Reduction and Fixation of Sacroiliac joint Dislocation by the Combined Use of S1 Pedicle Screws and an Iliac Rod
Kai-Uwe Lewandrowski, Donald L. Wise, Debra J. Trantolo, Michael J. Yaszemski, Augustus A. White in Advances in Spinal Fusion, 2003
The vertebral preparations were biomechanically, nondestructively tested for the range of motion (ROM) of the fused segment L4/5 and the neighboring nonfused segments L3/4 and L5/6 (Fig. 11). They were then examined to calculate the stiffness (Nm/°) of the individual vertebral motor segment in flexion and extension, lateral bending, and rotation. There was comparatively little movement in the fused versus the nonfused segments in all groups, resulting in higher stiffness values. In all six degrees of freedom, the autograft and the BMP samples did not differ significantly. The Kruskal-Wallis statistical analysis of stiffness of the nonfused segments did not result in any considerable differences between the test groups. DISCUSSION
Quality Assurance of Treatment Delivery
W. P. M. Mayles, A. E. Nahum, J.-C. Rosenwald in Handbook of Radiotherapy Physics, 2021
The standard table-tops of radiotherapy machines can be shifted (i.e. translated) along the three spatial directions: longitudinal, lateral and vertical. If motorised, this can be controlled from outside the room. Sometimes, couch rotation is also possible (e.g. isocentric), but it is designed to facilitate non-coplanar techniques and it is not useful for adjusting the patient position. Therefore, the re-alignment of a patient is traditionally performed by the technologists on the basis of the table shifts, but occasionally they have to lift and rotate the patient's body more or less empirically to improve the consistency of the setup (see also Section 48.2.2). When masks or cradles are used, they can be indexed to the table, i.e. have a fixed position defined during planning and reproduced for treatment. In this case, although some slight movements may still be possible, moving the patient relative to the table is impractical. On modern equipment, an integrated or additional table-top may be designed to offer six degrees of freedom (three translations and three rotations) and to control these movements from outside the room (Linthout et al. 2007; Meyer et al. 2007; Wilbert et al. 2010). Such solutions, based on robotics, are largely inherited from the pioneering developments of proton therapy (Devicienti et al. 2010) and are particularly well adapted to stereotactic treatments and radiosurgery. With the most sophisticated systems, the translations and/or rotations calculated from the registration algorithms can be converted into movements applied to the patient support system.
Physiology of Equilibrium
John C Watkinson, Raymond W Clarke, Christopher P Aldren, Doris-Eva Bamiou, Raymond W Clarke, Richard M Irving, Haytham Kubba, Shakeel R Saeed in Paediatrics, The Ear, Skull Base, 2018
Every motion in space can be broken down into three rotational degrees of freedom (yaw, pitch and roll) and three translational degrees of freedom (left–right, up–down, fore–aft). No event in one degree of freedom can be described by the others, hence every movement is uniquely and appropriately described by a combination of all six degrees of freedom. The anatomical design of the motion sensors in the peripheral vestibular system in the inner ear reflects these six degrees of freedom. The semicircular canals (SCCs) measure predominantly rotations whereas the maculae of the utricle and saccule detect mainly translations.
Modeling and simulation of musculoskeletal system of human lower limb based on tensegrity structure
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2019
Zhanxi Wang, Chaoran Yang, Kang Feng, Xiansheng Qin
The human lower limb system designed in this paper is composed of seven parts (including trunk, two thighs, two calves, and two feet), which are confined in a sagittal plane. The system has six degrees of freedom (Hardin et al. 2004). Park’s relevant research (Park 2008) shows that arm swing in sagittal plane will only have a slight impact on human gait, so the two-dimensional lower limb system is suitable for studying human gait characteristics and muscle tension control system simulation. In this paper, the human lower limb system is modeled in MATLAB. The human body data used in modeling process are Chinese adult human body size data provided by GB-10000-88. The specific parameters of model are shown in Table 1, which are average values of 26–35 years old adult males with height of 1775 mm and weight of 70 kg.
Review of the role of robotic surgery in male infertility
Published in Arab Journal of Urology, 2018
Mohamed Etafy, Ahmet Gudeloglu, Jamin V. Brahmbhatt, Sijo J. Parekattil
The da Vinci surgical system is currently the only commercially available USA Food and Drug Administration (FDA) approved robotic platform. Today all types of microsurgical procedures for male infertility can be performed using this robotic platform [3]. The latest version of the da Vinci robot features a high-resolution three-dimensional (3D) view (with up-to × 10–15 magnification) and three robotic instrument arms. These instruments are capable of six degrees-of-freedom, thus mimicking the surgeon’s hand, wrist and finger movements with 180° articulation and 540° rotation. It enhances the ability of the surgeon to rotate instruments to a wider range than the human hand and provides a new capability in microsurgery. The robotic instrument arms also eliminate physiological tremors and provide motion scaling. The surgeon console provides a comfortable, ergonomic interphase to minimise surgeon fatigue. Having an extra third robotic instrument arm also allows the surgeon to control one additional instrument and be less reliant on the surgical bedside assistant. This extra arm can also hold adjunctive imaging or sensing tools, e.g. a Doppler ultrasonography (US) probe and provide additional real-time inputs to aid the surgeon [4].
Propagation of registration errors into the change in maximum total point motion for determining stability of tibial baseplates
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2021
Abigail E. Niesen, Maury L. Hull
To quantify the bias and precision in ΔMTPM for stable baseplates, migration defined as the movement which occurs between a time zero reference exam and a single follow-up time point (e.g. 1 year) must be computed. Since migration can only be determined in the presence of random error due to registration in the clinical setting (thus making it apparent migration rather than true migration), a simulation which propagates the random error due to registration in six degrees of freedom under different cases of true displacement and true rotation is necessary to determine the impact of registration error on ΔMTPM. An important input to the simulation is the registration error in six degrees of freedom, which can be identified from double examinations. Double examinations involve acquiring two independent pairs of images at the same follow-up exam and can be used to compute either registration error (also termed measurement error) or repeatability (Ranstam et al. 1999). A single publication which computed the registration errors using marker-based and model-based RSA was selected to provide inputs for the random errors in six degrees of freedom (van Hamersveld et al. 2019). Since the registration errors for marker-based RSA differ from those for model-based RSA, the methods described below were first applied for marker-based RSA followed by model-based RSA.
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