Objective: The complex nature of Parkinson's disease (PD) makes difficult to rate its severity, mainly based on visual inspection of motor impairments. Wearable sensors have been demonstrated to help overcoming such a difficulty, by providing objective measures of motor abnormalities. However, up to now those sensors have been used on advanced PD patients with evident motor impairment. As a novelty, here we report the impact of wearable sensors in the evaluation of motor abnormalities in newly diagnosed, untreated, namely de novo, patients. Methods: A network of wearable sensors was used to measure motor capabilities, in 30 de novo PD patients and 30 healthy subjects, while performing five motor tasks. Measurement data were used to determine motor features useful to highlight impairments and were compared with the corresponding clinical scores. Three classifiers were used to differentiate PD from healthy subjects. Results: Motor features gathered from wearable sensors showed a high degree of significance in discriminating the early untreated de novo PD patients from the healthy subjects, with 95% in accuracy. The rates of severity obtained from the measured features are partially in agreement with the clinical scores, with some highlighted, though justified, exceptions. Conclusion: Our findings support the feasibility of adopting wearable sensors in the detection of motor anomalies in early, untreated, PD patients. Significance: This work demonstrates that subtle motor impairments, occurring in de novo patients, can be evidenced by means of wearable sensors, providing clinicians with instrumental tools as suitable supports for early diagnosis, and subsequent management.
In this paper, we report a high-performance balun with characteristics suitable for future broadband sub-THz differential circuits. The idea of the balun is based on three asymmetric coupled lines, which enhance the odd mode capacitances to equalize the even/odd mode phase velocities. The inner line of the three asymmetric coupled lines is configured to form the open stub ( /2), while the outer lines form short stubs ( /4). To further reduce the phase imbalance, the short stubs in one of the arms of the balun are connected with vias and a lower metal layer. The balun is developed using the standard 130-nm SiGe BiCMOSback-end process and EM simulated with ADS momentum and Sonnet. The −10-dB reflection coefficient (S ) bandwidth of the balun is 136 GHz (88–224 GHz). It shows insertion loss (including RF pads) <1.5 dB, phase imbalance <7 degrees, and amplitude imbalance <1 dB at 94–177 GHz. Furthermore, a scaled-down version of the balun operates on the WR-6, WR-5, and WR-4 frequency bands without significant degradation in its performance. Such characteristics of the balun make it an ideal candidate for various broadband differential circuits.
Power amplifiers (PAs) are the most power-consuming devices in a transmitter. Their performance in efficiency is crucial to the efficiency of the whole system. Therefore, the issue of high efficiency PA has remained hot over the years. This paper presents an approach to design an S-band single stage class-F PA biased in class-C condition. Through the manipulation of the 2nd harmonic at the input, shaping the voltage waveform at the gate node, a class-F PA with proper output matching network (OMN) is realized. The proposed class-C-F PA achieved 60% drain efficiency (DE) and 36.3 dBm of output power around the 3 dB compression point. The methodology of taking the input non-linearity into consideration is also presented. Its feasibility has been verified through both the design and measurements.