scholarly journals Synthetic Soft Tissue Characterization of the Mechanical Analogue Lumbar Spine

2008 ◽  
Vol 2 (2) ◽  
Author(s):  
Eugene E. Avidano ◽  
Leighton J. LaPierre ◽  
Elizabeth A. Friis ◽  
John E. James ◽  
Amy E. Johnson

Evaluation of spinal implants is limited by difficulties in testing biological structures. Soft tissues primarily control spinal biomechanical responses. The objective of this study is to show controllability of the synthetic soft tissue properties of the mechanical analogue lumber spine. The development of an analogue spine would answer a multitude of clinical questions and improve implant design. Polyester fibers in a wave pattern were embedded in a shore-A F55 polyurethane matrix to mimic the nonlinear properties of human ligaments. Ligaments with four different volume fractions (Vf) of fibers were tested to failure in tension using specially designed jigs in a MTS MiniBionix. Polyester fibers oriented at +∕−30degrees were embedded in F55 polyurethane to simulate the annulus fibrosis (AF). Discs with three different Vf’s and F5 polyurethane for the nucleus pulposus were tested in compression to 1.25mm using a self-aligning jig. Displacement control was used for all specimens at a rate of 0.04230mm∕sec. For the ligaments, the initial stiffness and strain at toe was similar and the mean secondary stiffness in MPa was 187±5%, 307±5%, 422±2%, and 511±3% as the Vf increased. For the discs, the mean initial and (secondary) stiffness in N∕mm was 158±14%(658±6%), 150±5%(666±8%), and 74±3%(1230±2%) as the AF Vf increased. The results showed that synthetic soft tissue properties are controllable and properties measured fall within the range of human cadaveric literature values. A wide variety of analogue models can be developed utilizing the control of soft tissues.

2016 ◽  
Vol 16 (08) ◽  
pp. 1640019 ◽  
Author(s):  
JAEHYUN SHIN ◽  
YONGMIN ZHONG ◽  
JULIAN SMITH ◽  
CHENGFAN GU

Dynamic soft tissue characterization is of importance to robotic-assisted minimally invasive surgery. The traditional linear regression method is unsuited to handle the non-linear Hunt–Crossley (HC) model and its linearization process involves a linearization error. This paper presents a new non-linear estimation method for dynamic characterization of mechanical properties of soft tissues. In order to deal with non-linear and dynamic conditions involved in soft tissue characterization, this method improves the non-linearity and dynamics of the HC model by treating parameter [Formula: see text] as independent variable. Based on this, an unscented Kalman filter is developed for online estimation of soft tissue parameters. Simulations and comparison analysis demonstrate that the proposed method is able to estimate mechanical parameters for both homogeneous tissues and heterogeneous and multi-layer tissues, and the achieved performance is much better than that of the linear regression method.


2003 ◽  
Vol 40 (5) ◽  
pp. 544-549 ◽  
Author(s):  
Virgilio F. Ferrario ◽  
Chiarella Sforza ◽  
Claudia Dellavia ◽  
Gianluca M. Tartaglia ◽  
Davide Sozzi ◽  
...  

Objective To supply quantitative information about the facial soft tissues of adult operated patients with cleft lip and palate (CLP). Design, Setting, and Patients The three-dimensional coordinates of soft tissue facial landmarks were obtained using an electromagnetic digitizer in 18 Caucasian patients with CLP (11 males and 7 females aged 19 to 27 years) and 162 healthy controls (73 females and 89 males aged 18 to 30 years). From the landmarks, 15 facial dimensions and two angles were calculated. Data were compared with those collected in healthy individuals by computing z-scores. Two summary anthropometric measurements for quantifying craniofacial variations were assessed in both the patients and reference subjects: the mean z-score (an index of overall facial size), and its SD, called the craniofacial variability index (an index of facial harmony). Results In treated patients with CLP, facial size was somewhat smaller than in normal individuals, but in all occasions the mean z-score fell inside the normal interval (mean ± 2 SD). Almost all patients had a craniofacial variability index larger than the normal interval, indicating a global disharmonious appearance. Overall, in patients pronasale, subnasale, and pogonion were more posterior, the nose was shorter and larger, the face was narrower, and the soft tissue profile and upper lip were flatter than in the reference population. Conclusions The facial soft tissue structures of adult operated patients with CLP differed from those of normal controls of the same age, sex, and ethnic group. In this patient group, surgical corrections of CLP failed to provide a completely harmonious appearance, even if the deviations from the reference were limited. Further analyses of larger groups of patients are needed.


2010 ◽  
Vol 22 (1) ◽  
Author(s):  
Weko Adhiarto ◽  
Sunardhi Mangundjaja ◽  
Makmuri Yusuf ◽  
Bambang Pontjo

The wound healing process of the soft tissue aims to accelerate the closing of the wound by recurring, restoring the function, and minimizing the scar tissue. This process has to occur in the surgery process to obtain better-wound healing. The aim of this study was to know the stimulation effect of the wound dressing to accelerate the wound healing process of the soft tissue using Collagen (amino acid) and Amnion (proteinase inhibitors). This true experimental study was done to 36 mice (Sprague Dawley) that were divided into three different groups, two groups were the treatment groups and one group was the control group. Each group was adapted in Pathology Laboratory of Faculty of Veterinary Medicine Bogor Agricultural University. All of the mice were injured on the skin by incising the right side of the back for 2 cm in length and 4 mm in depth and then cleaned with 0.9% NaCl solution. To the first group of treatment, the wound was applicated by Amnion, and the second group was applicated by Collagen. Each 4 mice of all group were a termination by ether and encryption on the wounded tissue was conducted on day 3rd, 7th, and 14th. Assessment for a number of fibroblast and collagen synthesis on the wound of back tissue was conducted with the histological examination by painted using hematoxylin-eosin. The results concluded that Collagen application was influencing the mean of fibroblast higher than Amnion, and the lowest was controlled with statistically significant. The mean of collagen used Collagen lower than Amnion, and the lowest was control with statistically significant. It could be concluded that collagen application was preeminent in increasing the productivity of the fibroblast, as well as in developing forms of the collagen synthesis compared with Amnion and control.


Author(s):  
Ming Jia ◽  
Jean W. Zu ◽  
Alireza Hariri

Knowledge of tissue mechanical properties is widely required by medical applications, such as disease diagnostics, surgery operation, simulation, planning, and training. A new portable device, called Tissue Resonator Indenter Device (TRID), has been developed for measurement of regional viscoelastic properties of soft tissues at the Bio-instrument and Biomechanics Lab of the University of Toronto. As a device for soft tissue properties in-vivo measurements, the reliability of TRID is crucial. This paper presents TRID’s working principle and the experimental study of TRID’s reliability with respect to inter-reliability, intra-reliability, and the indenter misalignment effect as well. The experimental results show that TRID is a reliable device for in-vivo measurements of soft tissue mechanical properties.


1995 ◽  
Vol 117 (4) ◽  
pp. 409-413 ◽  
Author(s):  
S. N. Robinovitch ◽  
W. C. Hayes ◽  
T. A. McMahon

Recent studies suggest that hip padding systems reduce the incidence of hip fractures during falls. However, no data exist on the force attenuating capacity of hip pads under realistic fall impact conditions, and thus it is difficult to compare the protective merit of various pad designs. Our goal is to design a comfortable hip padding system which reduces femoral impact force in a fall below the mean force required to fracture the elderly cadaveric femur. In pursuit of this objective, we designed and constructed a hip pad testing system consisting of an impact pendulum and surrogate human pelvis. We then developed a hip pad containing a shear-thickening material which allows for shunting of the impact energy away from the femur and into the surrounding soft tissue. Finally, we conducted experiments to assess whether the surrogate pelvis accurately represents the impact behavior of the human female pelvis in a fall, and to determine whether our energy-shunting pad attenuates femoral impact force in a fall more effectively than seven available padding systems. We found the surrogate pelvis accurately represented the human female pelvis in regional variation in soft tissue stiffness, total effective stiffness and damping, and impact force attenuation provided by trochanteric soft tissues. We also found that our padding system attenuated femoral impact force by 65 percent, thereby providing two times the force attenuation of the next best system. Moreover, the energy-shunting pad was the only system capable of lowering femoral impact force well below the mean force required to fracture the elderly femur in a fall loading configuration. These results suggest that the force attenuating potential of hip pads which focus on shunting energy away from the femur is superior to those which rely on absorbing energy in the pad material. While these in-vitro results are encouraging, carefully designed prospective clinical trials will be necessary to determine the efficacy of these approaches to hip fracture prevention.


2018 ◽  
Vol 4 (4) ◽  
pp. 1245-1250 ◽  
Author(s):  
Ahmed AL-Omar ◽  
Usama AL-Dakroroy

The objective of this study was to evaluate the soft tissue changes after anterior maxillary osteotomy using cone beam computed tomography. The study included twelve patients diagnosed as suffering from an excess of the anterior part of maxilla and required surgical correction by anterior maxillary osteotomy. Assessment of Cone beam computed tomography in evaluation the soft tissue changes. All cases subjected to anterior maxillary osteotomy using modified Cuper technique. Follow up of cases was does clinically and radio- graphically by cone beam computed tomography. The results of the study proved that the statistically significant increase in mean Nasolabial angle after 6 months was 5.2 degrees, the mean value of nasal width after 6 months was 0,9mm. The mean value of Philtrum length was 3.3mm. In conclusion, Cone Beam Computed Tomography can be used to obtain dimensionally accurate linear and angular measurement from bony maxillofacial structure and landmarks and allows accurate, three-dimensional imaging of hard and soft tissues.


2020 ◽  
pp. 20200191
Author(s):  
Eduarda Helena Leandro Nascimento ◽  
Rocharles Cavalcante Fontenele ◽  
Priscila de Azeredo Lopes ◽  
Gustavo Machado Santaella ◽  
Karla Faria Vasconcelos ◽  
...  

Objectives: To present the ballistic gelatin as a new material capable of simulating the soft tissues in cone-beam CT (CBCT) images. Methods: CBCT images of three piglet heads were acquired with their soft tissues intact (standard group). Subsequently, the piglet heads were fixed in a container using metallic pins and moulded with acrylic resin; the soft tissues were then removed and replaced by ballistic gelatin, with the same thickness of the original soft tissues. The images were evaluated by two oral radiologists, to check the adaptation on bone surfaces, thickness and density, penetration into large bone cavities and cancellous bone, and the presence of air bubbles using a 5-score scale. Additionally, an objective analysis was carried out by one oral radiologist. For each CBCT scan, three axial reconstructions were selected to represent the mandibular, occlusal, and maxillary levels. The mean and standard deviation (SD) of the grey values were calculated in four regions of interest determined on soft tissue areas and compared by two-way ANOVA. Results: The ballistic gelatin showed subjective scores ranging from good to excellent for all parameters evaluated. There was no significant difference in the mean and SD values of the grey values between ballistic gelatin and the gold standard groups for all levels (p > 0.05). Higher SD values were observed in the occlusal level for both groups (p < 0.05). Conclusions: Ballistic gelatin has visual and objective similarity with the gold standard. Thus, the ballistic gelatin is a promising material capable of simulating soft tissues in CBCT images.


2005 ◽  
Vol 42 (4) ◽  
pp. 410-416 ◽  
Author(s):  
Chiarella Sforza ◽  
Claudia Dellavia ◽  
Claudia Dolci ◽  
Elena Donetti ◽  
Virgilio F. Ferrario

Objective To supply quantitative information about the facial soft tissues of subjects with Down syndrome by using summary anthropometric measurements. Design, Setting, and Patients The three-dimensional coordinates of soft tissue facial landmarks were obtained using a computerized digitizer in 28 subjects with Down syndrome (11 girls and women and 17 boys and men aged 12 to 45 years) and 429 healthy controls matched for sex, age, and ethnicity. From the landmarks, 18 facial dimensions were calculated. Data were compared with those collected in healthy individuals by computing z-scores. Two summary anthropometric measurements for quantifying craniofacial variations were assessed in both the subjects with Down syndrome and the reference subjects: the mean z-score (an index of overall facial size) and its standard deviation, craniofacial variability index (an index of facial harmony). Results In subjects with Down syndrome, facial size was smaller than in normal individuals, and in 17 subjects the mean z-score fell outside the normal interval (mean ± 2 SD). Twenty subjects had a craniofacial variability index larger than the normal interval. Conclusions The facial soft tissue structures of subjects with Down syndrome differed from those of normal controls of the same age, sex, and ethnic group: a reduced facial size was coupled with a global anomalous relationship between individual measurements. The two indices allowed discriminating more than 89% of subjects with Down syndrome when compared with normal subjects.


2020 ◽  
Vol 40 (12) ◽  
pp. 1341-1348 ◽  
Author(s):  
Sebastian Cotofana ◽  
Michael Alfertshofer ◽  
Konstantin Frank ◽  
Vince Bertucci ◽  
Katie Beleznay ◽  
...  

Abstract Background Glabellar soft tissue filler injections have been shown to be associated with a high risk of causing injection-related visual compromise. Objectives The aim of this study was to identify the course of the superficial branch of the supratrochlear and of the deep branch of the supraorbital artery in relation to the ipsilateral vertical glabellar line and to test whether an artery is located deep to this line. Methods Forty-one healthy volunteers with a mean age of 26.17 [9.6] years and a mean BMI of 23.09 [2.3] kg/m2 were analyzed. Ultrasound imaging was applied to measure the diameters, distance from skin surface, distance between the midline, distance between vertical glabella lines, and the cutaneous projection of the supratrochlear/supraorbital arteries at rest and upon frowning. Results The mean distance between the superficial branch of the supratrochlear artery and the ipsilateral vertical glabellar line was 10.59 [4.0] mm in males and 8.21 [4.0] mm in females, whereas it was 22.38 [5.5] mm for the supraorbital artery in males and 20.73 [5.6] mm in females. Upon frowning, a medial shift in supratrochlear arterial position of 1.63 mm in males and 1.84 mm in females and of 3.9 mm in supraorbital arterial position for both genders was observed. The mean depth of the supratrochlear artery was 3.34 [0.6] mm at rest, whereas the depth of the supraorbital artery was 3.54 [0.8] mm. Conclusions The hypothesis that injecting soft tissue fillers next to the vertical glabellar line is safe because the supratrochlear artery courses deep to the crease should be rejected. Additionally, the glabella and the supraorbital region should be considered as an area of mobile, rather than static, soft tissues.


2004 ◽  
Vol 48 (11) ◽  
pp. 4246-4249 ◽  
Author(s):  
Florian Islinger ◽  
Rene Bouw ◽  
Mathias Stahl ◽  
Edith Lackner ◽  
Petra Zeleny ◽  
...  

ABSTRACT Free gemifloxacin concentrations in the interstitial space fluid of skeletal muscle and subcutaneous adipose tissue were measured by means of in vivo microdialysis to characterize the ability of gemifloxacin to penetrate human soft tissues. Twelve healthy volunteers received a single oral dose of 320 mg of gemifloxacin. The mean areas under the concentration-time curves from 0 to 10 h (AUC0-10) were significantly higher for soft tissue than for unbound gemifloxacin in plasma (P < 0.05). The ratios of the mean AUC0-10 for tissue to the AUC0-10 for free gemifloxacin in plasma were 1.7 ± 0.7 (mean ± standard deviation) for skeletal muscle and 2.4 ± 1.0 for adipose tissue. The AUC0-24 ratios for free gemifloxacin in tissues to the MIC at which 90% of frequently isolated bacteria are inhibited were close to or higher than 100 h. Therefore, based on pharmacokinetic and pharmacodynamic calculations, we conclude that gemifloxacin might be a useful therapeutic option for the treatment of soft tissue infections.


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