Modelling of pressure ulcer (PU) risk prediction system

Human skin deformation occurs due to external loading. As a result, blood flow in soft tissue becomes low and also the oxygenation decreases. Tissue under continuous loading results in tissue necrosis and leads to pressure ulcer (PU), also known as bedsore, decubitus ulcer, and ischemia. The amount of external load applied to the body support surface is associated with a subject's BMI (body mass index). Therefore interface pressure (IP) at the skin and the surface is the result of a subject's physical and support surface properties. Interface pressure increases, the blood flow decreases and a subject starts developing stage-1 pressure ulcer. Previous research suggests that interface pressure of 32 mmHg (4.26 kPa) can cause PU, but there is no strong evidence to show at what time that pressure is reached. Also interface pressure changes from subject to subject due to their body compositions. Three risk assessment scales are available to predict overall risk of PU formation. But none of these scales take interaction of body support surface materials into account. Also these do not provide any information at which area a subject is at risk of PU formation. In this work a study is presented where external load at different bony areas are measured using 11 volunteers. By measuring the external load for 11 subjects (age:33 ± 7 yrs and BMI:25.04 ± 3.01 kg/m2) at different bony areas, the relationship with the total body weight was identified. A mathematical model is proposed to predict the risk of PU formation combining the Waterlow risk assessment scales for bony areas and a graphic user interface to predict this is discussed

A Review on Pressure Ulcer: Aetiology, Cost, Detection and Prevention Systems

Pressure ulcer (also known as pressure sore, bedsore, ischemia, decubitus ulcer) is a global challenge for today’s healthcare society. Found in several locations in the human body such as the sacrum, heel, back of the head, shoulder, knee caps, it occurs when soft tissues are under continuous loading and a subject’s mobility is restricted (bedbound/chair bound). Blood flow in soft tissues becomes insufficient leading to tissue necrosis (cell death) and pressure ulcer. The subject’s physiological parameters (age, body mass index) and types of body support surface materials (mattress) are also factors in the formation of pressure ulcer. The economic impacts of these are huge, and the subject’s quality of life is reduced in many ways. There are several methods of detecting and preventing ulceration in human body. Detection depends on assessing local pressure on tissue and prevention on scales of risk used to assess a subject prior to admission. There are also various types of mattresses (air cushioned/liquid filled/foam) available to prevent ulceration. But, despite this work, pressure ulcers remain common.This article reviews the aetiology, cost, detection and prevention of these ulcers

Mathematical Modelling of Different Types of Body Support Surface for Pressure Ulcer Prevention

Pressure ulcer is a common problem for today’s healthcare industry. It occurs due to external load applied to the skin. Also when the subject is immobile for a longer period of time and there is continuous load applied to a particular area of human body, blood flow gets reduced and as a result pressure ulcer develops. Body support surface has a significant role in preventing ulceration so it is important to know the characteristics of support surface under loading conditions. In this paper we have presented mathematical models of different types of viscoelastic materials and also we have shown the validation of our simulation results with experiments