Jessica Vermeer
19 December 2019

In 2014, a urologist from Twente needed a solution to measure bladder content from outside of the body. The answer: an external wearable ultrasound device. Now, the first product has successfully hit the market, with a follow-up expected in early 2020. CEO Rob Tweehuysen and CTO Reinout Woltjer explain how Novioscan created the Sens-U Kids.

When giving children incontinence training, there are two main choices for the trickiest cases. Either provide the child with a timely alarm or put a moisture sensor in their diaper. The drawback, however, is that neither solution will teach the child to cope without an aid.

The Nijmegen-based start-up Novioscan has developed an ultrasound device that enables external monitoring of the bladder. The small, wireless wearable can be positioned on the lower abdomen. With ultrasound, it’s able to measure the total bladder volume. At 80 percent, the device vibrates, notifying the child to go to the bathroom.

Twente and Utrecht

Five years ago, Novioscan originated from another Nijmegen company, Noviotech. The inspiration came from Ger Dijkman, a urologist from Twente. He was looking for a solution to externally measure the content of the bladder. Research showed that this was a common question in his field and an untapped market. Dijkman’s idea was to use ultrasound to detect bladder volume. Together with Jan-Jaap Koning, Jeroen Langevoort and Rob Tweehuysen, he decided to start his own company.

At a Health Valley assembly, the foursome presented their plans. As it turned out, urologist Pieter Dik from the University Medical Center Utrecht (UMC) and medical entrepreneur Huibert Tjabbes were looking into a similar problem. In Twente, the main focus was to gain insight into how the bladder fills and empties under normal circumstances. In Utrecht, they were working on incontinence training for children that had followed multiple trainings already. They wanted a method to give biofeedback at 80 percent bladder volume.

The two sides quickly realized there was an opportunity for collaboration. They co-founded Novioscan and secured a license agreement with the UMC. The hospital was able to offer valuable support, as it was perfectly equipped to help such initiatives. There were budgets available for spin-off activities and support with clinical research.

Sens-U Kids

Since the bladder just grows with fluid volume, a device was built to determine how big the organ is. “Our Sens-U Kids product generates an ultrasound pulse, looks at the reflection from the front and back wall of the bladder and the time difference between the two. That difference is then converted into millimeters using the speed of sound,” explains Novioscan CTO Reinout Woltjer. “From six to eight measuring points in one plane, the volume is then calculated.”

Though the Sens-U Kids is capable of monitoring every second, it’s typically used to measure bladder content twice a minute. There’s an option to set a maximum threshold, to which the measured volume is compared. Once this level is reached, a warning will be issued – usually at 80 percent. The alarm is then repeated with increasing strength until the bladder is emptied. The device uses Bluetooth Low Energy to connect to a smartphone. By utilizing the Novioscan-developed app, users can set the maximum volume and get help positioning the system on the lower abdomen. After this, the solution works autonomically.

This essentially solves the questions posed in both Twente and Utrecht. An additional benefit of the Sens-U Kids device is the option to create a bladder diary, which is of great value for diagnostics, treatment and evaluation of treatments.

Minimum viable product

The greatest challenge for a wearable device is that it needs to work with a tiny battery. Mainstream ultrasound equipment, like the Bladderscan by Verathon, has a plug and needs a nurse to operate it. In addition, a medical CE marking requires validation of all claims made about what the device can do. That’s why Novioscan chose to initially aim for a minimum viable product.

“We wanted to hit the market as soon as possible,” says Woltjer. “Our only claim is that the device can measure bladder content. In reality, it may be used for incontinence training, but we left that out in our initial CE application. With the CE marking, the product can be applied in several hospitals for clinical tests, giving us valuable user information, which we could use to develop the next generation.” Although some examples showed children to successfully remain dry after removing the device, Novioscan is far away from clinically proving such functionality.

Development work for the Sens-U Kids mainly focused on creating a simple, cheap and energy-efficient design. The battery has about 10-20 percent the capacity of a mobile phone battery. Woltjer: “We claim it lasts for 24 hours, but practically, it’s about 4 or 5 days.”

Credit: Novioscan

Next generation

Novioscan is now working on a follow-up product, which is set to be released in the first quarter of 2020. Co-founder and CEO Rob Tweehuysen: “The new product will be more compact and comfortable to wear for children in wheelchairs. The functionality will be exactly the same but with an upgraded design. It will be 35 percent smaller and more rounded. This means we don’t need another CE review.” As soon as the new product is released, the old one will be taken off the market.

For now, the Sens-U Kids is a standalone system. All data is stored within the device. A physician can download everything in one go. In principle, the system could develop into a data collection device as well. But, as Woltjer points out, “Going to the cloud would mean meeting numerous privacy demands.”

The next generation will truly take things to the next level and will require a new CE application. Tweehuysen: “That device needs to work for adults as well, which is medically more challenging. The bladder is positioned deeper inside the body and the shape varies more, as does the BMI index of the person wearing it.” The target group will be elderly people in nursing homes. The current product does work for adults, but not nearly good enough. The development will, therefore, start from scratch again.

Generate cash

Currently, all turnover comes from doctors and hospitals. “A minimum viable product was a deliberate choice. We can get useful feedback from medical staff, which is what we need right now,” says Woltjer. The product is sold for 900 euros. Going to larger volumes, the price will naturally go down.

Financially, Novioscan is not yet ready for the next step. “We first need to generate cash,” notes Tweehuysen. Woltjer adds: “In the long term, we want to have a technology platform that can be used for different applications. To be and stay top-of-the-bill, maybe until we can insert ultrasound devices within the body.”