Ordinary people are living better with chronic conditions thanks to a recent explosion of developments in medical implants.
Beware, cyborgs walk among us. They’re mostly indistinguishable from regular humans and are infiltrating every nook and cranny of society. For full disclosure, I’m one myself. No, we’re not deadly intergalactic conquerors like the Borg race of Star Trek fame, just ordinary people living better with chronic conditions thanks to medical implants.
In recent years there has been an explosion of developments in implantable devices that merge multiple technologies into gadgets that work in concert with human physiology for the treatment of serious diseases. Pacemakers for the heart are the best-known implants, as well as other cardiac devices like LVADs (left-ventricular assist devices) and implanted defibrillators. Next-generation devices address an array of organ failures, and many are intended as permanent. The driving need behind this technology: a critical, persistent shortage of implantable biological organs.
The demand for transplantable organs dwarfs their availability. There are currently over 100,000 people on the transplant waiting list in the U.S., compared to 40,000 transplants completed in 2021. But even this doesn’t reflect the number of people in dire straits who don’t qualify for a transplant because of things like frailty, smoking status and their low odds of surviving the surgery.
My journey to becoming a cyborg came about because of a lifelong medical condition characterized by pathologically low motility of the digestive system, called gastroparesis. Ever since I was in my teens, I’ve had chronic problems with severe nausea. Flareups can be totally incapacitating and last anywhere from hours to months, interspersed with periods of relief. The cycle is totally unpredictable, and for decades my condition went both un- and misdiagnosed by doctors who were not even aware that the condition existed. Over the years I was labeled with whatever fashionable but totally inappropriate medical label existed at the time, and not infrequently, hypochondria.
Living with the gastric pacer is easy. In fact, most of the time, I don’t even know it’s there.
One of the biggest turning points in my life came when a surgeon at the George Washington University Hospital, Dr. Frederick Brody, ordered a gastric emptying test that revealed gastroparesis. This was in 2009, and an implantable device, called a gastric pacer, had been approved by the FDA for compassionate use, meaning that no other treatments were available. The small device is like a pacemaker that’s implanted beneath the skin of the abdomen and is attached to the stomach through electrodes that carry electrical pulses that stimulate the stomach, making it contract as it’s supposed to.
Dr. Brody implanted the electrical wires and the device, and, once my stomach started to respond to the pulses, I got the most significant nausea relief I’d had in decades of futile treatments. It sounds cliché to say that my debt to Dr. Brody is immeasurable, but the pacer has given me more years of relative normalcy than I previously could have dreamed of.
I should emphasize that the pacer is not a cure. I still take a lot of medicine and have to maintain a soft, primarily vegetarian diet, and the condition has progressed with age. I have ups and downs, and can still have periods of severe illness, but there’s no doubt I would be far worse off without the electrical stimulation provided by the pacer.
Living with the gastric pacer is easy. In fact, most of the time, I don’t even know it’s there. It entails periodic visits with a surgeon who can adjust the strength of the electrical pulses using a wireless device, so when symptoms are worse, he or she can amp up the juice. If the pulses are too strong, they can cause annoying contractions in the abdominal muscles, but this is easily fixed with a simple wireless adjustment. The battery runs down after a few years, and when this happens the whole device has to be replaced in what is considered minor surgery.
Such devices could fill gaps in treating other organ failures. By far most of the people on transplant waiting lists are waiting for kidneys. Despite the fact that live donations are possible, there’s still a dire shortage of organs. A bright spot on the horizon is The Kidney Project, a program spearheaded by bioengineer Shuvo Roy at the University of California, San Francisco, which is developing a fully implantable artificial kidney. The device combines living cells with artificial materials and relies not on a battery, but on the patient’s own blood pressure to keep it functioning.
Several years into this project, a prototype of the kidney, about the size of a smart phone, has been successfully tested in pigs. The device seems to provide many of the functions of a biological kidney (unlike dialysis, which replaces only one main function) and reliably produces urine. One of its most critical components is a special artificial membrane, called a hemofilter, that filters out toxins and waste products from the blood without leaking important molecules like albumin. Since it allows for total mobility, the artificial kidney will provide patients with a higher quality of life than those on dialysis, and is in some important ways, even better than a biological transplant.
The beauty of the device is that, even though it contains kidney cells sourced, as of now, from cadavers or pigs, the cells are treated so that they can’t be rejected and the device doesn’t require the highly problematic immunosuppressant drugs a biological organ requires. “Anti-rejection drugs,” says Roy, “make you susceptible to all kinds of infections and damage the transplanted organ, causing steady deterioration. Eventually they kill the kidney. A biological transplant has about a 10-year limit,” after which the kidney fails and the body rejects it.
Eventually, says Roy, the cells used in the artificial kidney will be sourced from the patient himself, the ultimate genetic match. The patient’s adult stem cells can be used to produce some or all of the 25 to 30 specialized cells of a biological kidney that provide all the functions of a natural organ. People formerly on dialysis could drastically improve their functionality and quality of life without being tethered to a machine for hours at a time, three days a week.
As exciting as this project is, it suffers from a common theme in early biomedical research—keeping a steady stream of funding that will move the project from the lab, into human clinical trials and eventually to the bedside. “It’s the issue,” says Roy. “Potential investors want to see more data indicating that it works, but you need funding to create data. It’s a Catch-22 that puts you in a kind of no-man’s land of funding.” The constant pursuit of funding introduces a variable that makes it hard to predict when the kidney will make it to market, despite the enormous need for such a technology.
Another critical variable is if and when insurance companies will decide to cover transplants with the artificial kidney, so that it becomes affordable for the average person. But Roy thinks that this hurdle, too, will be crossed. Insurance companies stand to save a great deal of money compared to what they ordinarily spend on transplant patients. The cost of yearly maintenance will be a fraction of that associated with the tens of thousands of dollars for immunosuppressant drugs and the attendant complications associated with a biological transplant.
One estimate that the multidisciplinary team of researchers involved with The Kidney Project are still trying to establish is how long the artificial kidney will last once transplanted into the body. Animal trials so far have been looking at how the kidney works for 30 days, and will soon extend that study to 90 days. Additional studies will extend much farther into the future, but first the kidneys have to be implanted into people who can be followed over many years to answer this question. But unlike the gastric pacer and other implants, there won’t be a need for periodic surgeries to replace a depleted battery, and the stark improvements in quality of life compared to dialysis add a special dimension to the value of whatever time the kidney lasts.
Another life-saving implant could address a major scourge of the modern world—heart disease. Despite significant advances in recent decades, including the cardiac implants mentioned above, cardiovascular disease still causes one in three deaths across the world. One of the most promising developments in recent years is the Total Artificial Heart, a pneumatically driven device that can be used in patients with biventricular heart failure, affecting both sides of the heart, when a biological organ is not available.
The TAH is implanted in the chest cavity and has two tubes that snake down the body, come out through the abdomen and attach to a 13.5-pound external driver that the patient carries around in a backpack. It was first developed as a bridge to transplant, a temporary alternative while the patient waited for a biological heart to replace it. However, SynCardia Systems, LLC, the Tucson-based company that makes it, is now investigating whether the heart can be used on a long-term basis.
There’s good reason to think that this will be the case. I spoke with Daniel Teo, one of the board members of SynCardia, who said that so far, one patient lived with the TAH for six years and nine months, before he died of other causes. Another patient, still alive, has lived with the device for over five years and another one has lived with it for over four years. About 2,000 of these transplants have been done in patients waiting for biological hearts so far, and most have lived mobile, even active lives. One TAH recipient hiked for 600 miles, and another ran the 4.2-mile Pat Tillman Run, both while on the artificial heart. This is a far cry from their activities before surgery, while living with advanced heart failure.
Randy Shepard, a recipient of the Total Artificial Heart, teaches archery to his son.
Randy Shepard
If removing and replacing one’s biological heart with a synthetic device sounds scary, it is. But then so is replacing one’s heart with biological one. “The TAH is very emotionally loaded for most people,” says Teo. “People sometimes hold back because of philosophical, existential questions and other nonmedical reasons.” He also cites cultural reasons why some people could be hesitant to accept an artificial heart, saying that some religions could frown upon it, just as they forbid other medical interventions.
The first TAHs that were approved were 70 cubic centimeters in size and fit into the chest cavities of men and larger women, but there’s now a smaller, 50 cc size meant for women and adolescents. The FDA first cleared the 70 cc heart as a bridge to transplant in 2004, and the 50 cc model received approval in 2014. SynCardia’s focus now is on seeking FDA approval to use the heart on a long-term basis. There are other improvements in the works.
One issue being refined deals with the external driver that holds the pneumatic device for moving the blood through a patient’s body. The two tubes connecting the driver to the heart entail openings in the skin that could get infected, and carrying the backpack is less than ideal. The driver also makes an audible sound that some people find disturbing. The next generation TAH will be quieter and involve wearing a smaller, lighter device on a belt rather than carrying the backpack. SynCardia is also working toward a fully implantable heart that wouldn’t require any external components and would contain an energy source that can be recharged wirelessly.
Teo says the jury is out as to whether artificial hearts will ever obviate the need for biological organs, but the world’s number one killer isn’t going away any time soon. “The heart is one of the strongest organs,” he says, “but it’s not made to last forever. If you live long enough, the heart will eventually fail, and heart failure leads to the failure of other organs like the kidney, the lungs and the liver.” As long as this remains the case and as long as the current direction of research continues, artificial organs are likely to play an ever larger part of our everyday lives.
Oh, wait. Maybe we cyborgs will take over the world after all.
Jessica Fitzjohn, a postdoctoral fellow at the University of Canterbury, demonstrates the novel breast cancer screening device.
Researchers at the University of Canterbury and startup Tiro Medical in Christchurch, New Zealand are hoping their new device—which doesn’t involve any radiation or compression of the breasts—could increase the accuracy of breast cancer screening, broaden access and encourage more women to get checked. They’re digging into clues from the way buildings move in an earthquake to help detect more cases of this disease.
Earthquake engineering inspires new breast cancer screening tech
What’s underneath a surface affects how it vibrates. Earthquake engineers look at the vibrations of swaying buildings to identify the underlying soil and tissue properties. “As the vibration wave travels, it reflects the stiffness of the material between that wave and the surface,” says Geoff Chase, professor of engineering at the University of Canterbury in Christchurch, New Zealand.
Chase is applying this same concept to breasts. Analyzing the surface motion of the breast as it vibrates could reveal the stiffness of the tissues underneath. Regions of high stiffness could point to cancer, given that cancerous breast tissue can be up to 20 times stiffer than normal tissue. “If in essence every woman’s breast is soft soil, then if you have some granite rocks in there, we’re going to see that on the surface,” explains Chase.
The earthquake-inspired device exceeds the 87 percent sensitivity of a 3D mammogram.
That notion underpins a new breast screening device, the brainchild of Chase. Women lie face down, with their breast being screened inside a circular hole and the nipple resting on a small disc called an actuator. The actuator moves up and down, between one and two millimeters, so there’s a small vibration, “almost like having your phone vibrate on your nipple,” says Jessica Fitzjohn, a postdoctoral fellow at the University of Canterbury who collaborated on the device design with Chase.
Cameras surrounding the device take photos of the breast surface motion as it vibrates. The photos are fed into image processing algorithms that convert them into data points. Then, diagnostic algorithms analyze those data points to find any differences in the breast tissue. “We’re looking for that stiffness contrast which could indicate a tumor,” Fitzjohn says.
A nascent yet promising technology
The device has been tested in a clinical trial of 14 women: one with healthy breasts and 13 with a tumor in one breast. The cohort was small but diverse, varying in age, breast volume and tumor size.
Results from the trial yielded a sensitivity rate, or the likelihood of correctly detecting breast cancer, of 85 percent. Meanwhile, the device’s specificity rate, or the probability of diagnosing healthy breasts, was 77 percent. By combining and optimizing certain diagnostic algorithms, the device reached between 92 and 100 percent sensitivity and between 80 and 86 percent specificity, which is comparable to the latest 3D mammogram technology. Called tomosynthesis, these 3D mammograms take a number of sharper, clearer and more detailed 3D images compared to the single 2D image of a conventional mammogram, and have a specificity score of 92 percent. Although the earthquake-inspired device’s specificity is lower, it exceeds the 87 percent sensitivity of a 3D mammogram.
The team hopes that cameras with better resolution can help improve the numbers. And with a limited amount of data in the first trial, the researchers are looking into funding for another clinical trial to validate their results on a larger cohort size.
Additionally, during the trial, the device correctly identified one woman’s breast as healthy, while her prior mammogram gave a false positive. The device correctly identified it as being healthy tissue. It was also able to capture the tiniest tumor at 7 millimeters—around a third of an inch or half as long as an aspirin tablet.
Diagnostic findings from the device are immediate.
When using the earthquake-inspired device, women lie face down, with their breast being screened inside circular holes.
University of Canterbury.
But more testing is needed to “prove the device’s ability to pick up small breast cancers less than 10 to 15 millimeters in size, as we know that finding cancers when they are small is the best way of improving outcomes,” says Richard Annand, a radiologist at Pacific Radiology in New Zealand. He explains that mammography already detects most precancerous lesions, so if the device will only be able to find large masses or lumps it won’t be particularly useful. While not directly involved in administering the clinical trial for the device, Annand was a director at the time for Canterbury Breastcare, where the trial occurred.
Meanwhile, Monique Gary, a breast surgical oncologist and medical director of the Grand View Health Cancer program in Pennsylvania, U.S., is excited to see new technologies advancing breast cancer screening and early detection. But she notes that the device may be challenging for “patients who are unable to lay prone, such as pregnant women as well as those who are differently abled, and this machine might exclude them.” She adds that it would also be interesting to explore how breast implants would impact the device’s vibrational frequency.
Diagnostic findings from the device are immediate, with the results available “before you put your clothes back on,” Chase says. The absence of any radiation is another benefit, though Annand considers it a minor edge “as we know the radiation dose used in mammography is minimal, and the advantages of having a mammogram far outweigh the potential risk of radiation.”
The researchers also conducted a separate ergonomic trial with 40 women to assess the device’s comfort, safety and ease of use. Angela was part of that trial and described the experience as “easy, quick, painless and required no manual intervention from an operator.” And if a person is uncomfortable being topless or having their breasts touched by someone else, “this type of device would make them more comfortable and less exposed,” she says.
While mammograms remain “the ‘gold standard’ in breast imaging, particularly screening, physicians need an option that can be used in combination with mammography.
Fitzjohn acknowledges that “at the moment, it’s quite a crude prototype—it’s just a block that you lie on.” The team prioritized function over form initially, but they’re now planning a few design improvements, including more cushioning for the breasts and the surface where the women lie on.
While mammograms remains “the ‘gold standard’ in breast imaging, particularly screening, physicians need an option that is good at excluding breast cancer when used in combination with mammography, has good availability, is easy to use and is affordable. There is the possibility that the device could fill this role,” Annand says.
Indeed, the researchers envision their new breast screening device as complementary to mammograms—a prescreening tool that could make breast cancer checks widely available. As the device is portable and doesn’t require specialized knowledge to operate, it can be used in clinics, pop-up screening facilities and rural communities. “If it was easily accessible, particularly as part of a checkup with a [general practitioner] or done in a practice the patient is familiar with, it may encourage more women to access this service,” Angela says. For those who find regular mammograms uncomfortable or can’t afford them, the earthquake-inspired device may be an option—and an even better one.
Broadening access could prompt more women to go for screenings, particularly younger women at higher risk of getting breast cancer because of a family history of the disease or specific gene mutations. “If we can provide an option for them then we can catch those cancers earlier,” Fitzjohn syas. “By taking screening to people, we’re increasing patient-centric care.”
With the team aiming to lower the device’s cost to somewhere between five and eight times less than mammography equipment, it would also be valuable for low-to-middle-income nations that are challenged to afford the infrastructure for mammograms or may not have enough skilled radiologists.
For Fitzjohn, the ultimate goal is to “increase equity in breast screening and catch cancer early so we have better outcomes for women who are diagnosed with breast cancer.”