18th October 2022
A significant study conducted by Tucker et al, measured geko™ device lower limb blood flow in both the femoral and popliteal veins and reported a blood flow increase rate equal to 60 percent of walking without the patient having to move. The increase was assumed to be as a result of an increase in venous flow from the deep calf veins, however, this had yet to be confirmed.
The study discussed in this blog, by Griffin et al, was commissioned to take direct measurements in the deep veins of the calf to confirm this assumption. The study compared blood flow volume and velocity in the peroneal, posterior tibial and gastrocnemial veins, with and without the geko™ device, and reported significant increases in all three veins studied.
The Griffin study is the first time that neuromuscular electrostimulation has been shown to be an effective method of increasing blood flow in the axial deep veins, where early thrombi most often form. Clotting in these veins is proven by Labropoulos et al who detected isolated calf DVT in 282 limbs of 251 patients examined – the peroneal veins were most frequently involved with 115 limbs (41%) affected. Posterior tibial and gastrocnemial involvement accounting for 37% and 29% respectively.
Enhancements of blood volume and velocity flow in the deep veins of the leg are key factors in the prevention of venous stasis and ultimately deep vein thrombosis (DVT). The Griffin findings justified the subsequent research that has further determined the efficacy of the geko™ device in the prevention of DVT – a life threating condition that each year leads to approximately 10 million cases of Venous thromboembolism (VTE) worldwide.
About the geko™ device
The geko™ device is a CE marked wearable watch-sized device that attaches to a patient’s leg and then uses electricity to stimulate a nerve, increasing blood flow equal to 60 percent of walking without the wearer having to move.
Designed, developed and manufactured by FirstKind Limited in the UK (a Sky Medical Technology company) the disposable, internally powered, NMES device is self-adhesive and applied to the outer aspect of the knee. This positioning enables integral electrodes to apply a stimulus to the common peroneal nerve, activating venous muscle pumps.
Stimulation of this nerve by the geko™ device is painless and causes the muscles to contract but it does not affect normal movement of the limb, so patients can move as normal. The device can be controlled by the patient to provide a suitable level of stimulation and can even be worn while the patient is sleeping.
About the study
The Griffin et al study was created to measure the precise effect of the geko™ device on the velocities and volumes of blood flow in the peroneal, posterial tibial and gastrocnemial veins. 18 healthy volunteers (nine male and nine female) were selected for the study. The ages of volunteers varied from 19-78 years in age. The volunteers were screened for specific study criteria to ensure that certain medical conditions were excluded from the study. All volunteers were also scanned to ensure a normal venous system.
The objective of the study was to measure the effectiveness of the geko™ device in stimulating both the velocity and volume of blood flow in this cohort. The study would also assess the safety of the geko™ device, which is made from soft moulding thermoplastic elastomer (TPE) with electronics housed in a polypropylene case. The device is mounted on a hydrogel layer to stick to the patient’s skin.
Participants in the study were fitted with the geko™ device and then placed in a sitting position for five minutes to establish a venous and arterial equilibrium. This ensured the study could measure volunteers’ baseline venous flow without the geko™ device’s stimulation.
Blood velocity and volume flows were measured in all three calf veins at rest and during the use of the device. The veins were monitored for blood flow by an ultrasonic scanner with measurements taken mid-calf. Each ultrasonic measurement was repeated three times on each vein with a mean value taken. The study measured both peak velocity of blood flow and volume flow during muscle contraction.
The study results
Venous flow in all calf veins significantly increased during stimulation from the geko™ device. The peroneal vein showed the largest increase in both peak velocity and volume flow, with an increase of 216 percent in peak velocity and 113 percent in volume flow during muscle contraction. However, both the gastrocnemius and posterior tibial veins also demonstrated significantly increased peak velocity and volume flow when stimulated by the geko™ device as below:
This study demonstrated an NMES device was effective at increasing blood flow in the deep veins of the calf. The responses – both in velocity and volume of blood flow – to electrical stimulus were identified in all three critical veins studied. The study concluded that the efficacy of the geko™ device in increasing blood flow in these clinically important veins could have a significant effect in enhancing future clinical management of DVT.
These findings are further supported by more recent studies including the VTE prevention in acute stroke patients (Natarajan 20201) as well as applications in obstetrics (Fawzy 2019) post-operative patients in orthopaedics (Wainwright 2020).