Dermatomes are devices for the procurement of skin grafts, which are essential for successful skin transplantation. Technologically advanced dermatomes, although effective at skin harvesting, are costly to maintain. Severe skin injury is a major public health problem in resource-limited settings, where most dermatomes are manual and yield poor-quality grafts. To address this issue, I along with a team of students in a Medical Device Design course at MIT (2.75/6.525), developed and presented a prototype dermatome with an oscillating blade and a thickness control module that has low operation and maintenance costs. A spiral torsion spring provides energy for blade oscillation. Preliminary tests on porcine skin revealed reliable procurement of homogeneous grafts but decreased thickness control accuracy for thin (<0.45 mm) grafts. The operationally straightforward prototype holds promise for cutaneous reconstruction in austere medical environments.
The dermatome was designed to use a single-edged generic surgical prep blade for cutting:
A blade carrier secures the blade in place with locating pins through three standard slots on its surface. The carrier is attached to two spring steel flexures for single-plane lateral motion.
The power module to achieve reciprocal, oscillating blade and carrier motion consists of a flat spiral torsion spring and gear train attached to the eccentric cam that drives the blade carrier. The user winds the spring before use. Upon release of the spring, its rotation is amplified and transmitted to the cam by the gear train.
The innovation of the device presented here lies at the intersection of manual and powered dermatomes. The device cuts with an oscillating blade and allows precise thickness control when the desired graft thickness is of the order of 1 mm, yet requires no external power source. It is readily serviceable by design, and operationally straightforward due to its intuitive blade power module. This device offers a superior alternative to manual dermatomes for the procurement of small skin grafts, and can lead to unprecedented improvement in the quality and outcome of skin wound care in austere medical environments.
Jonathan Casey*, Aikaterini Mantzavinou*, Bryan Ranger*, Rafael Secundo*, Robert Sheridan. “A cost-efficient spring-powered dermatome to treat skin trauma”. IEEE EMBS Special Topic Conference on Healthcare Innovation & Point-of-Care Technologies (2014).