The social issues around urinary incontinence are many. One Japanese corporation is tackling those issues with a new device that resolves the uncertainty incontinence creates for the elderly and people with disabilities, improving their quality of life and reducing the burden on carers. We spoke to the company’s CEO about the origins of the device, what it offers users, and plans for marketing it overseas.
The DFree device predicts when wearers will next need to urinate. The latest, fifth-generation model, shown here, is smaller and lighter for improved wearability.
Anxiety over bladder control can be a significant lifestyle inhibitor for older people and those with disabilities, making them reluctant to leave their homes. Dealing with urinary incompetence can also be a major burden on carers, whose routines can be thrown into disarray by toilet troubles. DFree Inc., a Tokyo-based company, offers a handy solution to these challenges.
The inspiration for this solution came to NAKANISHI Atsushi, CEO of DFree, when he was an exchange student in the United States and an unexpected toilet accident threw the close relationship between urinary control and self-esteem into sharp relief for him. At that time, adult incontinence was receiving new recognition as a social issue in Japan, with sales of adult diapers outpacing those of baby diapers for the first time. “As the elderly population rises around the world, more adults will struggle with incontinence,” says Nakanishi. “I felt intuitively that this was a global problem that could not be ignored.”
Nakanishi’s company introduced its first wearable device in 2017. The DFree device uses ultrasonic sensors, like those found in medical ultrasound equipment, to measure the amount of urine in the bladder and notify the wearer of urinary needs in advance. Because the DFree is affixed directly to the abdomen, says Nakanishi, “at first people said it was too large to be useful, but with repeated refinements we’ve achieved a practical design.”
The initial DFree prototype was about the size of a greeting card, making it unsuited for wearing against the body, but multiple revisions have resulted in a smaller, lighter device. The current fifth-generation design is approximately 50 mm wide, 36 mm high, and 10 mm thick, weighing just 20 grams—so small that, in Nakanishi’s words, “you forget you’re even wearing it.” Without imposing any physical burden on users, the fifth-generation DFree device can send notifications about urination timing to a smartphone app or dedicated receiver, according to the individual’s situation.
Left: The DFree device. Right: The device can be worn over the lower abdomen in one of two ways: in the pocket of an adhesive sheet, or attached directly via a gel pad.
The DFree device. The device can be worn over the lower abdomen in one of two ways: in the pocket of an adhesive sheet, or attached directly via a gel pad.
Many users and carers have praised the DFree. One older woman who had given up on travel due to bladder anxiety said that using the device had made it possible for her to visit distant friends again. The company has also received reports of the device enabling children with disabilities to urinate in the toilet for the first time. Successes like this not only cultivate a sense of self-reliance in users, but they also bring joy to carers. “Hearing from users who feel positive about life again is the greatest encouragement I could hope for,” says Nakanishi.
The DFree device has many other benefits. By clearly indicating when the user needs to urinate, it frees carers from constant toilet checks and allows them to use their time more efficiently. The DFree also permits more effectively timed diaper changes, reducing the risk of skin irritation or infection for those receiving care. What’s more, since diapers contain absorbent polymers and other oil-derived materials, using fewer diapers means lower CO2 emissions from incineration—an essential part of the effort to combat global warming.
The DFree device, worn against the abdomen, uses ultrasonic sensors to monitor urine levels in the bladder. When the level reaches the threshold configured for that user, a notification is sent to the carer’s smartphone or receiver.
The DFree device, worn against the abdomen, uses ultrasonic sensors to monitor urine levels in the bladder. When the level reaches the threshold configured for that user, a notification is sent to the carer’s smartphone or receiver.
DFree has also released a device for preventing fecal soiling. Called DFree Ben, it significantly reduces the burden on carers by notifying them when feces are detected in the user’s diaper, allowing a swift response, preempting fecal smearing or leakage onto bedding. The next step, currently under development at DFree, is technology for monitoring intestinal activity and predicting defecation in advance.
DFree has established a US subsidiary and is currently working to grow awareness of its product there through clinical trials and academic presentations in conjunction with local universities and medical device manufacturers. The company plans to actively market the product in the United States as soon as it receives government approval as a medical device. DFree also sees demand rising in Europe, China, and other regions with aging populations, and holds high hopes for global expansion. “The world is aging,” says Nakanishi. “We want to use our technology to support a society where everyone enjoys peace of mind throughout their lives.”
DFree Inc. CEO NAKANISHI Atsushi holds the latest DFree model. As of summer 2025, the DFree is used by around 300 facilities in Japan, with a total of 10,000 devices sold.
DFree is more than just a medical device developer—it is squarely addressing the challenges to human dignity that arise from urinary incontinence, with the goal of using technology to restore independence and peace of mind to users. The company’s solutions support not only those on the front lines of care but also every user as they go about their daily lives.
