Sensor Integration in Medical Equipment

🤩 Sensor Interface Circuit for Biomedical Devices & Biosensors 💥 💝 Learn How to Interface Glucose, Lactate and other Sensors with MCU 🧐 At the heart of most of these biosensors is LMP91000 by Texas Instruments which is a programmable analog front-end for use in micro-power electrochemical sensing applications. It provides a complete signal path solution between a sensor and a microcontroller that generates an output voltage proportional to the cell current. It supports multiple electrochemical sensors such as: 3-lead toxic gas sensors and 2-lead galvanic cell sensors. The core of the LMP91000 is a potentiostat circuit. It consists of a differential input amplifier used to compare the potential between the working and reference electrodes to a required working bias potential (set by the Variable Bias circuitry). The error signal is amplified and applied to the counter electrode (through the Control Amplifier - A1). Any changes in the impedance between the working and reference electrodes will cause a change in the voltage applied to the counter electrode, in order to maintain the constant voltage between working and reference electrodes. A Transimpedance Amplifier connected to the working electrode, is used to provide an output voltage that is proportional to the cell current. The working electrode is held at virtual ground (Internal ground) by the transimpedance amplifier. The potentiostat will compare the reference voltage to the desired bias potential and adjust the voltage at the counter electrode to maintain the proper working-to-reference voltage. How to build a circuit for your biomedical application? Orlando Hoilett built KickStat, a miniaturized potentiostat using LMP91000 with the processing power of the Arm Cortex-M0+ SAMD21 Microchip Technology Inc. microcontroller on a custom-designed 21.6 mm by 20.3 mm circuit board. By incorporating onboard signal processing via the SAMD21, h he achieved 1mV voltage resolution and an instrumental limit of detection of 4.5nA in a coin-sized form factor. He measured the faradaic current of an anti-cocaine aptamer using cyclic voltammetry and square wave voltammetry and demonstrated that KickStat’s response was within 0.6% of a high-end benchtop potentiostat. To further support others in electrochemical biosensors development, he has made KickStat’s design and firmware available in an online GitHub repository. 📢 KickStat Project: "KickStat: A Coin-Sized Potentiostat for High-Resolution Electrochemical Analysis" doi: https://lnkd.in/eFjdpWjQ GitHub repo: https://lnkd.in/eJAvT_kR Datasheet: https://lnkd.in/eKvkGWCt 💜 Share it with your biosensors, biomedical wearable network 👌 #biosensors #wearables #sensors #electronics #Potentiostat #lmp91000

This project integrates power management, microcontroller architecture, sensor interfaces, and various communication peripherals into a single optimized hardware platform. Here’s a detailed overview of the board’s key technical components: ⚡ Power Management & Regulation Architecture The system is powered via USB with a +5V primary supply. Using a MIC5219 LDO regulator, +5V → +3.3V conversion provides a clean and stable power line. Both input and output sides feature 2.2µF capacitors for improved supply stability. With a maximum output current of 500mA, the power structure reliably supports the MCU and peripheral sensors. 🧠 MCU Architecture: STM32F411CEU6 At the heart of the system lies the high-performance Cortex-M4–based STM32F4 MCU. Integrated components include a 16MHz crystal oscillator, SWD (Tag-Connect) programmer interface, USB D+/D− lines, and extended GPIO ports. Multiple 100nF + 2.2µF decoupling capacitors ensure power integrity across all supply and analog pins. USB data lines are protected using RCLAMP0521P ESD protection diodes. Optimized line impedance and series resistors were used for SDIO, I2C, USB, GPIO, and sensor communication lines to ensure stable and reliable operation. 📡 Sensor Integrations IMU (MPU-6050) A 6-axis IMU connected via I²C. Address configuration (0x68), REGOUT filtering, and CPOUT decoupling follow the manufacturer's recommended design guidelines. Barometric Sensor (SPL06-001) High-precision SPL06-001 barometric pressure sensor integrated over I²C. Proper VDD/VDDIO routing, 10k pull-ups, and 100nF bypass capacitors ensure stable and noise-free sensor performance. 💾 SD Card Interface High-speed SDIO-based SD card interface using a DM3CS-SF connector. Built-in card-detect circuitry incorporates the manufacturer’s typical ~50k pull-up definition. 22Ω series resistors on all data and clock lines enhance signal integrity. 🔌 Interfaces & Connectivity USB 2.0 Micro-B connector (VBUS, D−, D+, ID). Tag-Connect (TC-2030NL) interface for compact, solderless SWD programming. GHS-type GPIO expansion headers. ESD protection circuits and ferrite beads across key interfaces for enhanced noise immunity. 🎯 Project Purpose & Vision This board was designed to advance my embedded hardware development experience and create a platform that is modular, extensible, and sensor-focused. The goal was to build a compact system capable of: reliable acquisition of high-precision sensor data, high-performance MCU processing, stable and noise-resistant power and communication infrastructure. This process has been both technically and systematically insightful, helping me strengthen my skills in hardware design, power management, signal integrity, sensor interfacing, and high-speed communication. I’d be happy to hear any feedback, suggestions, or technical insights you may have. Reference : Philip Salmony

Another new paper from the group, titled ‘A Wireless, Skin-Integrated System for Continuous Pressure Distribution Monitoring to Prevent Ulcers Across Various Healthcare Environments,” published in the current issue of npj Flexible Electronics (https://lnkd.in/g_Q-cy6X). This publication describes a technology developed in tight collaborative efforts with physicians and nurses associated with the medical school at Washington University in St. Louis. The goal was to address a key challenge in patient care – the formation of pressure-induced ulcers for individuals with limited mobility or reduced sensation. This topic has been of interest to us for some years, first reported in a paper that we published in 2018 in Science Translational Medicine on a fully skin-like – or ‘epidermal’ – wireless sensor platform for battery-free, multisite pressure and temperature measurements, as an advanced demonstration of possibilities (https://lnkd.in/gFgVAnVn). Our current work focuses on similar functional capabilities, but enabled by platforms that (1) rely exclusively on commercially available components, configured in soft, flexible platforms that are compatible with high volume manufacturing practice, and (2) integrate with clinical-standard padding that is routinely applied to high-risk areas: the sacrum and the heel. A key aspect is in our use of off-the-shelf millimeter-scale barometers as pressure sensors formed by depackaging and back-filling with a low modulus silicone polymer molded in an optimized truncated cone geometry guided by computational modeling of the mechanics. The result is a temperature stabilized, low-cost digital sensor component with exceptional sensitivity and robustness in operation over a dynamic range aligned with clinical requirements. Thanks in particular to Prof. Seonggwang Yoo (former postdoc in the group, now on the faculty at Inje University), Prof. Jae-Young Yoo (former postdoc in the group, now on the faculty at Sungkyunkwan University) and Prof. Seyong Oh (former postdoc in the group, now on the faculty at Hanyang University) for their device and electronics work, to Dr. Zengyao Lyu (postdoc with Prof. Yonggang Huang) for his modeling efforts and to Dr. Nicholas Fadell (plastic surgeon at Washington University in St. Louis) for his help with hospital evaluations on patients in the ICU and the OR – and to all of the other co-authors. Also, it was also great to team with various talented senior collaborators on this project, including Dr. Justin Saks (Washington University in St. Louis), Dr. Matthew MacEwan (Washington University in St. Louis), Dr. Amanda Westman PhD (Washington University in St. Louis) and Prof. Yonggang Huang (Northwestern University). One of our more clinically focused projects, nuts and bolts… always energizing to work on engineering solutions to important unmet needs in patient care.

🚀Advancing Perioperative Organ Monitoring Through Bioresorbable #Bioelectronics! A recent study in Nature Portfolio introduces a programmable, bioresorbable electrochemical microneedle sensor array designed for continuous perioperative monitoring of deep organs. What’s different here isn’t just sensing—it’s how and where sensing happens. 🔍 Key technical advances • Flexible, 3D-programmed microneedles with backward-facing barbs for stable deep-organ anchoring • Multiplexed electrochemical sensing of electrolytes (Na⁺, K⁺, pH), metabolites (glucose, lactate, uric acid), oxygenation, and electrophysiology • Spatial mapping across up to 32 sites within organ parenchyma • A rolling bioresorbable e-suture that connects the implant to skin-mounted electronics • Electrically triggered self-destruction, eliminating the need for device retrieval Clinically, this enables something we’ve struggled to achieve: ➡️ real-time detection of ischemia ➡️ monitoring transplant rejection or metabolic dysfunction ➡️ continuous postoperative insight during the most critical recovery window From a research perspective, the work also stands out for its photolithography-free, 3D printing–based fabrication, suggesting a realistic path toward scalability—not just proof-of-concept elegance. This feels like a shift from: 📉 intermittent blood tests ➡️ 📈 continuous, localized organ intelligence 👏 Congratulations to Wei Ouyang, Xiangling Li, and the entire research team on this impressive publication in Nature Biomedical Engineering. 🔗 Full article link in the comments. #NaturePortfolio #Biosensors #Bioelectronics #TranslationalResearch #PerioperativeCare #MedicalDevices

Here is the TrueShock-HF is a wireless subcutaneous ICD with integrated pulmonary artery pressure monitoring, uniquely designed to treat only hemodynamically significant arrhythmias while simultaneously managing heart failure. Clinical Value Proposition: 1. Reduced inappropriate shocks Arrhythmia must show both electrical and hemodynamic instability → fewer unnecessary therapies. 2. Heart failure management Daily PA pressure data aids in early detection of decompensation → supports remote titration of diuretics/vasodilators. I am working on a closed loop treatment algorithm which will include integration of SC furosemide pump which is clinically available to prevent decompensated CHF hospital admissions and ER visits. 3. Improved safety profile Subcutaneous lead avoids transvenous complications (thrombosis, infection, lead fracture). 4. Wireless PA sensor is passive or low-power, designed for years of reliable function. 5. Patient quality of life Fewer inappropriate shocks. Integrated heart failure monitoring, reducing hospitalizations. Ultimately I will not even need the PA pressure sensor, I will be doing it all via the ICD SC lead via microsensors. It is time to revolutionize the acute and decompensated CHF treatment and eliminate the unnecessary ICD shocks which is 1/3 of the cases scares the patients, makes unnessary ER visits etc.