INTRODUCTION

Mobility is an extremely important factor of an individual’s physical and mental health. In aging populations, mobility can both predict quality of life and health outcomes [1]. Individuals with a lack of mobility have an increased risk of fall, more difficulty accessing healthcare providers, and increased psychological stress amongst several other negative health outcomes [1]. They must rely on others for assistance for activities such as transferring from bed to wheelchair and wheelchair to bed. These activities put both the patient and the caregiver at risk for further injury. Transfers are both physically and emotionally stressful for patients with limited mobility, and the lack of independence and increased physical demand can cause resistance towards transfer activities [2].

Many assistive technologies are currently on the market with mechanical assists being the most common for patients requiring maximum assistance. Mechanical assists such as ceiling lifts and floor lifts are a common solution but are very difficult to install and implement in home care settings [3]. Mechanical lifts require patient handling in order to position the sling under the patient which can be both difficult for the caregiver and uncomfortable for the patient. They also require the patient to be suspended in the air which can increase patient stress. Although mechanical transfer devices are shown to improve patients’ feelings of safety and security [4] they still do not completely solve the issues involved with patient transfer. 

The AgileLife Patient Transfer System developed by Next Health is a new transfer technology that requires no manual lifting or manual repositioning. The system uses a series of actuators and a conveyor to seamlessly transfer the user from bed to chair and vice versa at the push of a button. The purpose of this study is to examine user perceptions of the AgileLife Patient Transfer System. Specifically, satisfaction with transfer method, perceived physical and mental demand, perceived safety, and psychosocial impacts of the device were assessed. Findings from the study will determine if using the AgileLife PTS improves quality of life and user satisfaction with the transfer process.

METHODS

This study was approved by the University of Pittsburgh Institutional Review Board. Four participants were recruited for this study. All participants signed informed consent forms, and participants received a signed physician’s release before the study began. Inclusion criteria for subjects were defined as: 1) Has difficulty getting into and out of bed 2) Between 18 and 80 years old 3) Able to tolerate sitting upright in a wheelchair for at least 1 hour 4) Weighs less than 350 pounds and able to fit within the dimensions of the PTS wheelchair frame and 5) Does not require specialized postural supports.

Subjects

Participant A is a 39-year-old female weighing 262 pounds who underwent thoracic-lumbar surgery due to chronic low back pain. She has been a power wheelchair user for three years and reports nine hours of use per day, an average of nine transfers per day, and no falls during transfers. She is capable of ambulating over short distances and can use a standing pivot to transfer on level surfaces. She transfers into bed via a manual lift from her son.

Participant B is an 83-year-old male weighing 170 pounds who has had multiple strokes. He has been a manual wheelchair user for three years and reports four hours of wheelchair use per day, four to five transfers per day, and no falls during transfers. His current method of transfer is a standing-pivot transfer with a walker and with physical assistance from his wife.

Participant C is a 50-year-old female weighing 150 pounds who has arthritis and had a cervical spinal fusion performed. In addition to using a walker, she has been a power wheelchair user for 17 years. She reports 8 hours of wheelchair use per day, 5 transfers per day, and no falls during transfer. Her current transfer method is a standing pivot using the walker with some physical assistance from a caregiver.

Participant D is a 55-year-old year old male who was diagnosed with multiple sclerosis in 1993. He uses a cane, walker, and both a manual and power wheelchair. He has been a wheelchair user for 9 months, and he reports 1.5 hours of wheelchair use per day, 4-5 transfers per day, and no falls during transfer. His current transfer method is a manual lift from his wife.

Description of AgileLife Patient Transfer System

The AgileLife Patient Transfer System (PTS), shown in Figure 1, is composed of a hospital bed with a wheelchair docking station and a wheelchair. In addition to transfers to bed and to wheelchair, the bed also gives the patient and caregiver the ability to adjust bed height, head and foot position, and sheet position. To initiate a wheelchair to bed transfer, the caregiver brings the patient to the docking station at the foot of the bed, latching the chair into the docking station. The caregiver then holds down the “Transfer to bed” button on the primary user interface (PUI). The docking station pulls the wheelchair closer to the bed and the mattress rises to meet the back of the chair. When in position the system prompts the caregiver to manually lower the back of the chair and the mattress acts as the chair back. The seat of the wheelchair rotates backward as the bed begins to lower and the conveyer starts to gently pull the patient onto the bed. The system stops when it senses that the feet are past the foot of the bed. To transfer the patient from the bed to the chair the caregiver removes all blankets from the bed and holds the “Transfer to chair” button. The process proceeds in reverse with the system pausing to prompt the caregiver to raise the wheelchair back. The process can be paused at any time by simply releasing hold of the button on the PUI. Transfers require no lifting and can be completed in 90 seconds. 

Protocol

This study was set up as a single subject research study with a three-week baseline period and a six-week intervention period. The baseline period involved the participant using only the bed component with no transfer functions to ensure that all reported differences were due to the new transfer functions and not the introduction of a new bed. After three weeks the docking station and wheelchair component were installed. Participants and their caregivers were trained on the transfer functions of the PTS.

Questionnaires were given to the subjects at the beginning of the baseline period and at the end of the intervention period. The questionnaires consisted of a demographics survey and a transfer assessment survey asking about their current transfer habits. At the end of the intervention period, a Patient Transfer System Evaluation and the Psychosocial Impact of Assistive Devices Questionnaire (PIADS) were administered. The PTS evaluation used a 10 cm visual analog scale and asked the user three questions. The subject was asked to mark on the line to indicate their response. The first question asked users to indicate the amount of mental demand, physical demand, and feelings of safety when preparing for a transfer and when transferring from bed to wheelchair with 0 indicating ‘very low” and 10 indicating “very high”. The second question asked how the PTS compares to previously used transfer methods based on a series of metrics with 0 indicating “better” and 10 indicating “worse”. Finally, the third question asked how likely the user is to recommend the PTS to others with 0 being “not likely” and 10 being “very likely”. The PIADS is a measure of the impact of an assistive device on several aspects related to wellbeing and is broken up into 3 subscales that measure competence, adaptability, and self-esteem. Individuals score each category from -3 to 3, with -3 indicating maximum negative impact and 3 indicating maximum positive impact.

Data Analysis

Questionnaires were scored according to the instructions of the specific questionnaires. Baseline and post intervention scores were compared for differences.

RESULTS

Table 1 shows key results from the pre-intervention transfer evaluation and the post-intervention PTS evaluation in regard to preparing for and performing a transfer from bed to wheelchair.  Individual scores as well as group averages (±standard deviation) are reported.

Table 1. User evaluation of preparing for and performing transfer before and after PTS intervention

	Preparing for a transfer
	Mental Demand		Physical Demand		Safety
	Pre	Post	Pre	Post	Pre	Post
Participant A	10	0	10	0	5	10
Participant B	0	0	2.5	0	7.7	5
Participant C	0	0	2.3	0	10	10
Participant D	7.9	2.4	10	3.4	5	10
Average	4.5 (5.2)	0.6 (1.2)	6.2 (4.4)	0.8 (1.7)	6.9 (2.4)	8.7 (2.5)
	Transferring from bed to wheelchair
Participant A	10	10	10	10	5	10
Participant B	1.5	0	5	0	10	5
Participant C	0	0	0	0	10	10
Participant D	5	0.2	10	0.4	7.59	9.6
Average	4.1 (4.4)	3.8 (4.8)	6.3 (4.8)	0.5 (1.1)	8.1 (2.4)	8.8 (2.5)

Table 2 shows the participant’s comparison of the AgileLife PTS to other transfer assist devices and how likely the user was to recommend the PTS to another individual who would be appropriate for the technology.

Table 2. User evaluation of PTS

	Comparison of transfers with PTS to other transfer assist devices				How likely to recommend?
	Safety	Comfort	Ease of Operation	Overall Functionality
Participant A	5	10	10	10	10
Participant B	5	7.67	5	5	7.75
Participant C	10	10	10	10	10
Participant D	9.7	9.7	6.9	4.2	10
Average	7.4 (2.8)	9.4 (2.8	8.0 (2.5)	7.3 (3.1)	9.4 (1.1)

Table 3 shows the results from PIADS. Scores for each item within the subscales were averaged and reported. The mean score is an average of the subscale scores for each individual.

Table 3. Psychosocial Impact of Assistive Devices

Subject	Competence	Adaptability	Self-Esteem	Mean Score
Participant A	2	3	2.63	2.42
Participant B	0.17	-1.83	0.25	-0.27
Participant C	2.25	3	2.63	2.54
Participant D	1.75	2.67	1.5	1.88

DISCUSSION

While each participant’s experience with the AgileLife PTS varied, the majority of participants reported positive outcomes after routine use of the PTS. Participant A reported large improvements in physical burden, mental burden, and safety when preparing for a transfer. However, when preforming a transfer, she still reported high levels of physical and mental burden. A potential explanation is adjustment to new technology. While getting used to a new form of assistive technology, an individual may experience higher perceived mental and physical demand. Despite reporting high levels of mental and physical demand when transferring, Participant A rated the comfort, ease of operation, and overall functionality as much better than her previous method of transfer, reporting that she was highly likely to recommend the PTS to others. She also reported increases in competence, adaptability, and self-esteem as a result of routine PTS use.

Participant B reported having difficulty adjusting to the new technology when compared to using his previous transfer method. Although he reported small decreases in mental and physical burden when performing a transfer, he reported feeling less safe. When adjusting to new forms of assistive technology, it is possible that individuals may feel less safe, as transfers are a habitual activity for many wheelchair users. This is consistent with the PIADS scores reported by Participant B, who reported a decrease in adaptability. Despite his concerns about the new technology, Participant B still rated the PTS as equal to or better than his previous transfer method in terms of safety, comfort, ease of operation, and overall functionality.

Participant C did not report many changes in physical burden, mental burden, or safety after PTS use. This may be because she did not feel highly burdened prior to the intervention.  Participant C reported a slight decrease in physical demand when preparing for a transfer, which may be due to the automated repositioning functions associated with the PTS. Participant C rated the PTS very highly in terms of comfort, safety, ease of operation, and functionality in comparison to her previous transfer method. She also reported psychosocial improvements after PTS use, reporting improvements in confidence, adaptability, and self-esteem.

Participant D reported large decreases in physical and mental demand and large increases in safety. Participant D was a new wheelchair user, reporting only 9 months of wheelchair use prior to enrollment in the study. This may be a potential explanation for why Participant D saw more dramatic improvements when compared to other participants, as he was not as acclimated to his previous transfer method. Participant D also gave PTS favorable ratings in most categories when compared to prior transfer methods with the exception of overall functionality. His prior method of transfer was a manual lift, which can be performed quicker than a transfer using the PTS. In spite of this, Participant D reported improvements in adaptability, competence, and self-esteem after routine PTS use.

Overall, participants gave the AgileLife PTS high ratings when compared to other transfer methods. Despite individual drawbacks, all participants reported that they were likely to recommend the PTS to an individual appropriate for the technology. It is possible that participants scored the PTS lower than their previous transfer methods but were still likely to recommend it because they felt that although the PTS was not the right technology for them, it could be beneficial for others who have different mobility needs.

Limitations and Future work

Participants in this study had a previous transfer method that they were accustomed to using.  While the PTS may have lowered the required physical and mental demand, it may not have been to a degree that made them prefer it over their previous method. Individuals with more limited mobility and more difficult transfer methods may find the PTS more favorable. Additional education of participants, specifically regarding safety issues associated with manual lifting, may also lead to more consistent and positive feelings about the PTS.

CONCLUSION

In conclusion, the AgileLife Patient Transfer System resulted in positive psychosocial impacts for most participants. All participants in this study reported that they would be likely to recommend the AgileLife PTS to others, indicating a promising future for the technology. An analysis of more individuals who need transfer assistance would shed more light on the impacts of the AgileLife Patient Transfer System.