The Glia Stethoscope Project
The iconic stethoscope is a relatively simple instrument which allows a medical provider to auscultate (listen to) the sounds produced by the heart, lungs, stomach, and other internal organs. These sounds reach the providers ears via two earpieces connected to hollow tubing, which in turn connects to the chest piece and “bell”- a round, flat section equipped with an interior diaphragm. While universally recognized as a symbol of competent healthcare, for decades the stethoscope has experienced minimal fabrication or design innovation. Despite this, the Littmann Cardiology III, widely regarded as the field’s gold standard, still retails for over $100.
This cost is a barrier across diverse socioeconomic settings. In higher-income countries, allied professionals such as nurses and paramedics are often unable to afford expensive stethoscopes, particularly as an undergraduate requirement for clinical rotations. In low-middle income countries, especially those with rural areas, stethoscopes are a luxury item which are either unaffordable or simply non-existent. Many healthcare professionals in these environments have never used one.
Dr. Tarek Loubani, Glia Medical Director, first experienced this troubling access disparity in Gaza during a mass casualty event in 2012. He observed several emergency medicine providers actively treating patients while exhibiting dried blood on their ear and lateral head area. Dr. Loubani discovered that the dried blood came from providers putting their ear against an injured patient’s chest, trying to hear lung or heart sounds to appropriately triage casualties. This experience combined with a Fisher-Price toy doctor kit chance encounter inspired Dr. Loubani to create an affordable, clinically effective stethoscope which could also be fabricated in low-resource settings.
By 2014, significant research with an international team was underway for this project and initial prototypes were printed in Gaza by 2015, using the 1968 Littmann stethoscope design as inspiration. In 2016, manufacturing began in London, Ontario on the Glia Stethoscope, resulting in two hundred devices being distributed to the Western University Hospital Ontario emergency and internal medicine departments. In 2017, Glia Gaza was formally established with the stethoscope as a flagship production. In 2018, the Glia stethoscope research team published a peer-reviewed article, validating that the 3D-printable stethoscope performed at the same clinical standards of the Littmann Cardiology III.
The peer-reviewed validation of the Glia Stethoscope catalyzed a surge of interest in the device, especially by medical students at Schulich School of Medicine, the University of Ottawa, and the University of Toronto. As a result of stethoscope distribution, Glia inspired the founding of the Free & Open-Source Medical Club at Schulich, the members of which are enthusiastic Glia collaborators. Additionally, the Canadian Science and Technology Museum currently features a Glia stethoscope on the historic “wall of stethoscopes” for the Medical Sensations Exhibit.
Due to multiple access barriers to this basic yet primary medical tool, Glia was determined to produce a stethoscope that was open source and affordable, yet still performed equal to or better than gold-standard commercially available devices. Universal accessibility was targeted for all medical professionals, regardless of location or circumstance, to acquire this essential device. Glia addressed these goals by creating a stethoscope design which can be manufactured in low resource settings, is durable, uses commonly available components, and can be easily assembled - allowing the stethoscopes to be fabricated and shipped worldwide at a affordable cost.
To maintain low production cost, Glia 3D prints several stethoscope components- the chest-piece/bell, diaphragm retaining ring, Y-piece connector, binaural spring, and both binaural ear pieces. The device is finished with easily sourced silicone tubing, as well as a polyethylene diaphragm and soft self-sealing ear tips. The Glia Stethoscope can be manufactured for a total material cost of USD$7. Glia, accounting for all other associated production costs, is currently able to maintain a retail price of CAD$40. Glia continues to manufacture the stethoscope in both Canada and Gaza under a Health Canada Medical Device Establishment License (License #6823) to produce Class 1 devices.
Glia has continued to refine production standards for durability across various user settings. In 2016, PLA was used for the initial version but this was found to deform under heat exposure, including from extended storage in a hot car. PLA was then replaced with PETG, which is less susceptible to heat deformation. In 2019, the ear tube angle was adjusted for user comfort and in 2021, the diaphragm retaining ring was reconfigured for more robust wear.
Medical professionals who rely on premium brand counterparts have realized the far-reaching potential open-source devices portend for sustainable and self-reliant healthcare. In 2021, a UK medical student non-profit partnered with Glia to produce the first branded Make-A-Medic stethoscope for the Steth of Hope campaign- which ultimately distributed two hundred devices to 4th-year medical students in Kenya and Zambia. This successful campaign brought stethoscopes to medical providers and patients in an environment where stethoscopes had previously been unheard of.
With more than 3,000 printed and distributed since project inception, the Glia stethoscope is helping diagnose and treat patients around the world. Through open-source design development and innovation, as well as distribution efforts to low-resource areas, Glia supports healthcare professionals and creates equal care for all.