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Completed

NCT Number: NCT06026813

Pressure Alternating Shoes

The project is designed to develop and test Pressure Alternating Shoes (PAS), which will periodically off-load certain regions of the foot in order to prevent foot ulcers. An automated dual layer insole compromised of an active pressurized actuator array in combination with a passive compliant layer on top of each actuator to modulate and distribute the plantar surface pressure as desired will be tested. This device will allow us to simultaneously load and offload select areas of the foot using the active layer by inflating and deflating individual actuators using pressurized air. After offloading, the remaining load will be distributed to other areas with inflated actuators. Automatic modulation will be provided through programmable control hardware which will cyclically relieve mechanical loading based on a prescribed duration and frequency.

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Key information

Conditions

Foot Ulcer, Diabetic Cardiovascular Diseases Diabetes Complications Diabetes Mellitus Diabetic Angiopathies Diabetic Foot Diabetic Neuropathies Endocrine System Diseases Foot Ulcer Leg Ulcer Skin Diseases Skin Ulcer Skin and Connective Tissue Diseases Vascular Diseases

Age range

18 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

University of Texas Southwestern Medical Center

Dallas, Texas, 75390-8560, United States

About this study

The two-tier human subjects study will be conducted to assess the biomechanical characteristics of PAS. In the first tier, we will test PAS in healthy subjects and in the second tier, we will test PAS in Diabetic Neuropathy patients (DN).

Subjects will walk on a treadmill in their usual daily shoes for 5 minutes, then with standard diabetic shoes with the PAS insoles for 5 minutes. Subjects will wear body worn sensors that assess position of the body. Subjects will have the temperature of their feet measured via a special camera after walking. Subjects will rest for 30 minute washout period and have the blood flow in the soles of the feet measured via a special camera. 1 healthy subject will undergo MRI of the foot and ankle.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Healthy Controls:

Inclusion criteria

  • Age 18 or greater
  • Ability to wear insoles in shoes provided
  • Ability to walk unaided

Exclusion criteria

  • Diabetic Neuropathy
  • Charcot foot
  • Knee pain
  • Previous amputations
  • Inflammatory diseases such as rheumatoid arthritis
  • Open wounds, ulcers, sores or blisters on the feet; signs of infection in the feet

Diabetic population:

Inclusion:

  • Age 18 or greater
  • Ability to wear insoles in shoes provided
  • Ability to walk unaided
  • Diagnosis of diabetic neuropathy

Excluision:

  • Charcot foot
  • Knee Pain
  • Previous amputations
  • Inflammatory diseases such as rheumatoid arthritis
  • Open wounds, ulcers, sores or blistesr on the feet; signs of infection in the feet

Treatment and study plan

test pressure alternating shoes

Device

test pressure alternating shoes

Primary outcomes

  1. Maximum Average Pressure at Baseline With Pressure Alternating Shoes, Right Foot (Before Any Cells Were Offloaded)

    Time frame: Before any cells were offloaded (First 40-seconds of the walk)

    Maximum Average pressure values in the plantar regions before offloading during walking. The insole consists of seven air cells that align with specific regions: the big toe (cell 1), the area spanning from the second toe to the fifth toe (cell 2), metatarsal heads (cells 3 and 4), the midfoot (cells 5 and 6), and the heel (cell 7). Measurements were only obtained from the right foot.

  2. Maximum Average Pressure at After Offloading - Diabetic Footwear Equipped With PAS Device

    Time frame: After offloading (approx. 41- 200 seconds walk)

    Maximum Average pressure values in the plantar regions after offloading cells during walking. The insole consists of seven air cells that align with specific regions: the big toe (cell 1), the area spanning from the second toe to the fifth toe (cell 2), metatarsal heads (cells 3 and 4), the midfoot (cells 5 and 6), and the heel (cell 7). Measurements were only obtained from the right foot. The results reported represent results for footwear with PAS device.

  3. Peak Interface Pressure at Baseline (Before Offloading) - Diabetic Footwear Equipped With PAS Device

    Time frame: Baseline (First 40-seconds of the walk)

    Peak Interface Pressure values in the plantar regions before offloading during walking. The insole consists of seven air cells that align with specific regions: the big toe (cell 1), the area spanning from the second toe to the fifth toe (cell 2), metatarsal heads (cells 3 and 4), the midfoot (cells 5 and 6), and the heel (cell 7). Measurements were only obtained from the right foot. The results reported represent results for footwear with PAS device.

  4. Peak Interface Pressure at After Offloading - Diabetic Footwear Equipped With PAS Device

    Time frame: After offloading (approx. 41- 200 seconds walk)

    Peak Interface Pressure values in the plantar regions after offloading during walking. The insole consists of seven air cells that align with specific regions: the big toe (cell 1), the area spanning from the second toe to the fifth toe (cell 2), metatarsal heads (cells 3 and 4), the midfoot (cells 5 and 6), and the heel (cell 7). Measurements were only obtained from the right foot. The results reported represent results for footwear with PAS device.

  5. Max Average Pressure Change Among All Participants - Diabetic Footwear Equipped With PAS Device

    Time frame: Baseline (first 40-second walk), 201 seconds after the intervention ended

    Percentage change due to offloading for each participant is measured by dividing the pressure difference between the after offloading and before offloading values divided by the before offloading value. Measurements were only obtained from the right foot. The results reported represent results for footwear with PAS device.

  6. Peak Pressure Change Among All Participants - Diabetic Footwear Equipped With PAS Device

    Time frame: Baseline (first 40-second walk), 201 seconds after the intervention ended

    Peak pressure change due to offloading for each participant is measured by dividing the pressure difference between the peak after offloading and peak before offloading values divided by the peak before offloading value. Measurements were only obtained from the right foot. The results reported represent results for footwear with PAS device.

Secondary outcomes

  1. Plantar Skin Temperature at Baseline, Right Foot

    Time frame: Baseline before the intervention (30 minutes after start of visit 1)

    Plantar skin temperature measured by a noncontact thermal imaging camera (*Celcius) before the intervention and without footwear

  2. Plantar Skin Temperature Post Intervention, Right Foot

    Time frame: Post intervention (215 seconds)

    Plantar skin temperature measured by a noncontact thermal imaging camera (*Celcius) post intervention, without footwear

  3. Tissue Oxygenation (Oxygen Saturation) - for Plantar Lateral Foot

    Time frame: Baseline (30 minutes after start of visit 1)

    Plantar foot tissue oxygenation (Oxygen saturation) is measured by noncontact hyperspectral imaging camera (StO2). Only the right foot was analyzed and without footwear.

  4. Tissue Oxygenation (Oxyhemoglobin and Deoxyhemoglobin ) - for Plantar Lateral Foot

    Time frame: Baseline (30 minutes after start of visit 1)

    Plantar foot tissue oxygenation (Oxyhemoglobin and Deoxyhemoglobin) is measured by noncontact hyperspectral imaging (HSI) camera. Only the right foot was analyzed and without footwear. The accepted measure of oxyhemoglobin and deoxyhemoglobin is arbitrary units (AU). NIR spectrum light passes through skin and is reflected off the blood supplying the tissue. Wavelength dependent light absorption of hemoglobin differs if it is carrying oxygen or not, therefore detecting oxygenated and deoxygenated blood. This was derived from Beer-Lambert Law but would need to be verified by the manufacturer. There is no researcher drawn calculation as the device provides the arbitrary unit based on the reflectance detected back to the imaging device. No reference values or any standardization available but one would infer higher oxyhemoglobin level indicates better oxygenation and thus a higher deoxyhemoglobin would be indicative of poor oxygenation.

  5. Tissue Oxygenation (Oxygen Saturation) - for Plantar Medial Foot

    Time frame: Baseline (30 minutes after start of visit 1)

    Plantar Medial foot tissue oxygenation (Oxygen saturation) is measured by noncontact hyperspectral imaging camera (StO2). Only the right foot was analyzed and without footwear.

  6. Tissue Oxygenation (Oxyhemoglobin and Deoxyhemoglobin) - for Plantar Medial Foot

    Time frame: Baseline (30 minutes after start of visit 1)

    Plantar medial foot tissue oxygenation (Oxyhemoglobin and Deoxyhemoglobin) is measured by noncontact hyperspectral imaging (HSI) camera. Only the right foot was analyzed. Only the right foot was analyzed and without footwear. The accepted measure of oxyhemoglobin and deoxyhemoglobin is arbitrary units (AU). NIR spectrum light passes through skin and is reflected off the blood supplying the tissue. Wavelength dependent light absorption of hemoglobin differs if it is carrying oxygen or not, therefore detecting oxygenated and deoxygenated blood. This was derived from Beer-Lambert Law but would need to be verified by the manufacturer. There is no researcher drawn calculation as the device provides the arbitrary unit based on the reflectance detected back to the imaging device. No reference values or any standardization available but one would infer higher oxyhemoglobin level indicates better oxygenation and thus a higher deoxyhemoglobin would be indicative of poor oxygenation.

  7. Tissue Oxygenation (Oxygen Saturation) - for Plantar Lateral Foot

    Time frame: Post Gait (approx. 2015 seconds post intervention)

    Plantar foot tissue oxygenation (Oxygen saturation) is measured by noncontact hyperspectral imaging camera (StO2). Only the right foot was analyzed and without footwear.

  8. Tissue Oxygenation (Oxyhemoglobin and Deoxyhemoglobin ) - for Plantar Lateral Foot

    Time frame: Post Gait (approx. 2015 seconds post intervention)

    Plantar foot tissue oxygenation (Oxyhemoglobin and Deoxyhemoglobin) is measured by noncontact hyperspectral imaging (HSI) camera. Only the right foot was analyzed and without footwear. The accepted measure of oxyhemoglobin and deoxyhemoglobin is arbitrary units (AU). NIR spectrum light passes through skin and is reflected off the blood supplying the tissue. Wavelength dependent light absorption of hemoglobin differs if it is carrying oxygen or not, therefore detecting oxygenated and deoxygenated blood. This was derived from Beer-Lambert Law but would need to be verified by the manufacturer. There is no researcher drawn calculation as the device provides the arbitrary unit based on the reflectance detected back to the imaging device. No reference values or any standardization available but one would infer higher oxyhemoglobin level indicates better oxygenation and thus a higher deoxyhemoglobin would be indicative of poor oxygenation.

  9. Tissue Oxygenation (Oxygen Saturation) - for Plantar Medial Foot

    Time frame: Post Gait (approx. 2015 seconds post intervention)

    Plantar Medial foot tissue oxygenation (Oxygen saturation) is measured by noncontact hyperspectral imaging camera (StO2). Only the right foot was analyzed and without footwear.

  10. Tissue Oxygenation (Oxyhemoglobin and Deoxyhemoglobin) - for Plantar Medial Foot

    Time frame: Post Gait (approx. 2015 seconds post intervention)

    Plantar medial foot tissue oxygenation (Oxyhemoglobin and Deoxyhemoglobin) is measured by noncontact hyperspectral imaging (HSI) camera. Only the right foot was analyzed and without footwear. The accepted measure of oxyhemoglobin and deoxyhemoglobin is arbitrary units (AU). NIR spectrum light passes through skin and is reflected off the blood supplying the tissue. Wavelength dependent light absorption of hemoglobin differs if it is carrying oxygen or not, therefore detecting oxygenated and deoxygenated blood. This was derived from Beer-Lambert Law but would need to be verified by the manufacturer. There is no researcher drawn calculation as the device provides the arbitrary unit based on the reflectance detected back to the imaging device. No reference values or any standardization available but one would infer higher oxyhemoglobin level indicates better oxygenation and thus a higher deoxyhemoglobin would be indicative of poor oxygenation.

  11. Balance

    Time frame: Baseline

    Positional sense measured by body-worn sensors (cm)

Sponsors and collaborators

Lead sponsor

University of Texas Southwestern Medical Center

Other

Collaborators

  • National Institute on Aging (NIA)
  • The University of Texas at Arlington

Registry information

Official study title

Pressure Alternating Shoes (PAS) for Prevention of Diabetic Foot Ulcers

Acronym: PAS

Important dates

Study start
2024
Primary completion
2024
Study completion
2024
First posted
Sep 7, 2023
Registry last updated
Aug 12, 2025

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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