Apparatus for extracorporeal blood treatment with automatic monitoring of respiratory rate

Abstract

An apparatus and method for extracorporeal blood treatment, especially a dialysis apparatus, are disclosed, the apparatus includes a radar sensor for monitoring a patient located at a place of treatment.

Claims

1. A method for extracorporeal blood treatment, the method comprising: monitoring, with a radar sensor in an apparatus for extracorporeal blood treatment, a plurality of patients simultaneously who are being treated by the apparatus for extracorporeal blood treatment.

2. The method according to claim 1, the method further comprising: detecting at least one of respiratory frequency or respiratory amplitude of each of the plurality of patients with the apparatus and an evaluation unit for signals of the radar sensor.

3. The method according to claim 1, further comprising at least one of the steps of: positioning the radar sensor on the apparatus; and readjusting the radar sensor by means of a drive for readjusting alignment of the radar sensor relative to the plurality of patients.

4. The method according to claim 1, the method further comprising: shutting off, with at least one shutoff member of the apparatus, at least one of a line connected to a venous branch or a line connected to an arterial branch.

5. The method according to claim 1, wherein the extracorporeal blood treatment is a dialysis treatment.

6. The method according to claim 1, further comprising: establishing, with a control unit of the apparatus, a respiratory frequency of each of the plurality of patients by way of signals of the radar sensor.

7. The method according to claim 6, further comprising: triggering an alarm signal, with the control unit, if the respiratory frequency of any one of the plurality of patients deviates from one or more preset limit values.

8. A method for extracorporeal blood treatment, the method comprising: monitoring, with a radar sensor in an apparatus for extracorporeal blood treatment, a patient located on a place of treatment by the apparatus for extracorporeal blood treatment; detecting at least one of respiratory frequency or respiratory amplitude of the patient with the apparatus and an evaluation unit for signals of the radar sensor; and performing, with the evaluation unit, one or more of the following cycles: localizing or detecting one or more patients, converting a detected thorax movement to at least one of respiratory frequency or amplitude, comparing detected respiratory frequency or amplitude values to at least one predefined limit value, stopping a blood pump of the apparatus and closing at least one tube shutoff clamp upon at least one of exceeding or falling below the at least one predefined limit value, or triggering an alarm if the at least one predefined limit value is not observed.

9. The method according to claim 8, wherein the localizing or detecting one or more patients comprises: at least one of detecting, recognizing, or monitoring movements of a thorax of each patient.

10. The method according to claim 8, wherein the at least one predefined limit value includes a value of 12 to 18 respirations/minute, more than 20 respirations/minute (tachypnea), or less than 10 respirations/minute (bradypnea).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention is best understood from the following detailed description when read in connection with the accompanying drawings. Included in the drawings are the following figures:

(2) FIG. 1 shows a perspective view of the apparatus in the form of a device for hemodialysis, hemofiltration or plasma treatment and

(3) FIG. 2 shows a schematic representation of the substantial functional parts of the dialysis device.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

(4) FIG. 1 illustrates an embodiment of the apparatus 10 according to aspects of the invention in the form of a medical device 10 for extracorporeal blood treatment. It includes a device base 11 in which mechanical components such as e.g. lines, valves etc. not shown in the Figure are located. At its front side the base 11 supports a console 12 in which two blood pumps 13 accessible from outside are arranged. The blood pumps 13 are peristaltic pumps the tubes of which (not shown in the Figure) are inserted from the front side in a generally known manner.

(5) On the device base 11 a control unit 14 constituting an interface for communication with a user is located. The control unit 14 in this case includes a touchscreen monitor via which the user may retrieve various menus and may query operating states as well as enter data and instructions. A card reader 15 into which the user may insert a machine-readable ID card is provided.

(6) A radar sensor 17 is attached to a rod or infusion rod 16 preferably mounted on the device base/housing 11. Radar pictures recorded by the radar sensor 17 are wirelessly transmitted to the control unit 14 in the present embodiment. The radar sensor 17 is directed to a patient's place not shown but located in the vicinity of the apparatus 10, e.g. a couch on which the patient is lying during blood treatment. In this way, the patient is detected by the radar sensor 17. In this context, it is noted that the radar sensor 17 may also be mounted directly on the device base/housing 11.

(7) The patient is connected to the device 10 in a known way via tubes (not shown) of an extracorporeal blood tube system.

(8) In FIG. 2 a patient P is schematically represented. One arm of the patient P is provided with an arterial access 20 and a venous access 21. An arterial tube line 22 leads from the arterial access 20 to the blood pump 13. The latter pumps blood through a blood chamber 25a of a therapeutic device 25 in the form of a dialyzer 25; the two chambers 25a, 25b of which are separated by a membrane 26. The chamber 25b is a dialysate chamber through which dialysate flows.

(9) After leaving the chamber 25a the blood continues to flow into a venous tube line 23 connected to the venous vascular port 21 or access 21. In this way, a blood circulation is formed.

(10) Where appropriate, a pressure gauge 27 measures the arterial blood pressure in the arterial line 22. In the same way, a pressure gauge 28 measures the venous blood pressure in the venous line 23, where appropriate. Furthermore, the venous line 23 interacts indirectly or directly with a red detector 29, where necessary, which detects the presence of blood in the tube line and reports it to the control unit 14. For example, the venous line 23 comprises the detector 29. The pressure gauges 27, 28 as well as the detector 29 (if present) are connected to the control unit 14 for the purpose of control. The control unit controls the entire operation of the device 10 and monitors the described functions as well as a number of further functions not explained in detail here.

(11) In order to be able to shut off the blood circulation, preferably a tube shutoff clamp 30 controlled by the control unit 14 is provided in the venous line 23. In the arterial line 22, too, a shutoff member may be provided preferably in the form of the blood pump 13. The blood pump 13 is a peristaltic pump which is continuously pinched by a pinching member. In the case of standstill of the blood pump 13, the latter acts as a shutoff member which closes the tube line.

(12) The radar sensor 17 and its connection to the control unit 14 are evident from FIG. 2.

(13) A reference mark 35 which can be detected by the radar sensor 17 is preferably arranged on the body of the patient P, in this case on his/her thorax. The radar sensor 17 is adjusted, possibly automatically adjusted, by a motion drive (not shown) so that the reference mark 35 is located at a particular position in the radar picture. This helps to ensure that, irrespective of movements of the patient P, the radar sensor 17 is always directed to the desired target area.

(14) The control unit 14 in FIG. 2 is a computer comprising a memory unit. The latter performs all monitoring and control cycles as well as generations of alarm. The control unit 14 is connected to a display, operating and communication unit 14a.

(15) During dialysis, an extracorporeal blood flow of from 50 to 600 ml/min is taken from the patient P by the blood pump by withdrawing blood with the peristaltic pump 13 from the arterial cannula 20 and the subsequent line 22 and by returning blood via the venous cannula 21 and the subsequent line 23. The blood is guided in the lines 22, 23 to which components such as the cannulas 20, 21, the pressure sensors 27, 29 and the dialyzer 25 are connected. Control and monitoring are implemented with the control, computing and memory unit 14. The parameters for the patient P to be treated are entered via the display, operating and communication unit 14a. For interrupting the blood flow, the control unit 14 stops the blood pump 13 and closes the tube shutoff clamp 30. Moreover, an optical and acoustic alarm is triggered. This protects the patient P from further damage as no further blood loss may occur.

(16) During therapy, the control/analysis unit 14 continuously compares the current respiratory frequency (about 12-18 respirations/min) to set upper and/or lower limit values. For this purpose, the at least one radar sensor 17 detects the movements of the reference mark 35 and transmits corresponding signals to the control unit 14. The control unit establishes respirations from the received signals and herefrom calculates the respiratory frequency and/or the amplitude of the respirations. With a blood flow rate of 300 ml/min the patient may lose 600 ml of blood within two minutes after needle disconnection. This will quickly result in a state of shock with increased respiratory frequency and possibly shallower respiration. As soon as the analysis unit 14 has detected e.g. an increased respiratory frequency (>20 respirations/min) for a defined period of time (e.g. 30 sec), the blood pump is stopped and the alarm is triggered.

(17) The alarm might also be triggered via a limit value frame which the analysis unit 14 automatically establishes after the start of blood flow and a waiting period. Around said starting value (e.g. 16 respirations/min) then upper and lower limit values would be defined (for example upper limit value=20 respirations/min=start value+4 respirations/min and lower limit value=12 respirations/min=start value−4 respirations/min).