Analysis of healthy sitting behavior: Interface pressure distribution and subcutaneous tissue oxygenation (original) (raw)
Related papers
PLOS ONE
Pressure ulcers, by definition, are caused by external forces on the tissues, often in the regions of bony prominences. Wheelchair users are at risk to develop sitting-acquired pressure ulcers, which occur in the regions of the ischial tuberosities, sacrum/coccyx or greater trochanters. As a means to prevent pressure ulcers, instruction on performing pressure reliefs or weight shifts are a part of the rehabilitation process. The objective of this study was to monitor the weight shift activity of full-time wheelchair users with acute spinal cord injury over multiple epochs of time in order to determine consistency or routine within and across epochs. A second objective was to evaluate the accuracy of self-reported pressure relief frequency within each measurement epoch. A wheelchair in-seat activity monitor was used to measure weight shifts and other in-seat movement. The data was classified into multiple inseat activity metrics using machine learning. Seventeen full-time wheelchair users with spinal cord injury were measured within multiple epochs, each lasting more than 1 week. Across all in-seat activity metrics, no consistent pattern of activity changes emerged. None of the in-seat activity metric changed in any one direction across a majority of subjects. Subjects tended to overestimate their frequency of performing pressure reliefs. Self-reported pressure relief behaviors are not reliable, and therefore, cannot be used to evaluate preventative behaviors either clinically or within research. This study had the capability of fully investigating in-seat movements of wheelchair users. The results indicated that in-seat movement does not reflect a routine, either in pressure reliefs, weight shifts or other functional in-seat movements. This study has illustrated the complexity of assigning causation of pressure ulcer occurrence to seated behaviors of wheelchair users and identifies the need for improved clinical techniques designed to develop routine behaviors to prevent pressure ulcers.
Dynamic changes in seating pressure gradient in wheelchair users with spinal cord injury
Assistive Technology, 2019
Pressure ulcer interventions are commonly assessed with measures of seating interface pressure, such as peak pressure gradients (PPGs). Decreases in PPG magnitudes may reduce pressure ulcer risk by decreasing tissue deformation and increasing tissue perfusion of at-risk weight-bearing tissues. Changes in PPG directions, which have previously been overlooked in the seating pressure literature, may provide a transient increase in blood flow to at-risk tissues, even if the PPG magnitude and location remain the same. The purpose of this study was to assess both PPG components in response to combinations of wheelchair tilt and recline angles. Thirteen power wheelchair users were recruited into the study. Six combinations of wheelchair tilt (15°, 25°, and 35°) and recline (10° and 30°) were tested in random order. Each combination was tested with 5min upright sitting, 5-min tilt and recline, and 5-min maximal pressure relief recovery. Changes in PPG magnitudes and PPG directions under the left ischial tuberosity were computed for the six angle combinations. The findings in this study suggested that when combining wheelchair tilt and recline, the recline function may be particularly useful in reducing PPG magnitudes, while the tilt function may be particularly useful in manipulating PPG directions.
Repositioning and pressure ulcer prevention in the seated individual
2011
The presence of a pressure ulcer impacts negatively on the individual’s quality of life and may contribute to increased mortality. Pressure ulcers develop due to exposure to prolonged, unrelieved external mechanical forces. For the seated individual, the risk is greater than for those nursed in bed. This is due to the relatively small surface area which is absorbing the high pressures. Repositioning is advocated by international guidelines as being central to the prevention of pressure ulcers. This article will discuss the key considerations in the use of repositioning for the seated individual.
Pressure sore prevention for the wheelchair-bound spinal injury patient
Paraplegia
The concept of a wheelchair cushion fitting clinic for the prevention of pressure sores is reviewed in the light of recent estimates of the cost of pressure sores in the U.K. A method for measuring the pressure beneath the ischial tuberosities is discussed and techniques for measuring a patient's habitual exercise frequency and seated posture are described. Results from the records of 600 spinal injury patients including Rancho Los Amigos Hospital are reported and used to demonstrate the importance of low pressure beneath the ischial tuberosities as an indicator of wheelchair cushion suitability.
Wheelchair-based mobile measurement of behavior for pressure sore prevention
Computer Methods and Programs in Biomedicine, 1986
A recently developed device which provides continuous, direct monitoring of the pressure relief performance of persons confined to wheelchairs is reported. A custom portable computer records the data, which is transferred for analysis to an Apple lie. The mobile computer can also signal the patient to relieve pressure on the basis of preset criteria and the patient's performance. Teaching lift-offs to prevent ischial pressure sores is the object. Data collected with the device are used clinically and for research. Examples of such data are presented. The benefits of the device are reviewed.
… on Disability and …, 2010
Background: Disabled people suffering from decubitus ulcers under their ischial tuberosities are usually unsuccessfully treated by continuous bed rest. This can lead to depression, loss of muscle strength, as well as respiratory and venous compromise. The aim of our study was to allow disabled persons suffering from decubitus ulcers under their ischial tuberosities to sit up as long as they wish, every day, while accelerating the healing process. Methods: The alternating pressure relief wheelchair seating system relieves seating pressure completely for 8 s, every 3.5 min at every point in the seat, progressing sequentially from the front of the seat to the rear, and starting again repeatedly from the front and progressing to the rear. This seat was intended as a supplement to the normal medical treatment of decubitus ulcers, with the difference that continuous bed rest was eliminated. Results: Even though their ulcers had persisted for several months (in some cases 4 -5 years) before the patients began sitting on the alternating pressure relief wheelchair seating system, they began to heal, and exhibited accelerated healing to complete closure. Conclusions: This seat allows disabled people suffering from decubitus ulcers under their ischial tuberosities to sit up as long as they wish every day while their ulcers heal more rapidly. Because ulcers can heal while sitting on this seat, they are not likely to recur while using this seat. More tests are needed to compare ulcer healing rates with and without this seating system.
Design and Development of a Smart Seat for Reliefing From Pressure Ulcers
International Journal of Scientific Research in Science, Engineering and Technology, 2021
The long-term effects of sitting in a wheelchair can be painful. People who use wheelchairs can get muscle deformities and even serious injuries. Wheelchair injuries and pains, such as pressure ulcers, normally hit people who spend a significant amount of time in wheelchairs. Bad posture is another major challenge for people who use wheelchairs because they are not able to change their sitting position.