Technology and Health Care - Volume 19, issue 3

Authors: Poland, Michael P. | Nugent, Chris D. | Wang, Hui | Chen, Liming

Article Type: Research Article

Abstract: Smart homes are living spaces facilitated with technology to allow individuals to remain in their own homes for longer, rather than be institutionalised. Sensors are the fundamental physical layer with any smart home, as the data they generate is used to inform decision support systems, facilitating appropriate actuator actions. Positioning of sensors is therefore a fundamental characteristic of a smart home. Contemporary smart home sensor distribution is aligned to either a) a total coverage approach; b) a human assessment approach. These methods for sensor arrangement are not data driven strategies, are unempirical and frequently irrational. This Study hypothesised that sensor …deployment directed by an optimisation method that utilises inhabitants' spatial frequency data as the search space, would produce more optimal sensor distributions vs. the current method of sensor deployment by engineers. Seven human engineers were tasked to create sensor distributions based on perceived utility for 9 deployment scenarios. A Pure Random Search (PRS) algorithm was then tasked to create matched sensor distributions. The PRS method produced superior distributions in 98.4% of test cases (n=64) against human engineer instructed deployments when the engineers had no access to the spatial frequency data, and in 92.0% of test cases (n=64) when engineers had full access to these data. These results thus confirmed the hypothesis. Show more

Keywords: Sensor optimisation, smart homes, pure random search

DOI: 10.3233/THC-2011-0611

Citation: Technology and Health Care, vol. 19, no. 3, pp. 137-160, 2011

Authors: Ruan, Zhiyong | Luo, C. | Shi, Z. | Zhang, B. | Zeng, B. | Zhang, C.

Article Type: Research Article

Abstract: Objective: The aim of the study was to demonstrate the surgical work-flow of the intraoperative 3D fluoroscopy (Acadis)-aided reduction for distal tibiofibular joint. Material and method: Ten ankle fracture patients with dislocated syndesmosis were treated. The surgical work-flow of intraoperative 3D (Acadis)-fluoroscopy-aided reduction was described. Axial imaging was measured for quality of syndesmotic reduction by measuring the distance between the fibular and the posterior and anterior facet of tibial incisura along a line perpendicular to joint space. Result: Acadis 3D scan was successfully accomplished. The syndesmosis of the healthy side was symmetrical. The asymmetry …of syndesmosis prior to transsyndesmotic fixation (D) was 3.7 mm on average (2.2–8.2 mm). The asymmetry of syndesmosis after transsyndesmotic fixation (E) was 1.7 mm on average (1.2–4.2 mm). Conclusion: Intraoperative 3D-fluoroscopy was able to detect subtle malreduction of the syndesmosis in the operative treaetment of ankle fractures. The intraoperative 3D-fluoroscopy-aided reduction for the distal tibiofibular syndesmosis is effective. Show more

DOI: 10.3233/THC-2011-0618

Citation: Technology and Health Care, vol. 19, no. 3, pp. 161-166, 2011

Authors: Citak, Mustafa | Gessmann, Jan | Fehmer, Tobias | Russe, Otto | Schildhauer, Thomas A. | Seybold, Dominik

Article Type: Research Article

Abstract: Background: The infection of a total knee arthroplasty (TKA) has remained as one of the most devastating potential complications. In this context we developed a new technique that keeps the spacer in distraction during the cementation process to achieve better weight-bearing stability. Methods: We present a case of a 75-year-old male patient, who was treated in our hospital with an infected total knee replacement (TKR) using the distraction spacer. The operative technique includes the removal of the infected prosthesis after radical debridement. Then two carbon rods were inserted overlapping 2–3 cm in the medulla of the tibia …and femur. Afterwards an external fixateur with distraction module is attached with two Schanz screws into the distal femur and the proximal tibia. The cementation process was performed under distraction. After hardening of the cement the external fixateur and the Schanz screws are then removed. Results: Postoperatively the patient was mobilized with full weight-bearing using an extension splint. The antibiotic therapy was continued for five weeks. After sterile puncture, the reimplantation was performed using a Zimmer-Rotating-Hinge-Knee without any complications. Conclusions: This method allows cement hardening without micromovements and early mobilization with partial full weight bearing and prevents the contraction of the capsule and the ligaments during the prosthesis-free period, preparing the knee for a secondary TKA or an intramedullary arthrodesis with a titanium stem. Show more

Keywords: Two-stage revision, total knee arthroplasty, infection, static knee spacer, treatment

DOI: 10.3233/THC-2011-0619

Citation: Technology and Health Care, vol. 19, no. 3, pp. 167-171, 2011

Authors: Floerkemeier, Thilo | Aljuneidi, Wasim | Reifenrath, Janin | Angrisani, Nina | Rittershaus, Dina | Gottschalk, Daniel | Besdo, Silke | Meyer-Lindenberg, Andrea | Windhagen, Henning | Thorey, Fritz

Article Type: Research Article

Abstract: A quantitative device to gain information about bone healing after fracture or distraction osteogenesis would lower the risk of refracture, malunion and pseudarthrosis. To this date, different biomechanical methods have been proposed for this task with limited application. Furthermore, none of these devices allows monitoring of physiological motion. The aim of this study was to develop a telemetric method for in vivo measurement of compressive forces during physiological motion. An innovative method was developed that can be integrated in an external fixator and that transfers the data to the computer via Bluetooth. After ex vivo validation …it was applied to rabbit tibia for assessment of consolidation after tibial osteotomy. After development of the innovative method, the technique was validated ex- and in-vivo in a rabbit model. The presented method enables a telemetric measurement of compressive forces during consolidation. It proved that during consolidation the forces decreased over time from 27.6 to 15.7 Newton. This study presents a new technique to quantify bone healing of fracture or distraction osteogenesis by determination of compressive forces. The innovative of this technique compared to existing methods is the fact that it allows monitoring forces during physiological motion. Show more

Keywords: Bone healing, consolidation, distraction osteogenesis, quantitative measurement, telemetric in vivo measurement

DOI: 10.3233/THC-2011-0620

Citation: Technology and Health Care, vol. 19, no. 3, pp. 173-183, 2011

Authors: Wassilew, Georgi I. | Janz, Viktor | Heller, Markus | Wenzl, Marcus | Perka, Carsten | Hasart, Olaf

Article Type: Research Article

Abstract: The purpose of our study was to develop a simple and reproducible method for calculating post-operative acetabular cup position based upon computed-tomographic images. Next, we sought to examine the reliability, objectivity and accuracy of this method. We developed a 3D CT evaluation software based upon Amira® (data visualisation, analysis and modelling software) to calculate the abduction and anteversion of the acetabular cup relative to the APP (anterior pelvic plane). To test the accuracy of the method, we constructed a special phantom pelvic model as the gold standard, in which the acetabulum was mounted at various abduction and …anteversion angles that had previously been measured digitally. This phantom was then CT-scanned in 12 different cup positions (30° to 50° abduction, 0° to 30° anteversion) and then evaluated using the 3D CT evaluation software. In addition, we also examined the reliability and objectivity of this method in 10 patients following implantation of a hip prosthesis, as a clinical trial. We observed an average accuracy of the 3D CT evaluation software of −0.3° (range −1.4° to 1.3°; SD 0.6°) for abduction and 0.2° (range −1.4° to 1.4°; SD 0.6°) for anteversion compared with the gold standard. Moreover, a high intra- and inter-individual agreement in the resulting ICC well above 0.8 for abduction and abduction values in the phantom study and the clinical trial were observed. This study found that the 3D CT evaluation software provides high reliability, objectivity and accuracy. Thus, the 3D CT software is a method that permits very precise evaluation of the post-operative cup position independent of patient positioning or pelvic tilt. Show more

Keywords: Acetabular cup orientation, 3D CT measurement, accuracy, phantom model

DOI: 10.3233/THC-2011-0629

Citation: Technology and Health Care, vol. 19, no. 3, pp. 185-193, 2011

Authors: Daentzer, Dorothea | Reichwald, Kathleen | Floerkemeier, Thilo

Article Type: Research Article

Abstract: Objectives: Lumbar arthrodesis is a frequently performed intervention to treat several spinal disorders like degenerative or instable conditions. According to the demographic trend, more and more elderly patients are expected to become candidates for any kind of surgical procedures including operations of the spine. In case of more complex operations like fusion a higher risk potential in older persons could be assumed. The goal of our study was to analyze the clinical results after lumbar fusion and to find out, if there are differences in the outcome and complication rate in patients divided in two age groups. …Methods: 100 patients who consecutively had lumbar arthrodesis because of degenerative or instable conditions were retrospectively studied after a minimum of 12 months with regard to their clinical outcome and the complication rate. Statistical analysis was performed to find out any significant differences in patients younger and older than 65 years. Results: In both patient groups we found neither any statistically significant difference in all clinical outcome scores except for two items of the SF-36 nor in the complication rate. Conclusion: Older age should not be the only criterion for exclusion for more extensive surgical procedures of the lumbar spine like arthrodesis. Show more

Keywords: Arthrodesis, fusion, lumbar spine, age, complication, surgery

DOI: 10.3233/THC-2011-0630

Citation: Technology and Health Care, vol. 19, no. 3, pp. 195-202, 2011

Authors: Niederer, Peter

Article Type: Editorial

DOI: 10.3233/THC-2011-0585E

Citation: Technology and Health Care, vol. 19, no. 3, pp. 203-203, 2011

Authors: Verdonck, Pascal | Dumont, Kris

Article Type: Research Article

Abstract: A fluid is a medium which deforms, or undergoes motion, continuously under the action of a shearing stress and includes liquids and gases. Applying biofluid mechanics to the cardiovascular system requires knowledge of anatomy and geometry, pressure data and blood flow, volume and velocity measurements. A good example is the assessment of the haemodynamics of biological and mechanical heart valves.

Keywords: Pressure gradient, Bernoulli, Doppler measurement, effective orifice area and performance index, heart valve, regurgitation, laminar flow, turbulent flow, Reynolds number

DOI: 10.3233/THC-2011-0623

Citation: Technology and Health Care, vol. 19, no. 3, pp. 205-215, 2011

Authors: Hazenberg, Jan G. | Schmid, Johannes | Lee, T. Clive | Verkerke, Gijsbertus J.

Article Type: Research Article

Abstract: For simple constructions a mechanical analysis to determine internal stresses and deformation is possible using theoretical formulas. However, for complex constructions, like joint prostheses, this is not possible. Numerical simulation of internal stresses and deformations offers a solution for these constructions. The so-called Finite Element Analysis divides the complex structure in simple ones (elements), applies the mechanical formulas and adds the effect on each element to predict the behaviour of the complex contruction.

Keywords: Finite Element Analysis, mechanics, differential equation, node, stiffness matrix

DOI: 10.3233/THC-2011-0624

Citation: Technology and Health Care, vol. 19, no. 3, pp. 217-222, 2011