## 2 Literature Review
### Review of Current Service Robots in Medical Environments  
Mobile robots have been developed to assist in patient moving and lifting tasks that involve labor-intensive and non-ergonomic activities. The Robotic Nursing Assistant (RoNA) [9] is an early example, with two dexterous arms capable of lifting objects up to 500 pounds and is controlled directly by nurses via pressure sensors attached to the arms. Similarly, Robot for Interactive Body Assistance (RIBA) [7] uses two lifting arms equipped with tactile sensors to interact with nurses. Even though RIBA could lift a person from a wheelchair and a bed in a test, its payload is only up to 63 kg, indicating the need for improvements to lift heavier patients. The Smart Hoist [6] is an advanced patient lifter with sensors and powered wheels to reduce the physical strain of maneuvering a lifted patient. This robotic lifter maintains a manual control similar to a standard hoist but with torsion and deflection sensors integrated into the handles to easily control powered wheels for navigation. The Bed Transport Assistance Robot [25] is an extension attached to a patient bed to assist in moving patients up to 150 kg. It utilizes a handle with sensors recognizing the direction of the force applied by the nurse's hands. Several studies developed intelligent wheelchairs (IWs) with the capabilities to autonomously navigate dynamic surroundings and communicate with other systems (like elevators, service robots, and other wheelchairs). These IWs have various modes for user interaction, such as voice, manual, facial, and gesture recognition. [PERSON] et al. [10] presented a connected driverless wheelchair that supports interactions with the users, communication with the hospital information system, and safe navigation. [PERSON] et al. [11] developed a wheelchair with a robotic arm to help elderly patients and those with disabilities with the activities of daily living. Singapore-MIT Alliance for Research and Technology (SMART) [12] developed a Mobility-on-Demand (MoD) wheelchair with autonomous navigation. Delivery robots were developed to automate the transportation of materials within healthcare facilities, significantly reducing the logistical duties that typically occupy as much as 30% of nurses' time [26]. The HelpMate robot [27], developed by Transitions Research Corporation in 1994, was one of the first hospital delivery robots, utilizing ultrasonic ranging sensors and structured light to autonomously navigate hospital environments and deliver supplies and patient records between departments and nursing stations. The Pathfinder robot [28], developed for transporting medical supplies between warehouses and clinics, features a differential driving platform equipped with sensors and a shelf cabinet with a controlled lock for storing supplies. This robot utilized Simultaneous Localization and Mapping (SLAM) and Adaptive Monte-Carlo Localization (AMCL) technologies for map creation and robot localization within the map, respectively. The i-MERC [29] is a prototype mobile robot designed for transporting meals to patients in healthcare settings. It supports personalized meal ordering, food temperature maintenance, and dish return. Presently, there are several commercial delivery robots, such as TUG by Aethon [30], HOSPI by Panasonic [31], and Moxi by Diligent Robotics [14]. Notably, Moxi [14] has advanced features like a robotic arm and learning capabilities to perform diverse tasks, including delivering patient supplies and lab samples, fetching items from supply departments, distributing personal protective equipment (PPEs), etc. To minimize the risk of microorganisms in healthcare environments, mobile disinfection robots equipped with ultraviolet (UV) sterilization and hydrogen peroxide disinfection technologies have been introduced. An example from academic research [32] is a UV Sterilization Robot that uses UV-C lamps, emitting light in the 200-280 nm range.