AV biofeedback is a simple, personalised and interactive respiratory guide designed to facilitate regular patient breathing. The AV biofeedback system is shown below in Figure 1.
The problem that AV biofeedback is addressing is that should a patient’s breathing be irregular (see Figure 2a), it can result in incorrect information presented in medical imaging (see Figure 2b). Such irregularities and image artefacts can lead to incorrect tumour targeting in radiotherapy (see Figure 2c) or an increase in the radiation target volume resulting in an increase in radiation dose delivered to healthy tissue which damages the healthy surrounding organs which can lead to loss of function and even cancer reoccurrence. This problem affects the 44% of the 10,200 lung cancer patients treated with radiotherapy in Australia, and up to 71% of the 1.2 million lung cancer patients treated with radiotherapy in the world each year.
A number of studies have already been performed demonstrating the effectiveness of AV biofeedback in reducing breathing irregularities in addition to improving image quality, demonstrated in Figure 3.
AV biofeedback is now at a crucial stage towards commercialisation. This will be achieved through comprehensive clinical evaluations and technology assessments of the AV biofeedback device in prospective, randomised multi-institutional clinical trials, involving both lung and liver cancer patients across a range of imaging modalities; these will be the most thorough and significant studies of their kind to date.
Such audiovisual biofeedback studies include: