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This paper introduces the design and the optimization of a probe holder robot for tele-echography applications. To define its kinematic architecture, an approach based on motion capture of an expert's gestures during ultrasound examinations was proposed. The medical gestures analyzed consisted of ultrasound probe movements and were used to characterize the kinematic specifications of the proposed manipulator. The selected architecture was a Spherical Parallel Mechanism (SPM) with 3 degrees of freedom (DoF) and its optimal synthesis was performed using real-coded Genetic Algorithms (GA). The optimization criteria and constraints were established thanks to the collaboration of medical experts and were successively formulated and solved using mono-objective and multi-objective functions.

The neuro-endoscopy is a surgical technique that allows the neurosurgeon to maintain a visual contact while operating inside the brain of a patient. A special instrument called the neuro-endoscope is inserted in the brain until the neurosurgeon reaches his/her target. Its manipulation requires a high level of training for neurosurgeons. To enforce both quality and safety of neuro-endoscopy, we propose a robotic manipulator based on a Spherical Decoupled Mechanism. This mechanical architecture has been modified from a 5-Bar Spherical Linkages and adapted to this medical application. It is able to generate a Remote Center of Motion of 2 Degrees of Freedom. It merges the advantages of parallel mechanisms with the kinematic and control simplicity of decoupled mechanisms, while having a very simple architecture. Motion capture experiments using a brain simulation model have been performed with a team of neurosurgeons to obtain the kinematic data of the neuro-endoscope during brain exploration. Based on the identified workspace, the mechanism has been optimized using kinematic performance and architectural compactness as criteria. An optimum mechanism has been selected, showing better kinematic performances than the original 5-bar spherical linkage mechanism.

In this paper, we present study to integrate virtual fracture bone reduction simulation tool with a novel hybrid 3-DOF-RPS external fixator to relocate back bone fragments into their anatomically original position. A 3D model of fractured bone was reconstructed and manipulated using 3D design and modeling software, PhysiGuide. The virtual reduction system was applied to reduce a bilateral femoral shaft fracture type 32-A3. Measurement data from fracture reduction and fixation stages were implemented to manipulate the manipulator pose in patient's clinical case. The experimental result presents that by merging both of those techniques will give more possibilities to reduce virtual bone reduction time, improve facial and shortest healing treatment.

The objective of this article is to present the dimensional synthesis of serial and parallel spherical wrists, an important step in the design process of medical robots. This step is carried out to obtain optimal dimensions of tool-guidance medical robots. With this goal, we have first studied the specifications of two robots with different medical applications: one for tele-echography examination and one for minimally invasive surgery. Then, we have established that the medical needs expressed by the doctors were very different but the specifications in robotic terms have a lot of common points (kinematics, workspace, bulkiness). For both applications studied, robots need a mobility of three rotations around a fixed point (probe contact point on the patient’s skin or trocar incision). So, a spherical wrist architecture is adapted to their needs. An important constraint related to medical applications is that the robot must be compact in order to not obstruct or collide with its environment (medical personnel or patient). We perform dimensional synthesis allowing determination of dimensions of the mechanism for serial and parallel spherical wrists, for a tele-echography robot, and a serial wrist for a minimally invasive surgery robot. We use multi-criteria optimization methods minimizing a cost function to obtain both good kinematic performance and compactness for the architecture. The difficulty/challenge of this design process, depending of the studied applications, is the choice of efficient criteria describing the performances and the constraints of the robot. The design variables must faithfully represent the specifications of the robot so that its performance can respond to the medical requirements. We show, here, the different methods used for optimizing the chosen kinematic architecture for the particular medical application. These studies lead to prototypes which are validated after medical experiments. This process of dimensional synthesis will be applied to other medical applications with different sets of specified constraints.

This paper deals with the design process of a particular mechatronic system: a tele-echography robot. First, we describe the principle of robotized tele-echography and the prototypes already designed. Then, after having chosen the design process, we show two medical gestures analysis performed to define the required specifications of a tele-echography robot. Several kinematic synthesis allow demonstrating that the serial spherical wrist is the most adapted structure to this medical application. The kinematic performance of this structure is limited by the singularity position located at the centre of the workspace. An inclined spherical wrist structure is proposed to displace the singularity position in a less used workspace zone that the normal direction to the patients skin. In the dimensional synthesis phase, this structure is optimized. Then, a collaborative design study with designers is presented to improve aesthetic and ergonomic of the robot. This step was very interesting because it brought innovative propositions. Finally, a detailed phase allows defining the PROSIT 1 robot. It was manufactured and will be soon tested in clinical environment.

In severe fracture cases, a bone can be separated into two fragments and it is mandatory to reposition the bone fragments together. This type of surgery is called “bone reduction surgery”. Originally, the operation consisted in manipulating the bones fragments by hand in open surgery. The most advanced technique relies on robotic manipulators providing higher precision and stability. A new mechanical architecture is proposed based on a 3-RPS tripod parallel mechanism combined with a Double Triangular Planar parallel mechanism. Its kinematic and velocity models are calculated and the parasitic motion generated by the tripod mechanism is considered in the final result. The workspace it can generate is compared to the Stewart manipulator, which is a classical mechanism for the targeted application. The use of a robotic manipulator is due to be part of an entire surgical procedure involving a pre-operative simulation software dedicated to pre-planning reduction surgery, namely PhysiGuide. It is used to measure the kinematic associated with bone fragments manipulation and transfer it to the robot during the intra-operative phase. Simulations are then performed based on a real patient's fracture images showing the suitability of the present mechanism with bone reduction surgery.

Sarcopenia is the accelerated loss of skeletal muscle mass and function commonly, but not exclusively, associated with advancing age. It is observed across many species including humans in whom it can lead to decline in physical function and mobility as well as to increased risk of adverse outcomes including falls, fractures and premature mortality. Although prevalence estimates vary because sarcopenia has been defined in different ways, even using a conservative approach, the prevalence is between 5% and 10% in the general population. A life course framework has been proposed for understanding not only the occurrence of sarcopenia in later life but also influences operating at earlier life stages with potentially important implications for preventive strategies. Harnessing progress in understanding the hallmarks of ageing has been key to understanding sarcopenia pathophysiology. Considerable convergence in approaches to diagnosis of sarcopenia has occurred over the last 10 years, with a growing emphasis on the central importance of muscle strength. Resistance exercise is currently the mainstay of treatment; however, it is not suitable for all. Hence, adjunctive and alternative treatments to improve quality of life are needed. An internationally agreed approach to definition and diagnosis will enable a step change in the field and is likely to be available in the near future through the Global Leadership Initiative in Sarcopenia. In this Primer, Sayer et al. summarize current knowledge on the epidemiology of sarcopenia, and describe the mechanisms underlying this skeletal muscle disorder, as well as its diagnosis, prevention, management and impacts on quality of life.

A statically balanced mechanism is designed as a potential solution for the positioning of surgical instruments. Its kinematics with five degrees of freedom that decouples linear and angular motions is proposed for that objective. The linear motion of its end effector is provided by a classical parallelogram linkage. To enhance its adaptability, a mechanical system allows re-orienting the position mechanism in three different working modes (horizontal, upward and downward) while preserving its static balance. Based on the mechanical concept, a uniformized static balancing condition that considers all working modes is given. The orientation of the end effector is provided by a spherical decoupled mechanism. It generates a remote center of motion which is highly representative of kinematics in surgery requirements. Based on the mechanism kinematics, the evolution of its gravitational potential energy is studied. Two different mechanical concepts are then proposed to generate a compensating elastic potential energy. A CAD model of the entire mechanism has allowed the estimation of all mechanical parameters for the selection of the appropriate tension springs and for carrying out validation simulations. A prototype of the statically balanced mechanism is fabricated and successfully tested.

Background Frailty and impairment in intrinsic capacity (IC) have been shown to increase the risk of poor outcomes in older people. We aimed to determine the prevalence of frailty and its association with decline in IC among people aged 60 and over in Cameroon. Methods This cross-sectional study included community-dwellers aged ≥ 60 years. Frailty was assessed using Fried’s criteria and IC decline using step 1 of the Integrated Care for Older People (ICOPE). Any abnormality reported for one of the six IC domains was considered as a positive screening. The significance level was p  < 0.05. Results Among 108 participants included (64.8% women, median age 70 years (65–75)), all had a decline of at least one IC. The prevalence of frailty was 52.8%.The main domains involved were cognition (93.5%), vision (88%) and hearing (87%). Compared to participants without frailty, the frail group was older, achieved lower education, had fewer children, had a more frequent history of falls and a higher number of deficits in IC domains. In the multivariable model, after adjusting for age, sex and comorbidities, the participants with preserved mobility (OR 0.18, 95%CI 0.068–0.49) and vitality (OR 0.11 95%CI 0.04–0.28) were likely to have a lower risk of frailty. Conclusion Frailty and IC impairment were common in this group of older Cameroonians. Further research with the monitoring of trajectories of IC and frailty as a research outcome may allow better comparison to tailor interventions taking into account our local resources. Clinical trial number Not applicable. Significance What is already known on the topic? A growing body of evidence supports the validity of IC to assess healthy aging across various settings. Frailty and IC decline are two distinct constructs that share underlying mechanisms. What this study adds? Our results highlight the relationship between frailty and IC impairment among a group of older community-dwellers from Cameroon, a country with about 1 million older people and scarce policies on aging. This study may serve as a template for further research with the monitoring of trajectories of IC and frailty as a research outcome. This may also allow better comparison between the impacts of interventions and tailoring these interventions taking into account our local resources.

ObjectiveTo assess the level of knowledge, attitudes and practices (KAP) among patients with type 2 diabetes mellitus (T2DM) regarding cardiovascular risk factors (CVRF) and diabetes-related complications in two hospitals in the West Region of Cameroon during the COVID-19 pandemic.DesignThis was a prospective cross-sectional study conducted over 5 months from April to September 2022.SettingThis study was conducted in two tertiary hospitals in the West Region of Cameroon, in Central Africa.ParticipantsIt included all patients with T2DM receiving care at these two hospitals, having agreed to participate and followed up in both hospitals for at least 3 months.Primary and secondary outcome measuresSociodemographic, clinical and treatment data were collected using a data sheet, and KAP scores were based on the Essi and Njoya framework. Data collection and analysis were performed using SPSS V.23.0 software. Logistic regression was used to identify the factors associated with unacceptable KAP (p<0.05).ResultsA total of 140 participants (71 women) with an average age of 63 years and an average diabetes duration of 6.14±5.7 years were included. Most (55%) were managed by general practitioners. The main CVRFs identified were hypertension (11%) and overweight (6%), while the leading complications included visual disorders (10.7%), hypoglycaemia (6.4%) and erectile dysfunction (2.1%). Knowledge was good in 34.3% of participants, only 25.7% demonstrated correct attitudes, and merely 15.7% engaged in adequate practices. Unacceptable knowledge was associated with diabetes duration between 3 months and 5 years (OR: 0.34 (95% CI 0.14 to 0.85), p=0.021), follow-up by a specialist (OR: 0.31 (95% CI 0.13 to 0.74), p=0.009), the presence of at least one CVRF (OR: 0.03 (95% CI 0.00 to 0.23), p<0.001), and the presence of diabetes complications (OR: 0.26 (95% CI 0.09 to 0.78), p=0.016). No significant association was observed for unacceptable attitudes. Low economic status (OR: 3.7 (95% CI 1.55 to 8.82), p=0.003) was associated with unacceptable practices.ConclusionFew people with T2DM presented good knowledge, right attitudes and adequate practices. Enhanced patient education and increasing specialist numbers are essential to promote self-management of the condition and to decrease the incidence of complications and mortality.