54 - Design Informed by Anatomy – Prioritizing Anatomical Considerations in Surgical Patient Positioning Device Development

Poster Board Number: 54
There are separate poster presentation times for odd and even posters.
Odd poster #s – first hour
Even poster #s – second hour

Abstract Body : Introduction/Objective:
An overhead position of the arm is needed for cardiac catheterizations; however, patients are subjected to possible perioperative nerve stretch injuries throughout the procedure. Proper arm positioning and support can shorten procedure length, reducing injury incidence without compromising image quality. Further, no formal standardized overhead arm stabilization method exists. The purpose of this study is to create a template for optimizing device design by using anatomy to direct the creation of a patient positioning device – an arm support apparatus for future use in cardiac catheterizations.

Methods:
First, the patient population was determined to ascertain general size variance the device must accommodate. Next, a workspace was defined using normative range of motion data for relevant limb movements necessary for the patient position during the clinical procedure. Within this space, the position and limitations of key neurovasculature was considered. Finally, discussions with medical personnel were conducted to determine considerations and needs for the clinical function of the apparatus.

Results:
The patient population undergoing cardiac catheterizations ranges from infants to adults with congenital heart issues. Normative ranges of active shoulder flexion and abduction for the population established the anatomical constraints of the apparatus. Further, neurodynamic limitations were considered to retain the forearm in a neutral-to-supinated position to physically accommodate the ulnar nerve. Discussions with medical personnel revealed that maximal rotational capacity and a secure locking mechanism was needed. Once all factors were considered, a 3D model was created in Rhino® 7 CAD software (2022) and exported as a series of Standard Tessellation Language files into the slicing software Eiger (2022). The apparatus was printed on a fused deposition modeling 3D printer with a carbon-fiber reinforced nylon material. The final apparatus consists of four pieces: 1. affixes directly to siderails of the procedure table; 2. is height adjustable and slides vertically through the first; 3. articulates about a novel, pin-locking ball and socket joint for variable secure positioning; and 4. is a curved arm board with adjustable sliders to secure variable arm and forearm widths.

Conclusion:
The current study demonstrates using anatomy to drive design is not only possible but produced a functional apparatus that accounts for size variations between patients. It was designed using the mean range of motion, neural limitations, and needs of the clinicians, while providing maximal contact with the arm regardless of size or position. Patient positioning apparatuses must accommodate all end users: clinicians and patients, yet often they are created with the patient’s needs post-rationalized. This methodology is design driven by the anatomy – taking physical limitations and variations into account to improve patient safety.

Significance:
Anatomic considerations in design is valuable and works within the body’s constraints to best protect patients. This workflow can be applied to design other patient positioning devices. The adjustable arm holder apparatus will provide a standardized, safe method of arm stabilization in cardiac catheterizations. Future studies will first test the apparatus in healthy subjects to assess the comfort, fit and adjustability, then with patients during cardiac catheterizations.