Pressure ulcer risk: the effect of anatomical features on interface pressure and tissue deformation in people with spinal cord injury

Pressure ulcers are one of the most common secondary complications for people with spinal cord injury, and add $10 billion annually to healthcare costs in the US. They are the most frequently seen preventable hospital acquired condition. Recent pressure ulcer research has added examination of anatomical risk factors, mainly fat and muscle characteristics, to the many previously identified risk factors. Translation of the new anatomical-based risk assessment theories is contingent on development of clinical techniques for measurement and better understanding of relationships with known factors, which has slowed the integration of this research into clinical settings. This study was designed to help bridge this gap between lab and clinic, by examining how anatomical features affect both tissue deformation and interface pressure. Six participants – two control and four with spinal cord injury – underwent MRI imaging while seated on a variety of seat cushions and in an unloaded condition, as well as pressure mapping. Three dimensional models of the tissue were created from the images. Significant anatomical differences were observed between the two groups. People with SCI lack muscle under the ischial tuberosity when sitting. The results suggest that tissue thickness was the anatomical feature most indicative of pressure ulcer risk. Greater unloaded thickness was associated with lower interface pressure and less change in tissue volume under seated loads, signifying a decrease in pressure ulcer risk. Higher deformation asymmetry – an imbalance between the change in tissue volume from one side of the buttocks to the other – also suggested increased pressure ulcer risk. Deformation asymmetry is particularly important because it can be partially corrected by adjusting sitting posture. These important characteristics should be used to direct further efforts to implement a more personalized risk model based upon the anatomy of the tissues at risk of breaking down

Exploring Methods to Improve Pressure Ulcer Detection: Spectroscopic Assessment of the Blanch Response

Pressure damage in intact skin is difficult to detect, particularly in individuals with dark skin, because color changes and tissue blanching are masked by the skin's pigmentation. Tissue reflectance spectroscopy (TRS) may be able to detect the blanch response regardless of skin color by measuring the change in total hemoglobin (delta tHb) that occurs when pressure is applied to the skin. The objective of this dissertation was to examine the ability of TRS to detect the blanch response at sites at risk for pressure ulcer development in individuals with various levels of skin pigmentation. Three studies were conducted to address this objective. In Study 1, delta tHb was assessed at the heel and sacrum of light and dark-skinned healthy participants using a portable TRS system. Study 1 showed that a significant decrease (p less than 0.001) in tHb could be measured in both light and dark skinned-participants with good intra-rater reliability (ICC greater than or equal to 0.80) at the heel, but not at the sacrum. Study 2 was conducted to identify a reliable method of skin color description for use in subsequent studies of the spectroscopic blanch response. Two examiners (B and C) performed three skin color assessments at the volar forearm of ten healthy participants using Munsell color tile matching and colorimetry. Intra and inter-rater reliability was excellent for colorimetry (ICCs typically greater than or equal to 0.90). Reliability for Munsell color tile matching was highest for Munsell value within Examiner B (93% agreement, kappa 0.87-1.00), which was determined to be sufficiently high for use in subsequent studies. In Study 3, delta tHb was assessed at the heels of light, moderate, and dark-skinned elderly nursing home residents at risk for pressure ulcers. As in the pilot study, a significant decrease in tHb was observed in all skin color groups (p less than 0.05). Intra-rater reliability for delta tHb was moderate or greater (ICC greater than or equal to 0.61). In combination, the results of Study 1 and Study 3 demonstrated that a significant spectroscopic blanch response could be detected with moderate or greater intra-rater reliability at the heel regardless of age or pressure ulcer risk status

Book of Abstracts 15th International Symposium on Computer Methods in Biomechanics and Biomedical Engineering and 3rd Conference on Imaging and Visualization

In this edition, the two events will run together as a single conference, highlighting the strong connection with the Taylor & Francis journals: Computer Methods in Biomechanics and Biomedical Engineering (John Middleton and Christopher Jacobs, Eds.) and Computer Methods in Biomechanics and Biomedical Engineering: Imaging and Visualization (JoãoManuel R.S. Tavares, Ed.). The conference has become a major international meeting on computational biomechanics, imaging andvisualization. In this edition, the main program includes 212 presentations. In addition, sixteen renowned researchers will give plenary keynotes, addressing current challenges in computational biomechanics and biomedical imaging. In Lisbon, for the first time, a session dedicated to award the winner of the Best Paper in CMBBE Journal will take place. We believe that CMBBE2018 will have a strong impact on the development of computational biomechanics and biomedical imaging and visualization, identifying emerging areas of research and promoting the collaboration and networking between participants. This impact is evidenced through the well-known research groups, commercial companies and scientific organizations, who continue to support and sponsor the CMBBE meeting series. In fact, the conference is enriched with five workshops on specific scientific topics and commercial software.info:eu-repo/semantics/draf