Development of Intermittent Electrical Stimulation for the Prevention of Deep Tissue Injury

  • Author / Creator
    Solis Aguilar, Leandro R
  • The main goal of this thesis was to develop a novel intervention named Intermittent Electrical Stimulation (IES) to prevent the formation of deep tissue injury (DTI) in immobilized individuals, in particular those with spinal cord injury. Deep tissue injury is a type of pressure ulcer that originates at the deep bone-muscle interface due to the prolonged entrapment of soft tissue between a bony prominence and an external surface. Intermittent electrical stimulation is applied to muscles at risk of developing DTI and works by eliciting periodic muscle contractions in cycles of 10 seconds “ON” followed by a period of 10 minutes “OFF”, replicating the subconscious repositioning performed by able bodied individuals in response to sitting discomfort. These periodic IES-elicited muscle contractions are able to counteract both the mechanical and vascular factors leading to DTI. Four studies were conducted to test the effects of IES within the muscle and its effectiveness to prevent DTI. In able-bodied volunteers the use of IES reduced and redistributed superficial pressure around the ischial tuberosities. In addition, it increased the level of muscle oxygenation immediately after the IES-induced muscle contraction, and kept it elevated throughout the entire duration of each IES “OFF” phase. In studies conducted in adult pigs both intact and with spinal cord injury, the results of this thesis showed that peak internal pressures due to external loading was localized within a 2cm area centered around the ischial tuberosities. Peak internal pressures were approximately 2 times higher than peak superficial pressures. The use of IES effectively reduced internal pressure levels around the ischial tuberosities and redistributed internal pressure levels away from the ischial tuberosities during each IES-induced contraction. The effectiveness of IES was demonstrated in a study in adult pigs with injured spinal cords and atrophied muscles. An external load equivalent to 25% of body weight was applied to the paralyzed limb of each animal every day for 4hrs a day for 1 month. In the group of pigs that received the application of IES the extent of DTI was significantly less (8%) compared to the extent of DTI in the control group (48%).

  • Subjects / Keywords
  • Graduation date
  • Type of Item
  • Degree
    Doctor of Philosophy
  • DOI
  • License
    This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.
  • Language
  • Institution
    University of Alberta
  • Degree level
  • Department
    • Faculty of Rehabilitation Medicine
  • Specialization
    • Rehabilitation Science
  • Supervisor / co-supervisor and their department(s)
    • Dr. Vivian Mushahwar (Department of Physical Medicine and Rehabilitation)
    • Dr. Martin Ferguson-Pell (Faculty of Rehabilitation Medicine)
  • Examining committee members and their departments
    • Dr. Ted Tredget (Department of Surgery)
    • Dr. Richard Thompson (Department of Biomedical Engineering)
    • Dr. Yagesh Bhambhani (Department of Occupational Therapy)
    • Dr. Ming Chan (Centre for Neuroscience)
    • Dr. Amit Gefen (Univeristy of Tel-Aviv)