Measurement of the axial force during primary peristalsis in the oesophagus using a novel electrical impedance technology.
The oesophagus serves to transport food and fluid from the pharynx to the stomach. Oesophageal function is usually evaluated by means of manometry which is a proxy of the force in the radial direction. However, force measurements in the axial direction will provide a better measure of oesophageal transport function. The aim of this study was to develop a probe based on electrical impedance measurements to quantify the axial force generated by oesophageal contractions, i.e. probe elongation was associated with the axial force. Calibration with weights up to 200 g was done. The dispersion, creep, temperature and bending dependence were studied at the bench. Subsequently, the probe was tested in vivo in a healthy human volunteer. The probe showed good reproducibility and the dispersion was <0.04. Some dependence on temperature, creep and bending was found. Interpolation of the calibration curves made it possible to compensate for temperature fluctuations. The maximum deviation was 6.1 +/- 3.7% at loads of 50 g. The influence of creep showed a maximum net creep of 6.1 g after 8 s. The swallowed bolus size correlated with the axial force measurements (P = 0.038) but not with manometric measurements. In conclusion, the new technique measures axial force in the oesophagus and may in the future provide valuable information about oesophageal function.
Gravesen
F H
FH
Center for Visceral Biomechanics and Pain, Aalborg Hospital Science and Innovation Center, Sdr. Skovvej 15, 9000 Aalborg, Denmark.
McMahon
B P
BP
Drewes
A M
AM
Gregersen
H
H
D002138:Calibration; D002404:Catheterization; D003679:Deglutition / Q000502:physiology; D017097:Electric Impedance; D004566:Electrodes; D004947:Esophagus / Q000502:physiology*; D006801:Humans; D010528:Peristalsis / Q000502:physiology*; D010865:Pilot Projects; D012984:Software; D013696:Temperature