There have been several recent publications highlighting concern over urodynamics quality in current practice and need for appropriate training in operating equipment and reporting results [1, 2].  Often, difficulties are encountered by clinical staff uncomfortable with new software or technology, or through urodynamic parameters being displayed in training in a different way to that used on their own equipment.  Trainees may also be put off by the use of articially generated signals, such as simulating coughs by the raising and lowering of water-filled tubes. Thus, training should ideally be carried out on the machine and software that exist in their own department, and use real patient signals.  We aimed to design, test and manufacture a device that replays real patient pressure signals on a user's existing urodynamic equipment.

We designed and built a prototype handheld device that replays real, recorded patient pressure signals.  The urodynamic machine then displays the signals as if a patient is connected, simulating a real urodynamic test.  The trainer selects the features and artefacts they wish to introduce into the injected signal.  The trainee can then be led through appropriate responses and troubleshooting, using replays of recorded actual tests and artefacts, in order to deliver improved quality of urodynamic assessments and reliable patient care.  

To develop the most helpful user interface, a hardware mockup and several software models were developed using Powerpoint slides. Members of the local urodynamics team comprising several professional bvackgrounds were asked to comment on their preferences of the different menus.

It is not currently proposed to simulate the urine flow rate, just the pressure measurements, as the latter are the main focus of the training usually offered.  The system has however been designed to enable easy production of future models that simulate flow as well.

All common urodynamic features and artefacts have been selected from our library of actual clinical tests.  These have been incorporated into a microcontroller processor unit's code for replay when the operator requires it.  The features included currently are Calibration check, Compliance poor, Cough (good, with detrusor overactivity, poor), Demonstration test, Descending pressure, Detrusor overactivity, Expelled catheter, Flushed Line, Live signal loss, Position change, Pump vibrations, Rectal contractions, Resting pressure error, Talking / laughing, Tube knocks / patient movement, Valsalva, Zeroing.

To develop the best menu structure, members of the local urodynamic team, who are all regularly involved in training, were asked to assess a number of different menu structures.  A selection system based on two movement keys (up/down the menu) and a selection key (using the computer 'return' logo) was decided upon (see Figure 1).  A submenu is then entered where the operator can select a 'large' or 'small' feature, and, if relevant, which pressure line should display the artefactual signal.

The microcontroller used is the ATMega2560 board, generating voltage signals at a rate of 50Hz via two digital to analogue converters. Power supply is via any standard USB socket, no batteries are required. The current version uses connectors emulating the Smiths Medical MX960 pressure transducers.  However, in principle any type of connector can be accommodated through using adaptor cables to suit whichever transducer is supplied with a machine, since the strain gauge responses are the same across all pressure measurement devices currently in use.

Trials of the device are ongoing with users, trainers and manufacturer representatives.

Users or manufacturer representatives can inject prerecorded patient signals from our device into the actual machine trainees use, in the environment in which those trainees work.  We have thus proven the feasibility of using recorded pressure signals from a patient's urodynamic test to replay later for training purposes .  A handheld unit has been shown to be easy to use by an instructor in a training setting.

Improving the quality of urodynamic testing through more relevant, effective training will contribute to improving a necessary stage in the patient journey, as it is known that training in urodynamics changes practice [3].

The final version of the device will be supplied with cables to connect to any kind of pressure transducer cable, making the unit non-specific to any particular urodynamic manufacturer.  An option for simulation of flow/leak signals will be incorporated in a future model.

We have designed, have built and are testing a novel device for injecting real signals from a recorded urodynamic test into a user's own urodynamic machine.  This will enhance training by allowing urodynamic instruction on software familiar to the trainee.  Improving the quality of urodynamic testing through more relevant, effective training will contribute to improving the patient journey, as it is known that good training in urodynamics changes practice [3].

Aiello M et al. Neurourol Urodyn. 2020; 39(4):1170-1177.
Abrams P et al.  Neurourol Urodyn 2019; 38:838–856.
Ellis-Jones J et al. Neurourol Urodyn. 2006;25(5):406-10.

Continence 7S1 (2023) 100868
DOI: 10.1016/j.cont.2023.100868