Joseph Spano

A reconfigurable holonomic omnidirectional mobile bed with unified seating (RHOMBUS) for bedridden patients

A hybrid wheelchair/bed system for bedridden persons is developed and tested. A powered wheelchair can be docked to a bed portion and reconfigured to a flat stationary bed so that the bedridden person does not have to change seating when transferring between the chair and bed. Moreover the wheelchair can also be docked to a toilet directly and automatically. A holonomic omnidirectional vehicle with a ball wheel mechanism is used for the wheelchair. The high maneuverability and holonomic nature of the vehicle allow the chair to be docked easily and precisely against a fixture. The wheelchair is equipped with teleconferencing facility so that the bedridden patient may communicate face-to-face with a distal caregiver, friends and relatives. This paper describes the basic concept of the reconfigurable holonomic omnidirectional mobile bed with unified seating (RHOMBUS). Issues on the mechanical design of the vehicle, chair, and bed are addressed, followed by control issues. A force-guided docking control method using force sensors embedded in the bumper of the vehicle is developed. A prototype system is designed and tested.

Kinematic analysis and design of surface wave distributed actuators with application to a powered bed for bedridden patients

A surface wave distributed actuation method and its potential for transporting bedridden patients is explored. First, the basic principle of surface wave distributed actuation is presented, followed by kinematic modeling and analysis. Based on the analysis, modifications to natural wave transport are made to enhance transport efficiency and human comfort. Further kinematic analysis reveals that an object can be transferred by a simplified actuator architecture that makes the concept amenable to hardware realization. Two proof-of-concept prototypes are designed, built, and tested. The first is a powered water bed consisting of a water vat, a flexible mat placed on the water surface, and an exciter creating surface waves at resonant frequencies. The other is a powered mechanical bed having an array of coordinated active nodes that generate psuedo-continuum surface waves. Experiments demonstrate the surface wave actuation concept and verify the analytical results.

Design of surface wave active beds based on human tissue physiology

A surface wave distributed actuation method and its proper design for safely transporting bedridden patients is explored in this paper. First, the basic principle of surface wave distributed actuation is presented, including a new kinematic feature that augments natural surface wave motion for enhanced transport efficiency of humans and elastic bodies. Kinematic modeling and analysis reveals that an object can be transferred by a simplified actuator architecture that makes the concept amenable to hardware realization. A proof of concept prototype demonstrates that heavily loaded rigid objects, elastic objects and humans can be transported. Human tissue physiology is studied to establish worst-case criteria for safe and healthy interactions between the human and the support surface that depends on the duration of interaction. Static models are developed and solved using finite element methods to calculate interaction stresses for realistic, worst-case human-surface wave interaction scenarios. Based on these results a new two-mode surface is designed to secure safe interactions for both long-term support and short term transport tasks.

Surface waves for active transport of bedridden patients

Natural surface waves, created by periodic circular motion of material particles, can transfer a long object placed upon the crests of the waves in an arbitrary direction within the horizontal plane. Inspired by this natural behavior, a surface wave distributed actuation method and its potential for transporting bedridden patients is explored in this paper. First, the basic principle of surface wave distributed actuation is presented, followed by kinematic modeling and analysis. Based on the analysis, modifications to natural wave transport are made to enhance transport efficiency and human comfort. Further kinematic analysis reveals that an object can be transferred by a simplified actuator architecture that makes the concept amenable to hardware realization. Finally, design trade-offs and guidelines for developing a feasible and practical surface wave bed are discussed based on the prototyping and experiments.

Surface wave actuators for tangential transport of humans

Bedridden patients and elastic bodies are transported by generating surface waves on an active bed. Surface waves are shown to be a viable transport mechanism for large-scale, elastic bodies given certain conditions and constraints on the design. Surface wave actuation allows a bedridden patient to move freely while lying comfortably upon the bed. The motion of each node on the bed surface is coordinated such that it follows a circular trajectory with a certain phase lag from adjacent nodes. Basic properties of surface waves are presented. Based on these properties a new, concept, the extender, is added to the design to take advantage to the inherent rotational component of surface wave points. Kinematic analysis is performed to characterize the actuation concept. Sensitivity of design parameters on critical human transport issues is presented. Transport speed and efficiency are analyzed as well. A proof-of-concept prototype is designed, built and tested. It is demonstrated that a human is moved along the bed surface while lying on the bed.