TECHNICAL FIELD

The present invention pertains to a medical cooling device and method for reducing the body core temperature of a patient by medically cooling of a body part of the patient, and in particular the brain of the patient, in a non-invasive manner.

CROSS-RELATED APPLICATIONS

This application claims priority under 35 USC 119(a)-(d) to SE patent application Nos. 1451237-0 and 1451236-2, both of which were filed on Oct. 15, 2014, the entire contents of both of which are incorporated herein by reference.

BACKGROUND

Medical cooling of parts of the human body for reducing the body core temperature for hypothermia treatment is a useful tool to reduce adverse impacts on the same under certain conditions. For example, medical cooling may be used for cooling the brain of patient suffering from a stroke. By reducing the temperature of the brain the risk of tissue damage is reduced for those parts of the brain lacking an adequate oxygen supply during the stroke. Another application of medical cooling is to cool the scalp for patients going through chemo therapy, to avoid undesirable hair loss.

In animal models of stroke, target temperatures of between 24° C. and 34° C. are most efficacious for reducing infarct size. However, even a brain temperature of 35° C. reduces the infarct volume by 30%. Cooling to levels of 32° to 34° C. generally requires sedation, mechanical ventilation and admission to an intensive care unit. Owing to the limited availability of intensive care beds in most countries, treatment of even a minority of acute stroke patients to those levels is therefore precluded by substantial practical and logistical problems. Temperature reductions to 35.5° C. or 35.0° C. have been shown to be feasible and safe in awake patients with acute ischemic stroke by surface cooling, in combination with for exapethidine to treat shivering. Some studies of patients with severe traumatic brain injuries indicate that temperatures of 35 to 35.5° C. seem to be the optimal temperature at which to treat patients with severe traumatic brain injuries.

Under normal conditions when the body temperature decreases beyond a certain point, e.g. around 35° C., the body starts to shiver in an attempt of regaining the heat loss. Depending on the person involuntary shivering may be initiated at different temperatures. Moreover, there are also pharmaceuticals that lower the onset temperature of involuntary shivering.

An improved medical cooling device of reducing the body core temperature would be advantageous.

SUMMARY

An object of the present invention is to eliminate or alleviate at least one of the drawbacks mentioned above, which is achieved by assigning to the device the characteristics according to claim1.

According to a first aspect a control unit configured to control the operation of a medical cooling device conducting a non-invasive medical cooling process for reducing the body core temperature of a patient is provided. The operation of the medical cooling device is based on a number of process parameters. The control unit is configured to monitor at least one process parameter relating to a state of shivering of the patient. The control unit is further configured to make a decision relating to the state or degree of shivering of the patient based on the at least one monitored process parameter. The control unit is further configured to adapt a control process parameter based on the at least one monitored process parameter and the decision made to increase a body core temperature of the patient thereby putting the patient in a reduced state of shivering or a non-shivering state. Moreover, the control unit is configured to re-start the medical cooling process according to the adapted control process parameter.

According to a further aspect a medical cooling device for conducting a medical cooling process for cooling a body part of a patient is provided. The medical cooling device comprises a cooling fluid supply source, a supply line for supplying a flow of cooling fluid from the cooling fluid supply source to a patient, a return line for receiving the flow of cooling fluid from the patient, and the control unit of the first aspect.

In accordance with a further aspect, a method for controlling the operation of a medical cooling device conducting a medical cooling process for cooling a body part of a patient is provided. The operation of the medical cooling device is based on a number of process parameters, wherein the method comprises monitoring at least one process parameter relating to a state of shivering of the patient. The method further comprises making a decision relating to the state or degree of shivering of the patient based on the at least one monitored process parameter. Moreover, the method comprises adapting a control process parameter based on the at least one monitored process parameter and the decision made to put the patient in a reduced state of shivering or a non-shivering state. Furthermore, the method comprises re-starting the medical cooling process according to the adapted control process parameter.

The control unit, medical cooling device and method may be used to reduce the body core temperature of a patient during hypothermia treatment.

Control unit, medical cooling device, and method according to the aspects above are associated with a number of advantages. First and foremost, the negative impacts of the patient during medical cooling are avoided, by reducing or completely removing the waste of energy used by the patient in terms of shivering to counteract the medical cooling process. Another advantage is that the control unit, medical cooling device, and method may be used to detect a shivering state in any patient, irrespective of age, weight, and other factors having impact on the onset temperature of shivering.

