The term non-invasive
has two meanings:
For centuries, physicians have employed many simple non-invasive methods based on physical parameters in order to assess body function in health and disease (physical examination and inspection), such as pulse-taking, the auscultation of heart sounds and lung sounds (using the stethoscope), temperature examination (using thermometers), respiratory examination, peripheral vascular examination, oral examination, abdominal examination, external percussion and palpation, blood pressure measurement (using the sphygmomanometer), change in body volumes (using plethysmograph), audiometry, eye examination and many others.
The discovery of the first modern non-invasive techniques based on physical methods, electrocardiography and X-rays, dates back to the end of the 19th century. Since then, non-invasive methods – which penetrate the body nonetheless, but by electromagnetic or particle radiation rather than a scalpel – have continuously enlarged the scope of medical technology. Non-invasive techniques commonly used for diagnosis and therapy include the following:
A recent advance is the substitution of invasive medical tests, such as colonoscopy by computer-based 3D reconstructions, such as virtual colonoscopy.
- Radiation therapy and radiosurgery, procedures that uses external atomic particles (protons, neutrons, photons, alpha particles, etc.) or gamma rays to destroy pathological tissue within the body
- Lithotripsy, a procedure that uses ultrasound shock waves to break urinary calculus
- Defibrillation, a procedure to block heart fibrillation and start normal rhythm
- Mechanical ventilation, such as the iron lung.
- Transdermal patches, used to deliver drugs applied to the skin.
- CPAP (Continuous Positive Airway Pressure) used to treat sleep apnea
- Biphasic Cuirass Ventilation (BCV, eg. Hayek RTX)
- Photodynamic therapy
- Therapeutic ultrasound
- Extracorporeal thermal ablation
- Extracorporeal magnetic innervation
- Photo-infrared pulsed bio-modulation
- Transcranial magnetic stimulation
In some cases, non-invasive methods will not work for the intended purpose, so medical technology has developed minimally-invasive methods, such as hypodermic injection (using the syringe), endoscopy, percutaneous surgery, laparoscopic surgery, coronary catheterization, angioplasty, stereotactic surgery and many others.
The benefits for the patient are self-evident.
- Tachibana K. Emerging technologies in therapeutic ultrasound: thermal ablation to gene delivery. Hum Cell. 2004 Mar;17(1):7-15. Review. PMID 15369132
- Kim PE, Singh M. Functional magnetic resonance imaging for brain mapping in neurosurgery. Neurosurg Focus. 2003 Jul 15;15(1):E1. Review. PMID 15355003
- Richie RC. Non-invasive assessment of the risk of coronary heart disease. J Insur Med. 2002;34(1):31-42. Review. PMID 15303592
- Golder W. Magnetic resonance spectroscopy in clinical oncology. Onkologie. 2004 Jun;27(3):304-9. Review. PMID 15249722
- Cherry SR. In vivo molecular and genomic imaging: new challenges for imaging physics. Phys Med Biol. 2004 Feb 7;49(3):R13-48. Review. PMID 15012005
- Lymberis A, Olsson S. Intelligent biomedical clothing for personal health and disease management: state of the art and future vision. Telemed J E Health. 2003 Winter;9(4):379-86. Review. PMID 14980096
- Soling A, Rainov NG. Bioluminescence imaging in vivo - application to cancer research. Expert Opin Biol Ther. 2003 Oct;3(7):1163-72. Review. Biol Ther. 2003 Dec;3(8):1315. PMID 14519079
- Rohrscheib M, Robinson R, Eaton RP. Non-invasive glucose sensors and improved informatics--the future of diabetes management. Diabetes Obes Metab. 2003 Sep;5(5):280-4. Review. PMID 12940864
- Jacobs AH, Winkeler A, Dittmar C, Hilker R, Heiss WD. Prospects of molecular imaging in neurology. J Cell Biochem Suppl. 2002;39:98-109. Review. PMID 12552609
- Malhi GS, Valenzuela M, Wen W, Sachdev P. Magnetic resonance spectroscopy and its applications in psychiatry. Aust N Z J Psychiatry. 2002 Feb;36(1):31-43. Review. PMID 11929436
- Jacobs A, Heiss WD. Towards non-invasive imaging of HSV-1 vector-mediated gene expression by positron emission tomography. Vet Microbiol. 2002 Apr 22;86(1-2):27-36. Review. PMID 11888687
- Leman JA, Morton CA. Photodynamic therapy: applications in dermatology. Expert Opin Biol Ther. 2002 Jan;2(1):45-53. Review. PMID 11772339
- Richter JE. Ambulatory esophageal pH monitoring. Am J Med. 1997 Nov 24;103(5A):130S-134S. Review. PMID 9422638
- Yokoyama T, Fujita O, Nishiguchi J, Nozaki K, Nose H, Inoue M, Ozawa H, Kumon H. Extracorporeal magnetic innervation treatment for urinary incontinence. Int J Urol. 2004 Aug;11(8):602-6. PMID 15285749