Novel device for measuring pelvic floor muscle strength

It is estimated that urine loss affects 30% of women at some point in their lives. Despite this high incidence rate, up until now clinical evaluation of patients suffering from this problem has been based on tactile examination, a subjective procedure that is not carried out in a consistent way by different medical professionals.

Esteban Peña, a researcher with the Universitat Politècnica de Catalunya. BarcelonaTech (UPC)'s Department of Mechanical Engineering and the current director of the Manresa School of Engineering (EPSEM), took on a challenge posed by Dr Geòrgia Romero, who is attached to the Physical Medicine and Rehabilitation Service of Manresa Hospital. "The problem was that there was no reliable device for measuring a woman's perineal strength," says Peña. Pelvic floor muscle strength is a variable closely related to urinary incontinence in women.

Dr Romero knew exactly what was needed: a device to objectively measure the strength of the muscle that is related to urinary incontinence. It had to be a simple device that would be easy to use for all the professionals on the interdisciplinary team of the Althaia unit, which is responsible for treating pelvic floor dysfunctions at Manresa Hospital. The physical proximity of the EPSEM and the Althaia Foundation, which manages health services in Manresa, soon developed into a convergence of objectives.

A dynamometric speculum

According to the researcher, it was clear from the start that the solution could lie in adapting a speculum, the instrument used to perform gynaecological examinations. "We needed to determine the displacement of the muscle. So we thought, 'what would happen if we put a spring inside the speculum or inside a displacement sensor?'" says Peña.

Recently, three years after initiating the project, Esteban Peña and Geòrgia Romero presented the instrument they came up with, known officially as the "device for measuring pelvic floor muscle strength." The invention consists of a speculum with an attached sensor that measures the force (in newtons) made by a patient during an examination.

The final prototype is the result of extensive trial-and-error testing. Some women do not know how to contract only their perineum, so "a mechanism had to be added to distinguish the origin of the forces recorded by the dynamometer," says Peña. The device has a number of surface electrodes to differentiate the activity of muscles that could alter the force measured, such as the abdominal and gluteal muscles.

The new speculum has been tested on 140 patients. "To ensure the reliability of the instrument, studies are being carried out to compare results obtained using the device with those based on conventional tactile diagnosis," says Esteban Peña. The results obtained so far are satisfactory.

The patent for the instrument, which is unique in the world, is shared by the Manresa School of Engineering and the Althaia Foundation. "The UPC's Patents and Licences Office is giving us a lot of help in the process of looking for companies interested in marketing the device," says the researcher. Although there is "no definite arrangement" at the moment, negotiations are underway with several companies. Already the instrument has generated strong interest at trade fairs and rehabilitation conferences where it has been presented.