Frequency and distribution pattern of distant metastases in breast cancer patients at the time of primary presentation

Introduction.: For routine staging of patients with primary breast cancer, clinical practice guidelines of many medical societies recommend chest X-ray, liver ultrasound and bone scan. With respect to expanding health care costs and patients' psychological distress it has been supposed, that there might be a group of breast cancer patients, who do not need these imaging studies. Methods.: Four hundred and eighty-eight consecutive patients with primary breast cancer who had primary surgery at our institution and complete work-up for distant metastases including chest X-ray, liver ultrasound, and bone scan were studied. Results.: We found distant metastases at the time of primary diagnosis in 19 patients (3.9%). Bone metastases were found in 2.7%, liver metastases in 1.0%, and pulmonary metastases in 0.4%. However, in breast tumors smaller than 1cm, no metastatic lesions were found, whereas 18.2% of the patients with pT4 tumors had metastases. In 2.4% of screening imaging studies, metastases were ruled out by additional imaging. Conclusion.: Based on our data and a review of the literature, we suggest that chest X-ray, liver ultrasound and bone scan can be omitted in the staging of asymptomatic patients with pT1a or pT1b diseas

Modeling stratum corneum swelling for the optimization of electrode-based skin hydration sensors

We present a novel computational model of the human skin designed to investigate dielectric spectroscopy electrodes for stratum corneum hydration monitoring. The multilayer skin model allows for the swelling of the stratum corneum, as well as the variations of the dielectric properties under several hydration levels. According to the results, the stratum corneum thickness variations should not be neglected. For high hydration levels, swelling reduces the skin capacitance in comparison to a fixed stratum corneum thickness model. In addition, different fringing-field electrodes are evaluated in terms of sensitivity to the stratum corneum hydration level. As expected, both conductance and capacitance types of electrodes are influenced by the electrode geometry and dimension. However, the sensitivity of the conductance electrodes is more affected by dimension changes than the capacitance electrode leading to potential design optimization

Follow-up of women with breast cancer: comparison between MRI and FDG PET

Abstract.: The aim of this study was to compare MRI of the breast with 18F-fluoro-deoxy-glucose (FDG) positron emission tomography (PET) in patients with suspected local or regional breast cancer recurrence or suspected contralateral breast cancer. Thirty-two patients (mean age 57.2years, age range 32-76years) with suspected loco-regional recurrence (n=19), chest wall recurrence (n=5), and suspected secondary tumor of the contralateral breast (n=8) underwent MRI of the breast and FDG PET of the whole body and breast region. Cytology/histology (n=17) or a clinical follow-up examination (n=15) with additional imaging served as the standard of reference. A McNemar test was performed to compare PET and MRI, and kappa was determined to quantify agreement of both methods. Sensitivity was 79 and 100%, specificity was 94 and 72%, and accuracy was 88 and 84% for MRI and PET, respectively. Additional metastases outside the field of view of MRI were found in PET in 5 patients. In this study both imaging methods had comparable accuracy. The detection of distant metastases with whole-body PET imaging can influence patient managemen

A simple non-contact optical method to quantify in-vivo sweat gland activity and pulsation

Objective: Most methods for monitoring sweat gland activity use simple gravimetric methods, which merely measure the average sweat rate of multiple sweat glands over a region of skin. It would be extremely useful to have a method which could quantify individual gland activity in order to improve the treatment of conditions which use sweat tests as a diagnostic tool, such as hyperhidrosis, cystic fibrosis, and peripheral nerve degeneration. Methods: An optical method using an infrared camera to monitor the skin surface temperature was developed. A thermodynamics computer model was then implemented to utilize these skin temperature values along with other environmental parameters, such as ambient temperature and relative humidity, to calculate the sweat rates of individual glands using chemically stimulated and unstimulated sweating. The optical method was also used to monitor sweat pulsation patterns of individual sweat glands. Results: In this preliminary study, the feasibility of the optical approach was demonstrated by measuring sweat rates of individual glands at various bodily locations. Calculated values from this method agree with expected sweat rates given values found in literature. In addition, a lack of pulsatile sweat expulsion was observed during chemically stimulated sweating, and a potential explanation for this phenomenon was proposed. Conclusion: A simple, non-contact optical method to quantify sweat gland activity in-vivo was presented. Significance: This method allows researchers and clinicians to investigate several sweat glands simultaneously, which has the potential to provide more accurate diagnoses and treatment as well as increase the potential utility for wearable sweat sensors

Portable multi-wavelength fluorescence measurement device

​© 2022 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.Monitoring-based preventive medicine relies heavily on minimal or noninvasive, portable and cost-effective measurement solutions. This work presents a portable multi-wavelength fluorescence measurement system. The pinhole collimator, Fresnel focusing lens and PIN photo diode provide a cost-effective fluorescent light detection path. The with matte black filament 3D printed housing reduces unwanted reflections along the detection path. The integrated laser diode drivers ensure constant optical output power during operation. This is achieved by utilizing a laser diode package which incorporates both a laser and monitor diode. The monitor diode's output photocurrent is proportional to the optical output power, and thus provides, a feedback path for the driver. An optical diffuser is pre-mounted on each laser diode, providing a uniform illumination of the measurement area. The device adapts to a wide variety of fluorescent dyes by offering exchangeable laser diode modules and support of standard-sized optical thin film filters. The precision integrator transimpedance amplifier applies a switched-input photocurrent measurement technique that ensures the level of sensitivity required for clinical usage. Experimental validation indicates sensitivity in the pico-ampere range. Ex vivo and in vivo measurements, performed by the Faculty of Pharmacy at the Université de Montréal, confirm that the instrument matches its intended application

Portable multi-wavelength fluorescence measurement device : empirical evaluation

Monitoring-based preventive medicine relies heavily on minimal or noninvasive, portable, and cost-effective measurement solutions. In this study, we present a handheld multiwavelength fluorescence measurement system for detection of dermally injected fluorescent tracers. The circular detection area of the device is positioned on the sample containing the fluorescent marker. The marker is excited at regular intervals by a pulse of light. The optical output power is controlled by a laser diode driver, which receives direct feedback on the emitted light intensity from the monitor photodiode integrated into the laser diode package. An optical diffuser is located in front of each laser diode to ensure uniform illumination of the measurement area. Pulsed excitation of the fluorescent tracer allows alternate measurement of foreground and background light intensity. By subtracting the background from the foreground and using a switched-input photocurrent measurement technique, the measured photocurrent represents the actual light emission from the marker. The instrument has interchangeable modules that contain the excitation electronics and emission filter. These modules allow the instrument to be configured for a variety of different fluorescent markers. In vitro measurements show that the device is capable of performing fluorescence measurements for its intended use as a point-of-care device in preventive medicine

Development and clinical validation of the LymphMonitor technology to quantitatively assess lymphatic function

Current diagnostic methods for evaluating the functionality of the lymphatic vascular system usually do not provide quantitative data and suffer from many limitations including high costs, complexity, and the need to perform them in hospital settings. In this work, we present a quantitative, simple outpatient technology named LymphMonitor to quantitatively assess lymphatic function. This method is based on the painless injection of the lymphatic-specific near-infrared fluorescent tracer indocyanine green complexed with human serum albumin, using MicronJet600TM microneedles, and monitoring the disappearance of the fluorescence signal at the injection site over time using a portable detection device named LymphMeter. This technology was investigated in 10 patients with unilateral leg or arm lymphedema. After injection of a tracer solution into each limb, the signal was measured over 3 h and the area under the normalized clearance curve was calculated to quantify the lymphatic function. A statistically significant difference in lymphatic clearance in the healthy versus the lymphedema extremities was found, based on the obtained area under curves of the normalized clearance curves. This study provides the first evidence that the LymphMonitor technology has the potential to diagnose and monitor the lymphatic function in patients

Thermal analysis of new transdermal devices for power transfer to ventricular assist devices

Different engineered approaches have led the design of implants with controlled physical features to minimize adverse effects in biological tissues. Aiming to prevent infection, similar efforts have focused on optimizing the design features of drivelines used to transfer power to percutaneous ventricular assistance devices (VAD), omitting however a thorough look on the implant-skin interactions that govern local tissue reactions. Here, we utilized an integrated approach for the biophysical modification of transdermal implants and their evaluation by chronic sheep implantation in comparison to the standard of care VAD drivelines. We developed a novel method for the transfer of breath topographical features on thin wires with modular size. Moreover, we examined the impact of implant’s diameter, surface topography, and chemistry on macroscopic, histological, and physical markers of inflammation, fibrosis, and mechanical adhesion. All implants demonstrated infection-free performance. The fibrotic response was enhanced by the increasing diameter of implants but not influenced by their surface properties. The implants of 0.2 mm diameter promoted mild inflammatory responses with improved mechanical adhesion and restricted epidermal downgrowth, in both silicone and polyurethane coated transdermal wires. On the contrary, the VAD drivelines with larger diameter triggered severe inflammatory reactions with frequent epidermal downgrowth [1]. Furthermore, we performed COMSOL simulations to investigate the electrothermal implications of conductive wires with different sizes for the power transfer to VADs. In our model, we simulate the electrical properties of the prototype’s wires, to confirm that it does not produce a significant body temperature rise. The skin model (Fig. 1a) mimics the multiple skin layer’ properties of epidermis, dermis, fat and muscle [2]. Also, we include a PDMS layer (5 mm thickness) that represents the silicon-based material of the conductive skin. During the study, different thicknesses of the polyurethane (PU) insulating coating were tested for the wire of 0.2 mm diameter. However, no significant improvement was observed when increasing the insulation layer, since the temperature difference in the model was due to the temperature skin gradient and not the electric current. In this model, the dimensions of both the inner copper diameter and the PU coating thickness were obtained from the manufacturer’s specifications (0.2030 mm and 0.0105 mm, respectively). Our results show that when the wires are subject to the peak voltage for VADs (~14.5 V) and a steady-state current of 1.2 A (Fig. 1b), the temperature increases 0.65°C in the core of the copper wires (Fig. 1c), due to the inrush current. Nonetheless, the surface temperature of the patch in the steady state remains around 0.02°C, indicating that there is no significant risk for skin injury from heat dissipation. This combination of experimental and computational findings will enable the design of new percutaneous medical devices to support therapies that require safe exchange of power, signal, and mass through the human body

Rational design of a fluorescent microneedle tattoo for minimally invasive monitoring of lymphatic function

The monitoring of lymphatic drainage is of great importance, particularly in the context of the early detection and diagnosis of several diseases. Existing methods of imaging and monitoring lymphatic drainage can be costly and require trained personnel, posing problems for at-home or point-of-care monitoring. Recently, an alternative approach has been proposed, consisting of using microneedles to deliver a near-infrared (NIR) fluorescent tattoo to the skin, which can be monitored with traditional laboratory-based fluorescence detectors. In this work, we present further development of this approach, using a specifically designed NIR-fluorescent probe and rational optimization of microneedle properties and the spatial location of the NIR dye within the microneedles. Moreover, we demonstrate that this method is compatible with a custom-made portable fluorescence measurement device and able to discriminate between drainage and lack of drainage in vivo in rats

A capacitive color-changing electronic skin for touch sensing applications

© 2021 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.Robots are slowly becoming part of our civilization, or at least one of the main evolutions of the third millennium. Nowadays their integration is based on their aspects by looking more and more human. Additionally, not only considering the psychological aspects, our society will have to improve their interaction. Systems integrating a full spectrum of sensors will have to be implemented. In this framework, as a preliminary step, the implementation of a tactile robotic skin can be an interesting upgrade. To guarantee safety between robots and humans, it can be interesting to implement such robots with human-like tactile perception. In this work, we focus on the realization of innovative tactile skin model. This model allows to sense and indicate where the pressures have been applied by using a combination of a flexible polymeric capacitive skin model combined with a LED matrix