People with Parkinson’s disease (PWP) face critical challenges, including a lack of access to neurological care, inadequate measurement and communication of motor symptoms, and suboptimal medication management and compliance. The idea for the Quantitative Digitography (QDG) project emerged from a pressing need to improve the quantification of motor symptoms in PWP and translate them into a remote system with actionable outcomes. Traditional methods of monitoring Parkinson’s disease (PD) symptoms, such as the Movement Disorders Society-Unified Parkinson’s Disease Rating Scale (MDS-UPDRS), require in-person evaluations and are prone to variability. The Human Motor Control and Neuromodulation Lab, based on decades of research, recognized the potential for a remote technology that could provide real-time, quantitative metrics of motor symptoms, thus empowering both patients and healthcare providers. In collaboration with teams from the Stanford Byers Center for Biodesign and Stanford Medicine Catalyst, developed QDG Care: a unique connected care platform for PD that delivers validated, quantitative metrics of all motor signs in PD in real-time, monitors the effects of therapy adjustments and medication adherence, and is accessible in the electronic health record.
Figure 1: Overview of the QDG-Care platform demonstrating the data flow in the system.
The initial application of QDG technology comprises thirty seconds of repetitive alternating finger tapping (RAFT) on a digitography device. This task is easy to perform, yet more complex than single finger tapping, and generates validated metrics of all PD motor symptoms in real-time. Early prototypes, developed on MIDI keyboards and later on engineered levers, demonstrated the feasibility of this approach. One of the primary obstacles was creating a universal digitography device that was both accurate and user-friendly. The team needed to ensure that the device could precisely measure both the amplitude and timing of finger movements while being portable and easy for PWP to use at home. With meticulous work, the mechanical and electrical aspects of the previous devices were iteratively engineered to meet and exceed these standards. This resulted in the design of the KeyDuo, a small, stand-alone digitogrpahy device with two adjacent tensioned levers. The KeyDuo embodies a remote, Bluetooth-enabled, user-friendly design that takes into account the user’s needs and outputs high-resolution quantitative metrics. The KeyDuo was ultimately the result of numerous design iterations and PWP feedback.
Another significant challenge was integrating the system into the existing healthcare infrastructure. The data collected by QDG needed to be analyzed in real-time and made accessible to healthcare providers through their electronic health record (EHR) system. This required developing a robust connection with the device, a mobile application to pre-process data and provide a user-friendly patient interface, and a cloud-based service to execute the AI-based QDG algorithm. Providing actionable insights to clinicians in a web dashboard opens a wide range of possibilities, including the impact of QDG on medication management. Integrating QDG data into the EHR allows for seamless communication between PWPs and healthcare providers, facilitating timely and effective interventions. The high-resolution data QDG provides allows real-time monitoring of medication effects, enabling healthcare providers to make more informed decisions and optimize treatment plans. The Stanford Spezi open-source ecosystem of modules builds the foundation of the QDG mobile application. Spezi Bluetooth powers the app’s connection with the KeyDuo safely and reliably, augmented by several other Spezi Modules. The Spezi team designed an end-to-end cloud architecture for the QDG connected care platform, including integration with Stanford’s Epic EHR via SMART on FHIR APIs, hosted in a secure and HIPAA-compliant cloud environment managed by Stanford Medicine Technology and Digital Solutions (TDS).
Depiction of the QDG web dashboard which visualizes the calculated metrics from a single RAFT test for all the cardinal motor signs of Parkinson’s Disease.
A crucial component of a clinical remote system is easily digestible and useful metrics that reflect the state of the PWP. The QDG Mobility and Tremor Severity Scores provide a comprehensive view of a PWP’s voluntary motor function independently from the presence and severity of tremor, allowing for quick assessments and detailed analyses of specific symptoms. Rather than focusing on impairment, the QDG Mobility Score reflects the overall mobility of the PWP compared to expected performance of an age-matched healthy control. The two scores allow for quick evaluation of both voluntary and involuntary behavior that may affect therapeutic choices.
To validate the connected care platform in the first remote monitoring clinical trial, PWP participants were asked to perform QDG-RAFT at home twice a day for 30 days, in their best on and in their most off state. The primary outcome was compliance with performing a test on at least 16/30 days to satisfy the requirements for remote monitoring reimbursement. PWP were recruited by Stanford neurologists, who were able to view the QDG data in real time. This strategy showcased potential clinical applications, enhancing QDG’s visibility in the medical community. To ensure accessibility for older patients, the team created a comprehensive user manual and conducted detailed training sessions covering the tablet, QDG mobile application, KeyDuo, and wrist pad. Weekly video check-ins during the 30-day trial ensured correct task performance at home. These efforts resulted in high compliance and valuable clinical insights, such as detecting significant improvements in one participant’s motor symptoms following medication adjustments. This highlighted QDG-Care’s potential to transform PD management through personalized, remote monitoring.
The success of QDG illustrates the power of innovation and collaboration at Stanford, which has roots in decades of foundational research at the Bronte-Stewart lab. Stanford Medicine Catalyst, Stanford Medicine’s flagship innovation program, facilitated QDG’s translation into a solution benefiting patients at Stanford and beyond, enabling commercial-ready success. This transformative process exemplifies Catalyst’s role in accelerating innovative initiatives within the Stanford ecosystem for global impact. From its inception to its deployment, QDG has faced and overcome numerous challenges, driven by a clear vision to improve the lives of people with Parkinson’s disease. The Byers Center for Biodesign, Stanford Medicine Catalyst, and Stanford Medicine Technology and Digital Solutions support has been instrumental in bringing this vision to life, providing the resources and guidance needed to navigate the complex landscape of healthcare innovation.
The implementation of QDG has paved the way for further innovations. The team is exploring additional use cases, such as remote deep brain stimulation (DBS) evaluations and programming and as an adjunctive remote or in-clinic outcome metric for clinical trials. The flexible architecture of the QDG system allows for the integration of new algorithms, opening up possibilities for population-wide insights and the development of new digital biomarkers for PD. As QDG continues to evolve, it holds the promise of transforming not only the management of Parkinson’s disease but also the broader field of neurological diseases. QDG is setting a new standard for remote monitoring and personalized care by providing real-time, quantitative insights into motor function.
The research was funded by Stanford Medicine Catalyst; Stanford Biodesign and the Wu Tsai Neurosciences Institute, Stanford University; Fogarty Innovation Invention Acceleration Program; the Michael J Fox Foundation (9605); NIH/NIAAA R01 AA023165; Debbie and Andy Rachleff Foundation; and the John E. Cahill Family Foundation.