Actalent Enables Novel Acoustic Sensing Approach for Surgical Drilling Depth Detection

The Client

The client operates primarily in the healthcare sector, specifically across pharmaceuticals, biotechnology and medical devices. The organization researches, develops and manufactures prescription drugs and medical technologies that support improved patient outcomes and healthcare innovation.

The Challenge

An internal evaluation was undertaken to explore alternative, cost-effective sensing methods that could improve drilling and screw insertion accuracy during surgical procedures. Existing market solutions relied on technologies such as LIDAR, motor current feedback and torque sensing, which offered limited adaptability across varying patient anatomies. The goal was to determine whether sound, ultrasound and vibration-based sensing could reliably detect changes in material density, particularly transitions between cortical and cancellous bone, to help prevent screw over-penetration into surrounding soft tissue.

The client’s existing surgical handpiece lacked embedded sensing capabilities, increasing the risk of over-drilling and screw protrusion due to anatomical variability between patients.

Key challenges included:

• Identifying a sensing approach capable of adapting to variations in bone density
• Replicating realistic surgical conditions while maintaining experimental control
• Extracting meaningful insights from complex, high-frequency acoustic data
• Establishing a foundation for future real-time intraoperative guidance

As time progressed, the project evolved from simple endpoint detection to the development of a continuous, real-time anatomical topography view during drilling. This shift required rapid alignment of the technical strategy and analytical framework while maintaining project momentum and experimental rigor.

The Actalent Solution

Actalent was engaged to evaluate feasibility, develop detection algorithms and simulate real-time application potential. Using a structured proof-of-concept approach, the team combined experimental design, advanced signal processing and rapid prototyping.

Instrumented Test Environment and Data Capture

The team designed and built a controlled drill press setup integrating ultrasonic microphones, vibration transducers and RPM sensing. A comprehensive test matrix was developed using:

• Wood/plastic composites
• Bovine bone samples
• Orthopedic bone models for surgical fixation

Testing incorporated variations in drilling angles, speeds, screw geometries and operator-driven inconsistencies to replicate real-world surgical scenarios.

Advanced Signal Processing and Algorithm Development

Leveraging high-frequency ultrasonic data (150 kHz sampling), Actalent developed a custom signal processing pipeline using:

• Short-Time Fourier Transform (STFT)
• RMS-based feature extraction
• Signal integration techniques

This enabled the creation of a robust detection metric capable of identifying transitions between material layers. The hybrid DSP approach captured both coarse and fine signal characteristics, improving reliability across noisy and variable conditions and enabling clear differentiation between material types based on acoustic response.

Prototype Visualization and Real-Time Simulation

To demonstrate usability, the algorithm was integrated into a prototype LabVIEW-based GUI dashboard. This interface:

• Simulated real-time detection feedback
• Translated complex signal outputs into intuitive indicators
• Demonstrated potential for intraoperative application

The system architecture was also designed with scalability in mind, supporting future embedded system integration. In parallel, the team conducted a patent landscape assessment and developed a draft patent based on the novel acoustic sensing approach. The solution was delivered with flexibility to adapt to evolving client objectives, ensuring both technical validation and strategic value.

The Results

The Phase 1 engagement successfully demonstrated the feasibility of the sensing approach, achieving 100% detection accuracy across all six test trials and maintaining consistent performance under varying angles, speeds and handheld positioning. The system also reliably differentiated between cortical and cancellous bone layers based on acoustic response, producing stable and repeatable outputs that support future real-time embedded implementation.

Beyond the technical validation, the project established a strong foundation for commercial development. The results suggest opportunities to reduce hardware costs through low-cost sensor alternatives while lowering integration complexity compared to traditional LIDAR-based solutions. Early feasibility validation also reduced development risk and provided confidence in the technology’s scalability. The engagement delivered significant strategic value despite its limited scope. The novel sensing approach presents a potential patentable opportunity with no prior art identified, creating meaningful differentiation in the market. Executed by a small, agile team within a constrained budget and timeline, the project exceeded client expectations and accelerated the path toward commercialization.