SplitVent Update – March 30

IToday’s work was divided between testing and lot of show-n-listen with RTs, physicians, and hospital leadership. We enjoyed lots of great input from the twitterverse, please keep the comments coming!

The major updates from today:

  1. We re-tested the valve designed by Nate Surls and his colleagues. The most closed position now still allows flow through as a safety precaution. Also, the knob is much easier to manipulate and the threads seal better. Check GitHub for the latest STLs.
  2. The issue of controlling PEEP for each patient was raised by our clinicians as well as online. Initially we thought that the PEEP valves on our Ambus might work, but realized this isn’t the case. We’ve heard gootd things about this magnetic flow-through valve so we will order a sample tomorrow if they’re available https://iiimedical.com/product/be-30-142/
  3. Joe Koberg has done an amazing job with the software, transitioning the prior text-based proof of concept into the first version of our full fledged “virtual ventilator” screen, check out the screen shot below.
  4. I filmed a brief video update of everything below:
The respiratory rate issue has been fixed!

Things we are working on:

  1. Tomorrow will be primarily focused on testing and validation at the simulation center.
  2. We’re working on clinical protocol development including coming up with a training plan for RTs, nursing, and physicians.
  3. We are looking into adding pressure sensing — this requires a transducer than implementing it in software. We think we have the groundwork laid to a large degree.
  4. We are continuing to figure out scale-up including documentation, build instructions, and so on.

Want to implement at your hospital? All the latest code, STL files, instructions, and documentation is available on our GitHub.

SplitVent Update – March 29

As COVID19 cases pile up, including at the Indiana University hospitals, our team has been working incredibly hard to get a safe and effective split vent system ready for what seems like an inevitable need to ventilate multiple patients with a single ventilator. I’ll keep this as brief as I can.

The major updates from today:

  1. We’re one step closer to a final valve design. Nate Surls, Paul Holland, and Dr. Paul Yearling did an outstanding job designing and prototype printing it.
  2. We’re one step closer to a usable monitoring software. Joe Koberg in Atlanta has done an incredible job hacking a python-based system together heavily leveraging some phenominal open source biosignal processing code from BioPeaks.
  3. We did more lab testing today with only positive outcomes. I created an 8 minute video overview of the system and have posted it to YouTube (or see below).
  4. We reviewed everything with some of the ICU medical leadership at our hospitals as well as respiratory therapy and it sounds like they have the intention to scale up with implementation (still hoping we won’t ever need it). That means we’re going to be placing big orders for sensors and Raspberry Pis. We’re warming up the 3D printing lab and recruiting nible-fingered egineering students to start soldering!
  5. The SplitVent GitHub is now live and is being updated in real-time. This is where you can download the necessary 3D files as well as the source code for the monitoring system.

Things we are working on:

  1. Updates to the monitoring software to bring it out of the pacman era and into the 21st century. We will soon have a full featured graphical display with graphs and nicer display of the relevant information (tidal volume, flows, minute ventilation, etc).
  2. We continue to refine valve and other 3D printed part designs including connectors for the Sensirion sensor.
  3. Documentation and build instructions – we realize that we need to put something together which will be easy and safe enough to use in an actual clinical setting. As we scale up our implementation, all will be shared. This will include reliable places to source everything. This has been a major issue but vendors like Sensirion (sensors) and Adafruit (gadgets, gizmos, and Raspberry Pis) have stepped up to support us; this is an amazing testament to the world rising together in the face of catastrophe.

We’ll do our best to keep you up to date as everything changes in rapid succession. We hope that others will leverage our work so as busy as we are, please please please reach out with questions. We’re all in this together.

Splitting Vents

Rightfully so the world is going crazy over the ventilator shortage. Social media is blowing up on the topic. The societies have published position statements against doing it which make some valid points but are overall complete nonsense. New York Presbyterian has published guidelines which are awesome. PulmCrit‘s Josh Farkas is also developing great content on it which can be seen here and here. Also see this article from Hannah Pinson below as well.

To solve the shortage, I’m seeing people work down two main pathways. The first is that industrial players, academics, and Makers alike are rapidly developing simple ventilators. Most are basically a mechanical hand which squeezes an ambu bag at a set rate. In my opinion they are cute but as of yet I don’t see them as providing good quality ARDSnet ventilation. I fear we’re investing in and consuming valuable resources with something that will kick the mortality can down the road in terms of Covid19. For trauma patients with fundamentally healthy lungs, I’m all for it but the jury is out in terms of Covid19 lungs. The second pathway, is to split ventilators. It’s been done before with real humans, and it’s being done now in NYC but we can and should improve how we’re doing it.

To help, I’m trying my best to coordinate a “Split Vent” team comprised of some some very dedicated and talented people including (Nate Surls, Joe Koberg, Paul Holland, Brian Overshiner, Dr. Paul Yearling, Timothy Nisi and more). Everything we do is open source, licensed under under Creative Commons 4.0. Download it, hack it, re-contribute it — please! Here’s what we’ve been up to:

1) Basically in line with the ventilation approach described in the outstanding article by Hannah Pinson we have developed 3d printable restrictor valves that connect directly in line with ventilator tubing right before the wye. We’ve tested them in the lab and we have fine control of ventilation to each individual patient. The design is changing by the hour as we test, and ultimately we’ll get them published on GitHub but in the interest of sharing the design now below are the STL files for what we have. We will get more printing and assembly instructions out as soon as we can. Also below is a 3d printable splitter. All connections are the iso standard 22mm.

2) Although you can monitor patients using end tidal CO2 and serial arterial blood gasses, this isn’t ideal. As such, we are working on a monitoring system which will essentially give each patient their own “vent screen” with pressure, flow, and volume waveforms on it. Something that looks like this:

The system will run on a Raspberry Pi Zero computer ($10 each, Adafruit is willing to source them in quantity for healthcare applications) and display the real time curves on any HDMI monitor. Future plans are to add alarming. Sensirion, an amazing sensor company in Switzerland is actively ramping up production on their SMF3300 mass flow sensor and although their out of stock from DigiKey, Mouser, etc (we bought them all) they are putting in 200% effort to get us (and other sites) more this week. More to come on this as we get our prototype functional. If anyone has programming / engineering resources especially with signal processing we’re happy to have help.

If anybody has thoughts on what we are doing, or wants to contribute please be in touch.

Covid update from Indy

I’ve been getting a lot of questions about what it’s like to work on the “front lines” during this the Covid19 outbreak so I just wanted to write and share some experiences thus far. This won’t be pullitzer prize winning recount, but let’s hope there is at least something thought provoking. I won’t be offended if you don’t get through it all. Although I work at 4 hospitals and each represents a unique experience, this email is primarily about my experience at our academic health center which is the tertiary referral center where I’m primarily based right now. 


First, I think it’s important to acknowledge that although ICU is taking care of the sickest patients I don’t believe we are the front lines. Primary care and Emergency Departments are bearing the brunt of the high risk exposures and are addressing massive challenges around testing and triage. They have done a tremendous job quickly building out telehealth solutions and implementing advanced triaging systems. That said, we still get transfers from the general medical-surgical floors who are crashing but not properly isolated since they were not initially felt to be covid-rule outs. What’s impossibly hard is that patients are are presenting in very atypical ways, yesterday someone who was  admitted for 14 days with no suspected covid tested positive then subsequently coded and died. Hopefully all of our efforts towards infection control are not in vain.


Our center is starting to see covid cases rise at an exponential rate. Last week we had zero confirmed cases. By yesterday we had 10 plus a lot of persons under investigation (rule-out cases). While we all see the total number of cases going up at a staggering rate on TV, I think we are probably just recognizing cases that were missed due to inadequate testing until now so keep your fear in check! For us, and nationally, testing availability and speed has rapidly expanded in the last 7 days though is still inadequate on the whole. The number that we probably should be watching more closely than total cases, but unfortunately doesn’t really exist, is the number of hospital or ICU admissions. We are seeing it rise in Indy, we know anecdotally that ICUs across the country are seeing the same, but we don’t know this on a state or country level due to insufficient data sources and collaboration. We also don’t have clear understanding of who will get critically ill; based on what we are seeing it’s not just those with comorbidities or those who are old and frail.


We are fully expecting an on onslaught in the coming weeks that will likely last a prolonged period of time despite efforts for social distancing. We feel very fortune that we have the advantage of having learned from China, Korea, Italy and many US centers who are ahead of us in terms of case load. In addition to published literature, collaboration over social media has been a remarkable way for us to learn about innovative approaches to take care of these patients and reconfigure our hospital. It’s hard to do, but it does feel like taking those few extra seconds to send a tweet can change the world. We have a slack channel (like whatsapp group) with 50 intensivists and pulmonologists at IU that has provided thought provoking conversation going 24/7; it’s been challenging to keep my phone battery charged and also a little overwhelming sometimes. 


Some of the innovative work we’re learning about over social media includes: – Using 3d printing to make PPE like N95 masks and eye shields- Using 3d printing to build ventilator attachments that will allow using a single vent for multiple patients (this is a really complex problem)- How to move IV pumps outside the patient room in order to minimize the number of times nursing has to go in-and-out of the room thus limiting risk of exposure and PPE use- How to move ventilator controls outside of the rooms for this same reason


A group of fellows and other staff had a mini hackathon yesterday yesterday to try and put some of the above into action with good results. We are trying to implement creative long-term solutions that won’t rely on the typical supply chains which are totally overwhelmed right now. We will soon run out of PPE and don’t expect to be able to order more. As such, we have IU engineers working on 3d printing PPE which is reusable and constructed easily acquired materials. A requirement for everything we make is that we need it to be easily cleaned in new ways. For example we are soon going to run out of the chlorhexidine wipes that we typically sterilize objects with in the hospital so we are planning to get spray bottles to fill with bleach-water and setting up rooms with 50-gallon bleach-water dunk tanks for the PPE we 3d print. I am totally floored by the interdisciplinary collaboration happening right now.


Our pulmonary fellowship program director who is a medical ethicist has been working with a team to re-do the Indiana State Department of Health ventilator allocation guidelines which were initially written for H1N1 and are now out of date. Let’s hope we don’t get there though based on the Italy experience it seems very likely.


We have converted one of our ICUs to a covid unit with all negative pressure rooms but this is nearly full already. As such we are re-comissioning a decomissioned NICU to be a second covid unit now. This unit will only be for confirmed covid positive cases and will be a more open ward-style unit with multiple patients to a room which will allow us to more efficiently use nursing staff and also keep providers from having to change PPE. This unit probably will not be negative pressure which is fine as we intend to do aerosolizing procedures (intubation, bronchoscopy) in the existing negative pressure rooms then move patients up there. Once patients are intubated they are a “closed circuit” and N95s are not needed, only surgical masks which are less short in supply and could be replaced with washable reusable masks in time.


All of this has challenged our clinical decision making and will continue to do so. We are dealing with are shades of gray and there are no black and white answers. If we are going to provide durable care, meaning long enough to get through the pandemic, we must take risks and use our best judgement to turn best practices on their heads. For example, we typically are aggressive about limiting our use of central venous catheters (big IVs that we insert into the large vessels of the body) because they are susceptible to infection and insertion complications. However, we are starting to put them in most covid patients upon intubation because we don’t want to waste sterile PPE down the road. Plus, they require less frequent nursing checks thus limiting nurse PPE use and nursing exposure. It’s a balancing act between harm to the patient and the needs of a strained healthcare system. Another great example is what to do with covid patients who cardiac arrest — this is usually a very chaotic time which is high risk for provider exposure and would consume lots of PPE. We typically offer this “hail mary” to any patient who wants it, but now we probably now need to use this intervention judiciously and only in cases where we believe that we can successfully and durably reverse death. The list goes on and on.
Another challenge has been visitor restrictions – with a few exceptions no visitors are allowed in the hospital. Can you imagine not being able to be at your loved ones bedside while they are on life support? It’s inhuman and horrible, but it’s one of those gray zone decisions our hospitals have had to make. We are doing our best to keep families updated, and our nurses are shouldering a lot of the phone calls, but it’s hard. The end of life / goals of care conversations over the phone with multiple family members are heartbreaking to say the least. We are getting more access to telehealth / facetime solutions and trying our best to prioritize this, but as you can imagine there are a lot of balls in the air.


In addition to patient care, it has been difficult keeping up with the staggering amount of information that is coming our way. Our email boxes are filled with 50+ covid updates every day not to mention published literature. 


This last week I have been reflecting extensively on my medical education and I am grateful for the education I got at Ben Gurion. I took a course in disaster medicine which was taught by Israeli world experts and I am channeling a lot of that now. The most important lesson which are absolutely bearing truth right now is about the cultural shifts that we must have to approach unprecedented challenges. To effectively face the challenges that lie ahead the bureaucracy has to fade away and we need to empower people to innovate from the bottom up. This doesn’t come naturally to all people. Our bedside nurses have been incredible teammates in this process but we are finding in general that physicians are far more comfortable making hard calls and accepting the risk for doing so. Physician leadership has been very supportive of this approach but it’s hard getting everyone in the hospital on board since they typically are judged on very different measures (like central line infection rates). 


I get a lot of questions about social distancing and what social interactions are okay versus not. I don’t have the answer. Again, this is a situation of shades of gray. Social distancing will hopefully flatten the curve and keep our hospitals from getting overrun, but it’s also destroying the economy and will have effects which reverberate for generations to come. I fear that the long term suffering from this economic catastrophe will engender more suffering than the disease itself, but I am a doctor and my first allegiance is to the patient whether that is the one in front of me and the healthy person who I don’t want to have to admit to the ICU. So with that I’ll say we all need to do what we can to keep everyone safe. It’s like choosing between diarrhea and constipation, they’re both shitty situations.


What I can tell you is that public health and infection control experts are allowing covid positive healthcare providers to work in the healthcare system with appropriate monitoring and PPE. That tells me that in the coming weeks as we learn more and let this crisis settle down we will likely be able to safely relax some social distancing.  The challenge we will have is that American’s don’t follow rules well (as compared to let’s say Japenese) and it’s going to be an ongoing challenge to make policies to protect everyone, while giving enough leeway to those who can effectively self monitor and wash their hands singing happy birthday twice every single time.


To end on a positive note, I am inspired by on a daily basis by the people I work with and their dedication to the health and wellbeing of the families we have the privilege of taking care of. This includes my co-fellows, residents, attendings, nurses, respiratory therapists, cafeteria cooks, environmental services, clinical engineering and everyone I’ve left out. Covid19 has been a shock to an already broken healthcare system and I firmly believe that this defibrillation will have positive ripples that stay with us for much longer than this pandemic.


On a more personal note, Melinda will take a break from a 10-year career as a bedside nurse next week in order to focus on wrapping up her NP degree, take boards, and get ready for the baby boy. I am busier than ever but tend to thrive in chaos and I am finding immense meaning in my work which feels truer than ever to the Oath and Prayer of Maimonedes. I hope that each and every one of you to find ways to contribute their talents to alleviating the multidimensional suffering around us. I hope that each one will share their stories along the way so that the rest can learn from what the other is doing. Whether you thrive or dred the chaos surrounding us, please keep your eyes open for the silver linings that are all around us, stay safe, stay healthy, and stay happy — at the very least think how lucky we all are to be celebrating our birthdays about 100 times a day!