To date, the Department of Physiology at the University of Natal, Nelson Mandela Medical School and the University of Durban-Westville have performed the following scientific evaluations of this treatment, summarised below.
This initial phase was broken down into four separate investigations
Skin blood flow was measured in healthy volunteers, after 30 and 60 seconds of Jet Therapy using two different applicator heads and unheated air at 1 atmosphere pressure.
With the unheated Laser Doppler Fluxmetry probe sited on the dorsum of the foot, treatment at various sites on the foot resulted in a 5-7 fold increases in Laser Doppler derived skin blood flow.
Similar results were obtained when the probe was placed on the anterior compartment of the leg. The increase in skin blood flow rate measured appears to decay with distance of treatment from the probe.
Significant increases were noted as much as 5 cm away from the measuring site. Skin cooling of about 4c occurred.
With the measuring probes placed on the left foot and treatment performed on the right foot, no increase in skin blood flow inn the left foot was obtained.
This would suggest that it is unlikely that the effects of Jet Therapy are centrally mediated or carry over from one side of the body to the other.
Skin blood flow and skin temperature was measured in healthy volunteers, before treatment and every 5 minutes during Jet Therapy treatment, at 1 atmosphere pressure, on the footing using the "sport" and "agitator" applicator heads and unheated air.
With the probe sited on the dorsum of the foot, the foot was treated continuously for 45 minutes.
Measurements were taken during treatment at different sites on the dorsum and medial arch. No readings were taken with the Jet within 5 cms of the Laser Doppler probe.
Again, a sustained 5-10 fold increase in skin blood flow was noted throughout the treatment. On cessation of treatment it was noted that skin blood flow rapidly returned to normal values.
Skin blood flow and skin temperature was measured every minute for fifteen minutes after the 45 minute treatment of the foot.
The skin temperature rose slowly but after 15 minutes was still lower than the pre-treatment value.
Skin blood flow, which returned to normal immediately after treatment, did not rise significantly during this period.
This study measures the pressure generated by the air jet in subcutaneous fat and in the underlying muscle. Subcutaneous pressure and intracompartmental (ICP) muscle pressures were measured using the Stryker pressure transducer and monitor.
An 18 gauge needle was inserted either subcutaneously or into the muscle of the anterior thigh of 10 healthy volunteers.
Pressure measurements were made with the air Jet over the ICR needle and repeated with the jet 2, 4, 6, 8 and 10 cm proximal to the needle.
Air pressures raging from 0.5 - 4 atmospheres were used in 0.5 atmosphere increments.
Substantial increases in both intracompartmental and subcutaneous pressure were recorded, with pressures of up to 8OmmHg recorded at 4 atmospheres. At high applied pressure, the pressure decays within 4 cm of the Jet.
The data has not yet been fully analysed. These pressures can result in muscle cell damage, and care should be taken not to treat over a confined area, but rather to move the probe around to reduce the risk.
As stated earlier, no evidence of cell damage could be inferred from the blood results.
Two pilot studies have been conducted on a limited number of subjects, to investigate the possibility that Jet Therapy caused muscle cell damage and or damage to blood cells passing the air jet.
Venous blood was drawn from 5 subjects before and after a 'cellulite' treatment, and in a further 5 healthy subjects before and after a 45 minute treatment of the foot. No demonstrable changes were noted in the full and differential blood counts and no morphological changes were noted in the cells. Urea and electrolyte results were all within normal range before and after treatment. There was no increase in creatine kinase or lactate dehydrogenase. While these results indicate that there is no evidence of damage to blood cells or muscle, further work is required to increase the sample size, and to specifically investigate diabetic patients.