Bohan Shi

Mr. Bohan Shi

orcid

Research Focus & Metrics

Academic Career Length

5Years (2022-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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5 January 2022 in IEEE Transactions on Biomedical Engineering
Verified
Journal Article
Closed access
BSBohan Shi
Bohan Shi
ATArthur Tay
Arthur Tay
WAWing Lok Au
Wing Lok Au
DTDawn M. L. Tan
Dawn M. L. Tan
NCNicole S. Y. Chia
Nicole S. Y. Chia
SYShih-Cheng Yen
Shih-Cheng Yen
Parkinson’s disease (PD) is a chronic, non-reversible neurodegenerative disorder, and freezing of gait (FOG) is one of the most disabling symptoms in PD as it is often the leading cause of falls and injuries that drastically reduces patients’ quality of life. In order to monitor continuously and objectively PD patients who suffer from FOG and enable the possibility of on-demand cueing assistance, a sensor-based FOG detection solution can help clinicians manage the disease and help patients overcome freezing episodes. Many recent studies have leveraged deep learning models to detect FOG using signals extracted from inertial measurement unit (IMU) devices. Usually, the latent features and patterns of FOG are discovered from either the time or frequency domain. In this study, we investigated the use of the time-frequency domain by applying the Continuous Wavelet Transform to signals from IMUs placed on the lower limbs of 63 PD patients who suffered from FOG. We built convolutional neural networks to detect the FOG occurrences, and employed the Bayesian Optimisation approach to obtain the hyper-parameters. The results showed that the proposed subject-independent model was able to achieve a geometric mean of 90.7% and a F1 score of 91.5%.

27 October 2023 in JMIR AI
Verified
Journal Article
Open access
BSBohan Shi
Bohan Shi
SDSatvinder Dhaliwal
Satvinder Dhaliwal
MSMarcus Soo
Marcus Soo
CCCheri Chan
Cheri Chan
JWJocelin Wong
Jocelin Wong
SASeng Bin Ang
Seng Bin Ang
Background: Diabetes mellitus is the most challenging and fastest-growing global public health concern. Approximately 10.5% of the global adult population is affected by diabetes, and almost half of them are undiagnosed. The growing at-risk population exacerbates the shortage of health resources, with an estimated 10.6% and 6.2% of adults worldwide having impaired glucose tolerance and impaired fasting glycemia, respectively. All current diabetes screening methods are invasive and opportunistic and must be conducted in a hospital or laboratory by trained professionals. At-risk participants might remain undetected for years and miss the precious time window for early intervention to prevent or delay the onset of diabetes and its complications. Objective: We aimed to develop an artificial intelligence solution to recognize elevated blood glucose levels (≥7.8 mmol/L) noninvasively and evaluate diabetic risk based on repeated measurements. Methods: This study was conducted at KK Women’s and Children’s Hospital in Singapore, and 500 participants were recruited (mean age 38.73, SD 10.61 years; mean BMI 24.4, SD 5.1 kg/m2). The blood glucose levels for most participants were measured before and after consuming 75 g of sugary drinks using both a conventional glucometer (Accu-Chek Performa) and a wrist-worn wearable. The results obtained from the glucometer were used as ground-truth measurements. We performed extensive feature engineering on photoplethysmography (PPG) sensor data and identified features that were sensitive to glucose changes. These selected features were further analyzed using an explainable artificial intelligence approach to understand their contribution to our predictions. Results: Multiple machine learning models were trained and assessed with 10-fold cross-validation, using participant demographic data and critical features extracted from PPG measurements as predictors. A support vector machine with a radial basis function kernel had the best detection performance, with an average accuracy of 84.7%, a sensitivity of 81.05%, a specificity of 88.3%, a precision of 87.51%, a geometric mean of 84.54%, and F score of 84.03%. Conclusions: Our findings suggest that PPG measurements can be used to identify participants with elevated blood glucose measurements and assist in the screening of participants for diabetes risk.

22 April 2023 in JMIR Preprints
Verified
Preprint
Open access
BSBohan Shi
Bohan Shi
SDSatvinder Dhaliwal
Satvinder Dhaliwal
MSMarcus Soo
Marcus Soo
CCCheri Chan
Cheri Chan
JWJocelin Wong
Jocelin Wong
SASeng Bin Ang
Seng Bin Ang
BACKGROUND Diabetes mellitus is the most challenging and fastest-growing global public health concern. Approximately 10.5% of the global adult population is affected by diabetes, and almost half of them are undiagnosed. The growing at-risk population exacerbates the shortage of health resources, with an estimated 10.6% and 6.2% of adults worldwide having impaired glucose tolerance and impaired fasting glycemia, respectively. All current diabetes screening methods are invasive and opportunistic and must be conducted in a hospital or laboratory by trained professionals. At-risk participants might remain undetected for years and miss the precious time window for early intervention to prevent or delay the onset of diabetes and its complications. OBJECTIVE We aimed to develop an artificial intelligence solution to recognize elevated blood glucose levels (≥7.8 mmol/L) noninvasively and evaluate diabetic risk based on repeated measurements. METHODS This study was conducted at KK Women’s and Children’s Hospital in Singapore, and 500 participants were recruited (mean age 38.73, SD 10.61 years; mean BMI 24.4, SD 5.1 kg/m2). The blood glucose levels for most participants were measured before and after consuming 75 g of sugary drinks using both a conventional glucometer (Accu-Chek Performa) and a wrist-worn wearable. The results obtained from the glucometer were used as ground-truth measurements. We performed extensive feature engineering on photoplethysmography (PPG) sensor data and identified features that were sensitive to glucose changes. These selected features were further analyzed using an explainable artificial intelligence approach to understand their contribution to our predictions. RESULTS Multiple machine learning models were trained and assessed with 10-fold cross-validation, using participant demographic data and critical features extracted from PPG measurements as predictors. A support vector machine with a radial basis function kernel had the best detection performance, with an average accuracy of 84.7%, a sensitivity of 81.05%, a specificity of 88.3%, a precision of 87.51%, a geometric mean of 84.54%, and F score of 84.03%. CONCLUSIONS Our findings suggest that PPG measurements can be used to identify participants with elevated blood glucose measurements and assist in the screening of participants for diabetes risk.

15 December 2022 in TechRxiv
Verified
Preprint
Open access
PDF file
BSBohan Shi
Bohan Shi
ATArthur Tay
Arthur Tay
DTDawn M.L. Tan
Dawn M.L. Tan
NCNicole S.Y. Chia
Nicole S.Y. Chia
WAW.L. Au
W.L. Au
SYShih-Cheng Yen
Shih-Cheng Yen
Freezing of Gait is the most disabling gait disturbance in Parkinson’s disease. For the past decade, there has been a growing interest in applying machine learning and deep learning models to wearable sensor data to detect Freezing of Gait episodes. In our study, we recruited sixty-seven Parkinson’s disease patients who have been suffering from Freezing of Gait, and conducted two clinical assessments while the patients wore two wireless Inertial Measurement Units on their ankles. We converted the recorded time-series sensor data into continuous wavelet transform scalograms and trained a Convolutional Neural Network to detect the freezing episodes. The proposed model achieved a generalisation accuracy of 89.2% and a geometric mean of 88.8%.

22 January 2026 in medRxiv
Verified
Preprint
Open access
PDF file
MLMengcong Li
Mengcong Li
BSBohan Shi
Bohan Shi
ATArthur Tay
Arthur Tay
WAWing Lok Au
Wing Lok Au
DTDawn M.L. Tan
Dawn M.L. Tan
SYShih-Cheng Yen
Shih-Cheng Yen
Freezing of gait (FoG) prediction is clinically meaningful only when warnings arrive sufficiently early for subsequent action. Therefore, we adopt a Freezing Prediction Horizon (FPH) evaluation that reports prediction performance as a function of the warning horizon before onset, making the lead-time versus reliability trade-off explicit. Within this protocol, we develop a Transformer-based predictor with a progressive self-paced learning strategy and evaluate it on a 55-patient clinical dataset and two public datasets. The horizon–performance curves show that Macro-F1 remains stable up to approximately 2.5 seconds before FoG onset in our dataset, after which a gradual decline is observed. This horizon-based characterization replaces single, fixed ahead-of-onset windows with a continuous method that summarizes achievable advanced time at specified accuracy levels. In this way, it offers a principled basis for setting targets in real-time implementationslinking algorithmic early-warning capacity to the lead times that practical systems may require-while remaining compatible with conventional metrics. By centering evaluation on FPH, this study clarifies how far in advance FoG can be predicted with confidence, and it positions horizon-based assessment as a reproducible complement to standard reporting for future work on deployable FoG prediction. Ultimately, quantifying advance warning is a prerequisite for prevention-oriented use, by indicating whether sufficient time can be reserved for cueing prior to onset.

1 November 2023 in TechRxiv
Verified
Preprint
Open access
PDF file
BSBohan Shi
Bohan Shi
SDSatvinder Singh Dhaliwa
Satvinder Singh Dhaliwa
MSMarcus Soo
Marcus Soo
CCCheri Chan
Cheri Chan
JWJocelin Wong
Jocelin Wong
SASeng Bin Ang
Seng Bin Ang
Diabetes mellitus (DB) is the most challenging and fastest-growing global public health challenge. An estimated 10.5% of the global adult population suffers from diabetes, and almost half of them are undiagnosed. The growing at-risk population exacerbated the shortage of health resources, with an estimated 10.6% and 6.2% of adults worldwide having impaired glucose tolerance (IGT) and impaired fasting glycemia (IFG), respectively. All the current diabetes screening methods are invasive and opportunistic and must be conducted in a hospital or a laboratory by trained professionals. At-risk subjects might remain undetected for years and miss the precious time window for early intervention in preventing or delaying the onset of diabetes and its complications. This study was conducted at KK Womenâ\euro™s and Childrenâ\euro™s Hospital of Singapore, and five hundred participants were recruited (mean age 38.73 ± 10.61 years; mean BMI 24.4 ± 5.1 kg/m2). The blood glucose levels, for most participants, were measured before and after 75g of sugary drink using both the conventional glucometer (Accu-Chek Performa) and the wrist-worn wearable. The results obtained from the glucometer were used as the ground truth measurements. We propose leveraging photoplethysmography (PPG) sensors and machine learning techniques to incorporate this into an affordable wrist-worn wearable device to detect elevated blood glucose levels (⩾ 7.8mmol/L) non-invasively. Multiple machine learning models were trained and assessed with 10-fold cross-validation using subject demographic data and critical features extracted from the PPG measurements as predictors. Support vector machine (SVM) with a radial basis function kernel has the best detection performance with an average accuracy of 84.7%, a sensitivity of 81.05%, a specificity of 88.3%, a precision of 87.51%, a geometric mean of 84.54% and F-score of 84.03%. Hence, PPG measurements can be utilized to identify subjects with elevated blood glucose measurements and assist in the screening of subjects for diabetes risk.