In recent years, vaginal dynamometry (VD) using an elastometer has emerged as a potential
tool for the functional evaluation of the pelvic floor musculature, with early reports
suggesting that it accurately measures and discriminates pelvic floor muscle stiffness in
women of different parities, fitness levels and clinical situations including the evaluation
of stress urinary incontinence (UI) [11-14].
With the emerging promising reports confirming the accuracy of the dynamometer for assessing
PFM strength in various women groups and for investigating stress UI, a portable dynamometer
has recently been developed by our collaborators at the Auckland Bioengineering Institute
(ABI), led by Professor Poul Nielsen [15]. The device has several advantages over other
designs: (1) It is hand-held, portable; (2) It is designed to be operated by a medical
professional; (3) It measures in the coronal as well as the anteroposterior orientations; (4)
Data acquisition is at a high frequency (100Hz) and can be automated, and (5) Parameters are
adjustable to required protocols.
The device consists of a hand-piece comprising two aluminium arms, with detachable acetyl
plastic speculum ends, actuated via a load cell. The tip of the speculum is wider than the
neck in order to focus the measurements at the level of the puborectalis portion of the
Levator Ani (LA) muscle group by reducing contributions from perineal muscles. The hand-piece
is connected to a control box with a data acquisition device that communicates with a
computer via a USB connection. The device measures the passive force and the displacement
(i.e. speculum separation), and displays the data in a graph. The preliminary test of the
portable prototype conducted in Auckland found the device highly acceptable, consistent and
repeatable [15]. A recent study of 47 antenatal patients in Auckland showed 100% positive
feedback for the device to be used as a regular test in the antenatal unit (internal
communication).
Indicative approval has been discussed and agreed with the Department of Clinical
Engineering, subject to satisfactory safety checks scheduled for March 2014, that the device
is highly likely to meet safety regulatory standards for medical devices to be used on
patients in the National Health Service (NHS). The device has now arrived in Sheffield and
has successfully undergone safety checks in the Clinical Engineering Department of the Royal
Hallamshire Hospital (certificate attached). The investigators therefore envisage that a
pilot study can be carried out using the device in the Jessop Wing (JW) twice-monthly
perineal trauma clinic.
The clinical studies in this setting will generate, for the first time in the United Kingdom,
sensitivity and specificity data for vaginal dynamometry for detecting functional defects of
PFM tone post-delivery. The Investigators will accrue data regarding the correlation of
findings with clinically detected perineal muscle damage as well as radiologically-confirmed
LA hiatus defects.
The success of these pilot studies will provide strong support for the investigators to seek
funding for a large multicentre study of the clinical application of VD in screening and
management of PFMD to prevent long term pelvic floor laxity, stress UI, and pelvic organ
prolapse (POP).There is a paucity of reports regarding its application in clinical care for
managing PFMD from childbirth.
The investigators will prospectively recruit 50 consecutive women attending the perineal
trauma clinic (PTC) at the Jessop Wing of the Royal Hallamshire Hospital Sheffield for
standard clinical care and VD. Given limitations in funding and time duration for these
experiments, the investigators will adopt this pragmatic approach to recruit and study
consecutive consenting women over a 6-month period.
