When Nayyar Hussain was using a stethoscope to listen to a young girl’s heart and the girl sneezed on him, it caused him think about the limitations of stethoscopes and the hazards possible for his colleagues in contagious disease clinics. Brainstorming requirements for his ideal medical listening device he decided that a futuristic stethoscope should be simple to use with no buttons or screens, low noise amplification and give the medical professional assistive insights and feedback. Along with his group of engineers and industrial designers at M3DICINE, Hussain has launched Stethee, an AI-enabled stethoscope system. The device is placed against the patient’s chest and when pushed in takes data related to patient heart and lung function. Data is stored on the Stethee app.
Nayyar answered a few questions about the engineering and design behind the device. He said that the stethoscope has been a symbol of the medical profession for 200 years, and to redesign it the team worked around the user experience. Stethoscopes are carried by doctors for eight to twelve hours per day and used on a patient in a personal and intimate manner. Visually the device needs to look professional but also friendly to the patient - the anthropomorphic round shape and LED light ring were included to meet those goals. Push button operation meant that pressing down once takes a measurement and stores the data simply, making it easy to use and understand after one use.
Design required thinking about everyone who might use the device on a patient, including different sized hands and left or right handed users. When the decision was made to also develop Stethee as a veterinary diagnostic tool another layer of complexity was added to the system, with a variety of human and animal skin surfaces needing to be accommodated. An alloy of 6063 aluminum with magnesium and silicon was chosen as the base material to allow for forming the complex shape of the body and provide a smooth finish that could easily be anodized.
The AI for Stethee is code-named Aida and searches for variations and patterns in cardiac and respiratory rates. The baselines are then used to look for disease or find the unique heart sounds of specific individuals. Designing the AI meant working with cardiologists to develop math models for heart rate, systole and diastole intervals, and detecting heart murmurs. Major partners for the model development were MIT and the Cardiac Research Centre in Australia.
Stethee was developed under the ISO 13485 standard Medical devices – Quality management systems – Requirements for regulatory purposes, and the team has been working to obtain FDA approval since 2015. As an IOT device with hardware and software elements under FDA regulation, M3DICINE worked to find a manufacturing partner that could collect the data and present it in FDA application formats. According to the press release issued on January 25, “the FDA cleared Stethee Pro for medical and healthcare professionals, Stethee Vet for veterinarian and animal professionals, and Stethee Edu developed specifically as an education and research tool.”
We wrote about Stethee back when it was still in crowdfunding form, and it's great to see it now as a fully approved medical device. I'm interested to see how a radical redesign of a standard tool might affect one of the world’s largest industries. I know some health professionals who embrace new technology whenever possible, and also some who still take blood pressure manually instead of trusting an automated machine. Stethee feels like a great tool ready to help update the way that medical data is collected and stored.