Quantification of Progenitor Cell Circulation Following Vascular Resistance Exercise Using Delfi Tourniquet System
NCT ID: NCT07213726
Last Updated: 2025-12-08
Study Results
Results pending
The study team has not published outcome measurements, participant flow, or safety data for this trial yet. Check back later for updates.
Basic Information
Get a concise snapshot of the trial, including recruitment status, study phase, enrollment targets, and key timeline milestones.
Recruitment Status
ACTIVE_NOT_RECRUITING
Clinical Phase
NA
Total Enrollment
15 participants
Study Classification
INTERVENTIONAL
Study Start Date
2022-08-16
Study Completion Date
2026-11-20
Brief Summary
Review the sponsor-provided synopsis that highlights what the study is about and why it is being conducted.
The purpose of this observational study is to examine how slowing down blood flow to the legs- a practice called blood flow restriction (BFR)- during exercise by applying compression to the legs affects the way stem cells are released into the blood stream. This will be determined by drawing 6 cubic centimeters (ccs) of blood immediately post-exercise after the Delfi Personalized Tourniquet System (PTS) has been removed. 6 ccs of blood will also be taken prior to exercise and at the 20-, 40-, and 60-minute marks after exercise. The main question of this study is:
• Will the levels of stem cells extracted before and after exercise be the same if blood flow is restricted during exercise?
In this study, participants will undergo the following:
* 6 ccs of blood extracted from the forearm prior to exercise to establish a baseline
* 3 exercises- seated leg extension, semi-reclined leg press, and seated hamstring curl- consisting of 4 sets of 30-15-15-15 repetitions per exercise; resistance will be set to 30% of one-rep maximum (1-RM)
* Additional 6 cc blood draws will be performed immediately post-exercise and after 20, 40, and 60 minutes have elapsed
• Will the levels of stem cells extracted before and after exercise be the same if blood flow is restricted during exercise?
In this study, participants will undergo the following:
* 6 ccs of blood extracted from the forearm prior to exercise to establish a baseline
* 3 exercises- seated leg extension, semi-reclined leg press, and seated hamstring curl- consisting of 4 sets of 30-15-15-15 repetitions per exercise; resistance will be set to 30% of one-rep maximum (1-RM)
* Additional 6 cc blood draws will be performed immediately post-exercise and after 20, 40, and 60 minutes have elapsed
Related Clinical Trials
Explore similar clinical trials based on study characteristics and research focus.
Design Validation Hemodynamic Study of New Kendall SCD SmartFlow Compression System
NCT05945186
Hemodynamics
UNKNOWN
NA
Feasibility Study Focusing on Fit of Made-to-measure Compression Garments in Healthy Subjects II
NCT04714476
Product Use Issue
COMPLETED
NA
Demonstrating the Feasibility of a Novel Oxygen Delivery Device
NCT02824211
Increased Oxygen Demand
WITHDRAWN
NA
A New Intelligent Stocking for Quantification of Edema in the Lower Limbs
NCT05310435
Edema Leg
TERMINATED
OsciPulse Device for the Prevention of VTE
NCT04625673
Venous Thromboembolism
Deep Vein Thrombosis
Pulmonary Thromboembolisms
COMPLETED
NA
Detailed Description
Dive into the extended narrative that explains the scientific background, objectives, and procedures in greater depth.
The proposed study is a prospective, quasi-experiment, dual-center (exercise facility and laboratory) study involving 15 healthy, male and female volunteers. A potential subject must clear the screening, consent to the procedures of this study, and complete the medical interview before proceeding with the familiarization session. The familiarization process will include an introduction to the Delfi BFR Tourniquet System (Delfi Medical Innovations Inc., Vancouver, BC) and the exercises (seated leg extension, semi-reclined leg press, seated hamstring curl) that the subject will complete. The weight each subject will use for each exercise will be determined during this time. All familiarization procedures must be completed prior to the scheduling and execution of the first of twelve experimental testing sessions.
The experimental testing sessions will occur twice a week for six weeks (12 sessions) and will involve the BFR training utilizing the Delfi BFR Tourniquet System, as further described in the Experimental Testing Session section of the treatment plan (6.2). At the beginning of the first, the sixth, and the twelfth testing sessions there will be a blood draw requiring 6 cc of blood to be taken prior to exercise. Post-exercise, at each testing session, additional 6cc blood draws will be conducted immediately post exercise (time point 0), as well as 20- , 40- , and 60 minutes after the conclusion of the workout. Following every testing session workout, finger-prick blood samples for lactate testing will be taken. These blood samples are to be taken at Time point 0- (T 0), 10-, 20-, 30-, 40-, 50-, and 60-minutes following exercise. Once the twelfth experimental testing session has been completed, the subjects will have one final session that is to take place no more than five days following the twelfth testing session. This final session will include one final blood draw of 6 cc. Throughout the duration of the study, the blood drawn will be used for obtaining a complete blood count (CBC) and for cellular analysis to quantify peripheral hematopoietic progenitor cell concentration. The blood samples collected from subject's fingers throughout the study will be used for analysis using a portable lactate analyzer. Lactate analysis will allow researchers insight into each subject's exertion level reflected by the amount of lactate found within the samples collected.
The experimental testing sessions will occur twice a week for six weeks (12 sessions) and will involve the BFR training utilizing the Delfi BFR Tourniquet System, as further described in the Experimental Testing Session section of the treatment plan (6.2). At the beginning of the first, the sixth, and the twelfth testing sessions there will be a blood draw requiring 6 cc of blood to be taken prior to exercise. Post-exercise, at each testing session, additional 6cc blood draws will be conducted immediately post exercise (time point 0), as well as 20- , 40- , and 60 minutes after the conclusion of the workout. Following every testing session workout, finger-prick blood samples for lactate testing will be taken. These blood samples are to be taken at Time point 0- (T 0), 10-, 20-, 30-, 40-, 50-, and 60-minutes following exercise. Once the twelfth experimental testing session has been completed, the subjects will have one final session that is to take place no more than five days following the twelfth testing session. This final session will include one final blood draw of 6 cc. Throughout the duration of the study, the blood drawn will be used for obtaining a complete blood count (CBC) and for cellular analysis to quantify peripheral hematopoietic progenitor cell concentration. The blood samples collected from subject's fingers throughout the study will be used for analysis using a portable lactate analyzer. Lactate analysis will allow researchers insight into each subject's exertion level reflected by the amount of lactate found within the samples collected.
Conditions
See the medical conditions and disease areas that this research is targeting or investigating.
Blood Flow Restriction (BFR) Training Effects
Study Design
Understand how the trial is structured, including allocation methods, masking strategies, primary purpose, and other design elements.
Allocation Method
NA
Intervention Model
SINGLE_GROUP
Primary Study Purpose
HEALTH_SERVICES_RESEARCH
Blinding Strategy
NONE
Study Groups
Review each arm or cohort in the study, along with the interventions and objectives associated with them.
Healthy
This group consists of all participants in this study. Subjects must be healthy, and gender is not a factor for enrollment.
Group Type
EXPERIMENTAL
Delfi Personalized Tourniquet System
Intervention Type
DEVICE
Bilateral proximal thigh bands that will be applied and inflated to a pressure of 80% of occlusive pressure as determined by the automated tourniquet before exercise. A standard exercise session would not include any blood occlusion.
Interventions
Learn about the drugs, procedures, or behavioral strategies being tested and how they are applied within this trial.
Delfi Personalized Tourniquet System
Bilateral proximal thigh bands that will be applied and inflated to a pressure of 80% of occlusive pressure as determined by the automated tourniquet before exercise. A standard exercise session would not include any blood occlusion.
Intervention Type
DEVICE
Eligibility Criteria
Check the participation requirements, including inclusion and exclusion rules, age limits, and whether healthy volunteers are accepted.
Inclusion Criteria
1. Volunteer population of healthy males and females aged 18-45.
2. Subjects consent to attending a total of 14 visits over a time span of seven to nine weeks. The breakdown of the 14 visits is as follows: 1 familiarization session, 12 experimental testing sessions, 1 final session.
2. Subjects consent to attending a total of 14 visits over a time span of seven to nine weeks. The breakdown of the 14 visits is as follows: 1 familiarization session, 12 experimental testing sessions, 1 final session.
Exclusion Criteria
Volunteers who have medical history involving one or more of the following medical conditions:
1. Diabetes
2. Uncontrolled hypertension
3. Autoimmune disorders
4. Blood disorders
5. Ongoing infectious disease
6. Cancer
7. Any disorder requiring immunosuppression treatment
8. Steroid usage
9. Significant cardiovascular, pulmonary, hepatic, or renal disease.
10. Volunteers where 20 minutes of intense exercise is contra-indicated will also be excluded from the study.
11. Positive pregnancy test
1. Diabetes
2. Uncontrolled hypertension
3. Autoimmune disorders
4. Blood disorders
5. Ongoing infectious disease
6. Cancer
7. Any disorder requiring immunosuppression treatment
8. Steroid usage
9. Significant cardiovascular, pulmonary, hepatic, or renal disease.
10. Volunteers where 20 minutes of intense exercise is contra-indicated will also be excluded from the study.
11. Positive pregnancy test
Minimum Eligible Age
18 Years
Maximum Eligible Age
45 Years
Eligible Sex
ALL
Accepts Healthy Volunteers
Yes
Sponsors
Meet the organizations funding or collaborating on the study and learn about their roles.
Florida
OTHER
Sponsor Role
collaborator
Andrews Research & Education Foundation
OTHER
Sponsor Role
lead
Responsible Party
Identify the individual or organization who holds primary responsibility for the study information submitted to regulators.
Responsibility Role
SPONSOR
Principal Investigators
Learn about the lead researchers overseeing the trial and their institutional affiliations.
Tyler Opitz, DPT, SCS, CSCS
Role: PRINCIPAL_INVESTIGATOR
Physical Therapist
Locations
Explore where the study is taking place and check the recruitment status at each participating site.
Andrews Institute for Orthopaedics & Sports Medicine
Gulf Breeze, Florida, United States
Site Status
Countries
Review the countries where the study has at least one active or historical site.
United States
References
Explore related publications, articles, or registry entries linked to this study.
Weissman IL, Shizuru JA. The origins of the identification and isolation of hematopoietic stem cells, and their capability to induce donor-specific transplantation tolerance and treat autoimmune diseases. Blood. 2008 Nov 1;112(9):3543-53. doi: 10.1182/blood-2008-08-078220.
Reference Type
BACKGROUND
Zakrzewski JL, van den Brink MR, Hubbell JA. Overcoming immunological barriers in regenerative medicine. Nat Biotechnol. 2014 Aug;32(8):786-94. doi: 10.1038/nbt.2960.
Reference Type
BACKGROUND
Caplan AI. Mesenchymal stem cells. J Orthop Res. 1991 Sep;9(5):641-50. doi: 10.1002/jor.1100090504.
Reference Type
BACKGROUND
Marycz K, Mierzejewska K, Smieszek A, Suszynska E, Malicka I, Kucia M, Ratajczak MZ. Endurance Exercise Mobilizes Developmentally Early Stem Cells into Peripheral Blood and Increases Their Number in Bone Marrow: Implications for Tissue Regeneration. Stem Cells Int. 2016;2016:5756901. doi: 10.1155/2016/5756901. Epub 2015 Nov 9.
Reference Type
BACKGROUND
Agha NH, Baker FL, Kunz HE, Graff R, Azadan R, Dolan C, Laughlin MS, Hosing C, Markofski MM, Bond RA, Bollard CM, Simpson RJ. Vigorous exercise mobilizes CD34+ hematopoietic stem cells to peripheral blood via the beta2-adrenergic receptor. Brain Behav Immun. 2018 Feb;68:66-75. doi: 10.1016/j.bbi.2017.10.001. Epub 2017 Oct 7.
Reference Type
BACKGROUND
Callanan MC, Plummer HA, Chapman GL, Opitz TJ, Rendos NK, Anz AW. Blood Flow Restriction Training Using the Delfi System Is Associated With a Cellular Systemic Response. Arthrosc Sports Med Rehabil. 2020 Dec 27;3(1):e189-e198. doi: 10.1016/j.asmr.2020.09.009. eCollection 2021 Feb.
Reference Type
BACKGROUND
Hwang NS, Zhang C, Hwang YS, Varghese S. Mesenchymal stem cell differentiation and roles in regenerative medicine. Wiley Interdiscip Rev Syst Biol Med. 2009 Jul-Aug;1(1):97-106. doi: 10.1002/wsbm.26.
Reference Type
BACKGROUND
Docheva D, Popov C, Mutschler W, Schieker M. Human mesenchymal stem cells in contact with their environment: surface characteristics and the integrin system. J Cell Mol Med. 2007 Jan-Feb;11(1):21-38. doi: 10.1111/j.1582-4934.2007.00001.x.
Reference Type
BACKGROUND
Rochefort GY, Delorme B, Lopez A, Herault O, Bonnet P, Charbord P, Eder V, Domenech J. Multipotential mesenchymal stem cells are mobilized into peripheral blood by hypoxia. Stem Cells. 2006 Oct;24(10):2202-8. doi: 10.1634/stemcells.2006-0164. Epub 2006 Jun 15.
Reference Type
BACKGROUND
Hylden C, Burns T, Stinner D, Owens J. Blood flow restriction rehabilitation for extremity weakness: a case series. J Spec Oper Med. 2015 Spring;15(1):50-6.
Reference Type
BACKGROUND
Takarada Y, Takazawa H, Ishii N. Applications of vascular occlusion diminish disuse atrophy of knee extensor muscles. Med Sci Sports Exerc. 2000 Dec;32(12):2035-9. doi: 10.1097/00005768-200012000-00011.
Reference Type
BACKGROUND
Vechin FC, Libardi CA, Conceicao MS, Damas FR, Lixandrao ME, Berton RP, Tricoli VA, Roschel HA, Cavaglieri CR, Chacon-Mikahil MP, Ugrinowitsch C. Comparisons between low-intensity resistance training with blood flow restriction and high-intensity resistance training on quadriceps muscle mass and strength in elderly. J Strength Cond Res. 2015 Apr;29(4):1071-6. doi: 10.1519/JSC.0000000000000703.
Reference Type
BACKGROUND
Takarada Y, Takazawa H, Sato Y, Takebayashi S, Tanaka Y, Ishii N. Effects of resistance exercise combined with moderate vascular occlusion on muscular function in humans. J Appl Physiol (1985). 2000 Jun;88(6):2097-106. doi: 10.1152/jappl.2000.88.6.2097.
Reference Type
BACKGROUND
Feriche B, Garcia-Ramos A, Morales-Artacho AJ, Padial P. Resistance Training Using Different Hypoxic Training Strategies: a Basis for Hypertrophy and Muscle Power Development. Sports Med Open. 2017 Dec;3(1):12. doi: 10.1186/s40798-017-0078-z. Epub 2017 Mar 17.
Reference Type
BACKGROUND
Kaijser L, Sundberg CJ, Eiken O, Nygren A, Esbjornsson M, Sylven C, Jansson E. Muscle oxidative capacity and work performance after training under local leg ischemia. J Appl Physiol (1985). 1990 Aug;69(2):785-7. doi: 10.1152/jappl.1990.69.2.785.
Reference Type
BACKGROUND
Farup J, de Paoli F, Bjerg K, Riis S, Ringgard S, Vissing K. Blood flow restricted and traditional resistance training performed to fatigue produce equal muscle hypertrophy. Scand J Med Sci Sports. 2015 Dec;25(6):754-63. doi: 10.1111/sms.12396. Epub 2015 Jan 21.
Reference Type
BACKGROUND
Ellefsen S, Hammarstrom D, Strand TA, Zacharoff E, Whist JE, Rauk I, Nygaard H, Vegge G, Hanestadhaugen M, Wernbom M, Cumming KT, Ronning R, Raastad T, Ronnestad BR. Blood flow-restricted strength training displays high functional and biological efficacy in women: a within-subject comparison with high-load strength training. Am J Physiol Regul Integr Comp Physiol. 2015 Oct;309(7):R767-79. doi: 10.1152/ajpregu.00497.2014. Epub 2015 Jul 22.
Reference Type
BACKGROUND
de Freitas MC, Gerosa-Neto J, Zanchi NE, Lira FS, Rossi FE. Role of metabolic stress for enhancing muscle adaptations: Practical applications. World J Methodol. 2017 Jun 26;7(2):46-54. doi: 10.5662/wjm.v7.i2.46. eCollection 2017 Jun 26.
Reference Type
BACKGROUND
Vanwye WR, Weatherholt AM, Mikesky AE. Blood Flow Restriction Training: Implementation into Clinical Practice. Int J Exerc Sci. 2017 Sep 1;10(5):649-654. doi: 10.70252/LYGQ7085. eCollection 2017.
Reference Type
BACKGROUND
Loenneke JP, Fahs CA, Rossow LM, Abe T, Bemben MG. The anabolic benefits of venous blood flow restriction training may be induced by muscle cell swelling. Med Hypotheses. 2012 Jan;78(1):151-4. doi: 10.1016/j.mehy.2011.10.014. Epub 2011 Nov 1.
Reference Type
BACKGROUND
Wilson JM, Lowery RP, Joy JM, Loenneke JP, Naimo MA. Practical blood flow restriction training increases acute determinants of hypertrophy without increasing indices of muscle damage. J Strength Cond Res. 2013 Nov;27(11):3068-75. doi: 10.1519/JSC.0b013e31828a1ffa.
Reference Type
BACKGROUND
Loenneke JP, Abe T, Wilson JM, Thiebaud RS, Fahs CA, Rossow LM, Bemben MG. Blood flow restriction: an evidence based progressive model (Review). Acta Physiol Hung. 2012 Sep;99(3):235-50. doi: 10.1556/APhysiol.99.2012.3.1.
Reference Type
BACKGROUND
Reeves GV, Kraemer RR, Hollander DB, Clavier J, Thomas C, Francois M, Castracane VD. Comparison of hormone responses following light resistance exercise with partial vascular occlusion and moderately difficult resistance exercise without occlusion. J Appl Physiol (1985). 2006 Dec;101(6):1616-22. doi: 10.1152/japplphysiol.00440.2006. Epub 2006 Aug 10.
Reference Type
BACKGROUND
Inagaki Y, Madarame H, Neya M, Ishii N. Increase in serum growth hormone induced by electrical stimulation of muscle combined with blood flow restriction. Eur J Appl Physiol. 2011 Nov;111(11):2715-21. doi: 10.1007/s00421-011-1899-y. Epub 2011 Mar 12.
Reference Type
BACKGROUND
Schoenfeld BJ. Potential mechanisms for a role of metabolic stress in hypertrophic adaptations to resistance training. Sports Med. 2013 Mar;43(3):179-94. doi: 10.1007/s40279-013-0017-1.
Reference Type
BACKGROUND
Pearson SJ, Hussain SR. A review on the mechanisms of blood-flow restriction resistance training-induced muscle hypertrophy. Sports Med. 2015 Feb;45(2):187-200. doi: 10.1007/s40279-014-0264-9.
Reference Type
BACKGROUND
Manini TM, Yarrow JF, Buford TW, Clark BC, Conover CF, Borst SE. Growth hormone responses to acute resistance exercise with vascular restriction in young and old men. Growth Horm IGF Res. 2012 Oct;22(5):167-72. doi: 10.1016/j.ghir.2012.05.002. Epub 2012 Jun 23.
Reference Type
BACKGROUND
Takano H, Morita T, Iida H, Asada K, Kato M, Uno K, Hirose K, Matsumoto A, Takenaka K, Hirata Y, Eto F, Nagai R, Sato Y, Nakajima T. Hemodynamic and hormonal responses to a short-term low-intensity resistance exercise with the reduction of muscle blood flow. Eur J Appl Physiol. 2005 Sep;95(1):65-73. doi: 10.1007/s00421-005-1389-1. Epub 2005 Jun 15.
Reference Type
BACKGROUND
Takarada Y, Nakamura Y, Aruga S, Onda T, Miyazaki S, Ishii N. Rapid increase in plasma growth hormone after low-intensity resistance exercise with vascular occlusion. J Appl Physiol (1985). 2000 Jan;88(1):61-5. doi: 10.1152/jappl.2000.88.1.61.
Reference Type
BACKGROUND
Ganesan G, Cotter JA, Reuland W, Cerussi AE, Tromberg BJ, Galassetti P. Effect of blood flow restriction on tissue oxygenation during knee extension. Med Sci Sports Exerc. 2015 Jan;47(1):185-93. doi: 10.1249/MSS.0000000000000393.
Reference Type
BACKGROUND
Scott BR, Slattery KM, Sculley DV, Dascombe BJ. Hypoxia and resistance exercise: a comparison of localized and systemic methods. Sports Med. 2014 Aug;44(8):1037-54. doi: 10.1007/s40279-014-0177-7.
Reference Type
BACKGROUND
Narici MV, Kayser B. Hypertrophic response of human skeletal muscle to strength training in hypoxia and normoxia. Eur J Appl Physiol Occup Physiol. 1995;70(3):213-9. doi: 10.1007/BF00238566.
Reference Type
BACKGROUND
Provided Documents
Download supplemental materials such as informed consent forms, study protocols, or participant manuals.
Document Type: Study Protocol
Document Type: Informed Consent Form
Other Identifiers
Review additional registry numbers or institutional identifiers associated with this trial.
Extended Delfi
Identifier Type: -
Identifier Source: org_study_id
More Related Trials
Additional clinical trials that may be relevant based on similarity analysis.
Evaluation of the New Acceleromyograph TOF 3D
NCT05005676
UNKNOWN
NA
Human Research Program Flight Thigh Cuff
NCT06476106
ENROLLING_BY_INVITATION
NA
Clinical Evaluation of a Novel Wearable Compression Technology in the Treatment of Lymphedema, An Open-Label Controlled Study
NCT04659564
COMPLETED
NA
Evaluation of the Safety and Performance of Centaflow
NCT04438668
UNKNOWN
NA
Neck-Worn Monitoring Sensor for - A Study for Monitoring Subjects With Fluid-Management Issues During Dialysis
NCT02140905
COMPLETED
A Device to Determine Return of Sensation From Spinal Block
NCT04553913
COMPLETED
NA
Prospective Healthy Volunteer Study of the Securis™ Stabilization Device
NCT04841330
COMPLETED
A Randomized Trial Examining Plasma Exchange Using the Becton Dickinson (BD) Catheter In an Outpatient Apheresis Unit
NCT04253756
COMPLETED
NA
Minimally-Invasive Realtime Assessment of Continuous Lactate in Exercise
NCT04238611
UNKNOWN
NA
Evaluation of a Novel Method of Contrast Volume Quantification - AVERT PLUS 2.0
NCT02578173
COMPLETED
The Equivalency of the Imp SFB7+ (L-Dex U400) With the Imp XCA Device
NCT00766935
COMPLETED
T-Cell Mitochondrial Respiration Response to Ketone Monoester Supplement in Healthy Volunteers and COVID-19
NCT05798260
WITHDRAWN
Clinical Validation of the Fluispotter System for Serial Sampling of Venous Dried Blood Spots
NCT04594577
COMPLETED
NA
REduction of Contrast Via DyeVert Used in CTO Procedures
NCT03118544
TERMINATED
Autonomous Blood Drawing Optimization and Performance Testing
NCT05878483
RECRUITING
NA
Lymphedema Sensor Technology Development Study
NCT06778837
COMPLETED
Clinical Investigation of the Safety of the MediSieve Magnetic Haemofiltration System in Healthy Volunteers
NCT05713188
COMPLETED
PHASE1
Becker Continued Access Study
NCT01286870
TERMINATED
PHASE4
Safety and Efficiency of the PacePress to Prevent Hemorrhagic Complications in Patients Undergoing CIED Implantation.
NCT05292326
TERMINATED
NA
Healthy Volunteer Study to Assess Microcirculatory Function
NCT05608798
COMPLETED
NA
Evaluation of the CloSys Closure System as an Adjunct to Standard Compression
NCT00963690
TERMINATED
NA
Clinical Evaluation of the OEC Elite Vascular Mobile Fluoroscopy System
NCT03096483
TERMINATED
NA
AngioSafe Peripheral CTO Crossing System Study (RESTOR-1 Study)
NCT04663867
COMPLETED
NA
Prospective, Multi-center, Single-arm Study to Assess the Safety of Retrieval of the Recovery G2 Filter.
NCT00556426
COMPLETED
NA
Quantra® System With the QStat® Cartridge in Trauma
NCT05376462
TERMINATED