The differences in measured prostate material properties between probing and unconfined compression testing methods. (June 2020)

• Record Type: Journal Article
• Authors: Johnson, Blake; Campbell, Scott; Campbell-Kyureghyan, Naira
• Is Part Of: Medical engineering & physics. Volume 80(2020)
• Page Start: 44
• Page End: 51
• Publication Date: 2020-06
• Subjects: Prostate -- Compression -- Modulus -- Failure properties -- Strain rate; Biomedical engineering -- Periodicals; Biomedical Engineering -- Periodicals; Physics -- Periodicals; Génie biomédical -- Périodiques; Biomedical engineering; Electronic journals; Periodicals; 610.28
• DOI: 10.1016/j.medengphy.2020.03.006
• Languages: English
• ISSNs: 1350-4533

Abstract

Highlights: Prostate elastic modulus, failure stress, and failure strain were tested using compression and probing protocols for both human and porcine specimens at multiple strain rates. Elastic modulus was strain rate dependent but saturated at higher rates. Failure properties were not found to be strain rate dependent. Similar results were observed from the probing and compression testing methodologies. Mathematical models were developed for the measured mechanical properties. Abstract: Characterization of the mechanical properties of organs is important for determining their behavior under load and understanding and predicting their response. In order to appropriately understand behavior, including developing predictive models, the method used to measure the properties should match the application as different testing techniques can yield different results. One of the organs where little mechanical testing has been performed is the prostate. Therefore, the goal of this paper is to expand the knowledge of prostate gland mechanical behavior by using two different compressive testing methods under various loading rates. No differences were found between the elastic modulus measured using the compression and probing protocols for both human and porcine specimens. The elastic modulus ranged from 0.08 MPa at 1%/s to 0.24 MPa at 25%/s for human specimens and from 0.2 MPa at 1%/s to 0.4 MPa at 25%/s for porcine specimens. A strain rate dependency of the elastic modulus was observed for both testing methods. The dependency on strain rate started to saturate at higher rates and a material model was created to quantify this dependence as well as the stress-strain behavior. No strain rate dependency was observed for failure stress or failure strain. Overall, similar values of elastic modulus were found for both probing and compression protocols and the relationship developed between elastic modulus and strain rate could be implemented in models of the prostate gland to aid in understanding the response to dynamic loads.