Exequibilidade de um Sistema de Monitorização Ambulatorial do Fluxo Miccional: Desenvolvimento de um Fluxômetro Portátil em Código e Hardware Abertos.
home-based uroflowmetry, portable uroflowmeter, urinary flow, open-source.
Introduction. Uroflowmetry is an often-performed urological test, providing relevant
diagnostic information for many voiding disorders. Home-based uroflowmetry can
potentially better estimate the patient’s voiding pattern and could be more widely
adopted if an accurate low-cost device was available.
Objective. Development and initial evaluation of an open-platform, open-source
ambulatory uroflowmeter.
Patients and methods. A portable uroflowmeter was designed and built with a load
cell and a Secure Digital (SD) memory card unit connected to a Arduino Uno
microcontroller board. The device was powered by a 9-volt battery and mounted upon
a 3D-printed frame. Its output consisted of comma-separated value (CSV) tables, which
were plotted and analyzed with the R programming language. Twenty healthy male
urologists volunteered to test and assess the device with regards to ease of use and
portability. Each participant answered the International Prostatic Symptom Score (I-
PSS) and Peeling diagram, completed a 24 hour bladder diary, and a questionnaire to
evaluate user experience. Two experienced urodynamicists rated the quality of
uroflowmetric tracings with a 3-degree ordinal scale (1. Interpretable without artifacts;
2. Interpretable with artifacts; 3. Uninterpretable).
Results. Participants’ median age was 36 years old. None had an I-PSS above five or a
Peeling score greater than two. Overall, 138 voidings were recorded (77 daily and 61
nighly episodes). Assessments regarding ease of use, robustness and portability
obtained overall maximum score in 80% of the evaluations. Most uroflowmetry
tracings had no artifacts (91.30% and 84.06% according to urodynamicist A and B,
respectively). About 98% were considered interpretable by both evaluators.
Discussion. A wider adoption of ambulatory uroflowmetry has so far been hampered
by cost and limited device availability, which we conjectured could be circumvented by
a 3D printed portable uroflowmeter using widely accessible programmable
microcontroller boards as processing unit.
Conclusion. The construction of an accurate, easy-to-use, low-cost uroflowmeter
suitable for ambulatory use is feasible. This device can potentially increase access to
home-based and ambulatory uroflowmetry and improve knowledge about the
patients’ voiding patterns.