Critical care for lung cancer patients: surgical treatment during COVID-19 pandemic.

BACKGROUND: During the COVID-19 pandemic, some factors have led to changes in the management of patients with lung cancer. In our study, we aimed to present our surgical treatment approach to patients with NSCLC during the COVID-19 pandemic. METHODS: Patients who underwent surgery for NSCLC in our thoracic surgery clinic between March 2020 and March 2021 were evaluated retrospectively. The patients operated on were retrospectively evaluated in terms of sex, age, tumor staging, lung resection type, histopathological type, COVID-19 status, length of stay, complications, and mortality. RESULTS: Thirty-five patients, 27 men and 8 women, underwent surgery for lung cancer. The 2 most common types of surgery were lobectomy (in 32 patients) and pneumonectomy (in 3 patients). According to cancer staging based on 8th TNM, 14 patients were stage 2B, 12 patients were stage 2A, and 9 patients were stage 3A. The morbidity rate was 14 %. No postoperative mortality was observed. Nine patients had a history of COVID- 19 before surgery. No significant difference was found in terms of complications in patients with a preoperative history of COVID-19. In the postoperative period, COVID-19 was observed in no patient in our clinic. CONCLUSION: We think that surgical treatments should not be postponed for diseases such as lung cancer, where the mortality rate is high and early diagnosis and treatment are very important. There will be no delay or inadequacy in the treatment of patients if the rules determined during the COVID-19 pandemic and other types of pandemic possibly occurring in the future are followed (Tab. 1, Ref. 23).

Hemodialysis-related headache and how to prevent it.

BACKGROUND AND PURPOSE: Hemodialysis (HD) may have some adverse effects on the nervous system. Headache is the most commonly reported neurological symptom amongst HD patients. Our aim was to determine the frequency, clinical characteristics and triggering factors of HD-related headache (HRH) and to evaluate preventive strategies for reducing HRH. METHOD: In all, 494 patients were included. Comparative controls (CC) were classified within the same patients without headache. Arterial systolic/diastolic blood pressure, blood urea nitrogen (BUN) and creatinine were correlated before/after one HD. The urea reduction ratio during the dialysis session was determined. RESULTS: A total of 175 patients (35.4%) with a mean age of 57.3 ± 15.7 years were diagnosed with HRH. HRH was more common in males (P < 0.001). Headache was started a mean of 2.90 ± 0.86 h after the HD. The common localization of pain was reported to be bifrontal in 41.7% (n = 73). The mean duration of headache was 6.22 ± 7.8 h, with a duration of ≤4 h reported by 64.0% of patients. The mean Visual Analog Scale score was 5.64 ± 2.05. The differences between pre/post-dialysis BUN values were 94.6 ± 31.1 in HRH patients and 86.8 ± 28.5 in the CC group (P = 0.006). The systolic blood pressure difference between the pre/post-dialysis measurements was 22.4 ± 16.5 mmHg in HRH patients and 12.8 ± 19.4 mmHg in CC(P < 0.001). Patients with HRH had significantly higher mean systolic and diastolic blood pressure pre-dialysis values (systolic, P = 0.002; diastolic, P < 0.001). The differences in systolic/diastolic blood pressure between pre/post-dialysis were higher in the HRH group (P < 0.001, P = 0.001, respectively). CONCLUSION: Regulating the frequency and timing of dialysis may provide better management in HRH with high BUN levels and high pre-dialysis blood pressure.

A Super-Capacitive Pressure Sensor for a Urethral Catheter.

Urinary incontinence can be due to neuromuscular or structural problems in either the bladder or the urethra. Urodynamics is often used to analyze the patientspecific cause of urinary incontinence. In urodynamics, a challenging part of the studies involves measurement of the urethral (contact) pressure profile. Here we present an instrumented urethral catheter that is equipped with a novel super-capacitive pressure transducer that is highly sensitive to the applied pressure. A solid ionic electrolyte is used to create a high capacitance device. Through an innovative design the solid electrolyte is made and bounded to a 3d printed soft balloon and then assembled on a 6 Fr urethral catheter. In this paper the design, fabrication and evaluation of the highly-sensitive instrumented catheter's performance are discussed.

Wearable Water Content Sensor Based on Ultrasound and Magnetic Sensing.

Fluid accumulation in the lower extremities is an early indicator of disease deterioration in cardiac failure, chronic venous insufficiency and lymphedema. At-home wearable monitoring and early detection of fluid accumulation can potentially lead to prompt medical intervention and avoidance of hospitalization. Current methods of fluid accumulation monitoring either suffer from lack of specificity and sensitivity or are invasive and cost-prohibitive to use on a daily basis. Ultrasound velocity in animal and human tissue has been found to change with water content. However, previous prototype fluid monitoring sensors based on ultrasound are cumbersome and not wearable. Hence, in this research a compact water content sensor based on a wearable instrumented elastic band is proposed. A novel integration of magnetic sensing and ultrasonic sensing is utilized, where the magnetic sensor provides distance measurement and the ultrasonic sensor produces time-of-flight measurement. Magnetic field modeling with a Kalman filter and least squares linear fitting algorithms are employed to ensure robust sensor performance on a wearable device. The combination of the two measurements yields ultrasound velocity measurement in tissue. The water content sensor prototype was tested on a tissue phantom, on animal tissue and on a human leg. The error in velocity measurement is shown to be small enough for early detection of tissue edema.

Note: Development of leg size sensors for fluid accumulation monitoring.

A number of diseases can lead to fluid accumulation and swelling in the lower leg. Early detection of leg swelling can be used to effectively predict potential health risks and allows for early intervention from medical providers. Hence this note develops a novel leg size sensor based on the use of magnetic field measurement. An electromagnet is combined with two magnetic field transducers to provide a drift-free leg size estimation technique immune to environmental disturbances. The sensor can measure changes as small as 1 mm in diameter reliably during in vitro tests. Its performance is compared with that of other size measurement techniques.

Flexible Distributed Pressure Sensing Strip for a Urethral Catheter.

A multi-sensor flexible strip is developed for a urethral catheter to measure distributed pressure in a human urethra. The developed sensor strip has important clinical applications in urodynamic testing for analyzing the causes of urinary incontinence in patients. There are two major challenges in the development of the sensor. First, a highly sensitive sensor strip that is flexible enough for urethral insertion into a human body is required and second, the sensor has to work reliably in a liquid in-vivo environment in the human body. Capacitive force sensors are designed and micro-fabricated using polyimide/PDMS substrates and copper electrodes. To remove the parasitic influence of urethral tissues which create fringe capacitance that can lead to significant errors, a reference fringe capacitance measurement sensor is incorporated on the strip. The sensing strip is embedded on a catheter and experimental in-vitro evaluation is presented using a bench-top pressure chamber. The sensors on the strip are able to provide the required sensitivity and range. Preliminary experimental results also show promise that by using measurements from the reference parasitic sensor on the strip, the influence of parasitics from human tissue on the pressure measurements can be removed.

Distributed pressure sensors for a urethral catheter.

A flexible strip that incorporates multiple pressure sensors and is capable of being fixed to a urethral catheter is developed. The urethral catheter thus instrumented will be useful for measurement of pressure in a human urethra during urodynamic testing in a clinic. This would help diagnose the causes of urinary incontinence in patients. Capacitive pressure sensors are fabricated on a flexible polyimide-copper substrate using surface micromachining processes and alignment/assembly of the top and bottom portions of the sensor strip. The developed sensor strip is experimentally evaluated in an in vitro test rig using a pressure chamber. The sensor strip is shown to have adequate sensitivity and repeatability. While the calibration factors for the sensors on the strip vary from one sensor to another, even the least sensitive sensor has a resolution better than 0.1 psi.

Magnetic sensor for configurable measurement of tension or elasticity with validation in animal soft tissues.

This paper presents a novel Hall-effect-based magnetic sensor for handheld measurement of either elasticity or tension in soft tissues. A theoretical model is developed for the mechanical interaction of the sensor with the tissue, and conditions are established under which the separate effects of tension or elasticity can be measured. A model of the magnetic field within the sensor is developed and a technique to estimate the sensor response in the presence of multiple magnets is established. This paper then provides analytical sensor responses and compares them with experimental results obtained on synthetic materials. It is found that the sensor can measure tension values upto 100 N with a resolution of 10 N in handheld operation and elasticity of upto 0.87 MPa with a resolution of 0.02 MPa. Significant experimental characterization and statistical analysis of sensor repeatability is performed. The viability of this sensor to make tension and elasticity measurements with biological tissues is then demonstrated using turkey tendons and fresh swine tissues.

Novel MEMS stiffness sensor for in-vivo tissue characterization measurement.

This paper presents the design, mathematical model, fabrication and testing of a novel type of in-vivo stiffness sensor. The proposed sensor can measure both tissue stiffness and contact force. The sensing concept utilizes multiple membranes with varying stiffness and is particularly designed for integration with minimally invasive surgical (MIS) tools. In order to validate the new sensing concept, MEMS capacitive sensors are fabricated using surface micromachining with each fabricated sensor having a 1mm x 1mm active sensor area. Finally, the sensors are tested by touching polymers of different elastic stiffnesses. The results are promising and confirm the capability of the sensor for measuring both force and tissue compliance.

Passive wireless MEMS microphones for biomedical applications.

This paper introduces passive wireless telemetry based operation for high frequency acoustic sensors. The focus is on the development, fabrication, and evaluation of wireless, battery-less SAW-IDT MEMS microphones for biomedical applications. Due to the absence of batteries, the developed sensors are small and as a result of the batch manufacturing strategy are inexpensive which enables their utilization as disposable sensors. A pulse modulated surface acoustic wave interdigital transducer (SAW-IDT) based sensing strategy has been formulated. The sensing strategy relies on detecting the ac component of the acoustic pressure signal only and does not require calibration. The proposed sensing strategy has been successfully implemented on an in-house fabricated SAW-IDT sensor and a variable capacitor which mimics the impedance change of a capacitive microphone. Wireless telemetry distances of up to 5 centimeters have been achieved. A silicon MEMS microphone which will be used with the SAW-IDT device is being microfabricated and tested. The complete passive wireless sensor package will include the MEMS microphone wire-bonded on the SAW substrate and interrogated through an on-board antenna. This work on acoustic sensors breaks new ground by introducing high frequency (i.e., audio frequencies) sensor measurement utilizing SAW-IDT sensors. The developed sensors can be used for wireless monitoring of body sounds in a number of different applications, including monitoring breathing sounds in apnea patients, monitoring chest sounds after cardiac surgery, and for feedback sensing in compression (HFCC) vests used for respiratory ventilation. Another promising application is monitoring chest sounds in neonatal care units where the miniature sensors will minimize discomfort for the newborns.