Before PPIs existed. Before acid reflux had a brand name.
Before GERD was even a diagnosis.
For over sixty years, a capsule the size of a multivitamin has done something no pill, scan, or scope can do: tell a clinician, in real time, exactly how much acid a living human stomach is making. It survived the rise and fall of the H2 blocker, the proton pump inhibitor gold rush, and the FDA's most aggressive supplement-era enforcement actions. The Heidelberg pH Capsule System is the only commercially available device that measures real-time gastric acid secretion, a technology as valuable now as it has ever been. Under new leadership, a new chapter is being written. But here is the story of how we got here, beginning in a children's clinic on the Neckar, running through a Bell Labs patent symposium, and crossing an ocean in a single suitcase.
Our story begins with a doctor who refused to accept the way things were done.
In the 1950s, Dr. Hans-Günter Nöller was a young physician at the Universitäts-Kinderklinik Heidelberg, working under Prof. Philipp Bamberger. Bamberger had survived the Soviet siege of Königsberg in 1945, spent the final days of the war hiding orphans in a clinic bunker, and after deportation east, returned to rebuild a children's hospital from the rubble. By the late 1950s he had moved his clinic to the new Neuenheimer Feld campus and turned it into one of Germany's leading centres for clinical-experimental pediatrics. It was exactly the kind of place where a young doctor with an unusual idea would be taken seriously.
Nöller's earliest published work, in Klinische Wochenschrift in 1955, described a gentler method for drawing blood from infants. He was, from the beginning, a physician preoccupied with reducing what patients had to endure.
At the time, the only way to measure stomach acid was to feed a rubber tube through a patient's nose, into the stomach, and aspirate the contents for hours. Nöller wanted to know if there was another way. The answer came from an unlikely source.
In April 1952, Bell Telephone Laboratories in Murray Hill, New Jersey, had opened its transistor patent estate to the world at a legendary nine-day symposium. For a $25,000 entry fee, foreign firms could purchase the technical reference set engineers nicknamed "Ma Bell's Cookbook." Three German companies bought in, among them Telefunken, the electronics giant founded in 1903 as Kaiser Wilhelm II's compromise between AEG and Siemens. Telefunken had inherited decades of high-frequency radio engineering, Karl Ferdinand Braun's Nobel-winning wireless research, and a culture of miniaturisation that stretched back to wartime transmitter design. By the late 1950s, their facility in Ulm was producing West Germany's first commercial germanium transistors under that Bell license.
It was the perfect partner for what Nöller had in mind.
Together, they built something that had never existed: a swallowable radio transmitter. The capsule was small enough to swallow like a vitamin, sealed inside a medical-grade polyacrylate shell with a physiological battery that activated on contact with the body. Inside was a single transistor oscillator with an antimony pH electrode engineered to produce a remarkably stable signal, even in the heat, motion, and chemical environment of a living stomach.
The patient swallowed the capsule. It broadcast. An antenna belt picked up the signal. A chart recorder traced gastric pH in real time, minute by minute, without a single tube.
Nöller filed his German patent, DE 1 220 966 B, on 31 December 1958. The US patent, 3,340,866, "Ingestible pH responsive radio transmitter," was granted on 12 September 1967. His first major clinical paper appeared in Deutsche Medizinische Wochenschrift on 23 September 1960. Reading the abstract today, you can still feel a young doctor's pride in two things: that the device "permits gastric juice examination without any annoyance to the patient from a tube," and that it measured a wholly new clinical quantity he called Säurebildungsleistung. Acid-forming capacity.
That concept, measuring not just whether the stomach contains acid but how much acid it can actually produce under challenge, is the foundation our test still stands on today.
To understand why clinicians embraced the swallowable radio so quickly, you have to understand what came before it.
For most of the twentieth century, measuring stomach acid was an ordeal. The patient swallowed a rubber tube through the nose into the stomach and sat upright for hours while a technician aspirated gastric juice at timed intervals. It was uncomfortable, imprecise, and often produced unreliable results because the tube itself interfered with normal stomach function.
By the 1950s, physicians had added injectable stimulants to force the stomach to produce acid at maximum output. The side effects were significant: flushing, sweating, drops in blood pressure, rapid heartbeat. The tests were unsafe in pregnancy and heart disease, and essentially impossible to perform on children.
The most extreme version, developed in 1946, was designed to verify whether a surgical procedure had successfully cut the nerve supply to the stomach. It worked by deliberately inducing dangerously low blood sugar in a post-operative patient while a tube measured whether the stomach could still produce acid. The risks were serious enough that by the late 1970s, the procedure was widely acknowledged as too dangerous for routine diagnostic use.
This was the clinical world our capsule entered. Measuring stomach acid required a tube, a needle, a distressed patient, and hours of monitoring. A capsule you could swallow like a vitamin was not just an improvement. It was a transformation.
The Heidelberg test arrived in the United States in the mid-1960s in the hands of Carroll Hayward. He acquired the technology from Nöller's group in Germany, founded Heidelberg International in the Atlanta metro area, and dedicated his working life to manufacturing and distributing a single device. By 1969 the capsule had appeared in the American surgical literature as a "tubeless gastric analysis." Hayward sold it directly to clinicians, trained their staff, repaired their equipment, and built a loyal customer base one practitioner at a time.
What Hayward could not have known was that his timing would become the most valuable asset the company ever held.
On 28 May 1976, the Medical Device Amendments to the Federal Food, Drug, and Cosmetic Act took effect. Congress gave the FDA authority to regulate medical devices, but only going forward. Any device legally marketed in interstate commerce before that date was permanently designated a preamendments device, grandfathered into the new regulatory framework without requiring premarket review.
The Heidelberg capsule was already on the American market. It received product code FFT, regulation 21 CFR 876.1400, classified Class I, and was made explicitly exempt from 510(k) premarket notification.
That status cannot be reproduced. No company founded today, regardless of its engineering, can obtain preamendments grandfathered standing. The only way to hold it is to have been there before the spring of 1976. We were.
For over three decades, Carroll Hayward built and ran a successful business, manufacturing and distributing the Heidelberg system to clinicians across the country. In 1999, he formed Heidelberg Medical, Inc. when he moved the business to the north Georgia mountains, where the company has remained ever since. In 2006, Carroll retired, and Harry Simmons, alongside his family, continued the legacy, shipping capsules and systems to a growing network of practitioners nationwide: naturopaths, integrative physicians, and a dedicated group of gastroenterologists who understood the value of what this device could do.
The reason the medical establishment moved away from measuring stomach acid is straightforward: the pharmaceutical industry made it unnecessary to ask the question.
The shift began in London. Sir James Black, the Scottish pharmacologist who had already invented the beta-blocker propranolol, spent twelve years designing a drug that could block the histamine receptor responsible for driving acid secretion. Tagamet, the first H2 blocker, received FDA approval in August 1977. It cut gastric acid output by roughly 70 percent, healed ulcers without surgery, and by 1986 became the first pharmaceutical product to cross one billion dollars in annual sales. Black shared the 1988 Nobel Prize.
Glaxo followed with Zantac in 1983, pricing it at a premium to signal superiority. By 1987 it was the best-selling prescription drug in the world.
Then came the proton pump inhibitors. Researchers at Astra in Sweden had developed omeprazole, a compound that could suppress more than 90 percent of acid output by binding directly to the acid-producing pump on the parietal cell. The FDA approved it as Prilosec in 1989. Through the 1990s, American PPI use grew by 450 percent. Annual revenue passed six billion dollars.
When the patent expired, AstraZeneca isolated a molecular variant, patented it as a new compound, and launched Nexium weeks ahead of the generic. The pharmacological difference was marginal. Lifetime Nexium sales exceeded 52 billion dollars.
By the mid-2010s, more than fifteen million Americans were on chronic PPIs, with millions more purchasing them over the counter. The global market peaked at roughly 26 billion dollars. Studies suggest that up to sixty percent of those prescriptions lacked a documented clinical indication.
The drugs changed the diagnostic question itself. Physicians stopped asking how much acid a patient was making and started asking whether a PPI relieved symptoms. The empirical trial, prescribe it and see, became the default. Measuring gastric acid was no longer part of the conversation.
A parallel discovery in Perth completed the shift. Barry Marshall and Robin Warren identified Helicobacter pylori as the cause of most peptic ulcers, reframing ulcer disease as an infection rather than an acid-output disorder. Marshall famously drank a culture of the bacterium in 1984 to prove the point. The two shared the 2005 Nobel Prize. With ulcers redefined as infectious, the clinical interest in quantifying how much acid the stomach produced faded further.
Within a single generation, gastroenterology training programs stopped teaching gastric acid measurement. The diagnostic infrastructure disappeared. The drugs that suppressed acid had made the question seem irrelevant.
The Heidelberg test kept working. The question it answers never stopped mattering. The rest of medicine simply stopped asking it.
In 1973, Dr. Jonathan V. Wright, an internal medicine physician trained at Harvard and the University of Michigan, opened Tahoma Clinic in Tukwila, Washington. He bought a Heidelberg system early on. And then he did something almost no one else in America was doing: he tested every heartburn patient who walked through the door.
What Wright found challenged a generation of clinical thinking. Across thousands of patients tested at Tahoma over the next two decades, hypochlorhydria, not excess acid, was present in over 90 percent of those with mild to moderate heartburn, indigestion, bloating, and gas. Especially in patients over thirty-five. Their stomachs were not producing too much acid. They were producing too little. The reflux symptoms came from delayed gastric emptying, weakened sphincter tone, and bacterial overgrowth, problems that acid suppression made worse, not better.
Wright made this the centrepiece of his career. In 2001, he and co-author Lane Lenard published Why Stomach Acid Is Good for You, a book that laid out the clinical case in plain language. Tahoma Clinic ran continuously for fifty-two years before closing in April 2025, marking Wright's retirement.
He was not alone. A generation of practitioners built on the same foundation.Joseph Pizzorno co-founded Bastyr University in Seattle in 1978, the first accredited naturopathic medical college in the United States, and made gastric pH testing a cornerstone of his clinical teaching. His Textbook of Natural Medicine, co-authored with Michael T. Murray, is now in its fifth edition with over 100,000 copies in print across four languages. Murray taught a generation of naturopathic students that low stomach acid was a hidden driver of nutrient deficiency and chronic gastrointestinal conditions.
Stephen Barrie, ND, founded Great Smokies Diagnostic Laboratory in Asheville in 1986, later rebranded as Genova Diagnostics, building the functional medicine laboratory infrastructure in which Heidelberg gastric analysis became standard practice. Steven Sandberg-Lewis, whose textbook Functional Gastroenterology has been a clinical reference since 2009, taught Heidelberg testing as core practice at the National University of Natural Medicine in Portland and co-founded the NUNM SIBO Center for Digestive Health.
By the early 2000s, an estimated thousand American practitioners were running our test in their offices: naturopaths, integrative physicians, chiropractors, and a dedicated group of gastroenterologists who never stopped asking the question the rest of medicine had moved past.
The concerns that practitioners like Wright had raised for decades began appearing in the mainstream medical literature in the late 2000s.
In 2006, a study in JAMA showed that long-term PPI use raised the risk of hip fracture, prompting an FDA label change in 2010. The FDA followed with safety communications on PPI-associated magnesium depletion in 2011 and increased risk of C. difficile infection in 2012. Studies in JAMA in 2013 documented vitamin B12 deficiency in long-term PPI users. A meta-analysis the same year found that PPI use roughly doubled the risk of small intestinal bacterial overgrowth. Further studies in 2016 linked PPI use to increased incidence of dementia and chronic kidney disease.
But the most significant finding came in 2009, published in Gastroenterology. Researchers in Denmark randomised 120 healthy volunteers with no history of significant reflux to either twelve weeks of placebo or eight weeks of a PPI followed by four weeks of placebo. Forty-four percent of the volunteers who stopped the PPI developed clinically significant heartburn, regurgitation, or dyspepsia during withdrawal, compared with only fifteen percent in the placebo group.
The accompanying editorial stated it plainly: proton pump inhibitor therapy induces the symptoms it is used to treat.
People without reflux who took PPIs became people with reflux who needed PPIs. It was not a rare side effect. It was the pharmacology working as designed.The practitioners who had been using our test for years already knew this. They had been measuring the underlying physiology in their offices while the published literature caught up. The Heidelberg capsule had been providing the data all along. Now the evidence base confirmed what the data had been showing.
The wireless capsule diagnostics space that had grown alongside Heidelberg through the 1990s and 2000s has narrowed considerably. In June 2023, Medtronic discontinued the SmartPill, a wireless motility capsule that had been on the market for seventeen years, citing an inability to source critical specialised components. There was no replacement. In June 2025, the Bravo wireless esophageal pH capsule entered a Class I FDA recall after reported adhesive failures.
Neither of those devices did what ours does. The SmartPill measured motility and transit time. The Bravo measures esophageal pH for reflux assessment. Neither one has ever measured real-time gastric acid secretion. That capability belongs to one device, and it always has.
We are still here. We are still manufacturing. And we are the only ones left.
Our current chapter began in Los Angeles.
Dr. Farshid Sam Rahbar, MD, is a board-certified gastroenterologist and the founder of Los Angeles Integrative Gastroenterology & Nutrition. He is one of the country's most respected practitioners of integrative gastroenterology, combining conventional GI training with deep expertise in the complex chronic digestive conditions that standard workups often miss. He had been running Heidelberg studies for years.
In 2016, Dr. Rahbar introduced the Heidelberg test to Michael Erdman, a young English physician who had trained at King's College London School of Medicine. For the next decade, the two shared an office in Los Angeles, Erdman with GutRest Digestive Health and Rahbar with Los Angeles Integrative Gastroenterology & Nutrition. They worked side by side on the same patient population, driven by the same conviction that gastric acid function was central to understanding chronic digestive illness. Erdman performed hundreds of Heidelberg tests over that decade, building a depth of clinical experience with the device that few practitioners anywhere can match.
When Heidelberg Medical needed new leadership, Erdman became CEO. He brings a decade of experience as both a practitioner of the test and an advocate for it, educating clinicians and patients on the diagnostic system and its role in modern gastroenterology.
The company is now in a new era. Upgraded software. A growing practitioner network. And a single purpose: putting this test in the hands of every clinician and patient who needs it.
The Heidelberg pH Capsule System has been in continuous clinical use for over six decades. In that time, the medical landscape around it has shifted dramatically. The drugs changed. The guidelines changed. The training changed. The diagnostic tools came and went.
Our test stayed.It stayed because it answers a question nothing else can: how much acid is this stomach actually making, in real time, under challenge? That question mattered in 1964 when Nöller built the first capsule. It matters now, when millions of patients are on long-term acid suppression without ever having had their gastric acid function measured.
The foundation of this company was laid by Nöller and Bamberger in Heidelberg, by Carroll Hayward in Georgia, by the Simmons family who carried it forward for years, by Jonathan Wright who tested every patient who walked through his door, by Joseph Pizzorno and the generation of practitioners who made gastric acid assessment part of their clinical training, and by Dr. Rahbar and Dr. Erdman who spent a decade using the device on the patients who needed it most.
We carry all of that forward.
What comes next is already in motion. More will be shared soon.
The Heidelberg pH Capsule is a Class I medical device, 510(k)-exempt, listed with the U.S. Food and Drug Administration under 21 CFR §876.1400. Listing of a device does not denote FDA approval, clearance, or endorsement.