Accurate Guidance for Percutaneous Access to a Specific Target in Soft Tissues: Preclinical Study of Computer-Assisted Pericardiocentesis

1999 ◽  
Vol 9 (3) ◽  
pp. 259-266 ◽  
Author(s):  
OLIVIER CHAVANON ◽  
CATHERINE BARBE ◽  
JOCELYNE TROCCAZ ◽  
LIONEL CARRAT ◽  
CHRISTOPHE RIBUOT ◽  
...  
Keyword(s):  
Soft Tissues ◽  
Preclinical Study ◽  
Computer Assisted ◽  
Specific Target ◽  
Percutaneous Access

scholarly journals CAMM Techniques for the Prediction of the Mechanical Properties of Tendons and Ligaments Nanostructures

2005 ◽  
Vol 5 ◽  
pp. 564-570
Author(s):  
Simone Vesentini ◽  
Franco M. Montevecchi ◽  
Alberto Redaelli
Keyword(s):  
Mechanical Properties ◽  
Molecular Modeling ◽  
Connective Tissue ◽  
Soft Tissues ◽  
Collagen Molecule ◽  
Computer Assisted ◽  
Mechanical Function ◽  
Top Down ◽  
Structural Constituent ◽  
Structures And Properties

Theoretical prediction of the mechanical properties of soft tissues usually relies on a top-down approach; that is analysis is gradually refined to observe smaller structures and properties until technical limits are reached. Computer-Assisted Molecular Modeling (CAMM) allows for the reversal of this approach and the performance of bottom-up modeling instead. The wealth of available sequences and structures provides an enormous database for computational efforts to predict structures, simulate docking and folding processes, simulate molecular interactions, and understand them in quantitative energetic terms. Tendons and ligaments can be considered an ideal arena due to their well defined and highly organized architecture which involves not only the main structural constituent, the collagen molecule, but also other important molecular “actors” such as proteoglycans and glycosaminoglycans. In this ideal arena each structure is well organized and recognizable, and using the molecular modeling tool it is possible to evaluate their mutual interactions and to characterize their mechanical function. Knowledge of these relationships can be useful in understanding connective tissue performance as a result of the cooperation and mutual interaction between different biological structures at the nanoscale.

scholarly journals A Detailed analysis of Time taken in Robotic Surgery for Total Knee Replacement Arthroplasty and comparison with computer assisted navigation in Total Knee Replacement Arthroplasty

10.29007/65qr ◽  
2020 ◽  
Author(s):  
Kamal Deep ◽  
Frederic Picard
Keyword(s):  
Total Knee Replacement ◽  
Ct Scan ◽  
Knee Replacement ◽  
Soft Tissues ◽  
Computer Navigation ◽  
Computer Assisted ◽  
Assisted Navigation ◽  
Replacement Arthroplasty ◽  
Knee Replacement Arthroplasty ◽  
Total Knee

The accuracy of implantation using computer navigation and robotic total knee replacement (TKR) has been proven. Time taken during surgery has been a factor for surgeons for not using the technology. Aim of this study was to analyse time taken in different steps and identify which part needs improvement. Robotic time was compared to computer navigation. Methods: 15TKR were performed with MAKO robot. Software for the ligament balancing was used. All had CT scan preoperatively. Time of different surgical steps was recorded. Time for computer navigation was recorded too. After joint exposure, trackers and verification pins for tibia and femur were inserted. Femoral registration matching started at 10.8 minutes (SD3.3 Range7-20). It took 3.2 minutes to match femoral anatomy to CT scan. Tibial registration done at 14.1minutes (SD3 Range10- 23). Once matching was accepted to required accuracy, tibial cut was made at 22.2 minutes (SD4.4 Range 15-30). Next the soft tissues were assessed with tensioner. It took 6.3 minutes (SD 5.6). Final femoral preparation done at 35.7 minutes (SD 5.6 Range25-45). Trial performed at 52 minutes (SD7.3 Range42-63). Implants were cemented at 63.4 minutes (SD8 Range50-72). Wound closed at 77.6 minutes (SD9.5 Range65-97). The computer navigated TKR surgery took 70 minutes on an average. Compared to navigation, robotic technique took approximately 7 minutes longer, not significantly different. This could be due to learning curve of the surgical and theatre team. Improvement is required in different steps. The familiarity of staff will increase the efficiency. Registration matching took 11.4 minutes. Femoral preparation took 17 minutes. These steps could be streamlined.

scholarly journals Digital Workflow for Periodontal Crown Lengthening in Treatment of Altered Passive Eruption: Case Report

2020 ◽  
pp. 27-30
Author(s):  
Vilma A Umanzor ◽  
Hugo H Romero ◽  
Zamir Kafati ◽  
Ana Rodriguez ◽  
Juan Guifarro ◽  
...  
Keyword(s):  
Soft Tissues ◽  
Cone Beam ◽  
Computer Assisted ◽  
Surgical Guide ◽  
Computed Tomography Images ◽  
Surgical Guides ◽  
Planning Software ◽  
Cone Beam Computerized Tomography ◽  
Precise Representation ◽  
Crown Lengthening

This paper describes the treatment of a patient diagnosed clinically and based on cone beam computed tomography images with excessive gingival display caused by altered passive eruption Type 1B. A digitally computer designed and 3-D printed surgical guide was fabricated for crown lengthening to provide periodontal esthetics. The combination of intraoral scanners and cone-beam computerized tomography images, and use of planning software, provides a very precise representation of the real conditions of the hard and soft tissues. The design and fabrication of computer surgical guides can improve precision and predictability for surgical procedures and can be superior to conventional free-handed surgery in terms of efficiency and treatment outcomes. Surgical experience and general understanding of computer assisted systems and thorough knowledge of conventional protocols is mandatory to make routine use of these systems. To select a treatment modality, the etiology must be clearly identified and the patient has to be informed of his options for treatment which for this condition are a gingivectomy or an apically positioned flap with or without osseous reduction determined by the type of altered passive eruption.

scholarly journals Combining Intraoral and Face Scans for the Design and Fabrication of Computer-Assisted Design/Computer-Assisted Manufacturing (CAD/CAM) Polyether-Ether-Ketone (PEEK) Implant-Supported Bars for Maxillary Overdentures

Scanning ◽  
2019 ◽  
Vol 2019 ◽  
pp. 1-14 ◽  
Author(s):  
Francesco Mangano ◽  
Carlo Mangano ◽  
Bidzina Margiani ◽  
Oleg Admakin
Keyword(s):  
Soft Tissues ◽  
Previous Treatment ◽  
Digital Impression ◽  
Computer Assisted ◽  
Success Rates ◽  
Computer Assisted Design ◽  
Polyether Ether Ketone ◽  
Cad Cam ◽  
Passive Fit ◽  
Ether Ketone

Purpose. To present a digital method that combines intraoral and face scanning for the computer-assisted design/computer-assisted manufacturing (CAD/CAM) fabrication of implant-supported bars for maxillary overdentures. Methods. Over a 2-year period, all patients presenting to a private dental clinic with a removable complete denture in the maxilla, seeking rehabilitation with implants, were considered for inclusion in this study. Inclusion criteria were fully edentulous maxilla, functional problems with the preexisting denture, opposing dentition, and sufficient bone volume to insert four implants. Exclusion criteria were age<55 years, need for bone augmentation, uncompensated diabetes mellitus, immunocompromised status, radio- and/or chemotherapy, and previous treatment with oral and/or intravenous aminobisphosphonates. All patients were rehabilitated with a maxillary overdenture supported by a CAD/CAM polyether-ether-ketone (PEEK) implant-supported bar. The outcomes of the study were the passive fit/adaptation of the bar, the 1-year implant survival, and the success rates of the implant-supported overdentures. Results. 15 patients (6 males, 9 females; mean age 68.8±4.7 years) received 60 implants and were rehabilitated with a maxillary overdenture supported by a PEEK bar, designed and milled from an intraoral digital impression. The intraoral scans were integrated with face scans, in order to design each bar with all available patient data (soft tissues, prosthesis, implants, and face) in the correct spatial position. When testing the 3D-printed resin bar, 12 bars out of 15 (80%) had a perfect passive adaptation and fit; in contrast, 3 out of 15 (20%) did not have a sufficient passive fit or adaptation. No implants were lost, for a 1-year survival of 100% (60/60 surviving implants). However, some complications (two fixtures with peri-implantitis in the same patient and two repaired overdentures in two different patients) occurred. This determined a 1-year success rate of 80% for the implant-supported overdenture. Conclusions. In this study, the combination of intraoral and face scans allowed to successfully restore fully edentulous patients with maxillary overdentures supported by 4 implants and a CAD/CAM PEEK bar. Further studies are needed to confirm these outcomes.

Results of transarterial chemoembolization on rats with grafted hepatocellular cancer of liver

2016 ◽  
Vol 21 (5) ◽  
pp. 259-263
Author(s):  
Helena M. Treshalina ◽  
M. N Yakunina ◽  
A. Yu Fadeev ◽  
G. B Smirnova ◽  
Ju. A Borisova ◽  
...  
Keyword(s):  
Tumor Growth ◽  
Transarterial Chemoembolization ◽  
Soft Tissues ◽  
Specific Activity ◽  
Regional Blood Flow ◽  
Hepatocellular Cancer ◽  
Preclinical Study ◽  
Tumor Growth Rate ◽  
Control Group ◽  
Tumor Growth Inhibition

Modeling of a transarterial chemoembolization (TACE) is carried out on rats (n = 6) with hepatocellular cancer of liver RS1 (Vcp = 4.5 cm3) which has developed in muscles of the leg (i.m.). Sensitivity of a tumor to the single introduction of substance of doxorubicine (sDOX) in maximum tolerated doses (MTD) of 5-12 mg/kg with the achievement of significantly tumor growth inhibition on 55-77% (p = 0.001) is previously shown. TACE is executed with the elastic polyvinyl alcohol microspheres in size of 0.2 mm in diameter loaded with doxorubicine (MS/sDOX) with the release within 7 days. MS/sDOX in the volume of 0.034-0.1 ml (a cumulative dose of sDOX of 3.3-10.5 mg/kg) was introduced into a femoral artery (i/a) with a diameter of 0.16 mm under control of an embolization (MS or arterial ligature) and chemotherapy (sDOX). TACE gave rise in the cytoreductive effect of the tumor nodule by 67% (T/C = 33%, p = 0.0004) with the single regression and the development of the grade 1 therapeutical pathomorphosis (TP). The therapeutic gain of MC/sDOX manifested in coupled with the cytoreduction the decline of the tumor growth rate («т» = 11-16 against 1.9-2.0 days in the control group) and at the equal inhibiting action with sDOX dose reduced by 20% against MTD. Side effects of TACE (a necrosis of soft tissues, 7th-16th days) were not associated with the full stagnation of a regional blood flow due to the discrepancy of MS to diameter of the artery. The whole of the revealed effects has allowed to consider the modeling of i/m tumor on rats to be suitable for the screening of the specific activity of agents clients for TACE. The preclinical study of the method is rational to execute on the corresponding model on large animals with regional artery of the sufficient cross section of the vessel permitting to perform TACE satisfactory.

scholarly journals Effect of surgical experience on imageless computer-assisted femoral component positioning in hip resurfacing – a preclinical study

2015 ◽  
Vol 20 (1) ◽  
Author(s):  
Maik Stiehler ◽  
Jens Goronzy ◽  
Stephan Kirschner ◽  
Albrecht Hartmann ◽  
Torsten Schäfer ◽  
...  
Keyword(s):  
Femoral Component ◽  
Hip Resurfacing ◽  
Preclinical Study ◽  
Computer Assisted ◽  
Surgical Experience

scholarly journals Speed-of-sound imaging using diverging waves

2021 ◽  
Author(s):  
Richard Rau ◽  
Dieter Schweizer ◽  
Valery Vishnevskiy ◽  
Orcun Goksel
Keyword(s):  
Plane Wave ◽  
Speed Of Sound ◽  
Soft Tissues ◽  
Clinical Translation ◽  
Computer Assisted ◽  
Wavefront Aberration ◽  
Imaging Method ◽  
Ultrasound Images ◽  
Transmission Scheme ◽  
Low Contrast

Abstract Purpose. Due to its safe, low-cost, portable, and real-time nature, ultrasound is a prominent imaging method in computer-assisted interventions. However, typical B-mode ultrasound images have limited contrast and tissue differentiation capability for several clinical applications. Methods. Recent introduction of imaging speed-of-sound (SoS) in soft tissues using conventional ultrasound systems and transducers has great potential in clinical translation providing additional imaging contrast, e.g., in intervention planning, navigation, and guidance applications. However, current pulse-echo SoS imaging methods relying on plane wave (PW) sequences are highly prone to aberration effects, therefore suboptimal in image quality. In this paper we propose using diverging waves (DW) for SoS imaging and study this comparatively to PW. Results. We demonstrate wavefront aberration and its effects on the key step of displacement tracking in the SoS reconstruction pipeline, comparatively between PW and DW on a synthetic example. We then present the parameterization sensitivity of both approaches on a set of simulated phantoms. Analyzing SoS imaging performance comparatively indicates that using DW instead of PW, the reconstruction accuracy improves by over 20% in root-mean-square-error (RMSE) and by 42% in contrast-to-noise ratio (CNR). We then demonstrate SoS reconstructions with actual US acquisitions of a breast phantom. With our proposed DW, CNR for a high contrast tumor-representative inclusion is improved by 42%, while for a low contrast cyst-representative inclusion a 2.8-fold improvement is achieved. Conclusion. SoS imaging, so far only studied using a plane wave transmission scheme, can be made more reliable and accurate using DW. The high imaging contrast of DW-based SoS imaging will thus facilitate the clinical translation of the method and utilization in computer-assisted interventions such as ultrasound-guided biopsies, where B-Mode contrast is often to low to detect potential lesions.

scholarly journals Dynamic Instability in Young Adults with Symptomatic Hip Dysplasia: Analysis using a Computer-Assisted Image-Matching Procedure

2021 ◽  
Author(s):  
Hiroshi Imai ◽  
Yoshitaka Shiraishi ◽  
Shinichiro Sakai ◽  
Joji Miyawaki ◽  
Naohiko Mashima ◽  
...  
Keyword(s):  
Hip Joint ◽  
Image Matching ◽  
Soft Tissues ◽  
Dynamic Instability ◽  
Japanese Orthopaedic Association ◽  
Computer Assisted ◽  
Nonsurgical Management ◽  
Acetabular Head Index ◽  
Significant Difference ◽  
Matching Procedure

Abstract Background: Repeated microtrauma often causes damage to the periarticular soft tissues. This damage, together with the lack of acetabular bony coverage, such as developmental dysplasia of the hip (DDH), can contribute to various degrees of dynamic instability of the hip joint and cause progressive osteoarthritic changesThe purpose of this study was to use an image-matching procedure to compare dynamic instability of the hip joint in patients with DDH who did or did not undergo periacetabular osteotomy (PAO). Methods: Six patients (6 hips) with symptomatic DDH were enrolled. A 6-month trial of nonsurgical management was initiated at the first visit. PAO was performed in 3 patients who experienced persistent pain after conservative treatment. The dynamic instability of all 6 hips was evaluated. Results: Japanese Orthopaedic Association hip scores improved significantly in all hips regardless of PAO. At the first visit, the center-edge angle, Sharp angle, vertical-center-anterior angle, and acetabular head index were not significantly different between the PAO and non-PAO groups. Dynamic instability was defined as the 3D translation of the femoral head center for the acetabular center at hip abduction angles from 0° to 30°. In the non-PAO group, the mean sagittal, axial, and coronal translations were 2.4 mm, 2.2 mm, and 1.1 mm, respectively, and in the PAO group they were 2.4 mm, 7.2 mm, and 2.7 mm, respectively. There was a significant difference in axial translation between the 2 groups. Conclusion:Dynamic instability leads to periarticular soft tissue damage and insufficient bony coverage, and causes progressive osteoarthritic changes. Dynamic instability in the axial plane induces persistent hip pain after nonsurgical management. Affected patients should undergo PAO as soon as possible.

Development of a new percutaneous access device for implantation in soft tissues

1991 ◽  
Vol 25 (12) ◽  
pp. 1535-1545 ◽  
Author(s):  
J. A. Jansen ◽  
J. P. C. M. van der Waerden ◽  
K. de Groot
Keyword(s):  
Soft Tissues ◽  
Access Device ◽  
Percutaneous Access
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