| 21. |
- Ask, Per, et al.
(författare)
-
A simple device measuring differences in level in the oesophagus
- 1978
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Ingår i: Acta Oto-Laryngologica. - : Informa UK Limited. - 0001-6489 .- 1651-2251. ; 85:3-4, s. 296-297
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- A device for measuring the difference in level between the pressure transducer and a point of measurment is described. It can be used in oesophageal manometry with waterfilled catheters to measure and compensate for superimposed hydrostatic pressure. The practical application of the method is illustrated.
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| 22. |
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| 23. |
- Ask, Per, 1950-, et al.
(författare)
-
Clinical evaluation of different fluid-filled systems for oesophageal manometry
- 1979
-
Ingår i: Scandinavian Journal of Gastroenterology. - 0036-5521 .- 1502-7708. ; 14:1, s. 1-5
-
Tidskriftsartikel (refereegranskat)abstract
- In a clinical study of oesophageal manometry with fluid-filled catheters, both a non-perfused system and a perfused system with a syringe pump have been compared to a system with a low-compliance perfusion pump, which served as a reference. Significantly lower values of motility amplitudes, motility derivatives, and partly of LES pressures, and a time delay of up to 0.5 sec of the amplitude maximum were obtained with the non-perfused system and the system with a syringe pump in comparison to the low-compliance system. Since the oesophageal function can be erroneously evaluated by use of a non-perfused system or a perfused system with a syringe pump, such systems cannot be recommended for clinical use.
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| 24. |
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| 25. |
- Ask, Per, 1950-, et al.
(författare)
-
ECG Electrodes : A Study of Electrical and Mechanical Long-term Properties
- 1979
-
Ingår i: Acta Anaesthesiologica Scandinavica. - : Wiley. - 0001-5172 .- 1399-6576. ; 23:2, s. 189-206
-
Tidskriftsartikel (refereegranskat)abstract
- The long-term properties of commercially available ECG-electrodes were studied by investigating the parameters: polarization potential, electrical impedance, adhesion, and skin reactions during a period of 7 days. As expected, the most stable polarization potentials were obtained for Ag/AgCl electrodes. Certain simple disposable electrodes showed large polarization potential variations. The most stable electrode impedance was obtained for disposable electrodes with stable adhesion and equipped with an electrode cup or similar. Unchanged adhesion and mechanical properties during the test period were shown by the disposable electrodes with a large self-adhesive collar.
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| 26. |
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| 27. |
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| 28. |
- Ask, Per, et al.
(författare)
-
Frequency content of esophageal peristaltic pressure.
- 1979
-
Ingår i: American Journal of Physiology. - 0002-9513 .- 2163-5773. ; 236:3, s. E296-300
-
Tidskriftsartikel (refereegranskat)abstract
- Fourier analysis of esophageal peristaltic pressure waves was performed by computer fast Fourier transform. The highest power spectral density was obtained in the frequency range below 1 Hz. The Fourier analysis showed spectral components up to about 12 Hz in the upper esophageal sphincter (UES). The significance of different frequency components was investigated by low-pass filtering at different cut-off frequencies. A reduction in the amplitude of UES contractions was obtained at a cut-off frequency of 4 Hz, whereas the cut-off frequency of 8 Hz did not show any distortion. For perfused manometry systems, only a low-compliance perfusion pump will have sufficient bandwidth for accurate recording of esophageal peristaltic pressures.
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| 29. |
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| 30. |
- Ask, Per, et al.
(författare)
-
Mechanisms affecting lower oesophageal sphincter opening and oesophageal retention : A combined X-ray and manometry study
- 1978
-
Ingår i: Scandinavian Journal of Gastroenterology. - 0036-5521 .- 1502-7708. ; 13:7, s. 857-861
-
Tidskriftsartikel (refereegranskat)abstract
- Using simultaneous manometry and cineradiography, oesophageal evacuation was studied while contrast medium was infused via a catheter. The distal half of the oesophagus could be filled with contrast medium without triggering peristalsis. The hydrostatic pressure necessary to open the lower oesophageal sphincter (LES) was of approximately the same magnitude as the pressure gradient between oesophagus and LES. No significant relaxation of the LES could be observed at the initiation of swallowing. The LES may be looked upon not only as a sphincter preventing reflux but also as a gate which must be forced open by food.
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