The Locker showed a significant stabilizing effect on the spinal motion segment both in the intact and destabilized spine without any significant effect on adjacent segments. It also decreased the pressures of the posterior anulus and central nucleus significantly. However, in the destabilized spine, it showed no stabilizing effect in axial rotation. This biomechanical property should be considered in clinical application.

Mechanical shockwave therapy devices have been in clinical use for almost 40 years. While most often used to treat back pain, our understanding of their biomechanical performance is very limited. From biomechanical studies we know that biological tissue is viscoelastic and preferably excited around its resonance frequency. Targeting these frequencies has been the focus in extracorporeal shock wave lithotripsy, but these concepts are relatively new in orthopedic and rehabilitation therapies. The exact mechanism by which shockwave therapy acts is not known. Knowledge of the performance characteristics of these devices, correlated with clinical outcome studies, may lead to better patient selection, improvement of device functionality, and knowledge of the underlying working principals of therapy. The objectives of this study were to determine the ability of several commercial shockwave devices to achieve a desired thrust profile in a benchtop setting, determine the thrust profile in a clinical analog, and determine the influence of operator experience level on device performance. We conducted two different types of testing: (1) bench testing to evaluate the devices themselves, and (2) clinical equivalent testing to determine the influence of the operator. The results indicated a significant dependence of thrust output on the compliance of the test media. The Activator V-E device matched the ideal half-sine thrust profile to 94%, followed by the Impulse device (84%), the Activator IV/FS (74%), and the Activator II (48%). While most devices deviated from the ideal profile on the return path, the Impulse device exhibited a secondary peak. Moreover, the Activator V-E device provided evidence that the device performs consistently despite operator experience level. This has been a major concern in manual spinal manipulation. Based on our results, a hyper-flexible spine would receive a lower peak thrust force than a hypo-flexible spine at the same power setting. Furthermore, a hand-held operation further reduced the peak thrust force as it increased the system compliance. However, that influence was dissimilar for the different devices. Although controlled clinical trials are needed to determine the correlation between thrust profile and clinical outcome, already ongoing clinical studies indicate an improved patient satisfaction due to reduced treatment pain when devices are used with a thrust characteristic closer to an ideal sine wave.

Voiding dysfunction is a common disease that contributes to a lower quality of life and has an increased prevalence in the elderly population. Noninvasive and objective methods such as uroflowmetry (UFM) and voiding diaries (VDs) are essential for exact diagnosis and effective treatment of this condition because patients with different causes of voiding dysfunction can complain of the same lower urinary tract symptoms. Further, different treatment options can be determined based on the diagnosis made from these symptoms. In order to improve the quality of UFM and VDs and to provide a convenient testing environment, several advances have been made by previous investigators. In this study, we investigate the history and technological mechanisms of UFM and VDs. We also aim to review UFM from the viewpoint of clinical and at-home uses, including the recently proposed toilet-shaped UFM and electronic VDs.

This poper describes research pe$onned at the BioRobotics lab ai Stanford Universify on the development of a visio-haptic workstation for surgical simulation. This study focuses on the design trodeoffs and choices that must be mode to successfilly combine 3 0 stereo with haptic feedback lo enoble immersive interaction with simulated surgicol environments. Specifically, the study concentrates on building a matrix for evaluating 3 0 stereo haptic workstations. This research attempts to make quantitative comparisons by using Fitts ' Law and positioning test.This paper demonstrates that these methods are applicoble to /he evaluation of visio-hoptic worksrations and suggests directions far future research.