Heated Vest for Persons With Spinal Cord Injury
| Status: | Not yet recruiting |
|---|---|
| Conditions: | Hospital, Hospital, Orthopedic |
| Therapuetic Areas: | Orthopedics / Podiatry, Other |
| Healthy: | No |
| Age Range: | 18 - 68 |
| Updated: | 2/10/2019 |
| Start Date: | April 7, 2019 |
| End Date: | December 30, 2020 |
| Contact: | John P Handrakis, PT DPT EdD |
| Email: | John.Handrakis@va.gov |
| Phone: | (718) 584-9000 |
Developing a Feedback-Controlled Heated Vest to Address Thermoregulatory Dysfunction in Persons With Spinal Cord Injury
Persons with higher levels of spinal cord injury (above the 2nd thoracic vertebrae;
tetraplegia) are unable to maintain normal core body temperature (Tcore) when exposed to cool
environments. In persons with tetraplegia, even limited exposure to cool temperatures may
cause Tcore to approach hypothermic values and impair cognitive performance. Conversely, an
increase in Tcore from subnormal to normal range may improve cognitive performance. Prior
work has shown that cool seasonal temperatures have an adverse effect on personal comfort and
the ability to perform vital daily activities of self-care in persons with tetraplegia.
Interventions that address the vulnerability to hypothermia are limited. A self-regulating
heated vest designed specifically for persons with tetraplegia is a novel and promising
strategy to address this problem. By more effectively maintaining Tcore, the vest can
decrease the adverse impact of cool temperatures on comfort, quality of life, and performance
of vital daily tasks for Veterans with tetraplegia during the cooler seasons.
tetraplegia) are unable to maintain normal core body temperature (Tcore) when exposed to cool
environments. In persons with tetraplegia, even limited exposure to cool temperatures may
cause Tcore to approach hypothermic values and impair cognitive performance. Conversely, an
increase in Tcore from subnormal to normal range may improve cognitive performance. Prior
work has shown that cool seasonal temperatures have an adverse effect on personal comfort and
the ability to perform vital daily activities of self-care in persons with tetraplegia.
Interventions that address the vulnerability to hypothermia are limited. A self-regulating
heated vest designed specifically for persons with tetraplegia is a novel and promising
strategy to address this problem. By more effectively maintaining Tcore, the vest can
decrease the adverse impact of cool temperatures on comfort, quality of life, and performance
of vital daily tasks for Veterans with tetraplegia during the cooler seasons.
Persons with spinal cord injury (SCI), particularly cervical injuries (tetraplegia), are
unable to effectively regulate core body temperature (Tcore) due to interruption of motor,
sensory, and sympathetic pathways. Thus, control of distal extremity vasoconstriction (heat
conservation) and shivering thermogenesis (heat production) are impaired, and the ability to
maintain a constant Tcore is compromised. Persons with tetraplegia often report "feeling
cold," frequently present with subnormal Tcore (35-36.5 degrees C), and are particularly
vulnerable to hypothermia (Tcore<35 degrees C) and associated impairment in cognitive
performance, even when exposed to temperatures that are comfortable for able-bodied (AB)
individuals. Cool seasonal temperatures have been shown to have a greater adverse effect on
personal comfort, activities of daily living (ADLs), and vital daily activities in persons
with tetraplegia than that of AB controls. Conversely, a minimal increase in Tcore from
subnormal to normothermia, secondary to ambient heat may improve cognitive performance.
Interventions addressing the tendency to poikilothermia and enhanced vulnerability to
hypothermia in persons with tetraplegia are limited. Therefore, exploration of safe and
efficacious bioengineering solutions to address the physiological, cognitive, and quality of
life (QoL) issues associated with the routine exposure to cool temperatures that persons with
tetraplegia often encounter is warranted.
The goals of this pilot study are to: 1) fully bench-test the heated vest for safety before
performing any human subject testing; 2) study the safety and tolerability of a
feedback-controlled heated vest in AB controls; and 3) study the efficacy of this heated vest
to minimize the expected decline in Tcore and associated deterioration of cognitive
performance during 2 hours of cool exposure in persons with tetraplegia.
In persons with tetraplegia, a two-condition (heated vest, non-heated vest) prospective study
is being proposed to compare the physiological and cognitive responses to 2 hours of
controlled cool exposure (18 degrees C) with a prototype heated vest vs. a similar, but
non-heated vest (control condition). Eight subjects with tetraplegia (C3-T1, AIS A and B) and
eight AB controls will be recruited for study participation. Before the prototype is tested
on human subjects, it will have been fully bench tested and have satisfied all safety
requirements and specifications. AB subjects will be observed to ensure the safety of the
vest, which will be accomplished by determining the temperatures of the vest ( 39 degrees C)
and subjective thermal sensation of no greater than "warm" during a cool condition that will
be identical to the condition which subjects with SCI will be exposed. Subjects with
tetraplegia will test the efficacy of the heated vest, i.e. preventing the expected decline
in Tcore and cognitive performance and increase in thermal comfort.
After the feedback-controlled heated vest has been fully bench-tested and has satisfied all
safety requirements (interior vest temperature does not exceed 39 degrees C at maximal power)
and design specifications (lightweight, slim, easy to don doff), the following specific aims
will be addressed:
Primary Specific Aim: In a cool thermal chamber (18 degrees C), AB controls will wear the
heated vest at maximal setting for 120 minutes in the seated position to determine (1)
maximum temperatures of all areas of the interior (user's side) of the heated vest and (2)
subjective comfort of the heated vest (safety testing).
Primary Hypotheses: The study of AB controls will demonstrate (1) All areas under the vest
will have temperatures 39 degrees C. (2) All subjects will report a thermal sensation no
greater than "warm" this would include identification of "hot spots" (Zhang 9-point Thermal
Sensation Scale).
Secondary Specific Aim: During exposure to a cool environment (18 degrees C) for up to 120
minutes in the seated position, persons with tetraplegia will wear the heated vest to
determine (1) change in Tcore, (2) change in cognitive performance, and (3) change in thermal
comfort (efficacy testing).
Secondary Hypotheses: In persons with tetraplegia wearing the heated vest compared to the
same persons wearing the non-heated vest, it's expected that (1) 30% of the subjects will
have a decline of 0.5 degrees C in Tcore compared with 80% in the control condition, (2) 30%
of the subjects will demonstrate a decline of at least 1 T-score in at least one of the
following measures: Interference of Stroop Color and Word test, Digit Span of Wechsler Adult
Intelligence Scale-Fourth Edition, compared with 80% in the control condition, and (3) a
greater percentage of subjects reporting increased thermal comfort (Zhang 6-point Comfort
Scale).
unable to effectively regulate core body temperature (Tcore) due to interruption of motor,
sensory, and sympathetic pathways. Thus, control of distal extremity vasoconstriction (heat
conservation) and shivering thermogenesis (heat production) are impaired, and the ability to
maintain a constant Tcore is compromised. Persons with tetraplegia often report "feeling
cold," frequently present with subnormal Tcore (35-36.5 degrees C), and are particularly
vulnerable to hypothermia (Tcore<35 degrees C) and associated impairment in cognitive
performance, even when exposed to temperatures that are comfortable for able-bodied (AB)
individuals. Cool seasonal temperatures have been shown to have a greater adverse effect on
personal comfort, activities of daily living (ADLs), and vital daily activities in persons
with tetraplegia than that of AB controls. Conversely, a minimal increase in Tcore from
subnormal to normothermia, secondary to ambient heat may improve cognitive performance.
Interventions addressing the tendency to poikilothermia and enhanced vulnerability to
hypothermia in persons with tetraplegia are limited. Therefore, exploration of safe and
efficacious bioengineering solutions to address the physiological, cognitive, and quality of
life (QoL) issues associated with the routine exposure to cool temperatures that persons with
tetraplegia often encounter is warranted.
The goals of this pilot study are to: 1) fully bench-test the heated vest for safety before
performing any human subject testing; 2) study the safety and tolerability of a
feedback-controlled heated vest in AB controls; and 3) study the efficacy of this heated vest
to minimize the expected decline in Tcore and associated deterioration of cognitive
performance during 2 hours of cool exposure in persons with tetraplegia.
In persons with tetraplegia, a two-condition (heated vest, non-heated vest) prospective study
is being proposed to compare the physiological and cognitive responses to 2 hours of
controlled cool exposure (18 degrees C) with a prototype heated vest vs. a similar, but
non-heated vest (control condition). Eight subjects with tetraplegia (C3-T1, AIS A and B) and
eight AB controls will be recruited for study participation. Before the prototype is tested
on human subjects, it will have been fully bench tested and have satisfied all safety
requirements and specifications. AB subjects will be observed to ensure the safety of the
vest, which will be accomplished by determining the temperatures of the vest ( 39 degrees C)
and subjective thermal sensation of no greater than "warm" during a cool condition that will
be identical to the condition which subjects with SCI will be exposed. Subjects with
tetraplegia will test the efficacy of the heated vest, i.e. preventing the expected decline
in Tcore and cognitive performance and increase in thermal comfort.
After the feedback-controlled heated vest has been fully bench-tested and has satisfied all
safety requirements (interior vest temperature does not exceed 39 degrees C at maximal power)
and design specifications (lightweight, slim, easy to don doff), the following specific aims
will be addressed:
Primary Specific Aim: In a cool thermal chamber (18 degrees C), AB controls will wear the
heated vest at maximal setting for 120 minutes in the seated position to determine (1)
maximum temperatures of all areas of the interior (user's side) of the heated vest and (2)
subjective comfort of the heated vest (safety testing).
Primary Hypotheses: The study of AB controls will demonstrate (1) All areas under the vest
will have temperatures 39 degrees C. (2) All subjects will report a thermal sensation no
greater than "warm" this would include identification of "hot spots" (Zhang 9-point Thermal
Sensation Scale).
Secondary Specific Aim: During exposure to a cool environment (18 degrees C) for up to 120
minutes in the seated position, persons with tetraplegia will wear the heated vest to
determine (1) change in Tcore, (2) change in cognitive performance, and (3) change in thermal
comfort (efficacy testing).
Secondary Hypotheses: In persons with tetraplegia wearing the heated vest compared to the
same persons wearing the non-heated vest, it's expected that (1) 30% of the subjects will
have a decline of 0.5 degrees C in Tcore compared with 80% in the control condition, (2) 30%
of the subjects will demonstrate a decline of at least 1 T-score in at least one of the
following measures: Interference of Stroop Color and Word test, Digit Span of Wechsler Adult
Intelligence Scale-Fourth Edition, compared with 80% in the control condition, and (3) a
greater percentage of subjects reporting increased thermal comfort (Zhang 6-point Comfort
Scale).
Inclusion Criteria:
Subjects with spinal cord injury (SCI) and able-bodied subjects will be recruited according
to the following criteria:
- Duration of injury 1 year
- Neurological Level of SCI [C3-T1]; American Spinal Injury Association (ASIA)
Impairment Scale (AIS) A & B
- Euhydration
- Subjects will be instructed to avoid caffeine and alcohol
- maintain normal salt and water intake
- avoid strenuous exercise for 24 hours prior to study
Exclusion Criteria:
- Known heart, kidney, peripheral vascular or cerebrovascular disease
- High blood pressure
- History of Traumatic Brain Injury (TBI) or diagnosed cognitive impairment
- Untreated thyroid disease
- Diabetes mellitus
- Acute illness or infection
- Dehydration
- Smoking
- Pregnant women
- BMI>30 kg/m2
- Broken, inflamed, or otherwise fragile skin
We found this trial at
1
site
New York, New York 10010
Principal Investigator: John Philip Handrakis, PT DPT EdD
Phone: (718) 584-9000
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