Scientists are making machines, wearable and implantable, to act as kidneys
Like all those whose kidneys have failed, Scott Burton’s life revolves around dialysis. For nearly two decades, Burton has been hooked up (or, since 2020, has hooked himself up at home) to a dialysis machine that performs the job his kidneys normally would. The process is arduous, time-consuming, and expensive. Except for a brief window before his body rejected a kidney transplant, Burton has depended on machines to take the place of his kidneys since he was 12-years-old. His whole life, the 39-year-old says, revolves around dialysis.
“Whenever I try to plan anything, I also have to plan my dialysis,” says Burton says, who works as a freelance videographer and editor. “It’s a full-time job in itself.”
Many of those on dialysis are in line for a kidney transplant that would allow them to trade thrice-weekly dialysis and strict dietary limits for a lifetime of immunosuppressants. Burton’s previous transplant means that his body will likely reject another donated kidney unless it matches perfectly—something he’s not counting on. It’s why he’s enthusiastic about the development of artificial kidneys, small wearable or implantable devices that would do the job of a healthy kidney while giving users like Burton more flexibility for traveling, working, and more.
Still, the devices aren’t ready for testing in humans—yet. But recent advancements in engineering mean that the first preclinical trials for an artificial kidney could happen as soon as 18 months from now, according to Jonathan Himmelfarb, a nephrologist at the University of Washington.
“It would liberate people with kidney failure,” Himmelfarb says.
An engineering marvel
Compared to the heart or the brain, the kidney doesn’t get as much respect from the medical profession, but its job is far more complex. “It does hundreds of different things,” says UCLA’s Ira Kurtz.
Kurtz would know. He’s worked as a nephrologist for 37 years, devoting his career to helping those with kidney disease. While his colleagues in cardiology and endocrinology have seen major advances in the development of artificial hearts and insulin pumps, little has changed for patients on hemodialysis. The machines remain bulky and require large volumes of a liquid called dialysate to remove toxins from a patient’s blood, along with gallons of purified water. A kidney transplant is the next best thing to someone’s own, functioning organ, but with over 600,000 Americans on dialysis and only about 100,000 kidney transplants each year, most of those in kidney failure are stuck on dialysis.
Part of the lack of progress in artificial kidney design is the sheer complexity of the kidney’s job. Each of the 45 different cell types in the kidney do something different.
Part of the lack of progress in artificial kidney design is the sheer complexity of the kidney’s job. To build an artificial heart, Kurtz says, you basically need to engineer a pump. An artificial pancreas needs to balance blood sugar levels with insulin secretion. While neither of these tasks is simple, they are fairly straightforward. The kidney, on the other hand, does more than get rid of waste products like urea and other toxins. Each of the 45 different cell types in the kidney do something different, helping to regulate electrolytes like sodium, potassium, and phosphorous; maintaining blood pressure and water balance; guiding the body’s hormonal and inflammatory responses; and aiding in the formation of red blood cells.
There's been little progress for patients during Ira Kurtz's 37 years as a nephrologist. Artificial kidneys would change that.
UCLA
Dialysis primarily filters waste, and does so well enough to keep someone alive, but it isn’t a true artificial kidney because it doesn’t perform the kidney’s other jobs, according to Kurtz, such as sensing levels of toxins, wastes, and electrolytes in the blood. Due to the size and water requirements of existing dialysis machines, the equipment isn’t portable. Physicians write a prescription for a certain duration of dialysis and assess how well it’s working with semi-regular blood tests. The process of dialysis itself, however, is conducted blind. Doctors can’t tell how much dialysis a patient needs based on kidney values at the time of treatment, says Meera Harhay, a nephrologist at Drexel University in Philadelphia.
But it’s the impact of dialysis on their day-to-day lives that creates the most problems for patients. Only one-quarter of those on dialysis are able to remain employed (compared to 85% of similar-aged adults), and many report a low quality of life. Having more flexibility in life would make a major different to her patients, Harhay says.
“Almost half their week is taken up by the burden of their treatment. It really eats away at their freedom and their ability to do things that add value to their life,” she says.
Art imitates life
The challenge for artificial kidney designers was how to compress the kidney’s natural functions into a portable, wearable, or implantable device that wouldn’t need constant access to gallons of purified and sterilized water. The other universal challenge they faced was ensuring that any part of the artificial kidney that would come in contact with blood was kept germ-free to prevent infection.
As part of last year’s KidneyX Prize, a partnership between the U.S. Department of Health and Human Services and the American Society of Nephrology, inventors were challenged to create prototypes for artificial kidneys. Himmelfarb’s team at the University of Washington’s Center for Dialysis Innovation won the prize by focusing on miniaturizing existing technologies to create a portable dialysis machine. The backpack sized AKTIV device (Ambulatory Kidney to Increase Vitality) will recycle dialysate in a closed loop system that removes urea from blood and uses light-based chemical reactions to convert the urea to nitrogen and carbon dioxide, which allows the dialysate to be recirculated.
Himmelfarb says that the AKTIV can be used when at home, work, or traveling, which will give users more flexibility and freedom. “If you had a 30-pound device that you could put in the overhead bins when traveling, you could go visit your grandkids,” he says.
Kurtz’s team at UCLA partnered with the U.S. Kidney Research Corporation and Arkansas University to develop a dialysate-free desktop device (about the size of a small printer) as the first phase of a progression that will he hopes will lead to something small and implantable. Part of the reason for the artificial kidney’s size, Kurtz says, is the number of functions his team are cramming into it. Not only will it filter urea from blood, but it will also use electricity to help regulate electrolyte levels in a process called electrodeionization. Kurtz emphasizes that these additional functions are what makes his design a true artificial kidney instead of just a small dialysis machine.
One version of an artificial kidney.
UCLA
“It doesn't have just a static function. It has a bank of sensors that measure chemicals in the blood and feeds that information back to the device,” Kurtz says.
Other startups are getting in on the game. Nephria Bio, a spinout from the South Korean-based EOFlow, is working to develop a wearable dialysis device, akin to an insulin pump, that uses miniature cartridges with nanomaterial filters to clean blood (Harhay is a scientific advisor to Nephria). Ian Welsford, Nephria’s co-founder and CTO, says that the device’s design means that it can also be used to treat acute kidney injuries in resource-limited settings. These potentials have garnered interest and investment in artificial kidneys from the U.S. Department of Defense.
For his part, Burton is most interested in an implantable device, as that would give him the most freedom. Even having a regular outpatient procedure to change batteries or filters would be a minor inconvenience to him.
“Being plugged into a machine, that’s not mimicking life,” he says.
Why you should (virtually) care
As the pandemic turns endemic, healthcare providers have been eagerly urging patients to return to their offices to enjoy the benefits of in-person care.
But wait.
The last two years have forced all sorts of organizations to be nimble, adaptable and creative in how they work, and this includes healthcare providers’ efforts to maintain continuity of care under the most challenging of conditions. So before we go back to “business as usual,” don’t we owe it to those providers and ourselves to admit that business as usual did not work for most of the people the industry exists to help? If we’re going to embrace yet another period of change – periods that don’t happen often in our complex industry – shouldn’t we first stop and ask ourselves what we’re trying to achieve?
Certainly, COVID has shown that telehealth can be an invaluable tool, particularly for patients in rural and underserved communities that lack access to specialty care. It’s also become clear that many – though not all – healthcare encounters can be effectively conducted from afar. That said, the telehealth tactics that filled the gap during the pandemic were largely stitched together substitutes for existing visit-based workflows: with offices closed, patients scheduled video visits for help managing the side effects of their blood pressure medications or to see their endocrinologist for a quarterly check-in. Anyone whose children slogged through the last year or two of remote learning can tell you that simply virtualizing existing processes doesn’t necessarily improve the experience or the outcomes!
But what if our approach to post-pandemic healthcare came from a patient-driven perspective? We have a fleeting opportunity to advance a care model centered on convenient and equitable access that first prioritizes good outcomes, then selects approaches to care – and locations – tailored to each patient. Using the example of education, imagine how effective it would be if each student, regardless of their school district and aptitude, received such individualized attention.
That’s the idea behind virtual-first care (V1C), a new care model centered on convenient, customized, high-quality care that integrates a full suite of services tailored directly to patients’ clinical needs and preferences. This package includes asynchronous communication such as texting; video and other live virtual modes; and in-person options.
V1C goes beyond what you might think of as standard “telehealth” by using evidence-based protocols and tools that include traditional and digital therapeutics and testing, personalized care plans, dynamic patient monitoring, and team-based approaches to care. This could include spit kits mailed for laboratory tests and complementing clinical care with health coaching. V1C also replaces some in-person exams with ongoing monitoring, using sensors for more ‘whole person’ care.
Amidst all this momentum, we have the opportunity to rethink the goals of healthcare innovation, but that means bringing together key stakeholders to demonstrate that sustainable V1C can redefine healthcare.
Established V1C healthcare providers such as Omada, Headspace, and Heartbeat Health, as well as emerging market entrants like Oshi, Visana, and Wellinks, work with a variety of patients who have complicated long-term conditions such as diabetes, heart failure, gastrointestinal illness, endometriosis, and COPD. V1C is comprehensive in ways that are lacking in digital health and its other predecessors: it has the potential to integrate multiple data streams, incorporate more frequent touches and check-ins over time, and manage a much wider range of chronic health conditions, improving lives and reducing disease burden now and in the future.
Recognizing the pandemic-driven interest in virtual care, significant energy and resources are already flowing fast toward V1C. Some of the world’s largest innovators jumped into V1C early on: Verily, Alphabet’s Life Sciences Company, launched Onduo in 2016 to disrupt the diabetes healthcare market, and is now well positioned to scale its solutions. Major insurers like Aetna and United now offer virtual-first plans to members, responding as organizations expand virtual options for employees. Amidst all this momentum, we have the opportunity to rethink the goals of healthcare innovation, but that means bringing together key stakeholders to demonstrate that sustainable V1C can redefine healthcare.
That was the immediate impetus for IMPACT, a consortium of V1C companies, investors, payers and patients founded last year to ensure access to high-quality, evidence-based V1C. Developed by our team at the Digital Medicine Society (DiMe) in collaboration with the American Telemedicine Association (ATA), IMPACT has begun to explore key issues that include giving patients more integrated experiences when accessing both virtual and brick-and-mortar care.
Digital Medicine Society
V1C is not, nor should it be, virtual-only care. In this new era of hybrid healthcare, success will be defined by how well providers help patients navigate the transitions. How do we smoothly hand a patient off from an onsite primary care physician to, say, a virtual cardiologist? How do we get information from a brick-and-mortar to a digital portal? How do you manage dataflow while still staying HIPAA compliant? There are many complex regulatory implications for these new models, as well as an evolving landscape in terms of privacy, security and interoperability. It will be no small task for groups like IMPACT to determine the best path forward.
None of these factors matter unless the industry can recruit and retain clinicians. Our field is facing an unprecedented workforce crisis. Traditional healthcare is making clinicians miserable, and COVID has only accelerated the trend of overworked, disenchanted healthcare workers leaving in droves. Clinicians want more interactions with patients, and fewer with computer screens – call it “More face time, less FaceTime.” No new model will succeed unless the industry can more efficiently deploy its talent – arguably its most scarce and precious resource. V1C can help with alleviating the increasing burden and frustration borne by individual physicians in today’s status quo.
In healthcare, new technological approaches inevitably provoke no shortage of skepticism. Past lessons from Silicon Valley-driven fixes have led to understandable cynicism. But V1C is a different breed of animal. By building healthcare around the patient, not the clinic, V1C can make healthcare work better for patients, payers and providers. We’re at a fork in the road: we can revert back to a broken sick-care system, or dig in and do the hard work of figuring out how this future-forward healthcare system gets financed, organized and executed. As a field, we must find the courage and summon the energy to embrace this moment, and make it a moment of change.
Podcast: The future of brain health with Percy Griffin
Today's guest is Percy Griffin, director of scientific engagement for the Alzheimer’s Association, a nonprofit that’s focused on speeding up research, finding better ways to detect Alzheimer’s earlier and other approaches for reducing risk. Percy has a doctorate in molecular cell biology from Washington University, he’s led important research on Alzheimer’s, and you can find the link to his full bio in the show notes, below.
Our topic for this conversation is the present and future of the fight against dementia. Billions of dollars have been spent by the National Institutes of Health and biotechs to research new treatments for Alzheimer's and other forms of dementia, but so far there's been little to show for it. Last year, Aduhelm became the first drug to be approved by the FDA for Alzheimer’s in 20 years, but it's received a raft of bad publicity, with red flags about its effectiveness, side effects and cost.
Meanwhile, 6.5 million Americans have Alzheimer's, and this number could increase to 13 million in 2050. Listen to this conversation if you’re concerned about your own brain health, that of family members getting older, or if you’re just concerned about the future of this country with experts predicting the number people over 65 will increase dramatically in the very near future.
Listen to the Episode
Listen on Apple | Listen on Spotify | Listen on Stitcher | Listen on Amazon | Listen on Google
4:40 - We talk about the parts of Percy’s life that led to him to concentrate on working in this important area.
6:20 - He defines Alzheimer's and dementia, and discusses the key elements of communicating science.
10:20 - Percy explains why the Alzheimer’s Association has been supportive of Aduhelm, even as others have been critical.
17:58 - We talk about therapeutics under development, which ones to be excited about, and how they could be tailored to a person's own biology.
24:25 - Percy discusses funding and tradeoffs between investing more money into Alzheimer’s research compared to other intractable diseases like cancer, and new opportunities to accelerate progress, such as ARPA-H, President Biden’s proposed agency to speed up health breakthroughs.
27:24 - We talk about the social determinants of brain health. What are the pros/cons of continuing to spend massive sums of money to develop new drugs like Aduhelm versus refocusing on expanding policies to address social determinants - like better education, nutritious food and safe drinking water - that have enabled some groups more than others to enjoy improved cognition late in life.
34:18 - Percy describes his top lifestyle recommendations for protecting your mind.
37:33 - Is napping bad for the brain?
39:39 - Circadian rhythm and Alzheimer's.
42:34 - What tests can people take to check their brain health today, and which biomarkers are we making progress on?
47:25 - Percy highlights important programs run by the Alzheimer’s Association to support advances.
Show links:
** After this episode was recorded, the Centers for Medicare and Medicaid Services affirmed its decision from last June to limit coverage of Aduhelm. More here.
- Percy Griffin's bio: https://www.alz.org/manh/events/alztalks/upcoming-...
- The Alzheimer's Association's Part the Cloud program: https://alz.org/partthecloud/about-us.asp
- The paradox of dementia rates decreasing: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7455342/
- The argument for focusing more resources on improving institutions and social processes for brain health: https://www.statnews.com/2021/09/23/the-brain-heal...
- Recent research on napping: https://www.ocregister.com/2022/03/25/alzheimers-s...
- The Alzheimer's Association helpline: https://www.alz.org/help-support/resources/helpline
- ALZConnected, a free online community for people affected by dementia https://www.alzconnected.org/
- TrialMatch for people with dementia and healthy volunteers to find clinical trials for Alzheimer's and other dementia: https://www.alz.org/alzheimers-dementia/research_p...