Mechanical properties of the human umbilical artery.

More About This Textbook


Umbilical Cord Accidents (UCA) are a common birth complication that results in the deaths of 2 out every 1000 normal babies [4]. Because mechanical properties directly play a role in the response of the cord to deformation, understanding these properties is necessary to develop a structural model of the cord that could be used to predict UCA susceptibility. To validate testing and modeling procedures, the stress relaxation response of an equine umbilical vein and artery were fit to a model based on YC Fung's Quasilinear Viscoelastic (QLV) theory. Upon comparison, the model successfully reproduced the experimental stress relaxation response. Longitudinal stress relaxation and stress/strain tests were performed on samples of human umbilical artery, keeping track of their location in reference to the placenta to determine whether mechanical properties varied based on location. Parameters for the QLV model were derived from the stress relaxation test, but although there were differences based on location, the sample number (n=3) per group was too small to develop conclusions. The relaxation in each sample proceeded more rapidly and for a much longer time than data published for canine arteries. These results provided a stepping stone for future work. Final stress relaxation experiments were run on the fetal (n = 9), placental (n = 8), and middle (n=7) sections of human umbilical cords. Time-dependent QLV parameters were extracted from the hold section of the stress relaxation. The curve-fitting procedure was performed by iv the Matlab curve-fitting tool. Statistical analysis demonstrated that there were no differences between sections, with one exception. At the placental end, relaxation was initiated more quickly than in the other sections: a possible defense mechanism for rapid fetal movements. In each of the three sections, relaxation proceeded for an extended period of time (on the order of 10,000 seconds) in comparison to typical adult arteries (on the order of 600 seconds). From the ramp section of the stress relaxation test, stress/strain properties were investigated. Again, statistical analysis demonstrated that there were no differences between sections. While conclusions can be drawn from this work, much is still unknown about the function of the umbilical cord.
Read More Show Less

Product Details

  • ISBN-13: 9780549562436
  • Publisher: ProQuest LLC
  • Sold by: Barnes & Noble
  • Format: eTextbook
  • Pages: 107
  • File size: 2 MB

Customer Reviews

Be the first to write a review
( 0 )
Rating Distribution

5 Star


4 Star


3 Star


2 Star


1 Star


Your Rating:

Your Name: Create a Pen Name or

Barnes & Review Rules

Our reader reviews allow you to share your comments on titles you liked, or didn't, with others. By submitting an online review, you are representing to Barnes & that all information contained in your review is original and accurate in all respects, and that the submission of such content by you and the posting of such content by Barnes & does not and will not violate the rights of any third party. Please follow the rules below to help ensure that your review can be posted.

Reviews by Our Customers Under the Age of 13

We highly value and respect everyone's opinion concerning the titles we offer. However, we cannot allow persons under the age of 13 to have accounts at or to post customer reviews. Please see our Terms of Use for more details.

What to exclude from your review:

Please do not write about reviews, commentary, or information posted on the product page. If you see any errors in the information on the product page, please send us an email.

Reviews should not contain any of the following:

  • - HTML tags, profanity, obscenities, vulgarities, or comments that defame anyone
  • - Time-sensitive information such as tour dates, signings, lectures, etc.
  • - Single-word reviews. Other people will read your review to discover why you liked or didn't like the title. Be descriptive.
  • - Comments focusing on the author or that may ruin the ending for others
  • - Phone numbers, addresses, URLs
  • - Pricing and availability information or alternative ordering information
  • - Advertisements or commercial solicitation


  • - By submitting a review, you grant to Barnes & and its sublicensees the royalty-free, perpetual, irrevocable right and license to use the review in accordance with the Barnes & Terms of Use.
  • - Barnes & reserves the right not to post any review -- particularly those that do not follow the terms and conditions of these Rules. Barnes & also reserves the right to remove any review at any time without notice.
  • - See Terms of Use for other conditions and disclaimers.
Search for Products You'd Like to Recommend

Recommend other products that relate to your review. Just search for them below and share!

Create a Pen Name

Your Pen Name is your unique identity on It will appear on the reviews you write and other website activities. Your Pen Name cannot be edited, changed or deleted once submitted.

Your Pen Name can be any combination of alphanumeric characters (plus - and _), and must be at least two characters long.

Continue Anonymously

    If you find inappropriate content, please report it to Barnes & Noble
    Why is this product inappropriate?
    Comments (optional)