Blog #1

The Wheelchair Lifting Aid

Nurses and caretakers provide essential services to our community. Therefore, it is with great interest that their safety and wellbeing should be looked after likewise. In many cases, on the job, nurses can encounter potential injuries. These injuries are particularly happening when lifting patients or transporting them out of wheelchairs. As described by Konrad in "People Lifting Patterns-A reference Dataset for Practitioners", patient lifting is a routinary and basic procedure performed by caregivers. This is a task that requires physical exertion for long periods of time on a daily basis. As a result, caretakers can experience long term injuries such as musculoskeletal disorders (MSDs) or low back spinal disorders (LBDs). According to the National Institute for Occupational Safety and Health, the rate at which healthcare workers experience such injuries exceeds that of workers in construction, manufacturing, and mining. 

In addition, injuries entail high cost and as stated by Davis in "Workers' compensation costs for healthcare caregivers: Home healthcare, long-term care, and hospital nurses and nursing aides," over 5200 compensation claims from nurses and nursing aides who suffered injuries to their lower back, knee and/or shoulder over a 5-year period were obtained from the Ohio Bureau of Workers Compensation. It can also be noted that hospital nurses and nursing aides had the highest total claim costs of $5 million/year. 

Beyond Injuries and Costs

This high injury rate and its associated costs, opens the door for a potential healthcare crisis as described by Davis in "Workers' compensation costs for healthcare caregivers: Home healthcare, long-term care, and hospital nurses and nursing aides". Caretakers often turn to pain relief medication such as opioids to help alleviate the pain and continue with the job's responsibilities. However, this drug usage can place the caretakers at risk for future dependence on the medication and lead to health complications, overdose, or disabilities. 

The goal of the Wheelchair Aid 

To help minimize the caregiver's exposure to the work-related injuries previously mentioned, MSDs and LBDs, a wheelchair lifting aid can be introduced. The purpose of the wheelchair lifting aid would be to decrease the amount of work or load caregivers experience when they need to lift and/or handle patients off of wheelchairs. The following figures below demonstrate the current process which caregivers must undergo when handling patients off of wheelchairs. 

 

Image No. 1: Caregiver training. Initial position where the patient needs to move his/her weight to the front of the chair to be lifted by the caregiver. 

Image No. 2: Caregiver training. Caregiver manages to elevate his and the patient's weight to a standing position. 

Image No. 3: Caregiver training. Final position with the patient standing.

In the pictures above we can see how the caregivers help the patients stand up from the wheelchair. The main idea is to design and add to the wheelchair a device able to counteract the work done by the caregiver when lifting people off of the wheelchair. As a result, reduce the stress and lifting related injuries caregivers suffer. Also, the patients will not need to interact with the lifting device. This device is planned to be attached to the base of the wheelchair seat. The seat of the wheelchair will need to accommodate for the mechanism, so naturally a redesign must be made to the seat. 

A possible approach to a lifting mechanism can be achieved by a hydraulic set up with a foot pump as seen in image #4. The lifting mechanism is idealized to help the patient to stand up by only lifting the back side of the sitting surface in a circular way, letting the front of the sitting surface to only encounter rotational moves. To ensure the stability of the chair while the lifting process takes place, a wheel locking mechanism (front and back wheels) is going to be used before using the pump. The hydraulic set up is going to be foot operated for easier use as seen in image #5. A part connecting the end of the hydraulic and seat needs to be designed. The patient is going to be seated in a custom seat. The seat needs to be able to resist up to 300 lb which is the maximum allowable weight for a wheelchair.

Image No. 4: Foot operated lift table.

Image No. 5: Foot operated lift table.

It is to be noted that the solution proposal introduced above is one of the several approaches under consideration of team 8. Since there is still research being done on how to solve all the challenges presented by the initial problem statement. Such challenges include the selection of the type of lifting mechanism to be implemented (manual hydraulic system or an electric system). In addition stability, durability and safety of the overall system are to be accounted for as well as the design and assembly of a lifting mechanism that fits the standards (weight and dimensions) wheelchairs are subjected to. The mechanism must fit within the standardized width of 30 inches for wheelchairs, to ensure the practicality of the wheelchair.  Lastly is the validation, which will require the selection of the appropriate engineering analysis in order to obtain the necessary numerical data that proves the success or lack of success of the solution approach selected. Appropriate materials must be selected to ensure the longevity of the device, such as preventing rust and continuous loading. A stress analysis shall be conducted to see the behavior of the device under numerous loads and usages. 

References

“Caregiver Training: Assisting Someone with Getting Up from A Wheelchair - 24 Hour Home Care.” YouTube, 15 July 2015, https://youtu.be/ukmCZs61kjo. Accessed 28 Jan. 2023

Davis KG, Freeman AM, Ying J, Huth JR. Workers' compensation costs for healthcare caregivers: Home healthcare, long-term care, and hospital nurses and nursing aides. Am J Ind Med. 2021 May;64(5):369-380. doi: 10.1002/ajim.23237. Epub 2021 Feb 22. PMID: 33616226.

“Foot Operated Lift Table.” YouTube, 17 Dec. 2012, https://youtu.be/s0hVMt2FoWY. Accessed 28 Jan. 2023.

Khamaj AM, Ali AM, Alam MM. Investigating factors affecting musculoskeletal disorders: Predictive models for identifying caregivers at risk. Work. 2022;72(4):1311-1320. doi:10.3233/WOR-210309. PMID: 35723145.

Kluwak, K.; Klempous, R.; Chaczko, Z.; Rozenblit, J.W.; Kulbacki, M. People Lifting Patterns—A Reference Dataset for Practitioners. Sensors 2021, 21, 3142. https://doi.org/10.3390/s21093142   

 Texas Accessibility Design (TAS, 1999). Retrieved from: https://www.tdlr.texas.gov/ab/tas/tassection04_02_to04_09.pdf