A Looming Challenge
The Covid-19 pandemic has resulted in a dramatic, global shortage across the entire “Arsenal of Health” needed for this fight, including gloves, gowns, N95 masks, samplers, reagents, face shields, respirators, ventilators, and many other medical consumables and reusables. Indeed, WHO Director General Tedros Adhanom Ghebreyesus [1] stated,
“The chronic global shortage of personal protective equipment is now one of the most urgent threats to our collective ability to save lives.”
Closer to home, a surgeon in Fresno, Calif., starkly noted,
“We are at war with no ammo,”
lacking access to even the most basic surgical masks in her outpatient clinic and holding a limited supply of the tight-fitting respirator masks in the operating room [2]. A particular type of respirator, called a PAPR (short for powered purifying-air respirator), is a critical piece of clinical equipment that is used to protect health care workers during potentially risky aerosol generating procedures including intubation [3], but they too are in short supply [4]. Protecting the health care workers specially-trained to intubate Covid-19 patients is critical to ensuring the availability of critical care, so it is where we have focused our efforts in the OpenPAPR project.
A Promising Approach
The goal of the OpenPAPR project is to rapidly supply health care workers with safe, low-cost, and scalable PAPR devices that can be reconfigured and tailored to the available supply of key components including fans, filters, hoses, and hoods.
To date, the team has produced a PAPR design that includes a battery-powered blower unit, a disposable hood, a locking shroud, and a battery status indicator. The current system can use a variety of reusable commercial and custom filters.
There are many benefits to this design including that it is:
- Safe: Air flow matches commercial, medical grade PAPRs.
- Scalable: Constructed from readily available parts (> 10,000 available).
- Standardized: USB based charging and optional external power supply.
- Easy-to-Use: Disposable polyethylene bag costs just $0.10 per use.
- Untethered: Integrated Li-Ion batteries offer mobile operation.
- Informative: Displays battery life to prevent unexpected power loss.
- Modular: Parts from helmets to plastic bags support rapid field reconfiguration.
- Low-cost: Targeting ~$250/unit in materials and labor costs in volume.
But perhaps the most important benefit is that unlike most existing PAPRs, the OpenPAPR design can use a wide range of different standardized, laboratory tested, and certified filters, available from many manufacturers through numerous distribution channels. This flexibility is a great asset when supply chains are disrupted.
The first OpenPAPR units are undergoing clinical testing and performance evaluation. The design will soon begin the certification process.
The custom electrical and mechanical designs will be released after certification. That way, they can be freely replicated worldwide. The custom circuits include electronics for power conversion, motor control, battery charging and protection, and battery status display. The custom 3D-printed components include the blower housing, an intake filter cover, and mechanism for coupling/locking the hose and filter to the blower.
An Ecosystem of Components
Beyond today’s point solution, we envisions an adaptable design that can accommodate fluctuations in supply. The key idea is that rather than building vertically-integrated monolithic designs, the OpenPAPR ecosystem can support mixing-and-matching of the best available parts though modular design and the use of simple adapters and couplers. This approach also allows others, whether down the street or across the globe, to tailor the design to their own needs and resources.
