Effect of laparoscopic handle size on surgical performance: A randomized crossover trial.

Laparoscopic instrument handles design and dimensions are crucial to determine the configuration of surgeons' hand grip and, therefore, can have a deleterious effect on overall surgical efficiency and surgeons' comfort. The aim of this study is to investigate the impact of laparoscopic handle size and hand surface area on surgical task performance. A single-blind, randomized crossover trial was carried out with 29 novice medical students. Participants performed three simulated tasks in "black box" simulators using two scissor-type handles of different sizes. Surgical performance was assessed by the number of errors and time required to complete each task. Hand anthropometric data were measured using a 3D scanner. Execution time was significantly higher when cutting and suturing tasks were performed with the smaller handle. In addition, hand surface area was positively correlated with peg transfer task time when performed with the standard handle and was correlated with cutting task time in small and standard handle groups. We also found positive correlations between execution time and the number of errors executed by larger-handed participants. Our findings indicate that laparoscopic handle size and hand area influence surgical performance, highlighting the importance of considering hand anthropometry variances in surgical instrument design.

3D Multi-Modality Medical Imaging: Combining Anatomical and Infrared Thermal Images for 3D Reconstruction.

Medical thermography provides an overview of the human body with two-dimensional (2D) information that assists the identification of temperature changes, based on the analysis of surface distribution. However, this approach lacks spatial depth information, which can be enhanced by adding multiple images or three-dimensional (3D) systems. Therefore, the methodology applied for this paper generates a 3D point cloud (from thermal infrared images), a 3D geometry model (from CT images), and the segmented inner anatomical structures. Thus, the following computational processing was employed: Structure from Motion (SfM), image registration, and alignment (affine transformation) between the 3D models obtained to combine and unify them. This paper presents the 3D reconstruction and visualization of the respective geometry of the neck/bust and inner anatomical structures (thyroid, trachea, veins, and arteries). Additionally, it shows the whole 3D thermal geometry in different anatomical sections (i.e., coronal, sagittal, and axial), allowing it to be further examined by a medical team, improving pathological assessments. The generation of 3D thermal anatomy models allows for a combined visualization, i.e., functional and anatomical images of the neck region, achieving encouraging results. These 3D models bring correlation of the inner and outer regions, which could improve biomedical applications and future diagnosis with such a methodology.

An Anatomical Thermal 3D Model in Preclinical Research: Combining CT and Thermal Images.

Even though animal trials are a controversial topic, they provide knowledge about diseases and the course of infections in a medical context. To refine the detection of abnormalities that can cause pain and stress to the animal as early as possible, new processes must be developed. Due to its noninvasive nature, thermal imaging is increasingly used for severity assessment in animal-based research. Within a multimodal approach, thermal images combined with anatomical information could be used to simulate the inner temperature profile, thereby allowing the detection of deep-seated infections. This paper presents the generation of anatomical thermal 3D models, forming the underlying multimodal model in this simulation. These models combine anatomical 3D information based on computed tomography (CT) data with a registered thermal shell measured with infrared thermography. The process of generating these models consists of data acquisition (both thermal images and CT), camera calibration, image processing methods, and structure from motion (SfM), among others. Anatomical thermal 3D models were successfully generated using three anesthetized mice. Due to the image processing improvement, the process was also realized for areas with few features, which increases the transferability of the process. The result of this multimodal registration in 3D space can be viewed and analyzed within a visualization tool. Individual CT slices can be analyzed axially, sagittally, and coronally with the corresponding superficial skin temperature distribution. This is an important and successfully implemented milestone on the way to simulating the internal temperature profile. Using this temperature profile, deep-seated infections and inflammation can be detected in order to reduce animal suffering.

Proposal of custom made wrist orthoses based on 3D modelling and 3D printing.

Accessibility to three-dimensional (3D) technologies, such as 3D scanning systems and additive manufacturing (like 3D printers), allows a variety of 3D applications. For medical applications in particular, these modalities are gaining a lot of attention enabling several opportunities for healthcare applications. The literature brings several cases applying both technologies, but none of them focus on the spreading of how this technology could benefit the health segment. This paper proposes a new methodology, which employs both 3D modelling and 3D printing for building orthoses, which could better fit the demands of different patients. Additionally, there is an opportunity for sharing expertise, as it represents a trendy in terms of the maker-movement. Therefore, as a result of the proposed approach, we present a case study based on a volunteer who needs an immobilization orthosis, which was built for exemplification of the whole process. This proposal also employs freely available 3D models and software, having a strong social impact. As a result, it enables the implementation and effective usability for a variety of built to fit solutions, hitching useful and smarter technologies for the healthcare sector.

A method for generating 3D thermal models with decoupled acquisition.

BACKGROUND AND OBJECTIVE: Both thermal imaging and 3D scanning offer convenient advantages for medical applications, namely, being contactless, non-invasive and fast. Consequently, many approaches have been proposed to combine both sensing modalities in order to acquire 3D thermal models. The predominant approach is to affix a 3D scanner and a thermal camera in the same support and calibrate them together. While this approach allows straightforward projection of thermal images over the 3D mesh, it requires their simultaneous acquisition. In this work, a method for generation of 3D thermal models that allows combination of separately acquired 3D mesh and thermal images is presented. Among the advantages of this decoupled acquisition are increased modularity of acquisition procedures and reuse of legacy equipment and data. METHODS: The proposed method is based on the projection of thermal images over a 3D mesh. Unlike previous methods, it is considered that the 3D mesh and the thermal images are acquired separately, so camera pose estimation is required to determine the correct spatial positioning from which to project the images. This is done using Structure from Motion, which requires a series of interest points correspondences between the images, for which the SIFT method was used. As thermal images of human skin are predominantly homogeneous, an intensity transformation is proposed to increase the efficacy of interest point detection and make the approach feasible. Before projection, the adequate alignment of the 3D mesh in space is determined using Particle Swarm Optimization. For validation of the method, the design and implementation of a test object is presented. It can be used to validate other methods and can be reproduced with common printed circuit board manufacturing processes. RESULTS: The proposed approach is accurate, with an average displacement error of 1.41  mm (s = 0.74  mm) with the validation test object and 4.58 mm (s = 2.12  mm) with human subjects. CONCLUSIONS: The proposed method is able to combine separately a acquired 3D mesh and thermal images into an accurate 3D thermal model. The results with human subjects suggest that the method can be successfully employed in medical applications.

Generation of 3D thermal models for dentistry applications.

There are a variety of medical imaging modalities available, although each modality focus into different aspects, for example: anatomical, physiological or geometrical information. This paper presents a new imaging modality (3D THERMO-SCAN) that combines anatomical computer tomography (CT) imaging slices, together with 2D infrared thermography images and 3D scanned shaped models of the area under study. Therefore, it is presented the 3D reconstructions involving a case study of a volunteer with bruxism. Some characteristics of bruxism are the hyperactivity of the chewing muscles, which changes the dynamics of microcirculation, also changing the correspondent skin's temperature. The emphasis is to show the corresponding structures, such as jaw/mandibular region that will produce either decrease or increase in temperature, which are related to bruxism and the associated use of an occlusal splint, respectively.

3D thermal medical image visualization tool: Integration between MRI and thermographic images.

Three-dimensional medical image reconstruction using different images modalities require registration techniques that are, in general, based on the stacking of 2D MRI/CT images slices. In this way, the integration of two different imaging modalities: anatomical (MRI/CT) and physiological information (infrared image), to generate a 3D thermal model, is a new methodology still under development. This paper presents a 3D THERMO interface that provides flexibility for the 3D visualization: it incorporates the DICOM parameters; different color scale palettes at the final 3D model; 3D visualization at different planes of sections; and a filtering option that provides better image visualization. To summarize, the 3D thermographc medical image visualization provides a realistic and precise medical tool. The merging of two different imaging modalities allows better quality and more fidelity, especially for medical applications in which the temperature changes are clinically significant.