Session: 06-05-01: Biomedical Devices

Paper Number: 119917

119917 - Toward Scrubbing-Based Automatic Handwashing 

Healthcare-associated infections, which originate while a patient is in a medical setting, are one of the most frequent adverse effects that occur during treatment, and effective hand hygiene is a powerful tool for minimizing bacteriological spread through direct and indirect contact. Consequently, a faster and more effective method of handwashing as compared to manual hand washing can aid in minimizing healthcare-associated infections without placing a burden on healthcare workers. Within hospitals, current hand washing methods are time intensive, with cycles of scrubbing and washing taking upwards of 5 minutes or even longer, such as when prepping for surgery. Even when not accounting for the intensive cleaning procedures required for sanitization when entering an operating room (OR) to minimize bacterial transfer, medical professionals may need to clean their hands upwards of 10 times per hour of contact with patients. Thus, effective handwashing becomes a significant time investment for healthcare workers. In addition, hand washing compliance can be as low as 30% during emergency care. Development of a new and effective handwashing procedure that reduces washing time should increase compliance rates and allow medical professionals to treat more patients and to sanitize faster in response to an emergency, such as when treating a sudden injury.

This project proposes to improve the speed of effective handwashing in medical settings. This is accomplished by developing an automated scrubbing mechanical system for handwashing. This system focuses on disinfecting the hands by removing surface bacteria, rather than removing solid particulates, such as dust, or dirt. The mechanism is a scrubbing-based design, in comparison to existing water-jet-based systems. Because silicone is an acceptable substitute for replicating the mechanical and surface properties of skin, a silicone-based human hand analog is used to test the efficacy of the device in removing bacteria from the hand. An ATP-based system is used to measure relative contamination levels before and after testing via a swab; the reading is proportional to the amount of organic material collected by the swab. Baker’s yeast is used as the contaminant for all tests. First, contamination readings are taken before and after the hand is scrubbed, to assess the effectiveness of the hand scrubber. Following that, the impact of scrubbing force and scrubbing time are assessed by recording how the contamination level after scrubbing changes when modifying these parameters.

Preliminary data suggests the scrubbing device is effective at sanitizing, removing 95% of bacteria from the surrogate hand. Additional tests suggest a positive correlation between scrubbing force and sanitization, along with a positive correlation between total scrubbing distance and sanitization. A Tukey test is used to assess the significance of data; the difference between contamination levels of the hand before and after scrubbing is statistically significant. Additionally, the impact of the swab itself in removing bacteria before future swabs is statistically insignificant. 

Presenting Author: Aaron Mazzeo Rutgers University

Presenting Author Biography: Aaron Mazzeo is an associate professor and aerospace engineering undergraduate director in the Department of Mechanical and Aerospace Engineering, as well as a faculty fellow at the Honors College at Rutgers University. Prior to joining the faculty at Rutgers, he was a postdoctoral fellow at Harvard University in the Department of Chemistry and Chemical Biology, and he completed his undergraduate (S.B.) and graduate degrees (S.M. and Ph.D.) at MIT in the Department of Mechanical Engineering. The Mazzeo Research Group, or Rutgers Lab for Machines, Manufacturing, and Mechatronics, focuses on flexible and disposable electronics for mechanical and biological sensing, soft-hard robotics, cold plasma-based sanitization and treatments, and in-space manufacturing. Funding has come through Rutgers University, the NSF, NASA, the USDA, the DoD, and DARPA. Aaron has received an NSF CAREER Award, NASA MSFC Summer Faculty Fellowships, an A. Walter Tyson Assistant Professorship Award through the School of Engineering, a Rutgers Engineering Governing Council’s Professor-of-the-Year Award, and a Rutgers Presidential Fellowship for Teaching Excellence. He and his family also appreciated living and participating as members of the Rutgers Honors College community.

Authors:

Antonio Bu Sha Rutgers University - New Brunswick
Aaron Mazzeo Rutgers University