WEARABLE ULTRASOUND FOR CONTINUOUS BLADDER MONITORING

Project Information

BladderWatch

Grant agreement ID: 101189448

DOI

10.3030/101189448

Project closed

EC signature date 23 September 2024

Start date 1 October 2024

End date 31 March 2026

Funded under

• European Research Council (ERC)

Total cost

No data

EU contribution

€ 150 000,00

Coordinated by

KOC UNIVERSITY
Türkiye

Periodic Reporting for period 1 - BladderWatch (WEARABLE ULTRASOUND FOR CONTINUOUS BLADDER MONITORING)

Reporting period: 2024-10-01 to 2026-03-31

Summary of the context and overall objectives of the project

More than two billion people worldwide live with lower urinary tract dysfunction — a group of bladder conditions including overactive bladder, incontinence and urinary retention. Beyond the medical risks, these conditions cause discomfort, embarrassment and social isolation, and are a known driver of anxiety and depression. Yet the most important number for managing them — how full the bladder is at any given moment — can today only be measured inside a hospital, with catheters, scans or handheld ultrasound probes operated by trained staff. Once patients go home, monitoring effectively stops, and problems are often detected only after they cause harm.
BladderWatch addresses this gap with a soft, skin-worn ultrasound patch that continuously measures bladder volume during everyday life. Unlike existing wearables and clinical ultrasound, the device is wireless, gel-free and flexible, runs on safe low-voltage electronics, and uses several miniature transducers together with a simple time-of-flight method to reconstruct bladder filling with high accuracy. Results are sent to the user's smartphone, so patients and clinicians can follow trends in real time without specialist equipment.
The project has three overall objectives: to optimize the wearable transducer and its integrated electronics for bladder measurement; to validate the device in laboratory and human studies with clinical partners; and to prepare its route to patients through intellectual-property protection and a clear commercialization plan.
If successful, BladderWatch can shift bladder care from occasional hospital snapshots to continuous, comfortable, home-based monitoring supporting earlier intervention, fewer hospital admissions and a better quality of life. The same platform can later be applied to other unmet needs such as pregnancy and fretal monitoring, deep-vein thrombosis, and fluid build-up in heart or liver disease, opening a broader market for non-invasive wearable ultrasound.

Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far

The project delivered an end-to-end wearable ultrasound system for continuous bladder-volume monitoring, organized in two technical work packages: device development and clinical validation.
A flexible, skin-conformal ultrasonic patch was designed and built. The final device combines four miniature piezoelectric transducers operating at around 2 MHz with an air-backed, acoustically matched stack that allows the ultrasound signal to reach the typical depth of an adult bladder. A thin coupling layer at the skin interface was retained to ensure reliable signal transmission, a small adjustment to the originally fully gel-free target, but still more comfortable and lower-maintenance than the bulk ultrasound gel used in conventional scans.
The electronics components were built on a flexible printed-circuit board with a microcontroller, a low-voltage pulser at around 30 V (well below the ~150 V used by comparable published wearables), comparator-based echo detection, and a wireless BLE link to a custom smartphone application. Integrated water-tank tests with tissue-mimicking skin layers and 50–500 mL bladder-like phantoms demonstrated volume-estimation accuracy in the order of ±5–10%.
In the validation phase, prototypes were first tested in anatomical phantoms and then advanced into an ethics-approved first-in-human pilot study with healthy volunteers, carried out in collaboration with clinical partners. The volume-reconstruction algorithm was refined during the project to improve robustness on real anatomical signals, and the human study is ongoing.
The eventual outcome is a fully integrated wearable bladder-monitoring system including patch, electronics and mobile app, and demonstration of an end-to-end on human subjects. Results have been published in a peer-reviewed paper in Nature Communications, with a second manuscript reporting expanded in-vivo trials in preparation. Early feasibility tests also showed that the same platform can pick up vascular signals, supporting the broader vision of a single wearable ultrasound technology serving multiple unmet clinical needs such as deep-vein thrombosis monitoring.

Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far)

The closest published precedents for wearable ultrasound bladder monitoring are laboratory prototypes that rely on rigid, bulky electronics, bulk ultrasound coupling gel and excitation voltages around 150 V. These are not acceptable and comfortable for everyday wear. BladderWatch advances the state of the art on all three fronts at once: a flexible, skin-conformal four-element transducer patch that needs only a thin coupling layer instead of bulk gel; fully integrated low-voltage electronics at around 30 V on a flexible board; and wireless transmission to a smartphone application. To our knowledge, this is the first wearable bladder-volume monitor that combines these features in a single device and that has been tested head-to-head against clinical reference ultrasound, both in bladder-mimicking phantoms and in a first-in-human pilot study with healthy adult volunteers.
Beyond bladder monitoring, the same hardware platform also captured meaningful vascular signals, providing initial feasibility evidence for deep-vein thrombosis monitoring and supporting the broader vision of wearable ultrasound as a general, non-invasive window into internal tissues.
On the exploitation side, the project produced concrete translational outcome, the underlying invention is in the university's technology-transfer process toward patent filing; an advisory board of senior medtech executives is supporting commercial decisions; informal pre-submission dialogue with regulators has begun; and follow-on funding applications are under review.
To bring the device to patients, the key next-stage needs are a larger, multi-centre clinical study to build the evidence base required for medical use; formal regulatory approval under EU MDR, with parallel FDA clearance for international markets; follow-on scale-up funding for industrialization; and a route from lab-built prototypes to certified manufacturing. Engagement with the relevant medical ultrasound and urodynamics standards bodies — mapped during this project — is planned for the next phase.