DE102005019868A1 - Heating device for warming patient, controls heater based on heater temperature, and on patient's body temperature or expiration temperature - Google Patents

Abstract

A control device regulates a heater based on the output signal from a temperature sensor (6) which measures the temperature of the heater. The control device also receives a further signal that is dependent on a body characteristic of the patient (17) and/or dependent on a temperature, and additionally controls the heater based on this signal. The further signal may be dependent on the body temperature of the patient or an expiration temperature. Independent claims are included for an imaging diagnostic apparatus, and for a method of heating a patient.

Description

The The invention relates to a heater for warming a patient as well a method of warming a patient.

In diagnostic imaging and intervention as well as in everyday life Hospitalization for inpatient treatment are patients often unfavorable Exposed to climatic conditions. In particular, the temperature is in Examination and surgery rooms often lower than for the patient would be beneficial and enjoyable, so he by means of additional Heating systems warmed up should be. By heating The patient should have the temperature at physiologically normal levels, usually So over 36 ° C, held become. A physiological temperature level is just in infants and physically unstable persons of great importance because too low Temperatures have serious negative consequences for the recovery of the patient can have and in infants for the Health status in general are critical.

It It is known to provide active or passive heating systems, e.g. heated patient beds or blankets may include a physiological Ensure temperature level. To the heat output of the heating system To set correctly, the temperature must be at the known systems Patients are measured. The measurement must be repeated continuously at short intervals be and requires staffing. She is also in the Prone to the attention of nurses. in the If necessary, either the heat output changed manually be or an additional Ceiling for passive thermal insulation applied or removed become.

at Surgery or intensive care monitoring Station will be mainly active heating systems, e.g. Heizluftdecken or heating mattresses used. In active heating systems by the nursing staff too the temperature of the heating system measured on the patient and then, depending at the discretion of the doctor, the heating can be set manually. Nevertheless it can not be ruled out that through such systems superficial Burns on the skin of the patient are caused as the System can be controlled only by punctual temperature measurements and Often the temperature of the heating element is set only indirectly can be, by more or less energy is supplied. The adjustment usually takes place via a potentiometer or a two-position controller whose setting characteristics and inaccuracies additional uncertainties entail.

Out JP 2001 238924 discloses a mattress for a patient couch, which has an electrical heating element to a body temperature to keep the patient stable. The mattress is made of two foam cores constructed, between which the heating element is arranged, and on their surface a temperature sensor is arranged. A controller compares the temperature measured by the temperature sensor Temperature with a body temperature setpoint and regulates the heat output. The disadvantage of this, however, is that the or the temperature sensor regardless of whether they are in contact with the patient, record readings. Therefore It can happen that a Temperaurfühler example, the ambient air is exposed and therefore falsely Too low a temperature, resulting in a dangerous for the patient Raising the heating power through the regulator can lead.

From the DE 31 19 757 is a control device for controlling the surface temperature of a heated pad known. In order to always measure the actual surface temperature between the patient and the pad, a temperature sensor with a detector for detecting the application of a user is provided. This avoids the risk that a sensor which is not acted upon by a patient and instead, for example, exposed to the ambient air, cools accordingly and measures too low a surface temperature, which would lead to excessive heating of the cushion. However, the temperature sensor is relatively expensive due to the requirement of an additional detector. In addition, it allows only a punctual measurement.

Of the Invention is based on the object, a heater for heating a To create patients who are reliable and better at the actual Heat demand gives the patient coordinated heating power. Another task of Invention is an imaging diagnostic device with a Such a heating device and a corresponding method for controlling a Indicate heat output.

The Invention solves This object is achieved by a heating device having the features of FIG. Patent claim, by an imaging diagnostic device with the features of the 13th claim and by a method with the method steps of the 15th claim. advantageous Further developments of the invention are specified in the dependent claims.

A basic idea of the invention is to control the heating power not only one with the heater related temperature sensor, but at least one further temperature signal or at least one further information about a body feature of the patient.

• a) Erfassen einer Temperatur einer Heizvorrichtung,
• b) Erfassen mindestens einer weiteren Temperatur und/oder eines Körpermerkmals des Patienten,
• c) Regeln einer Heizleistung in Abhängigkeit von der erfassten Temperatur der Heizvorrichtung sowie der mindestens einen weiteren Temperatur und/oder des Körpermerkmals.

A heater based on this concept for warming a patient includes a heater configured to warm a patient, a temperature sensor configured to measure a temperature of the heater, and a controller connected to the temperature sensor and the heater configured therefor in that the heater is responsive to receiving an output signal of the temperature sensor, wherein according to the invention the controller receives at least one further signal dependent on a body feature of the patient and / or a temperature, and the heater in additional dependency thereon Signal activates. A method based on this basic idea comprises the method steps

• a) detecting a temperature of a heating device,
• b) detecting at least one further temperature and / or body feature of the patient,
• c) controlling a heating power as a function of the detected temperature of the heating device and the at least one further temperature and / or the body feature.

The Invention allows it, the heater depending from the actual Temperature of the patient and taking into account e.g. from that Weight, height and health to regulate automatically. For this, e.g. current patient information be read from an electronic patient record. The current Temperature values of the heater and the current others Temperature values are automatically at certain time intervals queried and taken into account in the regulation; this decreases on the one hand the effort of the nursing staff and on the other hand increases the reliability the temperature control. The heating device can be incorporated into a patient storage system, e.g. an operating table, a hospital bed or a normal bed integrated or designed as a mattress. With regard to imaging Diagnostic applications can make the heating element X-ray transparent and with less magnetic inductance be designed for MR applications, e.g. based on carbon fibers. For execution and placement of temperature sensors can be used on known measuring methods.

In An advantageous embodiment of the invention is a temperature sensor integrated into the heater, in particular as a strand in one Heating conductor. This ensures a measurement regardless of whether the temperature sensor or the heater by an overlying Patient is burdened. In contrast, an external would be on the heating system mounted sensor under different pressure loads through the Patients different sensor values depending on the current pressure load produce. In the worst case would too low a heating system temperature can be measured, resulting in a inappropriate increase lead the heating power would.

Further advantageous embodiments of the invention are the subject of exemplary embodiments, not as limiting are to be understood and are described below with reference to figures.

The Figures show:

1 schematic side view of a patient support device with heating pad,

2 schematic plan view of the patient support device,

3 X-ray device with patient bed with heating element, and

4 schematic representation of a system for controlling the heating power.

In 1 a patient support device with Heizauflage is shown schematically in side view. On a pedestal 1 is a surgical couch 2 fixed or movable. On the operating table 2 is a heating mat 3 applied, which can be used to warm a patient lying on it.

With regard to diagnostic imaging applications, surgical recliner 2 and heating mat 3 X-transparent, so that there is a X-ray transparent area A of the patient support device. On the other hand, that is the pedestal 1 Comprehensive area B is not an X-ray area and a patient may need to be appropriately placed on the operating table 2 be positioned. In the non-X-ray transparent area B is a heating temperature sensor 6 in the heating mat 3 integrated. Known heating temperature sensors with sufficient accuracy are not X-ray transparent, so that a positioning of the heating temperature sensor 6 in the X-ray transparent area A would not be useful. It is essential, however, above all, that the position of the heating temperature sensor 6 it also allows a lying patient to always on the heating temperature sensor 6 rests. Otherwise, the Heating temperature sensor 6 be exposed to the cooling ambient air and therefore falsely indicate too low temperature values.

The heating temperature sensor 6 must be in the heating element of the heating mat 3 be integrated, so that it can not be removed by third-party application or external influence, eg when placing or relocating a patient. Most suitably, it may be implemented as an NTC sensor by wiring the semiconductor to a highly flexible heating strand and completely insulating it. NTC sensors are temperature-dependent semiconductor resistors that conduct better at higher temperatures than at lower temperatures. So they have a negative temperature coefficient, which is why they are called NTC resistors (negative temperature coefficient). They are also referred to as thermistor and can be made of iron oxide (Fe ₂ O ₃ ), ZnTiO ₄ or magnesium dichromate (MgCr ₂ O ₄ ). The temperature-dependent resistance values are taken from characteristics that have to be made available to the heating control device.

In 2 the patient support device described above is shown in a schematic plan view. On the operating table 2 is the heating mat 3 but only partially covers them completely. The contour of the operating table 2 and the heating mat 3 results from the fact that in the X-ray transparent area A a particularly good accessibility to the patient should be ensured, which is why the operating table 2 here is cut narrower. In the non-X-ray transparent area B, on the one hand, the heating temperature sensor 6 arranged, on the other hand, the Heizstromanschlüsse 4 , About the heating power connections 4 become the heating elements 5 supplied with heating power. The heating elements are designed as carbon fibers, which are on the one hand X-ray transparent, on the other hand have a low magnetic induction, making them suitable for use in MR methods.

In 3 is schematically an X-ray device 10 shown in connection with which a heating device for a patient 17 is used. The X-ray device 10 includes a tripod 11 at which an examination couch 12 is stored. Into the examination couch 12 integrated is a heating element 13 That is the warming of an over lying patient 17 serves. The heating element 13 is via a Heizstromleitung 14 energized. In the heating element 13 integrated is a heating temperature sensor 6 that has a temperature sensor connection 16 is connected. Below the examination couch 12 is an x-ray detector 20 arranged, by means of which X-ray images of the overlying patient 17 can be detected.

Also mounted on the tripod is an x-ray source 18 passing through a power line 21 is supplied. The X-ray source 18 serves to generate an X-ray beam 19 that the patient 17 goes through and then on the X-ray detector 20 incident. The heating temperature sensor 6 is in an area outside the X-ray beam 19 arranged to cause disturbances in the X-ray.

A control cabinet 22 Includes the necessary high voltage and control electronics to power over power line 21 the X-ray source 18 to supply, via Heizstromleitung 14 the heating element 13 and about the temperature sensor connection 16 Signals from the heating temperature sensor 6 to recieve. The control cabinet 22 comprises a control device 23 with the necessary control and power control devices and for the operation of the heating temperature sensor 6 required sensor electronics.

The control device 23 is via a control signal line 24 with a data processing device 27 connected and controlled by this. The data processing device 27 includes a display device 29 and a keyboard 28 for use by a doctor or other nursing staff. It has a program memory 25 , the next to recording-specific X-ray programs for operating the X-ray source 18 and the X-ray detector 20 also a program for controlling the heating power for the heating element 13 includes. The data processing device 27 works in conjunction with the heater to warm the patient 17 as a control device and therefore additionally accesses a heating curve memory 26 to, in the heating curves are stored, which can be used as a control parameter or influencing variable for control.

In the heating curve memory 26 can use heating curves for different heating element types, different versions of the patient recliner 12 and accessible to patients of varying size, weight, disease or gender. To be able to dispose of patient information, the data processing device can 27 a connection, not shown, to a hospital information system (HIS), via which, for example, an electronic patient record can be accessed.

In 4 schematically is a control device for the heating power for heating a patient 17 shown. The patient 17 is in a care bed 37 , in which a heating element including integrated heating temperature sensor 6 is integrated. The heating element may be designed as a mattress pad, inner half of the mattress or as a blanket. At the patient 17 attached is a body temp ratursensor 34 as well as the heating temperature sensor 6 Information to a processor-controlled temperature controller 31 supplies. Another patient temperature is through the expiration temperature sensor 35 recorded, and in addition is a room temperature sensor 36 provided, both also provide temperature information to the temperature controller 31 deliver.

The temperature controller 31 obtains additional information from a hospital information system 30 and also can via a keyboard 28 User input received. From the received temperature and patient information as well as in response to user input, it generates a control signal that it sends to a heating system 33 emits. Depending on the control signal, the heating power of the heating system 33 set. With the set heating power is over the Heizstromleitungen 14 through the heating system 33 the patient 17 in the nursing bed 37 warmed.

The temperature controller 31 can eg within the data processing device described above 27 together with the control device 23 be realized. It automatically regulates the heating power for the heater and thus the patient temperature. About the information from the hospital information system 30 Weight, height, health or age of the patient may be taken into account. It outputs current values on a display device and also allows the transmission of all data via suitable external interfaces, eg RS232 or CAN. This allows the connection of the control system to the previously operated monitoring computer 32 or other, possibly already existing, security systems. The current temperature values of all temperature sensors 6 . 34 . 36 are recorded continuously and allow conclusions to be drawn about the patient's temperature. Based on the temperature values and taking into account body characteristics in the form of patient information, and possibly influenced by user input from a physician, the heating power is regulated. All input and output quantities are stored in a monitoring computer 32 logged and controlled in order to be able to recognize possible control errors at an early stage and to be able to reconstruct all control situations in the process.

The temperature controller 31 can be designed based on software as well as hardware. It may take into account, in addition to those described above, further or a smaller number of temperature values. It is essential, however, that at least one sensor is directly in the heating device, and another directly on the body of the patient 17 is appropriate. It is also particularly advantageous to consider a further temperature sensor for detecting the room climate.

The body temperature sensors on the patient 17 can be integrated into bracelets, chest bands or the like in a known manner and transmit current temperature values either by cable connection or by radio. Also possible are temperature sensors, which are stuck on the skin of the patient by means of plaster. Under stationary hospital conditions, additional measuring systems can be used for temperature detection, for example, in an artificially ventilated patient, an expiration temperature or in a catheterized patient, an arterial or venous temperature.

The sensor data are in the temperature controller 31 processed by means of algorithms provided for this, which determine a heating curve from the present measured values and the physiological data of humans (eg weight, size), by means of which the heating power is adjusted accordingly. The user, eg a doctor, has the additional possibility of changing the heating curve generated by the control at his own discretion, for example by increasing the heating temperature in infants or by lowering the temperature in patients with fever. To avoid incorrect settings, the temperature controller is set 31 however, the user has predetermined limit values within legal or technical specifications within which the temperature can be changed; For example, it can be provided that the temperature can only be changed within a range of +/- 3 ° C.

The Temperature control works steplessly and continuously throughout the control range let yourself current conditions of the patient and the clinical environment to adjust. This allows a sensitive and current each Temperature control for the Patients are reached and hypo- or hyper-thermals are prevented. In order to avoid local incorrect temperature control, in particular is the Placement of temperature sensors of great importance. In terms of on diagnostic imaging methods, the temperature sensors, as far as it is not transparent to x-rays and MR indifferent, not anywhere on the patient to be ordered. Indirect measurements, such as a Infrared measurement, are also only partially suitable, in particular the temperature between patient and heater can be detected needs to be local overheating to avoid.

Therefore, as previously described, temperature sensors are mounted in the environment of the diagnostic imaging outside of the X-ray transparent area of the patient support and mes Therefore, the temperature in so-called non-central location. In these cases, the most homogeneous possible heat distribution over the entire heating surface should be ensured. To make matters worse, that the patient may be partially covered for thermal insulation, so that the heater is partly covered, but partly exposed - which makes the heat distribution inhomogeneous. The temperature sensor can then come to rest both in the covered and in the exposed area, which would cause different temperature values and, consequently, a different control behavior.

Such situations can be caused by the temperature controller 31 be controlled by taking into account the body characteristics of the patient. For example, in a large patient it can be assumed that a large part of the heating device is covered by the patient or by a blanket applied for thermal insulation. For large patients, therefore, a high thermal insulation is assumed, which is why the temperature reading will generally be increased. Therefore, an offset is added to the heating curve. Conversely, in small patients, a low thermal insulation is assumed, which is why the temperature readings are expected to be generally lower. In small patients, therefore, an offset is subtracted from the heating curve. Further possibilities for compensation in homogeneous temperature distributions, for example as a function of the patient's weight, can be implemented in a comparable manner.

The invention can be summarized as follows: The invention relates to a method and a heating device for heating a patient 17 and a corresponding diagnostic imaging device. The respective device comprises a heating device for heating a patient 17 is formed, a temperature sensor 6 which is designed to measure a temperature of the heating device, and one with the temperature sensor 6 and the heating device connected control device, which is adapted to the heating device in response to an output signal of the temperature sensor 6 head for. In accordance with the invention, the controller receives at least one additional signal from a body feature of the patient 17 and / or is dependent on a temperature, and controls the heater in additional dependence on this further signal. It is essential that at least one sensor directly in the heater and another directly on the body of the patient 17 is appropriate. It is also particularly advantageous to consider a further temperature sensor for detecting the room climate. A method according to the invention comprises the method steps a) detecting a temperature of a heating device, b) detecting at least one further temperature and / or a body feature of the patient, and c) regulating a heating power as a function of the detected temperature of the heating device and the at least one further temperature and / or the body feature.

Claims (17)

Heating device for warming a patient ( 17 ) comprising a heating device for warming a patient ( 17 ) is designed, a temperature sensor ( 6 ), which is designed to measure a temperature of the heating device, and one with the temperature sensor ( 6 ) and the heating device connected control device, which is adapted to the heating device in response to receiving an output signal of the temperature sensor ( 6 ), characterized in that the control device receives at least one further signal which is from a body feature of the patient ( 17 ) and / or is dependent on a temperature, and controls the heater in additional dependence on this further signal. Heating device according to claim 1, characterized in that the further signal from a body temperature of the patient ( 17 ) is dependent. Heating device according to claim 2, characterized in that the further signal by the output signal of a body temperature sensor ( 34 ) and / or an expiration temperature sensor ( 35 ) is formed. Heating device according to one of the preceding claims, characterized characterized in that at least one further signal from an ambient temperature dependent is. Heating device according to claim 4, characterized in that the further signal by the output signal of a room temperature sensor ( 36 ) is formed. Heating device according to one of the preceding claims, characterized in that at least one further signal from a in a data processing device, in particular a hospital information system ( 30 ), stored body feature of the patient ( 17 ), in particular size and / or weight, is dependent. Heating device characterized by the features of the preceding claims 2 and 4. Heating device according to one of the preceding claims, characterized in that the heating device as a heating mat ( 3 ) and / or as in a couch ( 12 ) integrated heating element ( 13 ) leads is. Heating device according to one of the preceding claims, characterized in that the heating device is X-ray transparent, in particular consisting made of carbon fibers is. Heating device according to one of the preceding claims, characterized in that the temperature sensor ( 6 ) is integrated in the heating device, in particular as a strand in a heating conductor. Heating device according to claim 10, characterized in that the temperature sensor ( 6 ) is formed as a temperature-dependent semiconductor resistor having a negative temperature coefficient (NTC resistor). Heating device according to claim 10, characterized in that a heating curve memory ( 26 ), and that the control device is used as a data processing device ( 27 ), access to the heat curve memory ( 26 ) Has. An imaging diagnostic device comprising a heater for warming a patient ( 17 ) with a heating device for warming a patient ( 17 ), with a temperature sensor ( 6 ), which is designed to measure a temperature of the heating device, and one with the temperature sensor ( 6 ) and the heating device connected control device, which is adapted to the heating device in response to receiving an output signal of the temperature sensor ( 6 ), characterized in that the control device receives at least one further signal which is from a body feature of the patient ( 17 ) and / or is dependent on a temperature, and controls the heater in additional dependence on this further signal. according to claim 1. Imaging diagnostic device according to claim 13 comprising a heating device according to one of claims 2 to 12th Method for warming a patient ( 17 ), comprising the steps of a) detecting a temperature of a heating device, b) detecting at least one further temperature and / or at least one body feature of the patient ( 17 ), c) controlling a heat output in dependence on the detected temperature of the heating device and the at least one further temperature and / or the at least one body feature. A method according to claim 15, characterized in that as a further temperature a body temperature of the patient ( 17 ) is detected. Method according to claim 16, characterized in that that as additional another temperature a room temperature is detected.