Iris Needle Guidance For Lumbar Punctures: Interview With Dev Mandavia, CEO Of Ethos Medical

Ethos Medical, a startup founded by Georgia Tech alumni, has developed the Iris needle guidance system to assist clinicians in successfully performing lumbar punctures. The system allows a clinician to visualize the needle traveling through tissue in real time. Tracking the needle path in this way is intended to improve the success rate and reduce the chance of complications in such procedures.

Lumbar punctures are used to diagnose several diseases, including multiple sclerosis and meningitis. However, they aren’t always straight-forward, with certain patients posing a unique challenge to clinicians because of their spinal anatomy, or obesity.

Ethos Medical reports that between 20–40% of spinal taps fail, which typically involves frustration for medical staff during procedures, and a potentially distressing experience for patients, along with increased hospital stays and expenses.

A failed lumbar puncture often involves multiple needle reinsertions, which can be painful and uncomfortable for patients. At present, clinicians will typically insert the needle after palpating the area, without being able to see where exactly the needle is traveling within the tissue.

The Iris system aims to improve lumbar puncture success rates. The system consists of a handheld medical device that attaches to existing ultrasound probes. The attachment acts as a needle guide, and the accompanying software overlays the predicted needle trajectory onto the ultrasound image, enabling practitioners to properly orient the needle prior to insertion.




Ethos Medical was recently awarded a $225,000 grant from the National Science Foundation’s Small Business Innovation Research program—this funding will propel Ethos through cadaveric testing and towards commercialization.

See a video of the Ethos Medical co-founders discussing the technology:

Medgadget had the opportunity to talk to Dev Mandavia, co-founder and CEO of Ethos Medical, about his company’s technology.

Conn Hastings, Medgadget: Please give us an overview of the difficulties clinicians encounter in performing a lumbar puncture.

Dev Mandavia, Ethos Medical: The current standard of practice is to conduct lumbar punctures (LPs) “blindly,” and this has been the case since the procedure was first introduced in 1891—this involves practitioners (typically in emergency medicine or neurology) palpating the patient’s back and feeling for bony landmarks in order to paint a mental map of the patient’s spinal anatomy and determine where to insert the needle and at what angle. Once the needle is inserted, the practitioner is relying on tactile feedback to determine what type of tissue the tip of the needle is passing through and is expecting a particular sensation to guess whether or not the needle is on the right track.

Relying on tactile feel is subjective and no two patients have the same anatomy, which is why the learning curve is so high for new and training practitioners. Additionally, our testing indicates that LP needles curve a significant amount when being inserted and the degree of curvature can vary depending on the type of needle and depth the needle needs to be inserted. Even for extremely experienced practitioners, using the blind technique to perform LPs is especially challenging in patients who are obese, scoliotic, or older or in patients that have previously had back surgery.

Medgadget: What inspired you to design a device to assist in this process?

Dev Mandavia: During our final semester at Georgia Tech in 2018, Cassidy Wang, Lucas Muller, and I (the three current co-founders at Ethos) were a part of the same multidisciplinary Senior Design team in the Wallace H. Coulter Department of Biomedical Engineering. The beginning of the course revolved heavily around pain point identification, and we were tasked with selecting a medical procedure that we felt could be improved. After shadowing many local hospitals (Emory, Piedmont, Northside, and Grady, among others), we were consistently surprised that the blind technique was used for spinal access procedures, especially when juxtaposed with the expensive, specialized equipment, such as the da Vinci surgical system, that was also found at some of these facilities. During the course, we created a prototype of a needle stylet that could characterize tissue type at the tip of the needle the stylet was inserted inside of, thereby circumventing the need for practitioners to rely on tactile feel. We later learned that, while this device did address a pain point of the spinal access procedure, it was not the primary pain point of the procedure-what practitioners really wanted was “x-ray vision to see where the needle was going throughout the entirety of the procedure”! Since we couldn’t provide exactly that, we set off to develop the next best thing: a real-time needle guidance system. We’ve been working on it ever since.

Part of what inspired us to start over, and what continues to motivate us to this day, was the overwhelmingly consistent response we received from patients, practitioners, and administrators about the problems associated with the LP. After hundreds of interviews, we were confident that this was a problem worth solving.

Medgadget: Please give us a breakdown of how the Iris works.

Dev Mandavia: The Iris consists of three components: 1) A reusable attachment for ultrasound probes which houses electronics, 2) a disposable, rotatable needle-guide insert, and 3) a software overlay to display the needle’s trajectory on the ultrasound image. The reusable attaches to the head of the ultrasound probe, and the disposable insert slides onto the Iris reusable. Sensors in the reusable can detect rotation of the disposable—these data are converted into a trajectory and then overlaid onto the ultrasound image by our software. This enables practitioners to properly orient and set the rotatable needle-guide insert prior to insertion of the needle.

The Iris prototype we’ve been testing with is compatible with the Philips Lumify portable ultrasound, but we’ll be launching with a system that can interface with point-of-care ultrasound machines that are commonly found in hospitals today, such as the carted options developed by SonoSite.

Medgadget: Do clinicians require any training to use the device? Do they need experience in interpreting ultrasound images?

Dev Mandavia: The feedback we’ve received from practitioners that have handled the Iris so far is that it is quite intuitive.




Ultrasonography of the spine was not commonly taught in emergency medicine or neurology residencies until the last 5–10 years. So, while many practitioners in these specialties are familiar with the concept of using ultrasound for other procedures, the majority are not familiar with spinal ultrasound. Because of this, there will need to be some amount of training. During user testing, we typically spend the first 10–20 minutes (depending on the practitioner’s ultrasound proficiency) going through prepared materials that explain how to identify and interpret spinal ultrasound landmarks. So far, this has been sufficient for practitioners to use the Iris in a bench model we developed to mimic a worst-case scenario patient.

Our upcoming cadaver studies will provide us a better sense of the training necessary for practitioners to begin using our system. Our goal is to make the Iris as intuitive as possible and minimize the amount of training necessary to successfully navigate needles into the spine on the first attempt.

Medgadget: How will the recent National Science Foundation award help you to develop the technology?

Dev Mandavia: We’re ecstatic to have been awarded a competitive Phase I SBIR grant from the National Science Foundation—this funding will allow us to complete remaining R&D and conduct preclinical testing to prove the efficacy of the Iris, a milestone that will enable us to raise the remaining funding necessary to complete regulatory testing, receive FDA 510(k) clearance, and support initial sales.

Medgadget: When do you envisage that the Iris will be available? How has the system stacked up in tests so far?

Dev Mandavia: Based on our current projections, we’re estimating FDA clearance for sale in the United States in 2021 Q2–Q3 timeframe.

The Iris has been performing exceptionally well, even beating internal success rate requirements we set for ourselves—we’ve seen a 97% success rate among practitioners (of all levels of experience and ultrasound proficiency) who have used a functional prototype of the Iris to perform an LP in our bench model, which simulates the lumbar region of a patient with a worst-case scenario level of obesity. Existing training models and LP phantoms didn’t provide the fidelity we were looking for and were much easier to perform an LP on than in practice, so we had to develop our own bench model by embedding a 3D printed lumbar spine (pulled from a CT scan) at 10 cm of depth in an industry-standard gelatin mixture designed to mimic the mechanical and sonoacoustic properties of human tissue.

Our next step is to complete a series of preclinical studies in which practitioners will perform an LP on obese cadavers, either by using standard techniques or the Iris. This will allow us to compare the overall efficacy of our system, among other success metrics, in human tissue to those of current standard of practice. This will also allow us to gather user experience data which will be used to determine what additional changes need to be made before finalizing the design of the Iris and beginning regulatory certification testing for our FDA 510(k) submission.

Source