Apollo3 Patient Isolation Hood
The Apollo Patient Isolation Hood (PIH) is a localized negative-pressure ventilation system for hospital beds to help contain the droplet spread of COVID-19, including during aerosol-generating medical procedures such as intubation and extubation. The PIH encloses a patient’s upper torso and head in a negative-pressure environment. It provides barrier protection between a healthcare provider (HCP) and patient, and aerosol control via the negative pressure environment. The hood may also contain the spread of the virus from less critically- ill patients, reducing the need for invasive procedures.
The versatility of the Apollo PIH means that it can be used in any care setting (OR, PACU, ICU, ED, EMS) and can be rapidly secured to a variety of beds. The lightweight (<5 lbs) design allows for ease of assembly, use, and disposal. The primary structure is composed of a single flat sheet of PETG plastic that is assembled into a 3-dimensional form, minimizing the number of seams for optimal viewing clarity. Flexible sealed arm ports provide HCP access to patients. A minimal amount of folds and seams in the primary enclosure provide optimal viewing clarity.
The main intention was to use simple techniques of creating stable 3d forms from readily available flat sheets and minimal joinery, which can be rapidly deployed to help frontline medical workers. The design of the ‘Apollo’ is based on the principles of ‘Active Bending,’ which describes surfaces that base their geometry on the elastic deformation of initially straight elements((Gengnagel, Alpermann, and Hernández 2014)).
All initial small-scale prototypes were made of 130 gsm (80lb) Bristol paper with a Cricut Maker, which proved to be a quick and straightforward method for a rapid iterative process.
PETG, well known as a material for scaling up origami concepts (Baerlecken et al. 2014), was used to make prototypes at full scale. Both 30mil (1/32”) and 60mil (1/16”) PETG sheets work well based on the required size and stability that is needed for the PIH. Most of the prototyping was done with 60 mils and the final design is a combination of stability, flexibility, and lightness.
The initial guidelines of the design were flat foldability, optical clarity, and simple assembly. The origami approach catered to most of this requirement, but the designs still had seams at the folds.Hence the next step in the design process was to achieve bending without folding, and thus we looked at the principle of ‘Active Bending’.
Applying spherical linkages enabled us to get rid of the folds and have a seamless 3d form from flat sheets. Small single vertex spherical prototypes were made to test the stability of the structure. This concept was then applied to a simple unfolded cuboid based on the clinical dimensions with partial overlap between the sides. Modifications were made to improve the interface of the base perimeter with the bed and to taper the viewing angle.
The design went through numerous iterations based on the anthropometric, functional, and clinical requirements associated with the process of intubation and provided by the clinicians at MGB & BCH. The design needed to cater to a lot of different parameters and be adaptable so that it could be used in various hospital settings, attached to different sized hospital beds and be used on patients of varying age groups and body type. A variety of alternative designs were prototyped, which differed in size, attachment details (rivets, slots/tabs), and ability to nest on commonly available sheet stock as well as available fabrication infrastructure.
The novelty of the ‘Apollo3’ design is that it can be made up of thin sheets of flat materials, and based on the calculated overlap of the side-arms, a double thickness structure is provided at the base for stability while making the rest, pliable and light.
Step 01: Place Apollo PIH enclosure on a flat surface with the folded baseplate facing upwards.
Step 02: Fasten the opposing sides of the baseplate together using two push-in rivets located on the baseplate. See detail A for connection detail.
Step 03: Fold one side-arm toward the interior of the enclosure. Fasten to the central portion of the enclosure using (8) push-in rivets.
Step 04: Repeat Step 03 for the opposite side-arm.
Step 05: Place the Apollo PIH upright so that the baseplate is resting on a horizontal surface.
Step 06: Attach the plastic drape to the front edge of the Apollo PIH using double-sided tape.
Step 07: Fasten the provided straps to one side of the Apollo PIH.
Step 08: Adhere clear tape over the external seams of the Apollo PIH (one per side), taking care to cover the seam completely.
Several clinicians provided key clinical feedback that drove design decisions, from MGH Anesthesia: Samuel Smith, MD, MPH; JP Wang, MD, PhD; Michelle Szabo, MD; Scott Streckenbach, MD; Alex Kuo, MD; Kendrick Shaw, MD, PhD; Angela Dai; Matt Vanneman, MD; Celeste Day. From MGH Pediatrics, Kris Olson. From the MGB Center for COVID Innovation; Li Li, PhD; Aditya Kumar; and Gary Tearney, MD, PHD.
Chris Hansen, Digital Fabrication Technical Specialist at the Harvard GSD; Eric Howeler, Associate Professor of Architecture at the GSD; Saurabh Mhatre, Research Associate at the Harvard GSD & Harvard CGBC; and Nathan Phipps, played key roles in refining, prototyping, and coordinating fabrication of the Apollo 3 design. Zach Seibold, Jonathan Grinham, Daniel Tish, Daniel Castello and Ryan Pierce participated in design iteration and early prototyping.
James Weaver, Senior Research Scientist at the Wyss, facilitated the initial collaboration and has been instrumental in sourcing materials.
The Boston Children’s Hospital Surgical Innovation Fellowship team, including Heung Bae Kim, MD; Farokh Demehri, MD; Robert Crum, MD; Kyle Wu, MD; Brianna Slatnick, MD; and Alex Yang, BS, helped to develop the first versions of the Apollo design and provided clinical input throughout the design process.
Initial design prototypes were produced with the help of PolyFab, and Roger Diebold (CEO, Solchroma Technologies) along with H. Loeb Corporation.
A full attribution list is as follows Aaron Ross, Adam Smith, Aditya Kumar, Alex Kobald, Alex Yang, Alexander Kuo, Angela Dai, Brianna Slatnick, Celeste Day, Chris Hansen, Chris White, Daniel Castelo, Daniel Tish, David Concha, David Hamm, David Wallace, Eric Howeler, Euan Mowat, Farokh Demehri, Fernanda Sakamoto, Heung Bae Kim, James Weaver, Jonathan Grinham, Jonathan Langer, Koushik Garapti, Kristian Olson, Kyle Wu, Lara Tomholt, Martin Bechthold, Mehra Golshan, Michael Sherman, Michele Szabo, Norman Wen, Robert Crum, Ryan Pierce, Sam Smith, Saurabh Mhatre, Ted Ngai, Ted Sirota, Zach Seibold.