1
|
Yi J, Ren X, Li Y, Yuan Y, Tang W, Wang X, Yu J, Yu S, Li W, Wang J, Loh XJ, Hu B, Chen X. Rapid-Response Water-Shrink Films with High Output Work Density Based on Polyethylene Oxide and α-Cyclodextrin for Autonomous Wound Closure. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024; 36:e2403551. [PMID: 38837826 DOI: 10.1002/adma.202403551] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2024] [Revised: 05/28/2024] [Indexed: 06/07/2024]
Abstract
Conventional wound closure methods, including sutures and tissue adhesives, present significant challenges for self-care treatment, particularly in the context of bleeding wounds. Existing stimuli-responsive contractile materials designed for autonomous wound closure frequently lack sufficient output work density to generate the force needed to bring the wound edges into proximity or necessitate stimuli that are not compatible with the human body. Here, semi-transparent, flexible, and water-responsive shrinkable films, composed of poly(ethylene oxide) and α-cyclodextrin, are reported. These films exhibit remarkable stability under ambient conditions and demonstrate significant contraction (≈50%) within 6 s upon exposure to water, generating substantial contractile stress (up to 6 MPa) and output work density (≈1028 kJ m-3), which is 100 times larger than that of conventional hydrogel and 25 times larger than that of skeletal muscles. Remarkably, upon hydration, these films are capable of lifting objects 10 000 times their own weight. Leveraging this technology, water-shrink tapes, which, upon contact with water, effectively constrict human skin and autonomously close bleeding wounds in animal models within 10 seconds, are developed further. This work offers a novel approach to skin wound management, showing significant potential for emergency and self-care scenarios.
Collapse
Affiliation(s)
- Junqi Yi
- Institute for Digital Molecular Analytics and Science (IDMxS), Nanyang Technological University, 59 Nanyang Drive, Singapore, 636921, Singapore
- Innovative Centre for Flexible Devices (iFLEX), Max Planck-NTU Joint Lab for Artificial Senses, School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798, Singapore
| | - Xueyang Ren
- School of Biomedical Engineering and Informatics, Nanjing Medical University, Nanjing, 211166, China
- School of Biological Science and Medical Engineering, Southeast University, Nanjing, 210009, China
| | - Yanzhen Li
- Innovative Centre for Flexible Devices (iFLEX), Max Planck-NTU Joint Lab for Artificial Senses, School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798, Singapore
| | - Yuehui Yuan
- School of Biomedical Engineering and Informatics, Nanjing Medical University, Nanjing, 211166, China
| | - Wenjie Tang
- School of Biomedical Engineering and Informatics, Nanjing Medical University, Nanjing, 211166, China
| | - Xiaoshi Wang
- Innovative Centre for Flexible Devices (iFLEX), Max Planck-NTU Joint Lab for Artificial Senses, School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798, Singapore
| | - Jing Yu
- Institute for Digital Molecular Analytics and Science (IDMxS), Nanyang Technological University, 59 Nanyang Drive, Singapore, 636921, Singapore
| | - Shujin Yu
- Institute for Digital Molecular Analytics and Science (IDMxS), Nanyang Technological University, 59 Nanyang Drive, Singapore, 636921, Singapore
| | - Wenlong Li
- Institute of Materials Research and Engineering (IMRE), Agency for Science, Technology and Research (A*STAR), 2 Fusionopolis Way, Innovis #08-03, Singapore, 138634, Singapore
| | - Jianwu Wang
- Institute for Digital Molecular Analytics and Science (IDMxS), Nanyang Technological University, 59 Nanyang Drive, Singapore, 636921, Singapore
| | - Xian Jun Loh
- Institute of Materials Research and Engineering (IMRE), Agency for Science, Technology and Research (A*STAR), 2 Fusionopolis Way, Innovis #08-03, Singapore, 138634, Singapore
| | - Benhui Hu
- School of Biomedical Engineering and Informatics, Nanjing Medical University, Nanjing, 211166, China
- Jiangsu Province Hospital, The First Affiliated Hospital with Nanjing Medical University, Nanjing, 210029, China
| | - Xiaodong Chen
- Institute for Digital Molecular Analytics and Science (IDMxS), Nanyang Technological University, 59 Nanyang Drive, Singapore, 636921, Singapore
- Innovative Centre for Flexible Devices (iFLEX), Max Planck-NTU Joint Lab for Artificial Senses, School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798, Singapore
| |
Collapse
|
2
|
Spagnoli A, Alberini R, Raposio E, Terzano M. Simulation and optimization of reconstructive surgery procedures on human skin. J Mech Behav Biomed Mater 2022; 131:105215. [DOI: 10.1016/j.jmbbm.2022.105215] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Revised: 03/16/2022] [Accepted: 04/01/2022] [Indexed: 11/25/2022]
|
3
|
Stoecker A, Lear W, Johnson K, Bahm J, Kruzic JJ. Enhanced perfusion of elliptical wound closures using a novel adhesive suture retention device. Health Sci Rep 2021; 4:e364. [PMID: 34541331 PMCID: PMC8439428 DOI: 10.1002/hsr2.364] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Revised: 07/18/2021] [Accepted: 08/02/2021] [Indexed: 01/18/2023] Open
Abstract
BACKGROUND AND AIMS The purpose of this investigation was to test the hypothesis that a novel adhesive retention suture device (ARSD) can increase perfusion at elliptical wound closures by distributing stress away from the suture site. METHODS Stress in the skin around a suture both with and without support from an ARSD was evaluated using a finite element model. A single-center, randomized split-scar comparison trial using laser speckle contrast analysis was used to quantify the perfusion at elliptical wound closures in human patients both with and without an ARSD. RESULTS The finite element model revealed that the ARSD promoted load transfer to the skin over a larger area, thus reducing the local stress and deformation in the skin around the suture site. Results from the split-scar study showed a mean improvement of 25% perfusion units with the ARSD, and the improvement was statistically significant (p = 0.002). CONCLUSION The reduction in local stress and enhanced perfusion around the suture site reveals the potential benefit of using an ARSD to enable more efficient healing by avoiding complications associated with both low perfusion and skin tearing, such as dehiscence, infection, and cheese wiring.
Collapse
Affiliation(s)
- Allison Stoecker
- Departments of Dermatology and Dermatologic SurgerySilver Falls DermatologyCorvallisOregonUSA
| | - William Lear
- Departments of Dermatology and Dermatologic SurgerySilver Falls DermatologyCorvallisOregonUSA
| | - Karsten Johnson
- Departments of Dermatology and Dermatologic SurgerySilver Falls DermatologyCorvallisOregonUSA
| | | | - Jamie J. Kruzic
- School of Mechanical and Manufacturing EngineeringUniversity of New South Wales (UNSW Sydney)SydneyNew South WalesAustralia
| |
Collapse
|
4
|
Forces on sutures when closing excisional wounds using the rule of halves. Clin Biomech (Bristol, Avon) 2020; 72:161-163. [PMID: 31887483 DOI: 10.1016/j.clinbiomech.2019.12.018] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/05/2019] [Revised: 12/14/2019] [Accepted: 12/17/2019] [Indexed: 02/07/2023]
Abstract
BACKGROUND To close elliptical excisions, surgeons commonly use the rule of halves which involves initially closing of the middle portion of the wound, followed by closure of the remaining halves. Understanding the forces required for suturing such wounds can aid excisional surgery planning to decrease complications and improve wound healing. METHODS Following full thickness excision for removal of skin cancers, back wounds with 3:1 ratio of length-to-width were closed using the rule of halves. The force required to bring the wound edges into contact at the middle portion of the wound was measured, followed by the two bisected halves. FINDINGS The average force to close the center of the wounds averaged 3.7 N and was six times larger than that of the bisected halves. The forces to close the bisected halves were consistently small, and essentially negligible (<0.5 N) for ~50% of the cases. INTERPRETATION When planning excisional surgery to avoid complications such as tearing the dermis (cheese wiring), the use of special wound closure techniques (high tension and/or pully sutures, skin support or suture retention devices, etc.) should focus on the center suture only when using the rule of halves, as the remaining sutures require very low forces.
Collapse
|
5
|
Jeon EY, Lee J, Kim BJ, Joo KI, Kim KH, Lim G, Cha HJ. Bio-inspired swellable hydrogel-forming double-layered adhesive microneedle protein patch for regenerative internal/external surgical closure. Biomaterials 2019; 222:119439. [PMID: 31465886 DOI: 10.1016/j.biomaterials.2019.119439] [Citation(s) in RCA: 79] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Revised: 08/17/2019] [Accepted: 08/17/2019] [Indexed: 12/21/2022]
Abstract
Significant tissue damage, scarring, and an intense inflammatory response remain the greatest concerns for conventional wound closure options, including sutures and staples. In particular, wound closure in internal organs poses major clinical challenges due to air/fluid leakage, local ischemia, and subsequent impairment of healing. Herein, to overcome these limitations, inspired by endoparasites that swell their proboscis to anchor to host's intestines, we developed a hydrogel-forming double-layered adhesive microneedle (MN) patch consisting of a swellable mussel adhesive protein (MAP)-based shell and a non-swellable silk fibroin (SF)-based core. By possessing tissue insertion capability (7-times greater than the force for porcine skin penetration), MAP-derived surface adhesion, and selective swelling-mediated physical entanglement, our hydrogel-forming adhesive MN patch achieved ex vivo superior wound sealing capacity against luminal leaks (139.7 ± 14.1 mmHg), which was comparable to suture (151.0 ± 23.3 mmHg), as well as in vivo excellent performance for wet and/or dynamic external and internal tissues. Collectively, our bioinspired adhesive MN patch can be successfully used in diverse practical applications ranging from vascular and gastrointestinal wound healing to transdermal delivery for pro-regenerative or anti-inflammatory agents to target tissues.
Collapse
Affiliation(s)
- Eun Young Jeon
- Department of Chemical Engineering, Pohang University of Science and Technology, Pohang, 37673, South Korea
| | - Jungho Lee
- Department of Mechanical Engineering, Pohang University of Science and Technology, Pohang, 37673, South Korea
| | - Bum Ju Kim
- Department of Mechanical Engineering, Pohang University of Science and Technology, Pohang, 37673, South Korea
| | - Kye Il Joo
- Department of Chemical Engineering, Pohang University of Science and Technology, Pohang, 37673, South Korea
| | - Ki Hean Kim
- Department of Mechanical Engineering, Pohang University of Science and Technology, Pohang, 37673, South Korea
| | - Geunbae Lim
- Department of Mechanical Engineering, Pohang University of Science and Technology, Pohang, 37673, South Korea.
| | - Hyung Joon Cha
- Department of Chemical Engineering, Pohang University of Science and Technology, Pohang, 37673, South Korea.
| |
Collapse
|
6
|
Abstract
Skin injury is the most common type of injury, which manifests itself in the form of wounds and cuts. A minor wound repairs itself within a short span of time. However, deep wounds require adequate care and sometime clinical interventions such as surgical suturing for their timely closure and healing. In literature, mechanical properties of skin and other tissues are well known. However, the anisotropic behavior of wounded skin has not been studied yet, specifically with respect to localized overstraining and possibilities of rupture. In the current work, the biomechanics of common skin wound geometries were studied with a biofidelic skin phantom, using uniaxial mechanical testing and Digital Image Correlation (DIC). Global and local mechanical properties were investigated, and possibilities of rupture due to localized overstraining were studied across different wound geometries and locations. Based on the experiments, a finite element (FE) model was developed for a common elliptical skin wound geometry. The fidelity of this FE model was evaluated with simulation of uniaxial tension tests. The induced strain distributions and stress-stretch responses of the FE model correlated very well with the experiments (R2 > 0.95). This model would be useful for prediction of the mechanical response of common wound geometries, especially with respect to their chances of rupture due to localized overstraining. This knowledge would be indispensable for pre-surgical planning, and also in robotic surgeries, for selection of appropriate wound closure techniques, which do not overstrain the skin tissue or initiate tearing.
Collapse
|
7
|
CHANDA ARNAB, UNNIKRISHNAN VINU. A REALISTIC 3D COMPUTATIONAL MODEL OF THE CLOSURE OF SKIN WOUND WITH INTERRUPTED SUTURES. J MECH MED BIOL 2017. [DOI: 10.1142/s0219519417500257] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Wounds or cuts are the most common form of skin injuries. While a shallow wound may heal over time, deep wounds often require clinical interventions such as suturing to ensure the wound closure and timely healing. To date, suturing practices are based on a surgeon's experience and there is no benchmark to what is right or wrong. In the literature, there have been few attempts to characterize wound closure and suture mechanics using simple 2D computational models. In our current work, for the first time, a realistic three-dimensional (3D) computational model of the skin with the two layers, namely the epidermis and dermis, have been developed. A 3D diamond shaped wound with a varying cross-section has been modeled, and interrupted sutures have been placed numerically in multiple steps to close the wound. Nonlinear hyperelastic material properties have been adopted for the skin and a skin pre-stress was applied bi-axially. The force requirements for each suture were estimated numerically using a novel suture pulling technique. The suture forces were found to lie in the range of 0–5 N with a maximum value at the center. Also, the center suture was observed to require an approximately four times pull force compared to the first end suture. All these findings provide important guidelines for suturing. Additionally, the suture force can be approximated as a polynomial function of the displacement. Given a wound geometry, wound depth, skin material properties, skin pre-stress, suture wire material and cross-sectional area, using our computational model, such a relationship can be used to estimate and characterize the suture force requirements accurately. To our knowledge, such a 3D computational model of skin wound closure with interrupted sutures have not been developed till date, and would be indispensable for planning robotic surgeries and improving clinical suturing practices in the future.
Collapse
Affiliation(s)
- ARNAB CHANDA
- Department of Aerospace Engineering and Mechanics, University of Alabama, Tuscaloosa 35487, USA
| | - VINU UNNIKRISHNAN
- Department of Aerospace Engineering and Mechanics, University of Alabama, Tuscaloosa 35487, USA
| |
Collapse
|
8
|
Levi K, Ichiryu K, Kefel P, Keller J, Grice J, Belson O, Storne E, Safa B. Mechanics of Wound Closure: Emerging Tape-Based Wound Closure Technology vs. Traditional Methods. Cureus 2016; 8:e827. [PMID: 27882274 PMCID: PMC5106206 DOI: 10.7759/cureus.827] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2016] [Accepted: 10/12/2016] [Indexed: 11/05/2022] Open
Abstract
To date, there is still a lack of understanding of how wound closure methods perform comparatively under daily bodily movement during the course of healing and how they affect the mechanics of healing. The present study is a first step in understanding and objectively quantifying the gap. The study provides both a new method of metrology for noninvasive evaluation of skin mechanics at the onset of wound healing and an emerging tape-based wound closure technology. The latter shows better performance with respect to commonly used staples and sutures, holding the wound intact and providing uniform mechanical support across the incision.
Collapse
Affiliation(s)
| | | | | | | | | | | | | | - Bauback Safa
- Plastic Surgery, Hand Surgery, Microsurgery, The Buncke Clinic
| |
Collapse
|
9
|
Mermans JF, Peeters WJ, Dikmans R, Serroyen J, van der Hulst RRJW, Van den Kerckhove E. A comparative study of colour and perfusion between two different post surgical scars. Do the laser Doppler imager and the colorimeter measure the same features of a scar? Skin Res Technol 2013; 19:107-14. [DOI: 10.1111/srt.12014] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/09/2012] [Indexed: 11/29/2022]
Affiliation(s)
- J. F. Mermans
- Department of Plastic; Reconstructive and Hand Surgery; Maastricht University Medical Centre; Maastricht The Netherlands
| | - W. J. Peeters
- Department of Plastic; Reconstructive and Hand Surgery; Maastricht University Medical Centre; Maastricht The Netherlands
| | - R. Dikmans
- Department of Plastic; Reconstructive and Hand Surgery; Maastricht University Medical Centre; Maastricht The Netherlands
| | - J. Serroyen
- Department of methodology and Statistics; Research School CAPHRI; Maastricht University; Maastricht The Netherlands
| | - R. R. J. W. van der Hulst
- Department of Plastic; Reconstructive and Hand Surgery; Maastricht University Medical Centre; Maastricht The Netherlands
| | - E. Van den Kerckhove
- Department of Plastic; Reconstructive and Hand Surgery; Maastricht University Medical Centre; Maastricht The Netherlands
| |
Collapse
|
10
|
Capek L, Jacquet E, Dzan L, Simunek A. The analysis of forces needed for the suturing of elliptical skin wounds. Med Biol Eng Comput 2011; 50:193-8. [PMID: 22201040 DOI: 10.1007/s11517-011-0857-5] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2011] [Accepted: 12/12/2011] [Indexed: 01/30/2023]
Abstract
There is a lack of information regarding the forces required for suturing human wounds. The knowledge of suturing forces serves as complementary information for setting up the limiting geometry when using tissue adhesives and it might also be used in robot-assisted surgery. The main purpose of this paper was to evaluate the forces required for suturing selected skin wounds. An elliptical wound was chosen for our study. In this study a numerical analysis and in vivo experiments were performed. Regarding the numerical models, the maximum forces occurred in the middle of the elliptical wound in all cases. In the case of highest pre-stress used in these analyses the maximal force varied from 0.5 N for the smallest wound (30 × 5 mm) to 1.5 N for the largest wound (30 × 15 mm). The maximum peak force for the wound with a size of 46 × 13 mm was 3.2 N. The minimum peak force for the wound with a size of 36 × 5 mm was 1.1 N.
Collapse
Affiliation(s)
- Lukas Capek
- Department of Applied Mechanics, Technical University of Liberec, Studentska 2, 46117 Liberec, Czech Republic.
| | | | | | | |
Collapse
|
11
|
Scar Redness in Humans: How Long Does It Persist after Incisional and Excisional Wounding? Plast Reconstr Surg 2008; 121:487-496. [DOI: 10.1097/01.prs.0000299183.88334.37] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
12
|
Sakhnini L, Dairi M, Al-Taitoon N, Excel M. Determining mechanical properties of rabbit skin with light reflection technique verified with latex. JOURNAL OF BIOMEDICAL OPTICS 2006; 11:014030. [PMID: 16526907 DOI: 10.1117/1.2161169] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
An experimental technique to evaluate the elastic limit for rabbit skin is developed and described. The experimental technique is designed to measure small changes in the normalized reflectivity as a function of applied stretch, with a laser wavelength of 632.8 nm and power of 1 mW. When the samples of rabbit skin are stretched, the reflectivity increases until a critical point (elastic limit) is reached. After this point, the curve drops off very quickly. The elastic limit for the male dorsal samples is less than that for the female samples, with an average strain of 14.4 and 34.6% in males and females, respectively. Moreover, our results show that the average slope of the regression lines is greater for the male dorsal samples than the dorsal female samples. This indicates that the male dorsal skin is rougher than that of the female.
Collapse
Affiliation(s)
- Lama Sakhnini
- University of Bahrain, Department of Physics, College of Science, P.O. Box 32038, Isa Town, Kingdom of Bahrain.
| | | | | | | |
Collapse
|
13
|
Lott DA, Chaudhry HR. On the use of infinite elements for the determination of optimal closure patterns based on stress analysis. Comput Methods Biomech Biomed Engin 2003; 6:225-34. [PMID: 12959756 DOI: 10.1080/1025584031000149070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Solid infinite elements are used in conjunction with finite elements to compute the stress and displacement distribution resulting from the suturing of wounds of symmetric and nonsymmetric shapes in orthotropic, abdominal human skin. The optimal pattern of suturing of wounds are investigated from a stress perspective. Highly accurate, quantitative and qualitative improvements over the use of finite elements to approximate distant boundaries are obtained. Numerical results quantitatively agree with analytic results computed using complex analysis techniques. The technique used and the results obtained will aid surgeons in closing nonsymmetrical wounds on regions of the body that exhibit orthotropy.
Collapse
Affiliation(s)
- D A Lott
- Department of Mathematical Sciences, Center for Applied Mathematics and Statistitcs, New Jersey Institute of Technology, Newark, NJ 07102, USA.
| | | |
Collapse
|
14
|
Guzelsu N, Federici JF, Lim HC, Chauhdry HR, Ritter AB, Findley T. Measurement of skin stretch via light reflection. JOURNAL OF BIOMEDICAL OPTICS 2003; 8:80-86. [PMID: 12542383 DOI: 10.1117/1.1527936] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2001] [Revised: 03/26/2002] [Accepted: 07/17/2002] [Indexed: 05/24/2023]
Abstract
A noninvasive technique for measuring the stretch of skin is described. The technique utilizes changes in the reflectivity of polarized light intensity as a monitor of skin stretch. Measurements of in vitro pigskin and in vivo human skin show that the reflectivity of polarized light intensity increases linearly with stretch. The changes in diffusive reflectivity properties of skin result from the alterations that take place in the roughness across the thickness of the skin layers due to stretch. Conceptually, as the roughness of a layer decreases with stretch, a smoother reflecting media is produced, resulting in a proportional increase in the specular reflection. Results can be easily extended to a real-time stretch analysis of large tissue areas that would be applicable for mapping the stretch of skin.
Collapse
Affiliation(s)
- Nejat Guzelsu
- University of Medicine and Dentistry of New Jersey-SOM, Biomechanics Lab, Piscataway 08854, USA.
| | | | | | | | | | | |
Collapse
|
15
|
Affiliation(s)
- Luc Téot
- Burns and Plastic Surgery Unit, Hôpital Lapeyronie, Montpellier, France.
| |
Collapse
|
16
|
Abstract
Stress is one of the many biological factors that plays an important role in wound healing. It is therefore essential to analyze stresses around the wound closure theoretically, especially when no invasive/noninvasive technique to measure stress directly is available. The objective of this paper is to determine the regions of high stresses and the optimal pattern of suturing wounds of complex shapes. It is hypothesized that the optimal pattern of suturing wounds is that pattern which will produce minimum principal stresses. The finite element method (FEM) employing the basic equations of elasticity theory for orthotropic materials is utilized to compute the principal stresses and displacements resulting from suturing fusiform, elliptical and triangular wounds in human abdominal skin. The optimal suturing pattern for the triangular wound is determined. The average stress indices for varying suturing density are also determined which can provide useful clinical information for the surgeon. Since regions of high stresses in surgical closures produce adverse affects on healing and scar production, this work of predicting areas of high stresses is useful in indicating regions of slow healing in wounds.
Collapse
Affiliation(s)
- D A Lott-Crumpler
- Department of Mathematical Sciences, Center for Applied Mathematics and Statistics, New Jersey Institute of Technology, Newark 07102, USA.
| | | |
Collapse
|
17
|
Federici JF, Guzelsu N, Lim HC, Jannuzzi G, Findley T, Chaudhry HR, Ritter AB. Noninvasive light-reflection technique for measuring soft-tissue stretch. APPLIED OPTICS 1999; 38:6653-6660. [PMID: 18324202 DOI: 10.1364/ao.38.006653] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
A novel, to our knowledge, sensor for measuring the stretch in soft tissues such as skin is described. The technique, which is a modification of two-dimensional polarization imaging, uses changes in the reflectivity of polarized light as a monitor of skin stretch. Measurements show that the reflectivity increases with stretch. Measurements were made on guinea pig skin and on nonbiological materials. The changes in reflectivity result from the changes that take place in the interface roughness between skin or material layers and the consequential changes in the diffuse reflective characteristics of the skin. Conceptually, as the roughness of an interface decreases, a smoother reflecting interface is produced, resulting in a commensurate increase in specular reflection. A simple roughness model correctly predicts the main experimental results. Results can be extended easily to real-time stretch analysis of large tissue areas that would be applicable for predicting stresses in skin during and after the surgical closure of wounds.
Collapse
Affiliation(s)
- J F Federici
- Department of Physics, New Jersey Institute of Technology, Newark, New Jersey 07102, USA.
| | | | | | | | | | | | | |
Collapse
|