Socket Cooling Effectiveness Take Home Study
Condition: Amputation; Amputation; Traumatic, Leg, Lower; Amputation Stump; Limb; Absence, Congenital, Lower; Prosthesis User; Lower Limb Amputation Below Knee (Injury)
MeSH terms: Amputation, Traumatic
Study type: Interventional

Summary: 
      The comfort and fit of the residual limb within a prosthetic socket are of primary concern
      for many amputees. The residual limb is typically covered by non-breathable and non-
      thermally conductive materials that can create a warm and ultimately moist environment.

      To address this, Liberating Technologies, Inc. (LTI) and Vivonics, Inc. have developed a
      thermo-electric cooling (TEC)-based module called the Intrasocket Cooling Element (ICE), that
      can be embedded into the prosthesis in order to cool the residual limb. A technology that can
      provide thermal control while retaining adequate suspension, weight and other prosthetic
      characteristics would benefit many prosthesis wearers.
    

Detailed description: 
      The comfort and fit of the residual limb within a prosthetic socket are of primary concern
      for many amputees. The residual limb is typically covered by non-breathable and non-
      thermally conductive materials that can create a warm and ultimately moist environment.
      Studies found increases in socket temperature after the prosthesis was donned (0.8 degrees C)
      and after 30 minutes of walking (2.5 degrees C). Temperatures were found to remain elevated
      long after activity cessation and even a rest period of double the duration of the preceding
      activity period is insufficient to return the limb to its initial temperature. A study
      suggested that a modest temperature increase of only 2 degrees C may be responsible for
      reports of thermal discomfort by amputees. Therefore, a small amount of activity can cause
      the socket temperature to elevate and remain at an uncomfortable level for an extended period
      of time, which can lead to decreased wear times. In summary, an uncomfortable socket/residual
      limb interface decreases prosthesis use among amputees who want to remain active in their
      lives.

      To address this, Liberating Technologies, Inc. (LTI) and Vivonics, Inc. have developed a
      thermo-electric cooling (TEC)-based module called the Intrasocket Cooling Element (ICE), that
      can be embedded into the prosthesis in order to cool the residual limb. A technology that can
      provide thermal control while retaining adequate suspension, weight and other prosthetic
      characteristics would benefit many prosthesis wearers.

      This study will focus on investigating the efficacy of this novel socket cooling technology.

      The rationale for this study is to determine how well the new technology can cool the
      residual limb not only in a controlled laboratory environment, but also in a home environment
      where the device would ultimately be utilized.

      The primary objective of this study is to measure the effects of cooling the residual limb on
      quality of life (QoL) and functional outcomes. Cooling the residual limb inside the
      prosthetic socket would result in less sweating and greater comfort while wearing the
      prosthesis, and ultimately greater function and better quality of life as measured by
      standard functional and QoL outcome measures.

      A two group, prospective, double-blinded, block randomized, crossover study design will be
      implemented. Research participants will be consented and have baseline activity and socket
      temperature data collected from their usual prosthesis during normal use (4 weeks). The ICE
      system will be integrated into a custom, experimental socket for each subject. Two versions
      of the cooling module will be created: (1) a fully-functional, active ICE cooling module (the
      so called "ON", or experimental, condition), and (2) a placebo ICE module with the TEC unit
      replaced with an insulating material layer between the fan and the heat spreader such that
      even when the system is turned on, minimal heat transfer occurs (the control, or "OFF"
      condition). An ICE module with a heat spreader will be embedded into the socket and the fan
      will continue to run whether or not active cooling is engaged for both test conditions;
      however, no heat will be able to be transferred through the insulating layer in the OFF
      condition. The TEC inside the ICE unit will not be visible once assembled and the modules
      will be assembled independently; therefore, both the subject and the tester will be blinded
      to the condition being tested for both the in-lab and at-home testing. A serial number will
      be used to identify the assembled units and the master key stored separately.

      The participants will be divided into two groups and the order of the experimental conditions
      will be randomized. Each condition will be tested for 4 weeks. In-lab testing and functional
      measures will be assessed between testing periods as additional assessments of efficacy of
      the device. Testing will consist of 4 test site visits, as well as 1-2 visits to create and
      align the experimental socket. The entire study will continue for 3 months.

      Lower limb prosthesis users will be recruited for the study and consented with an approved
      protocol. Research participants will represent a convenience sample and will reflect the
      local population of both above-knee (AK) and below-knee (BK) amputees of various K-levels
      using a variety of suspension types who could benefit from temperature control within the
      socket.

      A maximum of 20 subjects will be recruited for this study. This is increased from the target
      16 subjects to account for any drop-outs, etc.
    

Intervention name(s): ICE Condition; Sham Condition
Intervention type(s): Device; Device
Intervention description(s): Experimental socket integrated with a heat spreader. An ICE Unit (includes TEC) is attached to the socket.; Experimental socket integrated with a heat spreader. A Sham Unit (excludes TEC) is attached to the socket.
Other intervention name(s): Cooling Unit; ICE Unit; Sham Unit
Allocation: Randomized
Intervention model: Crossover Assignment
Masking: Double (Participant, Investigator)
Primary purpose: Other
Keywords: cooling; amputee; lower limb absence; prosthesis; prosthetic leg; transtibial; below knee amputation; lower limb difference; lower limb loss; socket; prosthetist; sweat; active; walking; prosthetic liner; prosthetic sock; perspiration; moisture; heat; thermal