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.
3.2mm Ø or 2.4mm Ø (very flexible)
Typically 4-6cm or as specified
Metal diaphragm with directly deposited resistive strain gauges
5V AC r.m.s. maximum or 1V DC maximum
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
Compensated temperature range:
Temperature coefficient of zero:
Temperature coefficient of sensitivity:
Linearity and hysteresis error: