Focal Spot, Spring 2005

https://digitalcommons.wustl.edu/focal_spot_archives/1099/thumbnail.jp

3D-Wound Imaging: Precise, Consistent, and Efficient

Background: The most common method of obtaining wound measurements is the hand-ruler method. Studies show that the hand-ruler method results in the most inaccurate measurements with the lowest interrater reliability. Studies also show that using 3D-wound imaging yields the most accurate measurements with the best interrater reliability. 3D-wound imaging technology also increases efficiency by allowing users to obtain images and document assessments using one device at the bedside. Purpose: The purpose of this project is to make the process of assessing wounds more efficient by decreasing the time spent on photographing, measuring, and documenting wound assessments by implementing the use of 3D-wound imaging technology and software. Methods: Prior to the implementation of the 3D-wound technology, a baseline time of completing skin rounds assessments of wounds including imaging, measuring, and documentation was obtained via questionnaire asking nurses the average time they have experienced in completing all skin rounds duties including imaging, assessing, and documenting wounds. During implementation of 3D-wound imaging, start and end times were obtained through the 3D-wound software reporting dashboard. Other information collected included the number of wounds and number of patients that were seen. Post implementation data was analyzed 2-months after implementation. Evaluation/Results: After 2 months, the results showed a decrease in time to image wounds, conduct a full assessment and complete documentation by an average of 4.73 hours or 59%. Implementation of 3D-wound technology also allowed for realignment of the skin rounds team and decrease the number nursing personnel required on the team. Implications for Practice: Streamlining the process of wound assessment and documentation by implementing the use of 3D-wound imaging technology can be rolled out to the entire hospital, including outpatient clinics. A more widespread use of the technology can lead to decreased man-hours across the facility and therefore decreased costs. Conclusion: Future studies can show how clinicians use the accurate data provided by the 3D-wound imaging device in making treatment decisions which can ultimately lead to faster healing and decreased hospital bed days

CAT S60 smartphone as a portable wound care device in home care

The purpose of this work is to study the suitability of the CAT S60 smartphone with built-in thermal camera to be used in self and home care to detect the risk level of wound appearance in advance. The purpose was to clarify different conditions where thermal imaging might act as a resource in detecting changes in limb circulation before visual signs even occur. The purpose is to detect early incipient tissue damage in foot usually occur in diabetic patients. Thermal images were acquired from voluntary domesticated elderly people. Thermal pictures from limbs of 3 persons were studied in order to find thermal differences indicating possible changes in limb circulation. Noteworthy thermal differences between limbs were found in elderly people. A smartphone having built-in thermal camera enables to detect plantar and limb thermal differences with a sufficient accuracy. This may support home monitoring for elderly people and thus reduce foot ulcers and possible foot amputations due to earlier detection and identification of harmful changes in limb circulation. Earlier detection of circulatory insufficiency via thermal imaging makes possible for nurses to intervene and enable medical assistance

The Relationship between Force Platform Measures and Total Body Center of Mass

The ability of a person to maintain stable posture is essential for activities of daily living. Research in this field has evolved to include sensitive assessment technology including force platforms and 3-dimensional kinematic motion analysis systems. Although many studies have investigated postural stability under the auspice of posturography and the use of force platforms, relatively few have incorporated kinematic motion analysis techniques. Furthermore, of the studies that have utilized a multivariate research model, none have sought to identify the relationship between force platform measures including both the variation of movement of the x- and y-coordinates of the center of pressure (COP), and the 3-dimensional coordinates of the total body center of mass (COM). This study used a descriptive design to evaluate the relationship between force platform measures and the kinematic measures dealing with the total body COM in 14 healthy participants (height = 1.70 ± 0.09 m, mass = 67.7 ± 9.9 kg; age = 24.9 ± 3.8 yrs). Intraclass correlations (ICC) and standard error of measurements (SEM) were determined for common variables of interest used in standard posturography models. The results suggest that the variation of the excursion of the COP coordinates best represent the variation of the total body COM in the x- and y-directions. There was a force platform measure that correlated significantly with the vertical component of total body COM in only 3 of the 8 conditions. The ICC values obtained when analyzing individual conditions revealed that the variation in the force measurements were much more reliable than those representing the variation in movement of the COP, suggesting a need for the development of higher order methods of modeling 3-dimensional COM information from force platforms

Advances in non-invasive biosensing measures to monitor wound healing progression

Impaired wound healing is a significant financial and medical burden. The synthesis and deposition of extracellular matrix (ECM) in a new wound is a dynamic process that is constantly changing and adapting to the biochemical and biomechanical signaling from the extracellular microenvironments of the wound. This drives either a regenerative or fibrotic and scar-forming healing outcome. Disruptions in ECM deposition, structure, and composition lead to impaired healing in diseased states, such as in diabetes. Valid measures of the principal determinants of successful ECM deposition and wound healing include lack of bacterial contamination, good tissue perfusion, and reduced mechanical injury and strain. These measures are used by wound-care providers to intervene upon the healing wound to steer healing toward a more functional phenotype with improved structural integrity and healing outcomes and to prevent adverse wound developments. In this review, we discuss bioengineering advances in 1) non-invasive detection of biologic and physiologic factors of the healing wound, 2) visualizing and modeling the ECM, and 3) computational tools that efficiently evaluate the complex data acquired from the wounds based on basic science, preclinical, translational and clinical studies, that would allow us to prognosticate healing outcomes and intervene effectively. We focus on bioelectronics and biologic interfaces of the sensors and actuators for real time biosensing and actuation of the tissues. We also discuss high-resolution, advanced imaging techniques, which go beyond traditional confocal and fluorescence microscopy to visualize microscopic details of the composition of the wound matrix, linearity of collagen, and live tracking of components within the wound microenvironment. Computational modeling of the wound matrix, including partial differential equation datasets as well as machine learning models that can serve as powerful tools for physicians to guide their decision-making process are discussed

Identification of foot pathologies based on plantar pressure asymmetry

Foot pathologies can negatively influence foot function, consequently impairing gait during daily activity, and severely impacting an individual’s quality of life. These pathologies are often painful and correspond with high or abnormal plantar pressure, which can result in asymmetry in the pressure distribution between the two feet. There is currently no general consensus on the presence of asymmetry in able-bodied gait, and plantar pressure analysis during gait is in dire need of a standardized method to quantify asymmetry. This paper investigates the use of plantar pressure asymmetry for pathological gait diagnosis. The results of this study involving plantar pressure analysis in fifty one participants (31 healthy and 20 with foot pathologies) support the presence of plantar pressure asymmetry in normal gait. A higher level of asymmetry was detected at the majority of the regions in the feet of the pathological population, including statistically significant differences in the plantar pressure asymmetry in two regions of the foot, metatarsophalangeal joint 3 (MPJ3) and the lateral heel. Quantification of plantar pressure asymmetry may prove to be useful for the identification and diagnosis of various foot pathologies

Foot Deformity and Bone Strength in Charcot Neuropathic Osteoarthropathy

Charcot neuropathic osteoarthropathy: CN) is characterized by progressive degradation of bones and joints in a denervated, inflamed foot and ankle. Diabetes mellitus: DM) and peripheral neuropathy: PN) are the most common precursors of CN, which can lead to pedal fracture, subluxation, and dislocation. Bone injury and subtle articular damage characteristic of incipient CN are difficult to visualize with planar radiographs. As a result, CN often progresses until more serious, clinically obvious events occur, contributing to increased risk of ulceration, infection, amputation, and death. The overall purpose of this research was to develop methods using volumetric quantitative computed tomography: vQCT) to assess foot bone strength and foot deformity, in order to provide improved indices of CN onset and progression. Aim 1 describes the development of methods to assess bone mineral density: BMD) and geometric bone strength indices in human metatarsals, as well as an ex vivo validation of ultimate loading strength using cadaver samples. Results in Aim 1 showed that BMD and indices of compressive, bending, and buckling strength were strong correlates of metatarsal ultimate strength. Aim 2 provides group comparisons of vQCT-derived bone strength indices between CN and non-CN individuals, with results showing large decrements in BMD in individuals with CN, though no group differences were found for geometric strength indices. Aim 3 presents method development and reliability assessment of novel 3D techniques to assess foot deformities using bone surface atlases of the tarsal and metatarsal bones, with results suggesting that an automated, template-based method can provide equivalent measurement precision to expert testers. In Aim 4, vQCT-derived, 3D foot deformity measures were compared between CN and non-CN individuals; results showed significant alterations in bone-to-bone orientations that corroborate sagittal plane measurements from X-rays and also provide novel deformity measures that cannot be made using uni-planar X-rays. This dissertation research, completed under the direction of an interdisciplinary team of physical therapists, biomedical engineers, radiologists, and orthopedic surgeons, provides new information regarding bone strength and foot deformities in Charcot neuropathic osteoarthropathy. Most importantly, the tools developed in the course of this research have potential utility for future research to understand the pathophysiological pathways linking diabetes, peripheral neuropathy, foot deformities, and the development and progression of Charcot neuropathic osteoarthropathy

Developing Optical Imaging Tools to Investigate Metabolic and Structural Biomarkers in Rodent Injury Models

Optical fluorescence imaging is one of the vastly growing fields of imaging used in a broad variety of preclinical investigation with great interest in translating its principles into clinical applications. Optical fluorescence imaging provides images of functional and structural changes with cellular and subcellular resolution in tissues at a low-cost. This technique takes advantage of the absorption of light photons at a specific wavelength by intrinsic or extrinsic fluorophores and emission of photons at characteristic wavelengths. The characteristics of the emitted wavelengths such as their energy and illuminance give substantial information of the imaged tissue. In the research presented here, we probe two Krebs cycle intrinsic fluorescence metabolic coenzymes, reduced nicotinamide adenine dinucleotide (NADH) and oxidized flavin adenine dinucleotide (FAD) to study metabolic status changes during a human disease. The objective of my research can be categorized into two themes; I) Designing an optical imaging instrument called an in vivo fluorescence imager to quantitatively investigate the metabolic changes in tissue and customizing it to be suitable for human/clinical studies. II) Using optical imaging techniques to quantitatively investigate the 3D anatomical structure changes in vessel structure of organs. in vivo fluorescence imager can image many intrinsic and extrinsic fluorophores. However, we used it to track mitochondria bioenergetics NADH and FAD in wounds of diabetic mice. We also define the redox ratio (NADH/FAD) as a biomarker to investigate the effect of 670 nm photo-biomodulation in those wounds. In another study, we have used 3D optical imaging system on the biopsy of diabetic wounds to confirm the results from the in vivo fluorescence imager. It showed that our in vivo fluorescence imager could successfully track the changes in the metabolic state of non-treated and treated diabetic wounds with 670 nm photobiomodulation. Additionally, I validated a 3D vessel segmentation method developed in our lab by employing Murray’s law. Furthermore, I used the 3D optical cryo-imaging system and the segmentation method to quantitatively study the 3D vessel structure changes in irradiated animal model. The result of this study showed that radiation can adversely change the vasculature in irradiated kidneys and negatively affect kidney perfusion. In summary, my major contribution has been in device implementation and applications of imaging and image processing in studies of animal model diseases of humans

Wireless Pressure Measurement and Power Generation Using Sensor

This paper has implemented and designed for measurement of pressure using wireless and applied it for our day-to-day power requirements. The pressure acts between the skin surface and its supporting surface that humans experience during daily activities. Here, we prefer sensors to measure the pressure, voltage and angle. Piezoelectric sensors are used for measure the pressure & voltage through LCD. Micro-Electro Mechanical Sensor (MEMS) is used to measure the speed from the 3D angle values. The Controller is developed to interface the Micro-electromechanical (MEMS) sensors and piezoelectric sensors that have been designed for analysis the pressure and get power during the body movement. By using the zigbee module, the analyzed pressure is transmitted and stored in the PC. The great advantage of this project is that it doesn’t require any external power supply. Using the DC-DC booster it can increase the generated voltage and stored in battery. It provides power supply for this device and some electronic applications. Such device provides low power consumption, convenient and comfortable testing system