0.342 nW Class-AB enhanced flipped source follower low pass filter for biomedical applications.

Owing to the impact of process voltage and temperature variations, the design of low-power low-pass filters (LPFs) with improved linearity is still one of the most challenging tasks for effective biological signal processing. This paper presents the design of a fourth-order Class-AB enhanced flipped source follower (EFSF) LPF circuit aimed at the detection of electroencephalography signals. The simulated results attained using complementary metal-oxide-semiconductor 180 nm technology node in Cadence Analog Design Environment demonstrate that the EFSF LPF emulates a DC-gain of -88 mdB with a bandwidth of 100 Hz and consumes 0.342 nW power from a supply voltage of 0.5 V. The calculated figure of merit for the proposed filter is 5.983 × 10-15 J with a dynamic range (DR) of 43.54 dB and input-referred noise of 91 µVrms. It consumes an area of 0.0458 mm2. To check the robustness of the proposed filter circuit, we performed Monte Carlo simulations with 200 runs. The statistical results achieved for the DC-gain, DR, and total harmonic distortion of the proposed filter show mean values of -188.09 mdB, 43.10 dB, and -41.85 dB along with standard deviation values of 285.21 mdB, 718.72 mdB, and 4.52 dB, respectively. The proposed Class-AB EFSF LPF can be used to achieve high power efficiency in future low-voltage and low-power biological systems.

Clinical Value of Patient-Specific Three-Dimensional Printing of Kidney Before Partial Nephrectomy: A Qualitative Assessment.

Objectives: To qualitatively assess the clinical usefulness of patient-specific high-fidelity three-dimensional (3D) print model of kidney before partial nephrectomy (PN) and to identify subset domains where it may help in clinical terms. Materials and Methods: Thirteen 3D models were printed for tumors having RENAL nephrometry score of ≥8. Their usage for PN was assessed prospectively using a qualitative questionnaire to be answered on a Likert scale of 1-10. The questions focused on realistic resemblance, preoperative dry surgical run, intertest comparison, surgical impact, and overall beneficence domains as perceived by primary surgeons with respect to surgical conduct during PN. Results: Mean RENAL score was 9.15 (8-11). Models were rated high (9.07 ± 0.86) for realistic resemblance domain and were rated better than contrast-enhanced computed tomography (CECT) (8.38 ± 0.87) and intraoperative ultrasonography (8.07 ± 1.26) for orientation regarding resection margins. A further marginal improvement to 8.2 ± 0.84 was noted against ultrasound where surgeon did a dry cut preoperatively. Use of superselective arterial approach in four, precise awareness about dissection of a major vessel in four, retroperitoneoscopic approach in one, and surgical margin awareness in three were directly attributed to the model. Overall utility of having a model printed was rated high (8.23 ± 1.3). Conclusion: The 3D print models of complex renal tumors have high realistic resemblance to actual patient's anatomy. They were rated better than preoperative CECT or intraoperative ultrasonography for orientation regarding surgical resection margins. It may also help change or modify the surgical plan in a subset of patients with a potential to improve overall outcomes in these complex cases.

Conventional digital subtractional vs non-invasive MR angiography in the assessment of brain arteriovenous malformation.

OBJECTIVES: Digital subtractional angiography (DSA) is the standard method for diagnosis, assessment and management of arteriovenous malformation in the brain. Conventional DSA (cDSA) is an invasive imaging modality that is often indicated before interventional treatments (embolization, open surgery, gamma knife). Here, we aimed to compare this technique with a non-invasive MR angiography (MRI DSA) for brain arteriovenous malformation (bAVM). PATIENTS AND METHODS: Fourteen patients with ruptured brain AVM underwent embolization treatment pre-operation. Imaging was performed for all patients using MRI (1.5 T). After injecting contrast Gadolinium, dynamic MRI was performed with 40 phases, each phase of a duration of 1.2 s and having 70 images. The MRI results were independently assessed by experienced radiologist blinded to the cDSA. RESULTS: The AVM nidus was depicted in all patients using cDSA and MRI DSA; there was an excellent correlation between these techniques in terms of the maximum diameter and Spetzler Martin grading. Of the fourteen patients, the drainage vein was depicted in 13 by both cDSA and MRI DSA showing excellent correlation between the techniques used. CONCLUSION: MRI DSA is a non-invasive imaging modality that can give the images in dynamic view. It can be considered as an adjunctive method with cDSA to plan the strategy treatment for bAVM.