Mar 15, 20204 min read

Transformable Patient monitoring platform

Updated: Mar 11, 2021

This is a project initiated based on real problems that Sri Lankan healthcare sector faces in daily patient care. This project introduces a novel transformable platform with a real-time monitoring system, to assist bedridden and general patients within the Sri Lankan health care sector.

Final Year Project

Motivation

During the discussions had with the medical staff at Kalubowila hospital and the National institute of Nephrology in Borella, the following problems were pointed out by the doctors.

Lack of doctors in a ward which leads into difficulties in real time monitoring of patients in critical situations.
Outdated data recording and monitoring systems used by the medical staff.
Use of inadequate patient transferring platforms.

According to the problems mentioned above, the following requirements were identified:

A convertible trolley bed .
A real time patient data visualizing system.
Implementation of an active suspension system to uplift patient comfort.

Proposed System

The proposed system is a transformable mechanical platform which can be converted into a trolley, bed and a wheel chair. The platform is embedded with a hydraulic-based low-level controller and an IOT-based patient monitoring platform.

Figure 1 : Proposed system

Mechanical Design

The initial design parameters were identified through an extensive literature study which highlights the concerns and requirements of patient handling platforms in the field of healthcare. More information was collected from medical professionals and analysed to formulate final design parameters for the transformable platform. A design tree approach was used to translate these parameters and requirements into workable technical characteristics in the product development stage.The following video is an animation of the exploded view of the transformable platform.

The design parameters were finalized after discussing with the doctors and other medical staff at Kalubowila National Hospital. The following figure showcase the finalized design parameters of the transformable platform.

Figure 2 : Finalized design parameters (a) height and base width (b) Trolley and bed mode dimensions

For the needs of bedridden and general patients, posture changing and body transferring are two typical healthcare activities. Thus, designated bed motions are designed to modify patient's postures in five different ways: trolley/bed, sitting, 30 degree angle, Trendelenburg and Reverse Trendelenburg, as illustrated in figure 3.

Figure 3 : Key clinical postures and three main modes of operation

Control system

In order to safely and correctly operate the multifunctional bed, a mechatronic control system including actuators, sensors, and a main controller is developed. The actuators are used to change the postures and the modes of the transformable platform. The sensors are used to measure the limits of clinical postures and to ensure the smooth control and safety between the transition in key clinical modes of operation. The computer is used to receive the user inputs and to make decisions based on sensor data.

Figure 4 : Control system design

A specially designed electronic circuit - combined with a hydraulic system was used to control the platform. The hydraulic system used in the prototype was donated by Dr. Ratnasiri A. Hewage from the National Nepherology Hospital in Maradana. The hydraulic simulations and circuit designs were done using FluidSIM and Proteus software.

Figure 5 : Hydraulic and electrical control logic diagrams

Monitoring System Design

The IoT based monitoring system is developed according to the following diagram. The IoT hub is attached to the safety of the transformable platform, and the sensors which collect patient data can be connected to the platform directly.

Figure 6 : IOT based patient monitoring system

Furthermore, a basic fuzzy-based patient disease prediction system was developed. This is yet to be tested clinically; more information regarding the patient monitoring features will be added after all the publications.

Fabrication

The prototype was manufactured at University of Moratuwa with the help of the workshop staff. Almost all the machining, welding and other manufacturing work was done by the three group members for more than 8 months. The sand blasting and the powder coating were the only activities that were outsourced. The following captures our journey during the manufacturing stage.

Final Prototype

The fabricated prototype is illustrated in figure 7. The prototype was in fully working conditions with the expected functionalities. This was used to test the performance of the transformable mechanical structure and the monitoring system. The conversion to the three main modes of operation and the posture changing capabilities was experimentally tested.

Figure 7 : Final Prototype

We as a group, would like to thank our supervisors and the academic staff in the University of Moratuwa's Mechanical Engineering department for guiding us during the design and development of this final year project. We are privileged to get advice from doctors who were extremely supportive. The help and support of the workshop staff was a huge reason for the success of the prototype fabrication. Last, but certainly not least special thanks goes to our parents for providing us with financial and other resources.

Awards and Publications:

1. Innovation Award : Health Innovation for tomorrow -2020 (Organized by Sri Lanka Medical Association)

2. Design and development of a multi-functional patient monitoring platform for healthcare : Journal paper - IEEE / ASME Transactions on Mechatronics (Awaiting Reviews)

3. Mobil Award for the Best Mechanical Engineering Final Year Project. ( Sponsored by McLarens Lubricants Ltd.)