24 research outputs found
sj-pdf-1-ajs-10.1177_03635465231180616 – Supplemental material for Acute Bone Loss and Infrapatellar Fat Pad Fibrosis in the Knee After an In Vivo ACL Injury in Adolescent Mice
No full textSupplemental material, sj-pdf-1-ajs-10.1177_03635465231180616 for Acute Bone Loss and Infrapatellar Fat Pad Fibrosis in the Knee After an In Vivo ACL Injury in Adolescent Mice by Taeyong Ahn, Benjamin E. Loflin, Nicholas B. Nguyen, Ciena K. Miller, Kaitlyn A. Colglazier, Edward M. Wojtys and Stephen H. Schlecht in The American Journal of Sports Medicine</p
sj-pdf-1-ajs-10.1177_03635465231165753 – Supplemental material for An Adolescent Murine In Vivo Anterior Cruciate Ligament Overuse Injury Model
No full textSupplemental material, sj-pdf-1-ajs-10.1177_03635465231165753 for An Adolescent Murine In Vivo Anterior Cruciate Ligament Overuse Injury Model by Benjamin E. Loflin, Taeyong Ahn, Kaitlyn A. Colglazier, Mark M. Banaszak Holl, James A. Ashton-Miller, Edward M. Wojtys and Stephen H. Schlecht in The American Journal of Sports Medicine</p
Shoulder joint clearance detection for astronaut space suits using wearable electromagnetic resonant spiral proximity
No full textPresented to the 15th Annual Symposium on Graduate Research and Scholarly Projects (GRASP) held at the Rhatigan Student Center, Wichita State University, April 26, 2019.Research completed in the Department of Biomedical Engineering, College of EngineeringINTRODUCTION: Shoulder joint injury is a common musculoskeletal injury that occurs during astronaut training while they are wearing the space suit. There is restricted mobility around the shoulder joint due to the rigid inner components of the suit that constrains the desired range of motion for space mission tasks. This rigid piece of the suit is known as the hard upper torso (HUT), which allows for sealed connection between other components that sets upon the skin tight liquid cooling and ventilation garment (LCVG) that contains a tubing mechanics that keeps the body temperature regulated from reaching dangerous levels. During training sessions, astronauts can receive significant rotator cuff injuries from the lack of clearance between the LCVG and the HUT. A detection scheme that provides proximity, of a proposed minimum clearance distance of one centimeter to provide sufficient mobility, is lacking for space suit fitting. PURPOSE: The objective of this paper is to propose a novel detection scheme using an electromagnetic resonant spiral sensor that allows for quantitative measurements of proximity between the shoulder joint with the LCVG and the aluminum component of the HUT. METHODS: An LCVG model is created with net dressing and latex tubing in which the proximity sensor is placed upon. While water is continuously flowing through the tubing, a metal plate, which represents the scye bearing joint of the HUT, is placed in parallel to the sensor and measurements are increased every 0.5 mm until 10 mm is achieved. All 21 distances are measured in 20 separate repeated tests to run through a regression learning algorithm with half used to train and the other half to validate the response. Predictors were chosen based on the resonant frequency response with only the most parsimonious data chosen. RESULTS: The results indicate that using a fine decision tree regression algorithm, the algorithm is able to validate the response with an RMSE of 0.93 mm with a strong coefficient of determination (R2=0.93). This algorithm for this given scenario shows strong accuracy and repeatability for proximity detection up to 10 mm for reliable readings. CONCLUSION: This study presents a novel method of identifying proximity detection using an electromagnetic resonant spiral sensor for space suit fitting application. Using this knowledge will allow for future implementation into the space suit for quantitative fitting parameters to help adjust and avoid potential musculoskeletal shoulder joint injuries.Graduate School, Academic Affairs, University Librarie
Understanding spacesuit interaction using a wearable proximity sensing system for suit fit optimization
No full textThesis (M.S.)-- Wichita State University, College of Engineering, Dept. of Biomedical EngineeringThere is currently no quantitative method of measuring space suit fit for astronauts after they have put on the spacesuit. The primary concern for spacesuit fit is the hard upper torso (HUT),
which is composed of a rigid fiberglass shell with metal scye bearing joints where other suit components attach. There is a concern with how much shoulder mobility the HUT is providing for astronauts. As astronauts perform tasks in the suit, there are contact and strain injuries that come from the repeated shoulder joint movements. When the distance between the shoulder joint and the metal scye bearing joint is too small, there is higher likelihood for musculoskeletal injuries. The purpose of this research investigates the use of a wearable proximity sensor to
incorporate in the spacesuit to measure distance between the shoulder joint and metal scye bearing joint of the HUT. Two electromagnetic resonant spiral sensors were created and used
for proximity detection where the investigation of proximity response to a metal was used. These wearable proximity sensors were tested in various environments to resemble environments inside the spacesuit. The first environment tested two sensor designs in proximity to only metal and then expanded to test the proximity sensors resting on a cooling garment that is in the spacesuit. Next testing environment included multiple proximity sensors of the same design in
proximity to a curved metal sheet to more resemble the scye bearing joint. Results indicate that addition of the cooling garment reduces accuracy, although still has reliable accuracy of less than
one millimeter. Consequently, adding more proximity sensors for the same environment proves feasible with future scenarios to still be tested. This wearable proximity sensor system establishes quantitative measurements that will aid in optimization of spacesuit fit. The use of this system during fitting, donning, or training during various movements will be able to provide vital assessment of spacesuit fit to avoid shoulder joint injury
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Identification of Endogenous Substrates for ADP-Ribosylation in Rat Liver
Get PDFBacterial toxins have been shown to modify animal cell proteins in vivo with ADPR. Animal cells also contain endogenous enzymes that can modify proteins. Indirect evidence for the existence in vivo of rat liver proteins modified by ADPR on arginine residues has been reported previously. Presented here is direct evidence for the existence of ADP-ribosylarginine in rat liver proteins. Proteins were subjected to exhaustive protease digestion and ADP-ribosyl amino acids were isolated by boronate chromatography
Poster 254: Mechanical Response of ACL to Submaximal Fatigue Loading
No full textOBJECTIVES: It has been previously reported that the ACL increases in size and strength throughout rodent adolescence following both voluntary(1) and forced(2) endurance running. Here, we expand upon these findings to investigate how the ACL responds to submaximal fatigue loading. The ACL of sexually mature mice was subjected to 3 days of in vivo repetitive loading with an intervening day for recovery. We hypothesized that direct repetitive loading would should a greater positive change in ACL mechanical properties than what was previously observed following endurance running. To test this hypothesis, we designed a custom loading fixture to apply repetitive ACL loading cycles up to a predetermined percentage of the ACL failure load while approximating the knee kinematics of a jump-landing with a pivot shift. METHODS: With Institutional approval, 20 C57BL/6J 10-week-old female mice underwent ACL fatigue loading across 3 days with an intervening recovery day following each training session. For each loading session, the right rear leg of the mouse was placed in a custom loading fixture with the knee at 90° flexion and the sole of the foot at 20° inversion to induce a valgus moment across the knee (Fig. 1). Once positioned, the foreleg was internally rotated. Internal tibial rotation combined with a valgus moment across the knee generates maximum peak ACL strain and replicates a well characterized clinical ACL injury mechanism(3). Based on our previous in vivo work we chose two ACL ultimate tensile strength (UTS) loading percentages that represent low and moderate loads to repetitively fatigue the ligament. An in vivo 60% ACL UTS reliably generates collagen triple helix degradation followed by a proteoglycan response (Fig. 2), while no such changes occur at an in vivo 30% ACL UTS. Therefore, for each training session the ACL was cyclically loaded in vivo between 30% and 60% of ACL UTS for 440 cycles at a loading rate of 0.75 mm/s. After the third session mice were allowed to recover for 72 hrs. Following this, the tested and age-matched control ACLs were ruptured in vivo using the same knee kinematics at a loading rate of 2.7 N/s. All ACLs failed interstitially with there being no visible damage to other supporting knee ligaments or menisci. The resulting load-displacement curves were analyzed using custom MatLab code to quantify the mechanical properties of the fatigued and non-fatigued ACLs. In vivo measures quantified included ACL UTS, stiffness (S), total yield strength (TYS) and post-yield displacement (PYD). Data were analyzed using a two-way ANOVA with final body weight included as a covariate in order to determine the mechanical effect that the 3 days of submaximal fatigue loading had on the ACL compared to controls. RESULTS: The submaximal fatigue loading had a significant effect on ACL mechanical properties when compared to controls. Five mice suffered an ACL failure during the fatigue loading experiment, suggesting that 60% ACL UTS may be near the fatigue failure threshold in these mice. The remaining 15 mice that completed the fatigue study showed a 24.0% increase in UTS, a 26.8% increase in S, a 18.5% increase in TYS, and a 130.5% increase in post-yield displacement, compared to controls (Table 1). CONCLUSIONS: The outcomes of this study partially confirmed our hypothesis. Three days of direct repetitive loading elicited a greater ACL mechanical response than similar aged female mice following 4 weeks of endurance running. The marked improvement in ACL mechanics following repetitive training was likely due to the greater ACL loads experienced and the time allowed for tissue recovery. Rodent ligaments can turn collagen over in ˜24 hours(4). This suggests that the accumulation of degenerated ACL collagen triple helix structures was repaired during recovery for 75% of the mice. However, it also suggests that for some mice, ACL collagen degeneration was not repaired but rather accumulated and propagated hierarchically to the fibril and fiber level, resulting in tissue failure, as was previously observed in human cadaver knees subjected to submaximal ACL fatigue loading(5). This study further elucidates how the ACL responds to loading during adolescence. We have demonstrated that systematic repetitive ACL loading in adolescent mice can generate a positive mechanical response in the ACL. However, our findings also suggest that for a subset of mice participating in this training the submaximal fatigue load was too high and/or the duration of the recovery period was insufficient, resulting in catastrophic failure of the ligament prior to study completion. In the future, these failures should be able to be prevented by reducing the maximum load experienced by the ACL, increasing the duration of the recovery period, or both. If translatable to humans, these and future findings may assist clinicans in identifying potential risks for ACL injury related to an individual’s training intensity and help guide clinical inteventions. (1)Schlecht et al., J Orthop Res, 2019; (2)Cabaud et al., Am J Sports Med, 1980; (3)Wojtys et al., J Orthop Res, 2016; (4)Sodek, Arch Oral Biol, 1977; (5)Chen et al., Am J Sports Med, 2019
Evaluation of polyvinylidene fluoride (PVDF) integrated sensor for physiological temperature detection
No full textClick on the DOI link to access the article (may not be free)In the human body, maintaining the core body temperature (CBT) is vital to ensure proper cellular and body functions. The temperature of 37°C (98°F) is the well-established baseline for CBT, but significant deviations to under 35°C (95°F) or over 40°C (104°F) can result in several health complications. If unnoticed in spaceflight, astronauts CBT could reach dangerously high levels when doing physically challenging tasks such as spacewalking or exercise. Therefore, a real-time multi-physiological parameter sensing system is needed to noninvasively monitor the status of crew members in space. The purpose of this paper is to test a novel temperature sensor developed by integrating thin sheets of polyvinylidene fluoride (PVDF), a temperature dependent dielectric material, into the sensor system designed as a substrate. This substrate interacts with the electromagnetic field created by the spiral sensor to result in a quantitative temperature monitoring sensor with a resolution of 1°C.This work was supported in part by the National Aeronautics and Space Administration (NASA), Grant number: NNX16AQ99A, a Kansas NASA EPSCoR Programme (KNEP) grant. This material is also the result of the work supported with the resources and the use of the facilities at Wichita State University
A noninvasive, electromagnetic, epidermal sensing device for hemodynamics monitoring
No full textClick on the DOI link to access the article (may not be free).Non-intrusive monitoring of blood flow parameters is vital for obtaining physiological and pathophysiological information pertaining to dynamic cardiovascular events and is feasible to achieve via non-invasive, conformal, wearable technologies. Here, we present a proof-of-concept of a fully integrated, high frequency (bandwidth 40 MHz), electromagnetic sensing device for monitoring limb hemodynamics and morphology associated with blood flow. The sensing architecture integrates a novel radio frequency (RF) skin patch resonator embedded with a coplanar outer loop antenna and a scalable, standalone wireless readout hardware based on standing wave ratio (SWR) bridge. The resonator itself is a copper-based open circuit planar Archimedean spiral with a rectangular cross-sectional area, chemically etched on a flexible polyimide substrate. The readout hardware is developed exploiting off-the-shelf components, fabricated on the top of a rigid FR4 substrate. The proposed readout circuit can measure resonant frequency of an RLC network. When energized by the external oscillating RF field via loop antenna, the resonator produces an electromagnetic field response which can be perturbed by dielectric variation inside its field boundary. Through leveraging this principle, the in-vitro experimental results from the benchtop models suggest that the resonator's RF attributes such as resonant frequency shift and magnitude variation of reflection coefficient due to fluid volume displacement can be successfully detected through the proposed hardware architecture. Hence, the system could be an alternative to the conventional, multimodal, non-invasive wearable sensing with an unprecedented capability of ubiquitous fluid phenomena detection from multiple sites of the human body
Investigating the effect of temperature and frequency on dielectric properties of polyvinylidene fluoride (PVDF) for its application in a skin temperature sensor
No full textClick on the URI link to access the article (may not be free).Monitoring physiological parameters of crew on spaceflight missions is of upmost importance for long term microgravity expeditions. Body temperature is one particularly important parameter, as changes in thermoregulation or circadian rhythms may be connected to decreased mental and physical performance if it deviates significantly from 37° C. In this paper, the effects of temperature and frequency on the dielectric properties of 3D printed polyvinylidene fluoride (PVDF) discs were studied. The objective is to incorporate the polymer into an electromagnetic resonating sensor to measure skin temperature. The temperature dependent dielectric permittivity of the polymer interacting with the electromagnetic field of the sensor will result in a resonant frequency shift that can be correlated to report body temperature in a noninvasive, lightweight, and wireless fashion.National Aeronautics and Space Administration (NASA) (Grant NX16AQ99A) for funding this work. This material is also the result of the work supported with the resources and the use of the facilities at Wichita State University
Measuring Denatured Collagen Debridement After in vivo ACL Cyclic Loading in Mice
Get PDFBackground/Objective:Anterior cruciate ligament (ACL) injuries are one of the most common and debilitating injuries in sports. Once thought to be caused due to acute stress events, recent research has demonstrated that this could be from chronic overuse and fatigue. We hypothesized that the estimated time that denatured collagen removal occurs is around 6 days to start ACL repair and there will be no changes between right and left knee mechanical parameters.Methods:Forty B6 female 10-wk old mice were used in a custom setup that cyclically loads to 60% of the ACL’s max force for 500 cycles. All right legs were tested, and the specimens were randomly separated into four equal cohorts for rest times in 3-day increments. Following each cohort’s rest time, the left knee was loaded in the same manner (n=7) and the remaining from each group (n=3) were used as untested contralateral controls. Immediately after each cohort was tested, they were euthanized, and legs were harvested, fixated, and decalcified for paraffin infiltration. Tissue was sectioned and deparaffinized for staining with R-CHP for immunofluorescence, followed by Raman spectroscopy to examine proteoglycan activity.Results:Current results demonstrate the mechanical data of all tested ACLs via measures of hysteresis and stiffness. No statistical differences were found, except for the hysteresis of the left ACLs between cohorts 2 and 3 and upper stiffness of the right ACLs in all mice compared to the left ACLs in cohort 3. The results from CHP staining will be analyzed in future work.Conclusion and Implications:Ultimately, this study will help narrow down when denatured ACL collagen from fatigue begins as an indication of the repair process taking place. This knowledge may be used in athletes with strained ACLs to know how long to adequately rest before continuing sport activity
