Biomedical Engineering


Several biomedical devices are currently under development at MARCS Institute for Brain, Behaviour and Development. Some of these devices measure intrinsic body properties such as blood flow and respiration. Other devices actively interact with the user with the aim of improving human functions such as balance and sensory perception.

An overview of these biomedical devices can be found below.

VitalCore - An electrodeless, wearable system for simultaneous monitoring of cardiac and respiratory function

Complex interactions inextricably link the pulmonary and cardiovascular systems. It is unsurprising that chronic diseases such as chronic obstructive pulmonary disease and heart failure are prevalent comorbidities affecting a huge proportion of the world population.

Distinguishing their overlapping physiological effects is difficult. As a result the ability to monitor both cardiac function and respiration in a non-intrusive manner would be of great benefit to clinicians and researchers alike.

To address this need, we have developed an inexpensive wearable solution called VitalCore to monitor both cardiac and respiration volume.

VitalCore

HeMo - Hemodynamic monitor for rapid, cost-effective assessment of peripheral vascular function

Peripheral vascular diseases affect hundreds of millions of people worldwide and are often symptomless and undiagnosed. Early diagnosis is crucial for effective treatment and reducing personal and economic costs, particularly where early treatment is geared towards preventing lower extremity amputation. New diagnostic tools are needed to enable this earlier intervention.

We have developed a new low-cost, easy to use, non-invasive hemodynamic monitor, HeMo, to address this large and growing problem. Using a novel combination of impedance tomography and electrical volumetric measurements we can calculate real-time changes in peripheral blood volume.

We believe that this work will lead to the availability of a fast, easy to use and cost-effective vascular assessment tool, dramatically shortening the time to diagnosis and subsequently intervention, radically improving the prognosis of affected patients.

HeMo

SENS - Subsensory Electrical Noise Stimulation to enhance peripheral sensory function

Peripheral neuropathy is a common problem resulting in serious medical complications. In the elderly, reduced peripheral sensation is associated with recurrent falls and fractures. In diabetes, peripheral neuropathy is a significant risk factor for falls, foot ulceration and ultimately amputation.

Restoring this lost sensation would greatly improve quality of life and prognosis for these and other groups. However, currently there is no treatment available.

We have developed a new technique to enhance sensory perception, an innovation that is unique to this research team. We have already shown that subsensory electrical noise stimulation (SENS) can improve neural function. Our evidence suggests this is due to reduced jitter in individual neurons and enhanced synchronization between parallel neurons.

Using this intervention we can consistently lower vibrotactile detection thresholds by as much as 16 per cent and have recorded further enhancements in complex functions such as proprioception, balance and gait.

SENS

Vestr - Vestibular Function Restoration using Stochastic Resonance

Vestibular dysfunction is a common, but under-appreciated and often unrecognized condition. The vestibular system plays a vital role in maintaining balance and providing information about an individual's spatial orientation. Loss of vestibular cues results in disorientation and produces anxiety as well as nausea and dizziness in healthy individuals.

Vestibular impairment is not only associated with symptoms such as dizziness and vertigo but also poor balance, all of which contribute to significant reductions in quality of life. In addition, intact vestibular function is critical for complex tasks such as driving a vehicle, with ~40 per cent of patients with vestibular impairment reported that driving is difficult or dangerous.

In cooperation with international collaborators, we are investigating the use of electrical stochastic resonance to enhance vestibular function where it has been diminished.

Initial results using this technology have demonstrated that both the vestibular ocular reflex and balance can be improved in young and elderly patients as well as in veterans.

Braincubator™ - Extending brain slice lifespan

BraincubatorTo simplify brain research, neuroscientists use brain slices. A major concern regarding brain slices is their short lifespan (6-8 hrs) as it limits the time available to study the neuronal properties in the slice.

The main reason for the short lifespan is that the brain slices are susceptible to bacterial and environmental degradation and the cells die. Brain slices need an environment that simulates their natural environment to maintain slice metabolic activity and electrophysiological function. A few tools are available to attempt to maximise longevity, however, they are ad hoc.

Our researchers have invented a system, which can keep brain slices viable for research for 36+ hours. The Braincubator™, provides a simulated brain environment, which enhances slice metabolic activity and electrophysiological function by controlling the ionic environment, temperature, oxygen and glucose levels.

Importantly, the incubator provides for a bacteria free environment. All of these factors can be monitored and controlled leading to an extended brain slice lifespan.

Sutureless Quadripolar Active Nerve Graft

Peripheral nerve injuries may have severe consequences as those afflicted may lose complete or partial use of a limb. Peripheral nerve injuries are common and may occur as a consequence of minor day-to-day accidents (e.g. deep cut, limb distortion and or dislocation) or from a repetitive strain injury (e.g. compression, vibration).

The current treatment to repair nerve damage is typically surgery followed by intensive rehabilitation. Surgical procedures often require a piece of nerve to be removed from a living compatible donor or from a healthy limb of the subject. This nerve is grafted between the stumps of the injured nerve with the hope that the new piece will act as guidance for axons to reconnect and reinstate the electrical conductivity of the nerve.

The success of this technique, measured in terms of percentage nervous function restoration, is as low as 17 per cent even when followed by intensive rehabilitation. Patients may suffer numerous complications related to the surgical procedure, which may last two (2) to six (6) hours. Additionally, there is neither a standardized method to monitor recovery or a quantitative measure of the regained functionality of the repaired nerve.

To address these issues, a team of our researchers, along with the Western Sydney University School of Medicine and the School of Science and Health are developing novel alternative paradigms for peripheral nerve repair. This innovation utilises recently developed biocompatible materials (chitosan) that adhere to tissue upon laser irradiation. These materials are particularly suited for repairing damaged/severed peripheral nerves, as they comprise an extracellular matrix and factors to enhance axon regeneration and avoid the need for further damaging sutures.

Nerve 1

Nerve 2