Developing a novel force forecasting technique for early prediction of critical events in robotics

Model-free control for autonomous prevention of adverse events in robotics

Introduction: Preventive control is a critical feature in autonomous technology to ensure safe system operations. One application where safety is most important is robot-assisted needle interventions. During incisions into a tissue, adverse events such as mechanical buckling of the needle shaft and tissue displacements can occur on encounter with stiff membranes causing potential damage to the organ. Methods: To prevent these events before they occur, we propose a new control subroutine that autonomously chooses a) a reactive mechanism to stop the insertion procedure when a needle buckling or a severe tissue displacement event is predicted and b) an adaptive mechanism to continue the insertion procedure through needle steering control when a mild tissue displacement is detected. The subroutine is developed using a model-free control technique due to the nonlinearities of the unknown needle-tissue dynamics. First, an improved version of the model-free adaptive control (IMFAC) is developed by computing a fast time-varying partial pseudo derivative analytically from the dynamic linearization equation to enhance output convergence and robustness against external disturbances. Results and Discussion: Comparing IMFAC and MFAC algorithms on simulated nonlinear systems in MATLAB, IMFAC shows 20% faster output convergence against arbitrary disturbances. Next, IMFAC is integrated with event prediction algorithms from prior work to prevent adverse events during needle insertions in real time. Needle insertions in gelatin tissues with known environments show successful prevention of needle buckling and tissue displacement events. Needle insertions in biological tissues with unknown environments are performed using live fluoroscopic imaging as ground truth to verify timely prevention of adverse events. Finally, statistical ANOVA analysis on all insertion data shows the robustness of the prevention algorithm to various needles and tissue environments. Overall, the success rate of preventing adverse events in needle insertions through adaptive and reactive control was 95%, which is important toward achieving safety in robotic needle interventions.

Communicative health literacy in patients with non-communicable diseases in Ethiopia: a cross-sectional study

BACKGROUND

Health literacy plays a prominent role in empowering individuals for prevention as well as management of non-communicable diseases (NCDs). However, there is paucity of information on the health literacy of patients with non-communicable diseases in Ethiopia. Therefore, this study aimed to assess communicative health literacy and associated factors in patients with NCDs on follow-up at Jimma Medical Center (JMC), Ethiopia.

METHODS

A cross-sectional study was conducted from 4 May 2020 to 4 July 2020 with 408 randomly selected adult patients, attending outpatient department of JMC in Ethiopia. The final sample size was obtained by using single population proportion formula. All patients with NCDs who were on follow-up at chronic illness clinic, JMC, were used as a source population. All eligible patients with NCDs who fulfilled the inclusion criteria were included in this study. A simple random sampling technique was used to recruit study participants. Data were collected through structured interviewer administered questionnaires on the six of nine health literacy domains using Health Literacy Questionnaire (HLQ) containing 30 items, socio-demographic and socio-economic characteristics, disease-related factors, and health information sources. Multivariable logistic regression was executed to determine the associations.

RESULT

Descriptive analysis shows more than half of the respondents in four of the six health literacy domains had high communicative health literacy level (CHLL). The proportion of people with high CHLL across each of the domains was as follows: health care provider support (56.1%), social support for health (53.7%), active engagement with a healthcare provider (56.1%), and navigating healthcare system (53.4%). We found educational status was significantly associated with five of six health literacy domains whereas number of sources was associated with four of six health literacy domains.

CONCLUSION

The overall findings of the current study indicate that health literacy levels vary according to socio-demographic and disease characteristics of patients. Thus, healthcare professionals should assess patients' health literacy level and tailor information and support to the health literacy skills and personal context of their patients.