Extrinsic Calibration for a Modular 3D Scanning Quality Validation Platform with a 3D Checkerboard.

Optical 3D scanning applications are increasingly used in various medical fields. Setups involving multiple adjustable systems require repeated extrinsic calibration between patients. Existing calibration solutions are either not applicable to the medical field or require a time-consuming process with multiple captures and target poses. Here, we present an application with a 3D checkerboard (3Dcb) for extrinsic calibration with a single capture. The 3Dcb application can register captures with a reference to validate measurement quality. Furthermore, it can register captures from camera pairs for point-cloud stitching of static and dynamic scenes. Registering static captures from TIDA-00254 to its reference from a Photoneo MotionCam-3D resulted in an error (root mean square error ± standard deviation) of 0.02 mm ± 2.9 mm. Registering a pair of Photoneo MotionCam-3D cameras for dynamic captures resulted in an error of 2.2 mm ± 1.4 mm. These results show that our 3Dcb implementation provides registration for static and dynamic captures that is sufficiently accurate for clinical use. The implementation is also robust and can be used with cameras with comparatively low accuracy. In addition, we provide an extended overview of extrinsic calibration approaches and the application's code for completeness and service to fellow researchers.

Minimal Required Resolution to Capture the 3D Shape of the Human Back-A Practical Approach.

Adolescent idiopathic scoliosis (AIS) is a prevalent musculoskeletal disorder that causes abnormal spinal deformities. The early screening of children and adolescents is crucial to identify and prevent the further progression of AIS. In clinical examinations, scoliometers are often used to noninvasively estimate the primary Cobb angle, and optical 3D scanning systems have also emerged as alternative noninvasive approaches for this purpose. The recent advances in low-cost 3D scanners have led to their use in several studies to estimate the primary Cobb angle or even internal spinal alignment. However, none of these studies demonstrate whether such a low-cost scanner satisfies the minimal requirements for capturing the relevant deformities of the human back. To practically quantify the minimal required spatial resolution and camera resolution to capture the geometry and shape of the deformities of the human back, we used multiple 3D scanning methodologies and systems. The results from an evaluation of 30 captures of AIS patients and 76 captures of healthy subjects showed that the minimal required spatial resolution is between 2 mm and 5 mm, depending on the chosen error tolerance. Therefore, a minimal camera resolution of 640 × 480 pixels is recommended for use in future studies.

Automatic Vertebrae Localization and Spine Centerline Extraction in Radiographs of Patients with Adolescent Idiopathic Scoliosis.

Adolescent Idiopathic Scoliosis (AIS) is lifetime disorder indicated by the abnormal spinal curvature, and it is usually detected in children and adolescents. Traditional radiographic assessment of scoliosis is time-consuming and unreliable due to high variability in images and manual interpretation. Vertebrae localization and centerline extraction from a biplanar X-ray is essential for pathological diagnosis, treatment planning, and decision making. The aim of this paper is to develop a fully automated framework to provide correct evaluation of anatomical landmarks and to extract vertebral and intervertebral discs' centroids. By knowing coordinates of each centroid, developed framework will estimate 2D deformity curve (centerline) called Middle Spinal Alignment (MSA) in frontal plane. By analyzing the MSA lines and deformity segments, many deformity parameters can be calculated which include vertebral transpositions, Cobb angles, apex vertebra position, etc., for planning spinal correction strategies and monitoring.

An ontology-based module of the information system ScolioMedIS for 3D digital diagnosis of adolescent scoliosis.

BACKGROUND AND OBJECTIVE: Conventional information systems are built on top of a relational database. The main weakness of these systems is impossibility to define stable data schema ahead when the knowledge of the system is evolving and dynamic. The widely accepted alternatives to relational databases are ontologies that can be used for designing information systems. Many research papers describe various methods for improving reliability and precision in generating the type of the Lenke classification based on the image processing techniques or a computer program, but all of them require radiograph images. The main objective of this paper is to demonstrate the development of an ontology-based module of the information system ScolioMedIS for adolescent idiopathic scoliosis (AIS) diagnosis and monitoring, which uses optical 3D methods to determine the Lenke classification of AIS and to avoid harmful effects of traditional radiation diagnosis. METHODS: For creating an ontology-based module of the ScolioMedIS we used the following steps: specification, conceptualization, formalization and implementation. In the specification and conceptualization phase we performed data collection and analysis to define domain, concepts and relationships for ontology design. In the formalization and implementation stage we developed the OBR-Scolio ontology and the ontology-based module of the ScolioMedIS. The module employs the Protégé-OWL API, as a collection of Java interfaces for the OBR-Scolio ontology, which enables the creating, deleting, and editing of the basic elements of the OBR-Scolio ontology, as well as the querying of the ontology. RESULTS: The ontology-based module of ScolioMedIS is tested on the datasets of 20 female and 15 male patients with AIS between the ages of 11 and 18, to categorize spinal curvatures and to automatically generate statistical indicators about the frequency of the basic spinal curvatures, degree of progression or regression of deformity and statistical indicators about curvature characteristics according to the Lenke classification system and Lenke scoliosis types. Results are then compared with analysis of the Lenke classification of 315 observed patients, performed using traditional radiation techniques. CONCLUSIONS: This part of the system allows continuous monitoring of the progression/regression of spinal curvatures for each registered patient, which may provide a better management of scoliosis (diagnosis and treatment).

Towards a new protocol of scoliosis assessments and monitoring in clinical practice: A pilot study.

BACKGROUND: Although intensively investigated, the procedures for assessment and monitoring of scoliosis are still a subject of controversies. OBJECTIVE: The aim of this study was to assess validity and reliability of a number of physiotherapeutic measurements that could be used for clinical monitoring of scoliosis. METHODS: Fifteen healthy (symmetric) subjects were subjected to a set of measurements two times, by two experienced and two inexperienced physiotherapists. Intra-observer and inter-observer reliability of measurements were determined. Following measurements were performed: body height and weight, chest girth in inspirium and expirium, the length of legs, the spine translation, the lateral pelvic tilt, the equality of the shoulders, position of scapulas, the equality of stature triangles, the rib hump, the existence of m. iliopsoas contracture, Fröhner index, the size of lumbar lordosis and the angle of trunk rotation. RESULTS: Intraclass correlation coefficient was high (> 0.8) for majority of measurements when experienced physiotherapists performed them, while inexperienced physiotherapists performed precisely only basic, easy measurements. CONCLUSIONS: We showed in this pilot study on healthy subjects, that majority of basic physiotherapeutic measurements are valid and reliable when performed by specialized physiotherapist, and it can be expected that this protocol will gain high value when measurements on subjects with scoliosis are performed.

Complex regional pain syndrome type I in the upper extremity - how efficient physical therapy and rehabilitation are.

AIM: To evaluate the effects of early started combined therapy in Complex Regional Pain Syndrome-1 (CRPS-1) on the upper extremities. METHODS: The study included 36 patients in the first stadium of CRPS-1 on the upper extremities The mean age of patients was 42.6±14.6, the majority of them (26 of 36) were females. The right side of the upper extremity was affected much more then the left side. They were treated by combined therapy including analgetics, electrotherapy, magneto therapy and kinesitherapy. The average length of observation was 172.1 days (from 90 to 250 days). The average length of treatment was 91.5±42.16 days. Intensity of pain, swelling of the extremity, the change in skin coloration and cutaneous manifestations were assessed three times, at the beginning of the treatment, after 6 weeks and at the end of the treatment. RESULTS: The pain was registered in all patients at visit 1 (average pain intensity was 5.70 ±1.44 on 100 mm visual analogue scale), and it was progressively decreased during the treatment from 3.60±1.22 at the second visit to 0.34±0.68 at the third visit. Vasodilatation was registered in 30 (83.33%) patients and skin temperature asymmetries was found in 21 (58.33%) patients. The difference of size was detected in 30 (83.33%) patients at the first visit compared to four (11.11%) patients at the end of the treatment. There were six (16.66%) patients without swelling at the beginning compared to 26 (72.22%) at the end of the treatment (p less than 0.000). Complete healing was achieved in 32 patients (88.88%). CONCLUSION: The carefully chosen physical agents in combination with analgesic and non-steroidal anti-inflammatory drugs may benefit in patients with CRPS-1 on the upper extremity if the treatment starts as soon as possible.

ScolioMedIS: web-oriented information system for idiopathic scoliosis visualization and monitoring.

Adolescent idiopathic scoliosis is the most common type of abnormal curvature observed in spine and it progresses rapidly during the puberty period. The most followed clinical way of assessing the spinal deformity is subjective by measuring the characteristic angles of spinal curve from a set of radiographic images. This paper presents a web-based information system (called ScolioMedIS) based on parameterized 3D anatomical models of the spine to quantitatively assess the deformity and to minimize the amount of radiation exposure by reducing the number of radiographs required. The main components of the system are 3D parametric solid model of spine, back surfaces, relevant clinical information and scoliosis ontology. The patient-specific spine model is regenerated from the parametric model and surface data using anatomical information extracted from radiographic images. The system is designed to take inherent advantage of Web for facilitating multi-center data collection and collaborative clinical decisions. The preliminary analysis of patient data showed promising results, which involve improved documentation standard, clinical decision knowledge base record, facilitated exchange and retrieval of medical data between institutions in multi-center clinical studies, 3D visualization of spinal deformity, and permanent monitoring of treatments.