Mark Merlo

Second generation robotic systems for studying rodent locomotion following spinal cord injury

This paper describes the development of two generations of robotic systems to assist in quantifying and training treadmill locomotion in spinal-injured rodents. Design principles identified with the first generation systems and their incorporation into second-generation systems are described.

Completely-in-the-Canal Magnet-Drive Hearing Device A Temporal Bone Study

The magnet-drive hearing device (MHD) is a small completely-in-the-canal hearing aid prototype that drives the tympanic membrane (TM) through a magnetic interface. A cadaveric temporal bone was prepared. The MHD was coupled to a nickel-epoxy pellet glued to the umbo. Frequency sweeps between 0.3 and 10 kHz were performed, and the MHD was driven with various levels of current. Displacements of the posterior crus of the stapes were measured using a laser Doppler vibrometer and compared with sound-induced displacements. The MHD had a linear frequency response and low total harmonic distortion. The pellet placement altered the stapes movements; however, the changes were statistically insignificant. Inputs of 100 and 300 mV produced displacements equivalent to those of the natural sound at 70- and 80-dB sound pressure level, respectively. The coupling of this novel device using a magnetic interface to the umbo had a frequency output wider than air conduction devices, and its actuator was effective in driving the TM.

Development of a novel completely-in-the-canal direct-drive hearing device

To develop a novel completely‐in‐the‐canal device capable of directly driving the tympanic membrane (TM) and ossicular chain from the ear canal.

Investigation of a novel completely-in-the-canal direct-drive hearing device: a temporal bone study.

Hypothesis Whether a prototype direct-drive hearing device (DHD) is effective in driving the tympanic membrane (TM) in a temporal bone specimen to enable it to potentially treat moderate-to-severe hearing loss. Background Patient satisfaction with air conduction hearing aids has been low because of sound distortion, occlusion effect, and feedback issues. Implantable hearing aids provide a higher quality sound but require surgery for placement. The DHD was designed to combine the ability of driving the ossicular chain with placement in the external auditory canal. Methods DHD is a 3.5-mm wide device that could fit entirely into the bony ear canal and directly drive the TM rather than use a speaker. A cadaveric temporal bone was prepared. The device developed in our laboratory was coupled to the external surface of the TM and against the malleus. Frequency sweeps between 300 Hz to 12 kHz were performed in 2 different coupling methods at 104 and 120 dB, and the DHD was driven with various levels of current. Displacements of the posterior crus of the stapes were measured using a laser Doppler vibrometer. Results The DHD showed a linear frequency response from 300 Hz to 12 kHz. Placement against the malleus showed higher amplitudes and lower power requirements than when the device was placed on the TM. Conclusion DHD is a small completely-in-the-canal device that mechanically drives the TM. This novel device has a frequency output wider than most air conduction devices. Findings of the current study demonstrated that the DHD had the potential of being incorporated into a hearing aid in the future.

A rapid prototyping tool for interactive device development

Designers need rapid prototyping tools that are embeddable, easily configured and can control a large range of accessories. Current prototyping tools fall short on these requirements by requiring one or more of the following: a tether to a computer, textual programming, and/or limited accessory control. To overcome the limitations of current tools, we have developed Buttercup, a standalone embedded sensor/effector controller that provides a high degree of customization for rapid prototyping interactive devices. The keys to the implementation of Buttercup are its hardware and firmware architecture. By building a system focused on sensor and effector control, the hardware can be small and inexpensive. The firmware utilizes a unique mapping system that lends itself to robust control over its accessories while allowing intuitive configuration by the user through a graphical user interface.

A remotely powered and wirelessly controlled intraoral electrolarynx

Electrolarynx devices have restored the voice of many who would otherwise be unable to speak. Current intraoral electrolarynx devices either have unappealing transoral tubes or are too large to easily fit in the mouth. We introduce a novel, remotely powered and wirelessly controlled intraoral electrolarynx that addresses these issues. Due to its size, the intraoral part of the device is easily embedded into a maxillary denture or a dental appliance. Characteristics of the device, including operating distance, positional sensitivity and orientation sensitivity were investigated. The results show that the device can be remotely powered and wirelessly controlled for use as an intraoral electrolarynx. Speech intelligibility of the device is not presented, but will be in future studies.

Novel Completely-in-the-Canal Magnet-Drive Micro Hearing Aid

Objective: To describe a novel magnet-drive micro hearing aid (MMHA), a 3.5-mm wide device, that fits entirely into the bony canal and drives the tympanic membrane (TM) using a magnet in a noncontact fashion. To test the effectiveness and optimal positioning of the magnet on the TM. Method: Cadaveric temporal bones were prepared for laser Doppler vibrometry (LDV) of the stapes. MMHA was placed at 1 and 2 mm away from the TM, and the magnets were glued to umbo and lateral process of the malleus. Frequency sweeps between 300 Hz to 12 kHz were performed. Results: The MMHA showed frequency response from 300 Hz to 12 kHz at loudness levels from 60 to 120 dBA at 10 dBA steps. Placement of magnet on the umbo resulted in higher amplitudes and lower power requirements than placement on the lateral process. The same results were observed when the device was placed at 1-mm distance from the TM. Conclusion: MMHA is a small completely-in-the-canal hearing aid that drives the TM in a noncontact fashion through a magnet. This novel device has a frequency output wider than air conduction devices. The device’s ability to directly drive the TM enables it to potentially sound more naturally and similar to implantable devices.

System of Systems for Sensor and Actuator Networks

Sensor and actuator networks are often the backbone of control applications. They are used in many different fields, such as health care, home automation, and industrial control. Despite the prevalence of sensor and actuator networks, there is a lack of tools to support the rapid prototyping of sensing and control applications. We have developed a system to support a generic platform for rapid prototyping of sensing and control applications in which different sensors and actuators are brought together to perform specific functions. At the heart of the system-of-systems is the Control INterface to Devices and Instruments (CINDI), a small Linux-based box with a number of standard interfaces. The system was built with simplicity in mind and to support component reuse.