Kinematic Design of a 6-DOF Parallel Manipulator with Decoupled Translation and Rotation

A new three-limb, six-degree-of-freedom (DOF) parallel manipulator (PM), termed a selectively actuated PM (SA-PM), is proposed. The end-effector of the manipulator can produce 3-DOF spherical motion, 3-DOF translation, 3-DOF hybrid motion, or complete 6-DOF spatial motion, depending on the types of the actuation (rotary or linear) chosen for the actuators. The manipulator architecture completely decouples translation and rotation of the end-effector for individual control. The structure synthesis of SA-PM is achieved using the line geometry. Singularity analysis shows that the SA-PM is an isotropic translation PM when all the actuators are in linear mode. Because of the decoupled motion structure, a decomposition method is applied for both the displacement analysis and dimension optimization. With the index of maximal workspace satisfying given global conditioning requirements, the geometrical parameters are optimized. As a result, the translational workspace is a cube, and the orientation workspace is nearly unlimited.

‘Stakeholders’ views of legal and advice services for people admitted to psychiatric hospital’

This paper describes a study that used a mixed method approach to elicit the views of a range of stakeholders about experiences of compulsory admission to psychiatric hospital, and the use of the Mental Health Review Tribunal (MHRT). The paper begins with an introduction to the background of the study, one that took place in Northern Ireland, a region in the UK with its own mental health legislation and policy. A review of literature is then presented. This highlights some of the disadvantages that service users and carers face when dealing with professionals during and following compulsory admission to hospital. This section concludes with an overview of literature on the MHRT in the UK. A range of methods was used to gather data from the following stakeholders: five service user and carer focus group interviews (n = 44); interviews with four lawyers experienced in Tribunal work; an interview with a legal member of the Tribunal; a survey of solicitors who identified themselves as equipped to carry out Tribunal work; interviews with three managers of organisations that provided patient advocacy services; letters to hospital managers requesting information provided to patients and carers. The findings reveal a number of themes associated with these experiences of compulsory admission to hospital and subsequent use of the Tribunal. Service users and carers generally found it difficult to access relevant information about rights, information provided by hospital managers was uneven and lawyers were often not familiar with processes associated with compulsory admission. There was a range of views about the Tribunal. Most respondents felt that the Tribunal was necessary and mostly satisfactory in the way it carried out its functions, but stakeholders raised a number of issues. Carers in particular felt that they should be more involved in decision-making processes, whereas lawyers tended to be focused on more technical, legal issues. Problems of regrading prior to the Tribunal and in examining medical evidence were highlighted by lawyers. There was an appeal for better information and advice by service users and carers, and recognition of the need for better training and education for lawyers. The paper concludes with a brief discussion about current mental health law in the UK, arguing that, in this context, professionals should more proactively use information and advice that can enable service users and carers to defend their rights. Keywords: compulsory mental health; law; legal and advice services