Anne-Sofie Madsen Staples , Adam Bo Mandel , Leyre Azcarate , Marie Sand Traberg
{"title":"自动注射器施加力和屏蔽尺寸对腹部皮肤和皮下组织变形的影响——体内超声和数字图像的相关性研究","authors":"Anne-Sofie Madsen Staples , Adam Bo Mandel , Leyre Azcarate , Marie Sand Traberg","doi":"10.1016/j.jmbbm.2025.107186","DOIUrl":null,"url":null,"abstract":"<div><h3>Background</h3><div>Shield-triggered autoinjectors (AIs) aim to reduce needle phobia and accidental needlestick injuries and improve usability. However, they may cause deeper injections due to tissue compression. This study investigates the mechanical response of AI application into abdominal tissue in-vivo.</div></div><div><h3>Methods</h3><div>Tissue thickness/compression level, skin strain, and indentation depth were measured in 10 healthy participants. Digital image correlation (DIC) captured the skin surface, while an ultrasound (US) probe attached to a 3D-printed shield recorded the underlying skin and subcutaneous tissue (SCT) during application of forces up to 20 N using two indenter sizes (Ø15 mm and Ø30 mm).</div></div><div><h3>Results</h3><div>Increased force correlated with reduced skin + SCT layer thickness; however, a non-linear tissue lockup/plateau around 8–10 N was evident. The Ø30 indenter caused a 45 % mean compression, while the Ø15 resulted in 55 %. ANOVA revealed statistical differences between shield sizes for indentation depth and skin + SCT thickness reduction (p < 0.05). ANOVA further revealed a statistical difference between mean indentation depth for Ø15 (50.39 mm) versus Ø30 (34.84 mm) (p < 0.05). Average strain rates were higher (10.5 % versus 15 %) and skin surface deflection curves were steeper for Ø15 compared to Ø30.</div></div><div><h3>Conclusions</h3><div>Skin + SCT compression increases until it reaches a lock-up state, but indentation depth responds linearly to increases in force. The high level of tissue compression will increase the risk of intramuscular injections when using shield-triggered AIs, depending on needle length, activation force, and shield size. Therefore, increasing shield sizes to reduce tissue compression and indentation depth can enhance user experience and the probability of reaching the subcutaneous layer. Conclusions are drawn from a small, homogenous cohort, and although the trends are clear, variation between participants highlight the complex nature of human skin tissue. More user groups and injection sites should be investigated.</div></div>","PeriodicalId":380,"journal":{"name":"Journal of the Mechanical Behavior of Biomedical Materials","volume":"172 ","pages":"Article 107186"},"PeriodicalIF":3.5000,"publicationDate":"2025-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"The influence of autoinjector applied force and shield size on abdominal skin and subcutaneous tissue deformation – An in-vivo ultrasound and digital image correlation study\",\"authors\":\"Anne-Sofie Madsen Staples , Adam Bo Mandel , Leyre Azcarate , Marie Sand Traberg\",\"doi\":\"10.1016/j.jmbbm.2025.107186\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><h3>Background</h3><div>Shield-triggered autoinjectors (AIs) aim to reduce needle phobia and accidental needlestick injuries and improve usability. However, they may cause deeper injections due to tissue compression. This study investigates the mechanical response of AI application into abdominal tissue in-vivo.</div></div><div><h3>Methods</h3><div>Tissue thickness/compression level, skin strain, and indentation depth were measured in 10 healthy participants. Digital image correlation (DIC) captured the skin surface, while an ultrasound (US) probe attached to a 3D-printed shield recorded the underlying skin and subcutaneous tissue (SCT) during application of forces up to 20 N using two indenter sizes (Ø15 mm and Ø30 mm).</div></div><div><h3>Results</h3><div>Increased force correlated with reduced skin + SCT layer thickness; however, a non-linear tissue lockup/plateau around 8–10 N was evident. The Ø30 indenter caused a 45 % mean compression, while the Ø15 resulted in 55 %. ANOVA revealed statistical differences between shield sizes for indentation depth and skin + SCT thickness reduction (p < 0.05). ANOVA further revealed a statistical difference between mean indentation depth for Ø15 (50.39 mm) versus Ø30 (34.84 mm) (p < 0.05). Average strain rates were higher (10.5 % versus 15 %) and skin surface deflection curves were steeper for Ø15 compared to Ø30.</div></div><div><h3>Conclusions</h3><div>Skin + SCT compression increases until it reaches a lock-up state, but indentation depth responds linearly to increases in force. The high level of tissue compression will increase the risk of intramuscular injections when using shield-triggered AIs, depending on needle length, activation force, and shield size. Therefore, increasing shield sizes to reduce tissue compression and indentation depth can enhance user experience and the probability of reaching the subcutaneous layer. Conclusions are drawn from a small, homogenous cohort, and although the trends are clear, variation between participants highlight the complex nature of human skin tissue. More user groups and injection sites should be investigated.</div></div>\",\"PeriodicalId\":380,\"journal\":{\"name\":\"Journal of the Mechanical Behavior of Biomedical Materials\",\"volume\":\"172 \",\"pages\":\"Article 107186\"},\"PeriodicalIF\":3.5000,\"publicationDate\":\"2025-09-02\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Journal of the Mechanical Behavior of Biomedical Materials\",\"FirstCategoryId\":\"5\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S1751616125003029\",\"RegionNum\":2,\"RegionCategory\":\"医学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q2\",\"JCRName\":\"ENGINEERING, BIOMEDICAL\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of the Mechanical Behavior of Biomedical Materials","FirstCategoryId":"5","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S1751616125003029","RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"ENGINEERING, BIOMEDICAL","Score":null,"Total":0}
The influence of autoinjector applied force and shield size on abdominal skin and subcutaneous tissue deformation – An in-vivo ultrasound and digital image correlation study
Background
Shield-triggered autoinjectors (AIs) aim to reduce needle phobia and accidental needlestick injuries and improve usability. However, they may cause deeper injections due to tissue compression. This study investigates the mechanical response of AI application into abdominal tissue in-vivo.
Methods
Tissue thickness/compression level, skin strain, and indentation depth were measured in 10 healthy participants. Digital image correlation (DIC) captured the skin surface, while an ultrasound (US) probe attached to a 3D-printed shield recorded the underlying skin and subcutaneous tissue (SCT) during application of forces up to 20 N using two indenter sizes (Ø15 mm and Ø30 mm).
Results
Increased force correlated with reduced skin + SCT layer thickness; however, a non-linear tissue lockup/plateau around 8–10 N was evident. The Ø30 indenter caused a 45 % mean compression, while the Ø15 resulted in 55 %. ANOVA revealed statistical differences between shield sizes for indentation depth and skin + SCT thickness reduction (p < 0.05). ANOVA further revealed a statistical difference between mean indentation depth for Ø15 (50.39 mm) versus Ø30 (34.84 mm) (p < 0.05). Average strain rates were higher (10.5 % versus 15 %) and skin surface deflection curves were steeper for Ø15 compared to Ø30.
Conclusions
Skin + SCT compression increases until it reaches a lock-up state, but indentation depth responds linearly to increases in force. The high level of tissue compression will increase the risk of intramuscular injections when using shield-triggered AIs, depending on needle length, activation force, and shield size. Therefore, increasing shield sizes to reduce tissue compression and indentation depth can enhance user experience and the probability of reaching the subcutaneous layer. Conclusions are drawn from a small, homogenous cohort, and although the trends are clear, variation between participants highlight the complex nature of human skin tissue. More user groups and injection sites should be investigated.
期刊介绍:
The Journal of the Mechanical Behavior of Biomedical Materials is concerned with the mechanical deformation, damage and failure under applied forces, of biological material (at the tissue, cellular and molecular levels) and of biomaterials, i.e. those materials which are designed to mimic or replace biological materials.
The primary focus of the journal is the synthesis of materials science, biology, and medical and dental science. Reports of fundamental scientific investigations are welcome, as are articles concerned with the practical application of materials in medical devices. Both experimental and theoretical work is of interest; theoretical papers will normally include comparison of predictions with experimental data, though we recognize that this may not always be appropriate. The journal also publishes technical notes concerned with emerging experimental or theoretical techniques, letters to the editor and, by invitation, review articles and papers describing existing techniques for the benefit of an interdisciplinary readership.