Model of Guided Waves in Cortical Bones Coated with a Soft-Tissue Layer

2021 ◽  
pp. 371-379
Author(s):  
Ductho Le ◽  
Ngoc Anh Trinh ◽  
Son-Tung Dang ◽  
Emmanuel L. C. V. I. M. Plan ◽  
Minh Tuan Nguyen ◽  
...  
2008 ◽  
Vol 124 (4) ◽  
pp. 2364-2373 ◽  
Author(s):  
Petro Moilanen ◽  
Maryline Talmant ◽  
Vantte Kilappa ◽  
Patrick Nicholson ◽  
Sulin Cheng ◽  
...  

Author(s):  

Introduction After mastectomies, we do our reconstruction, either immediately or delayed. In both ways of reconstruction for post mastectomies defect, the most commonly performed reconstruction is by using breast prosthesis [1]. For many years, surgeons have been trying to find out any solution to reduce the rate of implant exposure and develop some new techniques and modifications. However, once the infection develops or implant expose the only permanent solution is to remove the implant [2-3]. Although there is less evidence found in the literature regarding the salvage of implant once the infection occurs and when implant becomes expose in implant-based reconstruction [4]. Radiation also plays additional role in post-operative complication rates following implant-based breast reconstruction, as it is well documented that the incidence of complications is to be higher in radiated breasts compare to similar non-radiated breasts [5]. With the new advancement in radiation therapy the number of patients have been increasing who are receiving radiation therapy after immediate breast reconstruction [5]. Description of the Technique For more than 15 years we have been reconstructing the breasts deformities after different types of mastectomies, ranging from skin sparing, nipple areola sparing to different types of lumpectomies, by immediate insertion of breast implants. The main problem which we face during post-reconstruction, is the exposure of implant in addition to infection. With the advent of ADM (Artificial Dermal Matrix) [6], serratus anterior muscle [7], rectus fascial flap [7] and inferior dermal flaps [8] although they do an addition to thickness of skin envelop over the implant after mastectomy, but still the rate of implant exposure has not changed noticeably. It has been well understood that of ADM expose in air it dries immediately which later on results in implant exposure. Meanwhile we have developed a novel tech- nique to augment the soft tissue coverage under the incision line over the ADM and implant. By this way, if there is any dehiscence over suture line, there will be no implant exposure as there is additional soft tissue layer of dermal flap. These dermal flaps are actually a de-epithelialized dermal flap from the inferior half of the breast skin, which we used to excise and throw it to the garbage, particularly in skin sparing mastectomies. In this technique we suture the inferior based dermal flap over the artificial dermal matrix in a way that suture lines of skin flaps of mastectomy lie over the de-epithelialized dermal flap, which actually in- crease the survivability of ADM as well as increase the thickness of soft tissue over the implant (figure 1 and 2). By addition of this layer of de-epithelialized dermal flaps over the artificial dermal matrix and breast implants have promising reduction effect over implant exposure as well as it provides the additional vascularized soft tissue layer over the implant. Although we are using dermal flap with ADM frequently in most of our skin spring mastectomies but we did this new technique in 2 patients till now with the mean follow up of 8 weeks till now there is not a single case report of implant exposure in those patients (figure 3).


2021 ◽  
Author(s):  
Xiaojun Song ◽  
Tiandi Fan ◽  
Jundong Zeng ◽  
QinZhen Shi ◽  
Qiong Huang ◽  
...  

Abstract Ultrasonic guided waves (UGW), which propagate throughout the whole thickness of cortical bone, are attractive in the early diagnosis of osteoporosis. However, it is challenging due to the impact of soft tissue and the inherent difficulties related to the multiparametric inversion of cortical bone quality factors, such as cortical thickness and bulk wave velocities. Therefore, an UGW based multiple-parameter inversion algorithm is developed to predict strength-related factors in this research. In simulation, a free plate (cortical bone) and a bilayer plate (soft tissue and cortical bone) are used to validate the proposed method. The inverted cortical thickness (CTh), longitudinal velocity (V L ) and transverse velocity (V T ) are in accordance with the true value. Then four bovine cortical bone plates are used in the in vitro experiments. Compared with the reference values, the relative errors for cortical thicknesses are 3.96%, 0.83%, 2.87% and 4.25% respectively. In the in vivo measurements, ultrasonic guided waves are collected from ten volunteers’ tibia. The theoretical dispersion curves depicted by the estimated parameters (V T , V L , CTh) match well with the extracted experimental ones. In comparison to the dual-energy x-ray absorptiometry (DXA), the results show that the estimated transverse velocity and cortical thickness are highly sensitive to the osteoporosis. Therefore, these two parameters (CTh and V T ) of long bones have potential to diagnose bone status in clinical applications.


2020 ◽  
Vol 59 (SK) ◽  
pp. SKKB05
Author(s):  
Leslie Bustamante ◽  
Masaya Saeki ◽  
Takashi Misaki ◽  
Mami Matsukawa

2018 ◽  
Vol 133 (1) ◽  
pp. 151-162 ◽  
Author(s):  
Peter Mahoney ◽  
Debra Carr ◽  
Karl Harrison ◽  
Ruth McGuire ◽  
Alan Hepper ◽  
...  

2017 ◽  
Vol 132 (2) ◽  
pp. 519-530 ◽  
Author(s):  
Peter Mahoney ◽  
Debra Carr ◽  
Richard Arm ◽  
Iain Gibb ◽  
Nicholas Hunt ◽  
...  

Author(s):  
Hoai Nguyen ◽  
Ductho Le ◽  
Emmanuel Plan ◽  
Son Tung Dang ◽  
Haidang Phan

Quantitative ultrasound has shown a significant promise in the assessment of bone characteristics in the recent reports. However, our understanding of wave interaction with bone tissues is still far from complete since the propagation of ultrasonic waves in bones is a very challenging topic due to their multilayer nature. The aim of the current study is to develop a theoretical model for guided waves in a bone-mimicking plate coupled with two soft-tissue layers. Here, the bone plate is modeled as an isotropic solid layer while the soft tissues are modeled as fluid layers. Based on the boundary conditions set for the three-layered structure, a characteristic equation is obtained which results in dispersion curves of the phase and group velocities. New expressions for free guided waves propagating in the trilayered plate are introduced. The amplitudes of wave modes generated by time-harmonic loads applied in the plate are theoretically computed by reciprocity consideration. As an example of calculation, the normalized amplitudes of the lowest wave modes are presented. The obtained results and equations discussed in this study could be, in general, useful for further applications in the area of bone quantitative ultrasound.


2019 ◽  
Vol 134 (3) ◽  
pp. 1007-1013
Author(s):  
Lea Siegenthaler ◽  
Florian Sprenger ◽  
Fabiano Riva ◽  
Matthieu J. Glardon ◽  
Beat P. Kneubuehl ◽  
...  

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