Patient Anatomy

The overall delivery of inhaled drugs to the effector site can be described by a number of steps. The variability in lung deposition thus depends on a large number of in vitro and in vivo factors—e.g., device performance, handling of the device, coordination of actuation and inhalation, inhalation flow, patient anatomy, etc. Variability in the different steps will add up to an overall variability in the amount of drug reaching the lungs. 

Patient Anatomy 7.2.7 Vein Anatomy 1.2.1.1 Subclavian Vein... 

A highly variable percentage range of complications and adverse incidents demonstrates that there are certain limitations for IVC filters. But the major limitation is that there has been no single prospective study to evaluate the clinical performance of the different designs. So there is no baseline for comparison. The frequency of adverse events is influenced by many factors, such as the style of filter, design, material, site of deployment, access approach and patient anatomy, pathology, and disease state. 

Presentation of imaging data can be as simple as an X-ray slice on a light box or computer screen or as complicated as intraoperative 3D displays, projections directly onto the patient, physical models created by rapid prototyping techniques, or the navigation of surgical tools relative to the patient anatomy. 

A variety of novel image-presentafion mefhods have been proposed for example, heads-up displays, as in the works of Rolland and Fuchs [63] or Salb et al. [64], in which a semitransparent display is mounted directly onto the surgeon s head. The projection of images directly onto the patient anatomy has also been the subject of recent research examples include ceiling-mounted projection [65], in which the patient is positioned underneath the projector and the internal anatomy is displayed directly on the skin. Handheld projection has also been explored this allows hidden anatomy or targehng information to be displayed directly on the patient [66]. 

Two approaches were proposed to overcome the issues presented by standard navigations (see Figure 4.9). The first involved the use of patient-specific templates or frames [76]. Based on the principles of the stereotactic frame, this approach involved the construction of a patient-specific drill guide specific to the patient anatomy and the locations of several preimplanted attachment posts. The constructed template is mounted to the posts, and the drill constrained to the planned path. The use of these frames is currently undergoing clinical evaluation [77]. The second approach involves the use of robotics early work involved the modification of industrial robots [78] however, suitable clinical accuracy could not be achieved and methods for integration into the operating room remained unsolved. 

Although it is useful to store and handle image data in a Cartesian CS, the data stiU must be defined relative to the patient anatomy. The anatomical CS is well-defined and standardized. Anterior and posterior refer to the patient s front and back, left and right refers to the patient s left and right, and superior is toward the patient s head whereas inferior is toward the patient s feet. The image Cartesian CS can then be defined relative to anatomical direction upon which each x, y, z axis lies. For example, in the DICOM system, x runs from right to left, y increases from anterior to posterior, and 2 increases from inferior to superior. 

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