Smart-e-Pants:
Intermittent Electrical Stimulation for the
Prevention of Pressure Ulcers
Chester Ho, MD
Head and Associate Professor
Division of Physical Medicine & Rehabilitation
Department of Clinical Neurosciences
University of Calgary
Calgary, Canada
AIHS Team in Smart Neural Prostheses:
Principal
Investigators
Project
SMART
Neuroscientists, Engineers, Cell Biologists,
Computer Scientists, Neurosurgeons,
Physiatrists, Biostatisticians
2
Objectives
• To describe the scope of problems with
pressure ulcers
• To review the use of intermittent electrical
stimulation in the prevention of pressure ulcer
• To discuss the design of Smart-e-Pants and its
feasibility testing
WHAT IS A PRESSURE ULCER?
Definition
• A pressure ulcer is localized injury to the skin and/or
underlying tissue usually over a bony prominence, as
a result of pressure, or pressure in combination
with shear. A number of contributing or confounding
factors are also associated with pressure ulcers; the
significance of these factors is yet to be elucidated*.
*National Pressure Ulcer Advisory Panel/European Pressure Ulcer Advisory Panel
Stage IV Pressure Ulcer
Big problem? Yes!
• US prevalence data by hospital setting:
– acute hospital: 3-11% (9.2% in a study of 148
acute care hospitals) (Meeham 1990)
– rehabilitation hospital: 6-40%
– skilled nursing facility. 5-26%
– home care: 20%
– hospice: 13%
Expensive problem? Yes!
• Cost of care: $9.1 – 11.6 billions spent per
year in US (ARHQ)
• CMS not paying for hospital-acquired stage III
or IV pressure ulcers since Oct 2008
Are they avoidable?
• Incidence not decreasing in US
• Expert consensus – most are avoidable but some are
not (Black 2011)
• Many risk factors are reversible – therefore
important to explore reversible factors
• Current prevention techniques are passive and do
not aim to actively reverse any underlying tissue
health risks… so what can we do?
Intermittent Electrical Stimulation (IES)
SMART-E-PANTS
Using Intermittent Electrical
Stimulation as a Means of Prevention
• Proof-of-principle established in short-term
experiments in animals (rats) and human
volunteers (intact, spinal cord injured):
 Increasing tissue oxygenation
 Redistributing pressure around bony prominences
 Increasing muscle mass
How Smart-e-Pants Works
(a)
alternating leftright activation
simultaneous leftright activation
left
bursts of pulses
during stimulus ON
left
left
sustained train of
pulses during
stimulus ON
right
“ON”
10 minutes
right
alternating leftright activation
simultaneous leftright activation
“OFF”
right
“ON”
sustained train of
pulses during
stimulus ON
(a)
right
10 sec
bursts of pulses
during stimulus ON
left
Patent pending
(b)
(b)
Gluteus maximus
motor point
Gluteus maximus
motor point
Gluteus
Maximus
Gluteus
Maximus
Ischial
tuberosity
Ischial
tuberosity
Intermittent Electrical stimulation (IES) is delivered to muscles
at risk (i.e. gluteus maximus) through surface electrodes
 Muscle contractions are elicited every 10 minutes for 10
seconds; 12 hours per day

Electrodes and Stimulator
Stimulator
Electrodes
Belt
Application
Smart-e-pants
Patent pending
SMART-E-PANTS FEASIBILITY STUDY
Objectives of
Smart-e-Pants Feasibility Study:
1. Test Smart-e-Pants safety, stability, ease of use and
acceptability by both caregivers and end-users
2. Evaluate feasibility of implementing Smart-e-Pants in:
 Acute care setting (Foothills Medical Centre, Calgary, AB)
 Rehabilitation hospital (Glenrose Rehabilitation Hospital,
Edmonton, AB)
 Long-term care facility (Allen Gray Continuing Care,
Edmonton, AB)
Time to Apply and Remove
Electrodes vs. Smart-e-Pants
LTCF - E
RH - E
RH - G
ANR - E
ANR - G
Care Facility
Stability of Muscle Contraction
Care Facility
Skin Response to Electrodes
Care Facility
Patient Response to Smart-e-Pants
Conclusions
• Intermittent electrical stimulation may prevent
pressure ulcers.
• Smart-e-Pants are an acceptable intervention for the
prevention of pressure ulcers (for both caregivers
and patients).
• While on the Smart-e-Pants protocol we have not
had any patient developing pressure ulcers or other
significant adverse events.
Next Steps
• Further enhancement of stimulator
• Clinical testing in at-risk populations
Acknowledgment
Smart-e-Pants Team Calgary
 Sean Dukelow, MD
 Chester Ho, MD
 Robyn Warwaruk Rogers, RN
Dukelow Lab
 Jennifer Semrau, PhD
 Sonja Findlater, BSc OT
Smart-e-Pants Team Edmonton
 Vivian Mushahwar. PhD
 Ming Chan, MD
 Richard Stein, PhD
 Su Ling Chong, BSc, PT
 Alisa Ahmetovic, BEng.
 Ryan Somer, BSc OT
 Dana Schnepf, RN BN
 Glen Isaacson
Thank you!