohms.
7. The method of claim 1 , wherein the swallow challenge medium has pH in a range of 3.5 to 9.0.