Offering bodily reduction for nurses by collaborative robotics

Collaborative robotic system

The robotic system used on this examine was a teleoperated robotic answer to assist address the rising demand for high-load caregiving. From a distant location, an operator managed the extremely delicate, anthropomorphic robotic arm (KUKA LBR iiwa 7 R800) mounted on the correct aspect of the care mattress (Figs. 1 and 2) through a digital actuality (VR) interface (see Supplementary Materials, Fig. 1). The robotic’s surrounding was noticed by a multi-depth digital camera system^31,35 that streamed the three-dimensional visible information on to the operator’s VR headset (Fig. 1). This allowed the operator to take part in care acts similar to affected person switch and repositioning duties, offering collaborative assist to the contributors utilizing superior robotic tools.

Though the robotic system has already been described intimately³¹, and this part focuses on its utility and potential for bodily reduction in care, the scope of the system is printed under.

The operator wore a VR headset (HTC Vive VR System), which enabled him/her to change into immersed within the digital setting throughout the Unity^® engine by Unity Applied sciences containing the visible information of the multi-depth digital camera system. With this method the operator was in a position to management the robotic system for the collaborated guide affected person dealing with job intuitively in real-time^30,31,35 (Fig. 1). For this objective, the operator was additionally geared up with a controller and an elbow tracker^30,31 (Fig. 1). The controller was used to set the place of the robotic’s finish effector and the elbow tracker corresponded to the robotic’s elbow joint to imitate the operator’s pure arm motion. For the precise robotic motion, the operator despatched the specified robotic positions from throughout the VR setting to a different laptop utilizing the Robotic Working System (ROS) Framework. The communication between the Unity^® laptop and the ROS laptop was dealt with with the ROS#³⁷ libraries using the RosBridgeClient. From there, the place indicators had been forwarded to the robotic’s controller through the Quick Robotic Interface (FRI). The robotic’s positioning was solved from throughout the Unity^® scene with a quick memetic evolutionary inverse kinematics algorithm known as BioIK³⁸. One benefit of the developed system is that there isn’t any dependence on a selected robotic. As quickly as an interface for the place specification of the robotic on the joint degree is on the market, this robotic is appropriate for the offered VR management. Needed is the preliminary setting of the robotic illustration in Unity^®, in order that the inverse kinematics of BioIK can be utilized accurately. Additional on, the VR scene confirmed the calibrated setting of the true world by the 3D digital camera setup with a low latency of 130 ms and as much as 30 fps refresh price. The coordinate system of the perspective was adjusted in response to the participant’s head place and rotation³¹. Thus, the operator noticed the care mattress and the quasi-opposite participant (Fig. 1) and used the controller to collaboratively help through the carried out guide affected person dealing with duties, thereby shifting the affected person simulator collectively (see Supplementary Materials, Fig. 1). For this objective, the multi-depth digital camera system^31,35 generated correct three-dimensional, coloured level clouds of the scene. The Microsoft Kinect 4 Azure sensors (K4A) captured depth pictures and coloration data. Right here, the Amplitude Modulated Steady Wave (AMCW) Time-of-Flight (ToF) precept was used to report the time for the sunshine exiting the sensor, mirrored, and returned to the sensor³¹. Coloured three-dimensional level clouds had been generated by combining the depth and coloration data from the K4A’s RGB digital camera alongside camera-specific calibration parameters utilizing the Close to Area of View (NFOV) operation mode at a price of 30 Hz with a decision of 640 × 576³¹. Unity 3D was used to visualise the purpose cloud information³¹. General, 4 K4A had been used to get rid of occlusion of vital areas attributable to individuals or obstacles on the scene (e.g., nurse, affected person, robotic). The K4As had been put in across the care mattress, with the depth pictures focusing on the principle focal point at the scene. All 4 K4A had been mounted on 1.8-m excessive tripods protecting an space of roughly 2 m × 2 m.

Experimental design

The investigation was carried out within the totally built-in sensor- and actor-based AAL/Care Laboratory of the Carl von Ossietzky College of Oldenburg to allow a complete measurement-based methodology³⁴. A set of successive measurements was taken to evaluate the bodily reduction in guide affected person dealing with (Fig. 2). Three totally different guide affected person dealing with methods had been carried out to research their potential for load discount when repositioning a affected person simulator from a supine to a lateral place in a care mattress, together with (1) standard switch (non-ergonomic), (2) ergonomic switch, and (3) switch in collaboration with a robotic system (Figs. 1 and 2).

A pressure plate was used to measure the exterior floor response forces (GRF) and pressure plate moments (FPM) that occurred³⁴ (Figs. 1 and 2). Non-invasive floor electromyography (EMG) recorded {the electrical} motion potentials related to muscle contraction of the decrease limb and backbone, offering data on the activation habits of chosen muscle teams (Fig. 3). As well as, a 3D multi-depth digital camera system^31,35 was used to manage the robotic system and to allow the visible examination of the duties carried out. To regulate for expertise bias, the contributors had been launched to the setting of our laboratory³⁴ and requested to apply the affected person dealing with procedures previous to testing. As well as, the contributors got the time to familiarize themselves with the affected person simulator and the robotic system. After the familiarization course of, mattress top adjustment was carried out individually, and each the multi-depth digital camera system and pressure plate functioning had been checked and calibrated. Every job needed to be carried out on the pressure plate with the depth cameras specializing in the scene.

Transferring a affected person from a supine to a lateral place in a care mattress is assessed as a job related to the event of degenerative ailments of the lumbar backbone^39,40. Each motion and/or bodily burden affecting the human physique is transmitted through the sacroiliac joints (SIJ) to the hip joints, and eventually to the legs, and vice versa⁴¹. Therefore, excessive shear forces burden the ligaments of the SIJs. Further muscle teams are important to compensate for potential overload results because the ligamentous constructions of SIJs are unable to switch masses in an remoted and efficient manner from the lumbar backbone to the pelvis⁴¹. SIJ actions and their stabilization mechanisms are influenced by the use of lever arms of the muscular tissues of the decrease limb and the again extensors, since efficient load switch whereas stopping shearing of SIJ ligaments is achieved by compression of the joints by ergonomic guide affected person dealing with^41,42. Because of this, EMG electrodes had been positioned on the next muscular tissues to report activation habits in response to the duties carried out: vastus medialis (VM), rectus femoris (RF), biceps femoris (BF), gluteus maximus (GM), left erector spinae (ESL), and proper erector spinae (ESR) (Fig. 3). For reference functions, every participant carried out a 60-s sit-to-stand (STS) check^43,44 (see Supplementary Materials, Fig. 2).

Guide affected person dealing with

Three units of guide affected person dealing with duties had been carried out (Fig. 2). For our investigation, the Rescue Randy affected person simulator (80 kg, 180 cm)⁴⁵ was used as a substitute of an actual affected person. The contributors had been instructed to carry out all duties from the left aspect of the affected person simulator and the care mattress with out stepping off the pressure plate or supporting themselves on the mattress body. The beginning place was standing with each toes on the pressure plate going through the mattress. In the beginning of every job, the affected person simulator was already mendacity in a supine place (Fig. 1). Then, the simulator was moved sideward (“Pull”), stabilized for a second (“Maintain”), and returned (“Push”) to the supine place (Fig. 4). Every switch job was full when the contributors had returned to an upright place going through the care mattress. General, three totally different guide affected person dealing with methods had been carried out and described within the following.

Standard

Initially, guide affected person dealing with was carried out conventionally (Fig. 2). The contributors repositioned the affected person simulator with out contemplating ergonomic switch methods or biomechanical rules. Consequently, the contributors had been instructed to bend their trunk ahead to the affected person simulator, greedy underneath its proper shoulder with each palms to powerfully drag the simulator sideward, maintain it, and return it to the supine place.

Ergonomic

Subsequently, guide affected person dealing with corresponded to an ergonomically and biomechanically optimized repositioning method (Fig. 2). This system concerned the contributors endeavor a number of pre-positioning actions and preparations to begin the caregiving exercise accurately. This preliminary step concerned restricted bodily interplay between the participant and the affected person simulator. It included pulling up the affected person simulator’s knee and bending its leg in preparation for the switch job. The contributors tailored their posture by standing upright parallel to the care mattress, with their toes shoulder-width aside. The contributors then inclined their trunks to the simulated affected person and flexed their knees, shifting their our bodies to a steady place. The contributors positioned their left hand on the simulator’s pulled up knee and their proper hand underneath its proper shoulder. They had been instructed to make sure ergonomic repositioning of the affected person simulator by not utilizing their backbone muscular tissues however their leg muscular tissues. Every participant due to this fact utilized their very own physique weight and squatted with barely flexed knees (90°) whereas shifting the affected person simulator. The again and neck had been stretched, making certain that the duty was not carried out with a bent or twisted backbone. A hunchback place was to be prevented all through the duty.

Robotic

The final step concerned the switch being carried out in the identical manner as within the ergonomic job, however with the assist of the robotic system (Figs. 1 and 2). The participant initiated the switch by barely lifting the affected person simulator in order that the robotic was touching the shoulder area of the affected person simulator, aiding the participant. As soon as the robotic was involved with the affected person simulator, the participant stabilized the simulator and moved it from a supine to a lateral place within the care mattress utilizing the remotely managed robotic arm. Consequently, repositioning was carried out collaboratively. Which means, the contributors and the robotic moved the affected person simulator collectively.

Knowledge assortment and processing

Contributors

The contributors had been recruited through mailing lists from the College of Oldenburg and quite a lot of hospitals. The contributors had been knowledgeable that examine participation was voluntary, and that they may withdraw from the examine at any time. After signing their knowledgeable consent, a complete of twelve wholesome people with a nursing background had been included within the examine. The contributors additionally consented in writing to the publication of identifiable pictures. A brief questionnaire was used to gather demographic information and bodily traits. Moral approval was obtained for the examine design (moral vote: Carl von Ossietzky College of Oldenburg, Drs.EK/2019/078). The examine was carried out in accordance with the accepted pointers.

Measured information

An AMTI Accupower system (AMTI, Watertown, MA, USA), consisting of a pressure plate and a specialised {hardware} and software program system, was used to measure GRF and FPM. Knowledge was acquired at 200 Hz, displaying GRF within the X (mediolateral), Y (anteroposterior), and Z (longitudinal) route (F_X, F_Y, F_Z) and respective pressure plate moments (M_X, M_Y, M_Z) by means of piezoelectric sensors (Figs. 2 and 4). The pressure plate’s sensitivity was primarily based on 8900 N full-scale F_Z capability and a 12-bit inside analog-to-digital conversion unit³⁴.

A 6-channel EMG system from Biovision (Biovision Inputbox and Dasy-Lab 4.010 software program) and bipolar floor electrodes (GE Medical/Hellige, 14 mm diameter and 10 mm inter-electrode distance) supplied the indicators from the muscular tissues of the left decrease limb and the lumbar backbone underneath investigation (Figs. 3 and 4). Earlier than making use of the electrodes, the pores and skin was gently cleaned with water after which ready to scale back the pores and skin–electrode impedance. To this finish, the hair rising above every muscle was eliminated with a disposable shaver, abraded with positive sandpaper, and eventually cleaned with 70% alcohol⁴⁶. In accordance with SENIAM suggestions⁴⁶, the electrodes had been connected to the pores and skin with out impeding the vary of movement in any place. To validate the EMG indicators for crosstalk evaluation, low noise values, and correct acquire adjustment, numerous muscle-specific isometric contractions, and muscle palpations had been obtained after attachment. The identical skilled assessor at all times positioned the electrodes. The EMG indicators had been sampled at 1000 Hz and amplified (× 2500) utilizing native amplifiers. The indicators had been then bandpass filtered (10–700 Hz) and despatched to the enter field utilizing a 14-bit analog-to-digital conversion unit (Nationwide Devices USB-6009).

For additional evaluation, the information was synchronized by a set off sign, which concerned leaping on the pressure plate firstly and finish of every job.

Knowledge evaluation

The information collected was analyzed utilizing customized capabilities written in MATLAB (R2021a, MathWorks, Inc., Natick, MA, USA). Step one of knowledge evaluation concerned visually analyzing and elaborating the recorded biomechanical information set. After the visible examination, the guide affected person dealing with duties had been synchronized and temporally segmented. Kinematic information of the multi K4A system was solely used to visualise the postures and motion methods adopted by the contributors and relate them to the kinetic and muscle exercise information set at any time. The perspective of the recordings was adjustable, enabling the duties carried out to be displayed and analyzed from totally different angles. Word that for the guide affected person dealing with duties, solely the a part of the “Pull” shifting phases (Fig. 4) had been thought-about for evaluation.

Utilizing the pressure plate software program system, it was attainable to decide on quite a lot of check sequences. The plain forces had been of curiosity when analyzing indicators for uneven loading of the lumbar backbone in guide affected person dealing with. Because of this, the GRF measurement system was used with the Forces Solely check, and the ensuing diagrams of GRF and FPM had been used for additional evaluation. F_Z pressure plate information was normalized to every participant’s physique mass, and F_X, F_Y, F_Z had been mixed to a resultant vector, figuring out the utmost peak of each guide affected person dealing with job. On this case, we analyzed lateral flexion and torsional FPMs ensuing from bending or twisting the trunk to the aspect, together with related laterally directed GRF elements.

Muscle exercise was quantified by rectification, root imply sq. (RMS), and imply worth for each muscle and topic. To lower the inter-individual variability, EMG information was normalized to the height RMS amplitude recorded throughout STS (see Supplementary Materials, Fig. 3) individually for every muscle and every participant. Furthermore, occasional EMG baseline offsets had been corrected after visible examination utilizing an offset correction operate. EMG information was associated to corresponding kinematic and kinetic information in p.c. Consequently, time axes of collected information had been normalized to the interval of every job carried out utilizing linear interpolation and divided into respective segments, e.g., “Pull” the affected person simulator sideward in guide affected person dealing with duties (Fig. 4).

Statistical evaluation

First, we evaluated the conventional distribution of our information utilizing the Shapiro–Wilk check. For the reason that pattern dimension was small and the information set included non-normal distributed information, we used the two-sided Wilcoxon signed rank check and the Mann–Whitney check for non-parametric testing to measure vital modifications of kinetic and muscle exercise information in every of the duties carried out. We carried out inter-group and intra-group comparisons. Impact dimension (r) statistics had been supplied for each statistical assessments. A p-value < 0.05 was thought-about as statistically vital. Statistical evaluation was carried out utilizing IBM SPSS Statistics software program, model 27.0 (IBM Corp., Armonk, NY, USA). All values are reported as means and normal deviations.