Medical devices & diagnostics · Acoustic lung and heart monitoring
Tambua Health
A Nairobi founded startup that built a multichannel acoustic stethoscope meant to turn a smartphone into a lung imaging and lung function testing tool. As of September 2026, Y Combinator's own listing for the company describes a different product with a different name.
A cough into a microphone
The pitch, in its earliest form, did not need any hardware. A patient coughs three or four times into a smartphone microphone, twelve seconds each, standing close in a quiet room. The app runs a spectral analysis on the recording and returns a read on whether the cough pattern looks like tuberculosis or pneumonia. That was Tambua Health's first product, described in its own words in a 2018 submission to the MIT Solve competition: “The Tambua app is very easy to use, the user coughs into his/her microphone in a quiet room without any extraneous noise.”
By the time the company reached Y Combinator's Winter 2020 batch, the idea had grown a hardware layer. The T-Sense was a wearable pad of 32 microphone transducers, worn against the thorax, that picked up the vibrations of air moving through the lungs from more than 80 points on the body at once. Paired with software called T-Lab, it generated a moving, color coded image of the lungs, built to compete with an X-ray without the radiation.
The gap it aimed at
The case rested on a blunt fact: the stethoscope, medicine's default tool for listening to the chest, has barely changed in two centuries. “Did you know the traditional stethoscope hasn't changed in over 200 years?” a 2020 profile by Built In Africa opened, before describing how Tambua Health was trying to apply machine learning to the same job.
The scale of the problem was real. Respiratory disease killed about one in six people worldwide, roughly 2.5 million deaths a year, and more than $25 billion was spent annually on respiratory diagnostics, according to figures the company and its investor Ventures Platform cited in 2020. X-ray and CT machines are accurate but expensive and radioactive; spirometry needs trained staff the developing world often lacks. A device that could be manufactured for under $100 and read out through an ordinary smartphone, as Future Africa described it, was aimed squarely at that gap.
Three engineers and a government mapping project
Lewis Wanjohi, Daniel Gathigai and Eric Kirima met in Kenya while building a tuberculosis mapping system for the Kenyan Ministry of Health and USAID, per the company's MIT Solve submission. Wanjohi had worked with IBM and the MIT Media Lab; Gathigai, a mathematics and computer science graduate, had built health tech software and consulted for IBM and Safaricom; Kirima led machine learning.
The three were not first time founders. Two years earlier, Future Africa's profile says, they built Micronet, a rural Wi-Fi service using repurposed analogue TV signal processing, which reportedly served 20,000 users and had generated hundreds of thousands of dollars in revenue by the time Tambua Health started.
From a Merck bootcamp to Silicon Valley
The company's public path is well documented through 2020. In May 2018, as Tambua Intelligent Diagnostics, it won the Merck Accelerator Nairobi Satellite Programme's demo day, taking a $3,000 prize and a trip to Merck's Germany innovation center, Disrupt Africa reported. In 2019, Wanjohi and Gathigai became Echoing Green Global Fellows, and Digest Africa's funding record shows the company took in $100,000 from the Backstage Accelerator.
The bigger jump came in early 2020: acceptance into Y Combinator's Winter 2020 batch, one of three Kenyan startups in that cohort, with the standard $150,000 YC check. Techpoint Africa's coverage of the demo day described the pitch plainly: “A healthtech startup, Tambua, via its device, T-Sense, uses sound to take a picture of the lungs and replaces the radiation process of an X-ray with sound.” A few months later, Ventures Platform Fund and then Future Africa added Tambua Health to their portfolios. Neither disclosed an amount.
What is proven, and what is still claimed
| Evidence | What the record shows | Source type |
|---|---|---|
| FDA clearance | openFDA searches for a 510(k) or PMA applicant named “Tambua” or “Yoneda” return no matches, as of Sep 24, 2026. | Public record |
| “FDA & CE Approved” claim | Two aggregator profiles describe a product called the T-Scope as “the first FDA-approved mobile handheld ultrasound system.” No such clearance appears in openFDA, and no ultrasound product of this kind appears anywhere in the company's own materials. | Differs from record |
| Clinical study claim | The company's own site says: “We conducted a clinical study showing comparable results to an X-ray in the diagnosis of diseases like Pneumonia.” No registered trial and no PubMed paper naming Tambua Health has been found. | Not found |
| Grant and patent claims | Company materials say it received a grant from MIT and Harvard, and “has filed over a dozen patents.” No matching NIH or NSF award appears in the federal grant record. Patent searches were blocked; the one stethoscope patent that does turn up in a general search, US 11,399,772, belongs to Western Michigan University and has no visible link to Tambua. | Not found |
| Clinics and revenue | A 2020 investor profile says the device “is being piloted as a diagnostics tool in 267 clinics and has generated tens of thousands of dollars in monthly recurring revenue,” naming Stanford and MIT as COVID-research customers. Not independently confirmed. | Company-stated |
| PubMed record | A PubMed search for Tambua Health returns seven results, all an unrelated Oxford HIV study called Tambua Mapema that shares only the Swahili word tambua, meaning to know or identify. No paper on the company's technology has been found. | Not found |
| Current product | Y Combinator's live page for the tambua.health URL, checked Sep 24, 2026, is titled “Yoneda Health” and describes “NoDraw by Tambua Health,” a smartphone camera app reading optical signals from the eye and skin to estimate blood markers. This is not an acoustic or lung product, and it is not what any 2018 through 2020 source describes the company as building. | Differs from earlier record |
Read plainly: the acoustic device Tambua Health built its early reputation on, the Merck prize, the Echoing Green fellowship, the YC batch, the venture checks, is documented by independent reporting through 2020. The clinical study, the grant, the patent count and the clinic figures the company itself has claimed are not. And the company's own current listing describes a different diagnostic entirely, built around blood rather than breath.
What to watch
- Whether NoDraw, now listed under the Tambua Health name and the Yoneda Health brand, is a continuation of the same company and team, or a separate pivot that kept the domain and YC listing.
- Any FDA submission, for either the acoustic T-Sense platform or the NoDraw blood app. None has been found for either.
- Published, independent validation of the cough or lung sound diagnostic claims made between 2018 and 2020.
- A clear, current statement of what Tambua Health sells and to whom, given how far the public record diverges from the 2026 product description.
In their words
“The Tambua app is very easy to use, the user coughs into his/her microphone in a quiet room without any extraneous noise.”
Tambua Health, MIT Solve submission, 2018 · Company-stated
“While most respiratory diseases have a cure and are manageable, early diagnosis is the most essential for successful treatment. Unfortunately, medical imaging devices are invasive and expensive making them out of reach for some health care facilities. This is why the acoustic-based lung imaging and lung function test device built by Tambua is in itself revolutionary.”
Kayode Oyewole, partner at Ventures Platform Fund, quoted by Techpoint Africa, May 2020 · Independent
“A healthtech startup, Tambua, via its device, T-Sense, uses sound to take a picture of the lungs and replaces the radiation process of an X-ray with sound.”
Techpoint Africa, Y Combinator Winter 2020 demo day coverage, March 2020 · Independent
“We conducted a clinical study showing comparable results to an X-ray in the diagnosis of diseases like Pneumonia.”
Tambua Health company page, 2020 · Company-stated
“They are the developers of the T-Scope ultrasound platform, the first FDA-approved mobile handheld ultrasound system that brings high-quality whole-body ultrasound imaging to any smartphone.”
Halcyon, venture profile, accessed 2025 · Unverified claim
“NoDraw captures optical signals from the eye and skin, infers core blood markers, and returns confidence-scored outputs for clinical workflows.”
Tambua Health website, 2026 · Company-stated
Related companies
Sources
- Public recordopenFDA device 510(k) and PMA search, applicant Tambua and Yoneda
- Public recordPubMed search for Tambua Health and related terms
- Public recordClinicalTrials.gov search for Tambua
- IndependentKenyan e-health startup wins Merck Accelerator Nairobi bootcamp
- IndependentHere are the African startups that pitched at Y Combinator's Winter 2020 Demo Day
- IndependentHere are the African startups and Africa-focused firms from Y Combinator's W20 Demo Day
- IndependentVentures Platform Fund invests in three African startups as portfolio passes 30
- IndependentTambua Health Using Machine Learning to Diagnose Respiratory Diseases
- IndependentDaniel Gathigai, Fellows Directory
- IndependentLewis Wanjohi, Fellows Directory
- IndependentTambua Health Inc., company and funding record
- IndependentTambua Health, company profile
- CompanyInvesting in Tambua Health, Brass and FunnelJoy
- CompanyTambua Health helps doctors diagnose respiratory diseases
- CompanyTambua Intelligent Diagnostics, solution submission
- CompanyTambua Health website, home, company, technology, lung imaging, lung function testing and clinical trials pages
- CompanyTambua Health, Backstage Capital headliner profile
- CompanyTambua Health, LinkedIn company page
- CompanyTambua Health / Yoneda Health, company page
- CompanyTambua Health, venture profile
- CompanyTambua Health, venture profile
Profile researched and written by Healthcare Discovery. Last updated September 29, 2026.
