The parasympathetic nervous system (PNS) and sympathetic nervous system (SNS) both work in balance and together make up the autonomic nervous system (ANS), which is responsible for many of the bodies autonomic (unconscious) processes. The parasympathetic system has been referred to as 'rest and digest' and the sympathetic system to that of 'fight or flight'. Activating the PNS will reduce SNS activity and vice versa as these systems work in balance. From a therapeutic standpoint it is beneficial to be able to promote parasympathetic activity on demand (or reduce sympathetic activity) which has led to developments in safe and effective ways to achieve this.
The Vagus Nerve interfaces with the PNS and activity of the Vagus Nerve is correlated with autonomic nervous system activity. As a result it was hypothesised that targeted stimulation of the Vagus Nerve (with micropulses of electrical current) could lead to activation of the parasympathetic system as well as harnessing therapeutic mechanisms of the ANS.
Vagus Nerve Stimulation
Stimulating the Vagus Nerve has been well used in clinical practice through surgically implanting an electrode onto the nerve and inserting a pacemaker type device however this procedure is costly, access is limited and there are complications associated with the surgery. Parasym developed a device which targets stimulation through a branch of the Vagus Nerve that runs by the outer ear. This method is now known as Transcutaneous Vagus Nerve Stimulation (tVNS), or non-invasive stimulation of the Vagus Nerve (nVNS).
The Parasym Device
A controlled clinical study which measured the effect of the Parasym Device on the autonomic nervous system found that just 60 minutes of use had a significant increase in parasympathetic activity in the majority of participants. Parasympathetic and sympathetic activity are commonly measured through recording Heart Rate Variability (HRV), which measures the time interval between heart beats.
The Parasym device significantly increased variability of R-R intervals in 75% of participants and HRV age was decreased in 70% of participants. Either the variability of R-R intervals was increased or the HRV age decreased in 90% of participants. The study results showed that one 60 minute session with the Parasym Device improved measures associated with increased parasympathetic activation in the majority of subjects.
This study included 97 participants 44 male and 53 female; age range from 18–70 years. No adverse effects were observed by any of the participants.