University of Twente Student Theses


Objective quantification of in-hospital patient mobilisation after cardiac surgery

Haaren, J.H.L. van (2020) Objective quantification of in-hospital patient mobilisation after cardiac surgery.

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Abstract:Introduction Early patient mobilisation is important to ensure fast recovery after cardiac surgery. Mobilisation can be improved using patient-specific information and exercises that match their current functional level. To achieve this, first patient mobilisation should be quantified objectively. Purpose To determine a method to quantify in-hospital mobility objectively in patients after cardiac surgery. Methods A list of device requirements was made, used to select a tri-axial accelerometer suitable for clinical research. A neural network algorithm was developed to classify accelerometer data into classes of physical activities of interest. In experimental setting, optimal dual sensor placement configuration was determined. A clinical pilot study was conducted aimed at classifying postoperative physical activity of inpatients after cardiac surgery, using one sensor attached the right upper leg and one attached to the right upper arm. To make reliable classifications, preoperative physical activity data from patients was used to train the neural network. Results The device regarded best for use in this research was the AX3 accelerometer (Axivity Ltd.). Preoperative data from 31 patients resulted in a trained algorithm with overall activity classification accuracy of 96%. Postoperative physical activity was classified in 29 patients. Patients spent most of their time lying or sitting. The amount of other forms of physical activity was low, mostly demonstrated between 8 a.m. and 11:59 a.m. No significant differences were found between male and female patients. Conclusion The method used was successful at obtaining objective quantification of inpatient mobilisation after cardiac surgery. Results suggest sufficient scope to motivate inpatients to be more (frequently) active on a daily basis. Keywords: cardiac surgery, inpatient mobilisation, objective quantification, accelerometry, Machine Learning, neural network
Item Type:Essay (Master)
Faculty:TNW: Science and Technology
Subject:44 medicine
Programme:Technical Medicine MSc (60033)
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