Oesophageal (Upper GI)Spinctometer Sensor

An oil filled thin wall silicone rubber tube with a Gaeltec miniature pressure transducer

Developed to measure sphincter activity where a point sensor would not be adequate. For instance, in oesophageal ambulatory recording when the catheter cannot be kept stationary over time.

The sensor is an oil filled thin wall silicone rubber tube with a standard Gaeltec miniature pressure transducer within it. This has the property of integrating the pressure and the length that is pressurised, which gives an output in proportion to the sphincter competence.

Due to the construction using silicone rubber there are additional limitations to the performance compared to the standard point sensor. Primarily a positive baseline shift during soaking in water has to be allowed for. Pre-soaking for six hours before measurement will reduce this effect to a minimum. The sensor is also sensitive to acute bending which in normal use should be at an acceptable scale of error.

The sphinctometer sensor can be supplied as a single sensor catheter or as the tip of a multisensor catheter up to five sensors in total.

Sterilisation is by means of cold aqueous solutions of detergicide (e.g. Cidex) or by ethylene oxide gas. Do not use sodium hypochlorite solution.

Technical details:

Diameter of oil cell:

3.2mm Ø or 2.4mm Ø (very flexible)

Length of oil cell:

Typically 4-6cm or as specified

Sensor:

Metal diaphragm with directly deposited resistive strain gauges

Excitation:

5V AC r.m.s. maximum or 1V DC maximum

Bridge resistance:

1.5kΩ nominal

Sensitivity:

5µV/V/mmHg when pressurised over the full length. Output is proportional to the pressure and length pressurised and should be referred to in units that reflect this, e.g. mmHg.cm

Linear pressure range:

0 - 150mmHg

Compensated temperature range:

15 - 40°C

Temperature coefficient of zero:

< 0.05%FS/C°

Temperature coefficient of sensitivity:

< 0.2%/C°

Linearity and hysteresis error:

< ±1%FS BSL

Useful information

See our information section for anything from "What a Gaeltec Pressure Transducer is" to "Can I have a Transducer with Double Lumen, Twin Bore, Pig Tail with an Extended Tip?" Click here

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